Type 1 diabetes mellitus (T1DM) is an autoimmune multifactorial disease. Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene encodes lymphoid-specific tyrosine phosphatase (Lyp), an inhibitor of T cell activation. PTPN22 C1858T polymorphism was associated with T1DM in populations of Caucasian origin. The aim of this study was the investigation for the first time of the association of PTPN22 C1858T polymorphism with T1DM in Greek population. We studied 130 children and adolescents with T1DM and 135 healthy individuals of Greek origin. The polymorphism was genotyped using polymerase chain reaction with restriction fragment length polymorphism. C1858T and T1858T genotypes as well as 1858T allele were found more frequently in patients  than in healthy individuals  but at non statistically significant level. There was no statistically significant association found with gender, age at diagnosis, severity of onset, history of Hashimoto thyroiditis or family history of T1DM. Increased frequency of 1858T allele in patients than in controls, implying a probable association, agrees with results of similar studies on other populations. The inability to find a statistically significant difference is probably due to the decreased frequency of minor allele in Greek population, indicating the need for a larger sample. It is considered a multifactorial disease, requiring the interaction of genetic and environmental factors in triggering autoimmunity [Type 1 diabetes mellitus (T1DM) is characterized by autoimmune destruction of insulin-producing beta cells of pancreatic islets by CD4immunity .PTPN22 gene is located on chromosome 1p13.3-p13.1 and encodes the lymphoid-specific tyrosine phosphatase (Lyp), an important inhibitor of the activation and proliferation of T lymphocytes. Downregulation is achieved through interaction of Lyp with the C-terminal Src tyrosine kinase (Csk), which suppresses T cell receptor (TCR) signaling .For the first time, Bottini et al.  reportedIn Greece, two studies have been conducted in populations from Crete. The minor allele was not associated with psoriasis in the first study , while iThis is a case-control study in a population of Greek origin. We studied 130 children and adolescents  with T1DM  and 135 healthy subjects  without a family history of T1DM. In order to minimize genetic heterogeneity, we included unrelated individuals with a history of at least three generations of Greek origin. Patients are followed up at the Pediatric Diabetes Outpatient Unit, 4th Department of Pediatrics, Faculty of Medicine, Aristotle University of Thessaloniki, Papageorgiou General Hospital. All patients were diagnosed with T1DM before the age of 15 years and were insulin dependent. Parameters included in the statistical analysis were gender, age at the entry to the study, age at diagnosis, severity of onset (presence or absence of ketoacidosis), personal history of Hashimoto thyroiditis (HT), and family history of T1DM of at least one first-degree relative. Control group consisted of children and adolescents older than 10 years, staff of Papageorgiou General Hospital, and students of the Medical Faculty of Aristotle University of Thessaloniki. Before entering the study, an informed consent was obtained by adult participants and parents or guardians of individuals younger than 18 years. The research protocol was declared at the service of ClinicalTrials.gov and approved by the Ethics Committee of Faculty of Medicine of Aristotle University of Thessaloniki. The study was conducted according to the criteria of the Declaration of Helsinki.The method includes four stages: (a) genomic isolation of deoxyribonucleic acid (DNA), (b) polymerase chain reaction (PCR), (c) incubation of PCR products with restriction enzymes, and (d) electrophoresis. Whole blood was collected in a sterile vial containing anticoagulant ethylenediaminetetraacetic acid (EDTA). DNA was isolated using the QIAamp DNA Blood Mini Kit  according to the instructions of the manufacturer and was stored at −20°C. The piece of PTPN22 gene including polymorphism at position 1858 was amplified with specifically designed primers, PTPN22 forward 5-ACTGATAATGTTGCTTCAACGG-3 and PTPN22 reverse 5-TCACCAGCTTCCTCAACCAC-3. PCR products were incubated with the restriction enzyme RsaI  at 37°C overnight. The enzyme cuts C allele into two fragments of 172 base pairs (bp) and 46 bp, while T allele remains intact (218 bp). Electrophoresis of the products of digestion in 2.3% agarose gel followed.2 or Fisher exact test. Normal distribution of quantitative variables was examined using the Kolmogorov-Smirnov test. Normally distributed mean age at diagnosis was analyzed according to genotype analysis using analysis of variance (ANOVA). The level of statistical significance was defined at P < 0.05.Data were analyzed using the IBM program SPSS Statistics 19. Expected and observed frequencies of genotypes and alleles in patients and controls were compared in 2 × 3 and 2 × 2 tables, respectively, according to the Hardy-Weinberg equilibrium. The differences in frequencies of genotypes and alleles between patients and controls and between patient subgroups based on qualitative variables were analyzed by ×P = 0.605 and P = 0.930, resp.). The 1858T allele was detected more frequently in patients (5.8%) compared to controls (3.0%) but at nonstatistically significant level   =  2.00, and confidence interval (CI)  =  0.83–4.81). The T1858T genotype showed a reduced incidence in patients (0.8%) and was not detected in controls. The C1858T genotype was significantly more frequent in patients (10.0%) compared to controls (5.9%), but a statistically significant difference was not found. Because of the low frequency of 1858T allele, the C1858T and T1858T genotypes were grouped for statistical analysis. The C1858T and T1858T genotypes were detected more frequently in patients (10.9%) than in healthy subjects (5.9%) but not in a statistically significant level . Furthermore, there was a tendency for the 1858T pubertal carriers to be more susceptible to T1DM than prepubertal (P = 0.361).The mean age at diagnosis was 7.35 ± 3.73 years (range 0.57–14.59). Statistical analysis after grouping patients according to age at diagnosis found that the PTPN22 C1858T polymorphism had the same effect in patients with early onset (age at diagnosis ≤10 years) as well as to those with late onset (age at diagnosis >10 years) of T1DM. The mean age at diagnosis was similar in patients with C1858T and T1858T genotypes as well as in those with C1858C genotype  but not in a statistically significant higher rate.Moreover, we investigated the role of PTPN22 C1858T polymorphism in autoimmunity. Among C1858T and T1858T genotype carriers, HT presented with marginally increased incidence (14.8% T1DM + HT versus 9.7% T1DM only). We did not find statistically significant association of PTPN22 C1858T polymorphism with a positive family history of T1DM. The distribution of PTPN22 C1858T polymorphism in patients according to the analyzed parameters is shown in In this case-control study, the role of PTPN22 C1858T polymorphism was investigated for the first time in children and adolescents of Greek origin with T1DM. The first report of the association of PTPN22 C1858T polymorphism with T1DM by Bottini et al. . This fiThe studies conducted in different populations can indirectly reveal an interesting feature of PTPN22 C1858T polymorphism, the large geographical variation in the frequency of the 1858T allele. There is a tendency for increased frequency of the 1858T allele in healthy Caucasian populations in Europe (from southern to northern). More specifically, its frequency was found to be 2% in Italy, 6% in Spain, 12% in Sweden, and 15.5% in Finland. However, it seems to be almost absent in populations from Asia and Africa . In GreeAlthough T1DM is an autoimmune disease without gender differentiation in prevalence, we found a tendency towards higher frequency of C1858T and T1858T genotypes in males. The lack of statistically significant association of the PTPN22 C1858T polymorphism with gender agrees with the majority of studies , 27. In It has been reported that genetic factors may influence the age of diagnosis. In this context, it was examined whether predisposing 1858T allele is associated with the age at diagnosis of T1DM. The mean age at diagnosis in 1858T allele carriers was similar to those of the remaining patients, in agreement with the conclusions of other researchers , 21, 27.Taking into account the fact that autoimmune diseases accumulate in individuals and families, we studied the possibility of association of PTPN22 C1858TT polymorphism with personal history of HT and family history of T1DM without positive results in the study population. Recently published meta-analysis suggests association of the PTPN22 C1858T polymorphism with HT . HoweverIn conclusion, the finding of increased frequency of the 1858T allele in patients with T1DM compared to healthy subjects agrees with the results of similar studies in other populations. The inability to detect statistically significant differences may be due to low frequency of the minor allele in Greek population. In order to make safe conclusions regarding the association of the PTPN22 C1858T polymorphism with T1DM in Greek population, a larger sample is needed because of the found rarity of the 1858T allele in Greeks.


UCHL1  S18Y variant and Parkinson’s disease (PD) showed a significant inverse association between the Y allele and PD; the individual studies included in that meta-analysis, however, have produced conflicting results. We examined the relationship between UCHL1  S18Y single nucleotide polymorphism (SNP) and sporadic PD in Japan.A recent meta-analysis on the Included were 229 cases within 6 years of onset of PD, defined according to the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 357 inpatients and outpatients without neurodegenerative disease. Adjustment was made for sex, age, region of residence, smoking, and caffeine intake.UCHL1  S18Y SNP, those with the AA genotype had a significantly increased risk of sporadic PD: the adjusted OR was 1.57 (95 % CI: 1.06 − 2.31). Compared with subjects with the CC or CA genotype of UCHL1  S18Y and the CC or CT genotype of SNCA SNP rs356220, those with the AA genotype of UCHL1  S18Y and the TT genotype of SNP rs356220 had a significantly increased risk of sporadic PD; the interaction, however, was not significant. Our previous investigation found significant inverse relationships between smoking and caffeine intake and PD in this population. There were no significant interactions between UCHL1  S18Y and smoking or caffeine intake affecting sporadic PD.Compared with subjects with the CC or CA genotype of UCHL1  S18Y variant is a risk factor for sporadic PD. We could not find evidence for interactions affecting sporadic PD between UCHL1  S18Y and SNCA SNP rs356220, smoking, or caffeine intake.This study reveals that the  The ubiquitin proteasome system regulates the degradation of key regulatory proteins as well as misfolded and damaged proteins . UbiquitUCHL1  gene is located on chromosome 4p14. The S18Y variant arises due to a cytosine-to-adenine transversion at codon 18 of exon 3 (rs5030732). Ragland et al. ), whereas, under a recessive model, the AA genotype was non-significantly positively associated with the risk of sporadic PD in a Caucasian population (crude OR = 4.76 [95 % CI: 0.52 − 226.8]); furthermore, the frequency of the AA genotype was much lower among Caucasians than among Japanese. A case–control study of Australians found a non-significant positive association between the AA genotype of UCHL1  S18Y SNP and PD under a recessive model (crude OR = 3.14 [95 % CI: 0.76 − 18.32]) ) . The curP and PD  ; Hideyuki Sawada, Eiji Mizuta, and Nagako Murase ; Tsuyoshi Tsutada and Takami Miki ; Jun-ichi Kira ; Tameko Kihira and Tomoyoshi Kondo ; Hidekazu Tomimoto ; Takayuki Taniwaki ; Hiroshi Sugiyama and Sonoyo Yoshida ; Harutoshi Fujimura and Tomoko Saito ; Kyoko Saida and Junko Fujitake ; Naoki Fujii ; Masatoshi Naito and Jun Arimizu ; Takashi Nakagawa, Hirofumi Harada, and Takayuki Sueta ; Toshihiro Kikuta and George Umemoto ; Eiichi Uchio and Hironori Migita ; Kenichi Kazuki, Yoichi Ito, and Hiroyoshi Iwaki ; Kunihiko Siraki and Shinsuke Ataka ; Hideo Yamane and Rie Tochino ; Teruichi Harada ; Yasushi Iwashita, Motoyuki Shimizu, Kenji Seki, and Keiji Ando .AP, Attributable proportion due to interaction; CI, Confidence interval; OR, Odds ratio; PD, Parkinson’s disease; RERI, Relative excess risk due to interaction; S, Synergy index; UCHL1, Ubiquitin carboxy-terminal hydrolase L1.All authors declare that they have no competing interests.YM contributed to the study design, data collection, overall management, statistical analysis, data interpretation, and writing of the manuscript. KT and WF contributed to the study design, data collection, and data management. SS and CK contributed to the study design. YT, TY, TO, TM, NK, NS and HF contributed to the outcome definition and case recruitment. YH and MN contributed to the supervision of the design and execution of the study. Authors listed in the Appendix contributed to case or control subject recruitment. All authors contribute to the preparation of the manuscript and approved the final version submitted for publication.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2377/12/62/prepub


Accumulating evidence suggests the involvement of the endocannabinoid-system in liver disease and related complications. In particular, hepatoprotective properties for Cannabinoid Receptor Here, in order to clarify the role of CB2 in severity of childhood NAFLD, we have investigated the association of the CB2 Q63R variant, with histological parameters of liver disease severity in 118 Italian children with histologically-proven NAFLD.CB2 Q63R genotype was assigned performing a TaqMan assay and a general linear model analysis was used to evaluate the association between the polymorphism and the histological parameters of liver damage.p = 0.002) and the presence of NASH (p = 0.02).We have found that whereas CB2 Q63R variant is not associated with steatosis or fibrosis, it is associated with the severity of the inflammation (Our findings suggest a critical role for CB2 Q63R variant in modulating hepatic inflammation state in obese children and in the consequent increased predisposition of these patients to liver damage. Non-alcoholic fatty liver disease (NAFLD) comprises a spectrum of disease ranging from simple steatosis to inflammatory steatohepatitis (NASH) with different degrees of fibrosis that can ultimately progress to cirrhosis Evidence that only a minority of patients with NAFLD progress to NASH suggests that disease progression is likely to depend on complex interplay between environmental factors and genetic predisposition Cannabinoid receptors (CBs) are seven-transmembrane domain G protein-coupled receptors that bind phyto-derived, as well as endogenous cannabinoids, among which anandamide (AEA) and 2-arachidonoylglycerol (2-AG) are the best characterized. Two types of CBs are known to date, namely CB1 and CB2, respectively. CB1 are expressed at high levels in the central nervous system (CNS), whereas CB2 are found predominantly, but not exclusively, outside the CNS. CBs, together with the enzymes metabolizing AEA and 2-AG, form the endocannabinoid (EC) system The EC system is involved in a wide range of regulatory functions and is now emerging as critical mediator of both acute and chronic liver injury Particularly, hepatoprotective and antifibrogenic properties have been recently suggested for CB2 receptors both through experimental murine models of liver injury and association study between a common functional variant of CB2, Q63R, with liver enzymes in a cohort of 438 Italian obese children with steatosis at ultrasound imaging In order to clarify the role of CB2 in severity of childhood NAFLD, in this study we have investigated the association of the Q63R CB2 variant with histological parameters of liver damage in a large series of Italian children with biopsy-proven NAFLD.This study was carried on 118 consecutive untreated children and adolescents  with biopsy-proven NAFLD who were referred to Bambino Gesù Children's Hospital between May 2006 and November 2009 Anthropometric and biochemical investigations, as well as evaluation of histology on liver biopsies were performed as previously described The diagnosis of NASH was based on the pathologist's overall impression according to Kleiner et al. Steatosis, inflammation, hepatocyte ballooning, and fibrosis were scored using the NAFLD Clinical Research Network (CRN) criteria As recommended by a recent NASH CRN article CNR2 rs35761398 polymorphism (CAA/CGG), underlying the Q63R CB2 substitution, was performed by using a TaqMan Assay .After a written informed consent from parents and assent from children were obtained, genomic DNA was extracted from peripheral whole blood with a DNA extraction kit . Detection of the 5′-GTGCTCTATCTGATCCTGTC-3′ and Anti-sense primer 5′-TAGTCACGCTGCCAATC-3′; AA-Probe 5′-CCCACCAACTCCGC-3′ and GG-Probe 5′-CCCACCGGCTCCG-3′ . Both polymerase chain reaction, performed according to the manufacturer's instruction, and post–polymerase chain reaction allelic discrimination through the measurement of allele-specific fluorescence were carried out on an ABIPRISM 9600 apparatus . Random samples were confirmed by direct genotyping performing a PCR consisting in 94°C for 4 min followed by 31 cycles of 94°C for 30 s, 60°C for 30 s and 72°C for 30 s with Forward 5′-GAGTGGTCCCCAGAAGACAG-3′ and Reverse 5′-CACAGAGGCTGTGAAGGTCA-3′ primers. PCR products were analysed by using an ABI PRISM 3100 automated sequencer . All primers were picked by using Primer3 software.Primers and probes were the following: Sense Primer Patients were also screened, as previously described p-values less than 0.05 were considered to be statistically significant.Results are expressed as means ± standard deviations. Mean values were compared by analysis of ANOVA, followed by Student–Newman–Keuls post hoc test. The differences in genotype and allelic frequencies and the association between the Q63R CB2 polymorphism with different clinical and liver histological parameters were evaluated by general linear model analysis including gender, age, waist circumference and HOMA-IR as covariates. Moreover we performed a multiple test including PNPLA3 genotype as covariate and then a multivariate analysis incorporating I148M PNPLA3 as well as Q63R CB2 variants for the whole cohort. Analyses were carried out by using Stat-Graph 3.0 software. In all cases To determine the influence of the Q63R variant on susceptibility to NASH, we examined whether this variant was associated with histological parameters of liver disease severity in a cohort of children with biopsy-proven NAFLD. Clinical and histological data of the children involved in the study are reported in As expected the great majority of the children was obese.The frequency distribution of the Q63R CB2 SNP was in Hardy-Weinberg equilibrium. Heterozygosity for the at-risk allele encoding for R was observed in 39% of patients, and homozygosity was observed in 50%.The Q63R genotype was not significantly associated with body mass index, lipid levels, insulin resistance, insulin sensitivity index, AST, ALT and gamma-GT levels .A weak association was found with HOMA-IR index. Since the degree of insulin resistance is known to affect both severity of lobular inflammation and NASH, in the statistical analysis performed on liver histological data, beside age, sex and waist circumference, we added HOMA-IR index as covariate.p = 0.0022; The Q63R genotype was strongly associated with the severity of inflammation. Grade 2 of inflammation was observed in 0 of 13 children with the QQ genotype, in 10 of 46 with the QR genotype (22%), and in 13 of 59 with the RR genotype (22%) .The Q63R SNP was not associated with the severity of steatosis (grades 0–3) (p = 0.02).The prevalence of NASH according to the Q63R CB2 variant is shown in The relative odds ratios are shown in We also investigated the role of I148M PNPLA3 variant on NAFLD severity and, according to previous report p = 0.069 and p = 0.12, respectively).When the PNPLA3 genotype was included in the multivariate analysis the association between Q63R genotype and the severity of inflammation or the presence of NASH did not appear still significant (p<10−4), whereas the association with fibrosis was not (p = 0.08)  .p = 0.001; p value was 0.0001.When we stratified the sub-group of 55 children I148M PNPLA3 heterozygous for the Q63R CB2 variant, we found that the presence of NASH among these patients was significantly associated to the presence of the R63 CB2 allele (Considering that only a portion of patients with NAFLD will progress from simple fatty liver (steatosis) to inflammation (steatohepatitis), fibrosis and ultimately cirrhosis, it appears as an important goal to understand the mechanisms leading to this progression It has been shown in rodents that the setting of simple hepatic steatosis is associated with a chronic hepatic inflammatory state, due to increased activation of the nuclear factor κB (NF-κB) transcription factor which, in turn, functioning as a pro-inflammatory switch, induces the transcription of inflammatory cytokines, including TNFα and IL-6, in the hepatocytes and in the Kupffer cells The production of these inflammatory cytokines seems to play a major role in the further step from steatosis to steatohepatitis progression.The well-know effects of CB2 receptor on both peripheral and central inflammatory response and mainly its ability to modulate both activation of NF-κB and the production of TNFα and IL-6 appear of particular interest in the context of the study we have performed. Experimental studies have, in fact, demonstrated that CB2 stimulation is able to inhibit NF-κB translocation into the nucleus, interfering with the phosphorylation of its activator, and to decrease both TNFα and IL-6 production, enhancing the expression of their synthesis inhibitor, the anti-inflammatory cytokine IL-10 In 118 Italian children with biopsy-proven NAFLD, the CB2 variant carrying an arginine at codon 63 was not associated with steatosis, but was associated with the severity of the NAFLD inflammatory component, this increasing the risk for NASH appearence. In a previous study It has been recently demonstrated that the CB2 exhibiting an arginine at codon 63 (R63) shows a reduced function when activated by an endogenous cannabinoid ligand, compared to the CB2 variant with the glutamine at the same codon (Q63) Nevertheless the lack of association of CB2 polymorphism with fibrosis may simply reflect the young age of the cohort (10.2±2.6) as they have no sufficient time for the disease to progress.Recently, the functional variant I148M of PNPLA3, a gene likely involved in hepatic triglyceride hydrolisis, has been associated with steatosis severity and with the presence of NASH in the same cohort here studied Accordingly, stratifying CB2 polymorphism on I148M PNPLA3 variant, we have noticed that the effect of R63 CB2 variant on NASH appearance was emphasized in the sub-group of patients carrying the M148 PNPLA3, which is associated to severe steatosis.The data reported in this work, therefore, may be explained by the existence of different pathways contributing to liver damage progression in NAFLD, suggesting an important role of the inflammatory component in its pathogenesis and in its progression towards more severe liver disease.Considering that NAFLD is the most common cause of chronic liver disease in children and given the highly heritable nature of this disease Table S1Multivariate analysis incorporating both I148M PNPLA3 and Q63R CB2 variants, as well as age, sex, waist circumference and HOMA-IR.(DOC)Click here for additional data file.Table S2p-values were significant only for the presence of NASH. It worth of notice that the odds ratio for inflammation risk with respect the CB2 variant is 0 for the QQ allele, since none of QQ subjects show a grade 2 of inflammation.Odds ratio for liver disease features with respect the Q63R CB2 variant. According to the data from the multivariate analysis, odds ratio associated (DOC)Click here for additional data file.


Evidence implicates cyclin D1 (CCND1) G870A polymorphisms as risk factors for various cancers. An increasing number of investigations have been conducted on the association of CCND1 G870A polymorphisms with susceptibility to oral carcinoma, and have yielded inconclusive results. The aim of the present study was to derive a more precise estimation of the correlation. Meta-analyses examining the association between CCND1 G870A polymorphisms and oral carcinoma were performed. Separate analyses on ethnicity, smoking status and control sources were also implemented. Eligible studies were identified prior to February 2012. From the overall data from 1,128 cases and 1,276 controls, no associations of CCND1 G870A polymorphisms with oral carcinoma were observed . In the subgroup analysis by ethnicity, smoking status and control sources, no significant associations of CCND1 G870A polymorphisms and oral cancer were observed for the three genetic models. Collectively, the data failed to suggest CCND1 G870A polymorphism as a low-penetrant risk factor for developing oral carcinoma. Additional studies with large sample sizes concerning different ethnicities in different areas are required. Oral squamous cell carcinoma is one of the most common cancers in the world and its main risk factors are cigarette smoking and alcohol consumption ,2 as welOur previous meta-analyses revealed GSTM1 genetic variation as a risk factor for oral cancer, whereas the CYP1A1  or TP53 Cyclin D1 (CCND1) is a key regulatory protein that plays an important role in the transition from G1 to S phase of the cell cycle during cell division. Inhibition of CCND1 function often results in cell cycle arrest, whereas overexpression of CCND1 may disrupt normal cell cycle control and subsequently contribute to oncogenesis . EvidencPreviously, a common functional polymorphism, G870A, of CCND1 has been widely studied as a possible low-penetrant susceptibility allele for various cancers . CCND1 GPublished data on the possible association of CCND1 G870A polymorphism with oral carcinoma have generated inconclusive results. To the best of our knowledge, the question of whether the CCND1 G870A polymorphism increases oral cancer risk remains uncertain. To clarify this association may elucidate the possible risk of oral cancer and therefore contribute to its prevention. As a single study may have been underpowered in clarifying the associations of CCND1 G870A polymorphisms with oral carcinoma susceptibility, in the present study we performed evidence-based quantitative meta-analyses that increased statistical power to address this controversy.We carried out a search in the Medline, EMBASE, OVID, Sciencedirect and CNKI databases without a language limitation, including all manuscripts published until February 2012, with a combination of the following keywords: cyclin D1, CCND1, oral, mouth neoplasm, tumor, cancer, variation and polymorphism. All searched studies were retrieved and the bibliographies were checked for other relevant publications. Review articles and bibliographies of other relevant studies identified were hand-searched to find additional eligible studies.The following criteria were used for the literature selection: First, studies should concern the association of CCND1 G870A polymorphism with oral cancer risk; second, studies should be observational studies (case-control or cohort); third, manuscripts must offer the size of the sample, odds ratios (ORs) and their 95% confidence intervals (CIs), the genetic distribution or the information to infer the results. After searching, we reviewed all manuscripts in accordance with the criteria defined above for further analysis.Data were extracted from all eligible publications independently by two of the authors according to the inclusion criteria mentioned above. For conflicting evaluations, an agreement was reached following a discussion. If a consensus could not be reached, another author was consulted to resolve the dispute and then a final decision was made by the majority of the votes. The extracted information was entered into a database. For data not provided in the main text, the relevant information was obtained by contacting corresponding authors if and when possible.The OR of CCND1 G870A polymorphisms and oral cancer was estimated for each study. The pooled ORs were calculated for the additive model (AA vs. GG), dominant model (AA+AG vs. GG) and recessive model (AA vs. AG+GG), respectively. For detection of any possible sample size biases, the OR and its 95% CI from each study was plotted against the number of participants. A Chi-square based Q-statistic test was performed to assess heterogeneity. If the result of the heterogeneity test was P>0.1, ORs were pooled according to the fixed-effects model (Mantel-Haenszel), otherwise, the random-effects model (DerSimonian-Laird) was used. The significance of the pooled ORs was determined by Z-test. The Hardy-Weinberg equilibrium (HWE) was assessed via Fisher’s exact test.Publication bias was assessed by visual inspection of funnel plots , in whicPublications relevant to the key words were retrieved and screened. A total of 52 studies on CCND1 were searched and screened for retrieval, of which 43 irrelevant studies were excluded. Two studies ,22 were All the included six studies were written in English. We established a database according to the extracted information from each article. The relevant information is listed in Of the included studies, two studies were on Caucasian ,34, threAs shown in We analyzed the heterogeneity of an additive model (AA vs. GG), dominant model (AA+AG vs. GG) and recessive model (AA vs. AG+GG).As shown in In subgroup analysis stratified by ethnicity, no significant associations were identified among Asians, Caucasians or mixed ethnicities for the three genetic models. In subgroup analysis with regard to smoking status and control source, no significant association of the CCND1 polymorphism with oral cancer susceptibility was observed.When the effects-models were changed, the significance of the overall data for the three models was not statistically altered (data not shown). We then excluded two studies ,30 whoseFunnel plots were created for the assessment of possible publication biases. Egger’s linear regression tests were used to assess the symmetry of the plots . The datIn the present study, the results of meta-analyses failed to reveal a significant association of CCND1 G870A polymorphism with oral cancer risk.Recently, several meta-analyses have been conducted to assess the association of CCND1 G870A polymorphisms with cancer risks. The A allele has been suggested to increase risk of digestive tract  and coloSmoking is a well-known risk factor for a number of cancers, including lung and oral cancer. Effects of interactions between smoking and the CCND1 genotype on lung cancer risk have been suggested previously ,43. In tBetween-study heterogeneity was observed in Publication biases were assessed via funnel plots and their symmetries were further evaluated by Egger’s linear regression tests. No evident biases were observed, suggesting little influences of publication biases on the results.Several limitations may be included in the present study. First, in this meta-analysis, the majority of published studies were written in English, Chinese and Portuguese, as cited by the databases consulted. It is possible that certain published or unpublished studies written in other languages that met the inclusion criteria were missed. Hence, inevitable publication biases may exist, although the funnel plots and Egger’s linear regression tests implied no marked publication biases. Second, the subgroup analysis concerned only Caucasians, Asians and mixed ethnicities. Data with regard to other ethnicities were not identified. The Asian populations were confined to Indians and Chinese in Taiwan. Studies conducted in Southeast Asia, Japan and mainland China are required to increase statistical power for the demonstration of this association. Third, hospital-based controls were used in some included studies. Hence, non-differential misclassification bias may exist. However, subgroup analysis was carried out and no evident influence on the results was identified. Gene-gene and gene-environment interactions should also be considered in further studies. However, the sensitivity analysis and publication bias analysis showed the stability and credibility of the present meta-analysis.In summary, despite the limitations, the results of the present meta-analysis failed to suggest a significant association between CCND1 G870A genetic variations and oral cancer risk.


MDM2) SNP309 polymorphisms have been reported to influence the risk of lung cancer. However, the published studies together with four subsequent meta-analyses have yielded contradictory results. To examine this inconsistency, we conducted a meta-analysis of 6,696 lung cancer cases and 7,972 controls from eight published case-control studies using METAGEN. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated with STATA software and used to assess the strength of the association. In the overall analysis, a significant association between MDM2 SNP309 polymorphism and lung cancer risk was observed . Moreover, stratified by ethnicity, a significant association was found in Asians , but not in Europeans. Subgroup analysis of gender, histology and smoking status suggested that the MDM2 SNP309 genotype was associated with increased lung cancer risk in women  and never smokers . No statistically significant association was observed in males and ever smoking population, and no association was found in subgroup analysis based on histology. In conclusion, the association between MDM2 SNP309 and lung cancer was statistically significant, particularly in Asians, women and never smoking population.Lung cancer is the most common diagnosed malignancy and the leading cause of cancer-related mortality worldwide. Murine double minute 2 ( Lung cancer is the most common malignancy diagnosed in males, and the fourth most common diagnosed malignancy in females worldwide. Moreover, it is the leading cause of cancer-related mortality in males and the second leading cause of cancer-related death in females. Based on the GLOBOCAN 2008 estimates, lung cancer accounts for 13% (1.6 million) of the total cases and 18% 1.4 million) of deaths in 2008  million  also plaMDM2) gene located on chromosome 12q13–14 encodes an important negative regulator for the p53 tumor suppressor, resulting in its ubiquitination by direct binding to p53  in the first intron of the  pathway . Subsequn Asians ,17–19 Can Asians –22 and An Asians . However results ,24 and o results ,26. To r METAGEN . In addi METAGEN ,24, we cMDM2’, ‘polymorphism’ and ‘lung cancer’. The search was conducted until February 2012, and was limited to English language studies. To obtain additional potentially eligible studies we also reviewed the reference lists of the original studies identified, as well as reviews and previous meta-analyses.Pubmed, Embase and HuGENet databases were searched using the following terms or combinations: ‘murine double minute 2’, ‘SNP309’, ‘MDM2 SNP309 polymorphism and lung cancer risk, ii) studies containing useful genotype distribution information, iii) case-control or cohort studies and iv) studies with a control population without prior or current severe respiratory disease and malignant disease. The exclusion criteria were: i) studies analyzing the same patient population (the most recent or complete study was chosen) and ii) case-only studies, which were studies without a healthy control group.The eligible studies assessed in our meta-analysis had to achieve all of the following criteria: i) original studies concerning From each eligible study, we extracted data consisting of the first author, year of publication, ethnicity of the population, the genotype frequency of the cases and controls, diagnostic criteria and genotyping methods. For studies including the the frequency of genotypes of the cases and controls according to different subgroups for gender, histology and smoking status, data were separately extracted for each subgroup whenever possible.I2) (2>50% to indicate significant heterogeneity (MDM2 SNP309 T>G polymorphism and lung cancer risk. Three genetic models: dominant (GG/TG vs. TT), recessive (GG vs. TG/TT) and co-dominant (GG vs. TG and TG vs. TT) were used to evaluated the risk. The methodology used to determine the most appropriate genetic model was reported by Bagos and Nikolopoulos  = αi + θ2 zi2+θ3 zi3 and ORAB/AA= exp(θ2), ORBB/AA= exp(θ2); where αi are indicators of the study-specific fixed-effects, and θ2 and θ3 are dummy variables of genotypes AB and BB. The appropriate genetic model was identified using the following criteria (2=θ3 (ORAB/AA = ORBB/AA = 1)no association: θ2≠0, θ3≠0 and θ2=θ3 (ORAB/AA = ORBB/AA≠1)dominant model: θ2=0 (ORAB/AA = 1) and θ3≠0 (ORBB/AA ≠ 1)recessive model: θ2≠0, θ3≠0 and 2θ2=θ3 (OR2AB/AA = ORBB/AA)co-dominant model: θHardy-Weinberg equilibrium (HWE) for the genotype distributions in the controls of each study was assessed using Pearson’s Square (P≥0.05) . CochranI2)  were nexogeneity ,32. In tlopoulos . Two parcriteria :no assoFinally, once the most approtriate genetic model was identified, it was used to again pool the results for both logistic regression analysis and heterogeneity assessment. Subgroup analysis also abided by this procedure.http://bioinformatics.biol.uoa.gr/~pbagos/metagen/) and STATA version 11.1 . All P-values were two-sided.Publication bias was assessed using Egger’s tests and Begg’s funnel plot . The staMDM2 SNP309 polymorphism and lung cancer risk retrieved. We reviewed all full-text studies intensively and excluded four studies without a control group  concerning the associated of the MDM2 SNP309 polymorphism and lung cancer risk were included in this meta-analysis  with 95% confidence intervals (CIs). In the overall analysis, using the fixed-effect model, significant associations between the MDM2 SNP309 polymorphism and lung cancer risk were observed in the recessive model . Moreover, following the stratification of studies according to ethnicity, a statistically significant association was noted in Asian  while not in European population. In the subgroup analysis based on gender, we found that the MDM2 SNP309 GG genotype conferred a statistically significant increased risk of lung cancer development in females . However, we did not observe a similar result in males. In the subgroup analysis based on smoking status, a statistically significant association was observed in never smokers  but not in the ever smoking group. However, there was no evidence of a statistically significant association between the MDM2 SNP309 polymorphism and lung cancer risk in the subgroup analysis based on histology.We performed Egger’s test to access the publication bias. There was no indication that the shapes of the funnel plots exhibited obvious asymmetry, indicating any obvious evidence of publication bias in this meta-analysis.MDM2 SNP309 polymorphism and lung cancer risk have provided discrepant results. Gui et al (MDM2 309G allele is a low-penetrant risk factor for developing lung cancer in Asians, yet Bai et al (MDM2 SNP309 GG genotype enhanced the risk of lung cancer development in never smokers with statistical significance, but no statistically significant was noted in Asian and European individuals. The main difference between these two meta-analyses was the genetic model selection. Hence, we conducted the present meta-analysis, one study more than these two meta-analyses (MDM2 SNP309 polymorphism increases the risk of lung cancer development with a statistical significance, particularly in never smoking and Asian populations, we explored the relationships between the MDM2 SNP309 polymorphism and the risk of lung cancer based on subgroups of different gender and histology using the most appropriate genetic model. We detected a statistically significant association between the MDM2 SNP309 polymorphism and the risk of lung cancer in females.Previous meta-analyses elucidating the link between the ui et al  found thai et al  conducteanalyses ,24 usingMDM2 SNP309 polymorphism was statistically significantly associated with the risk of lung cancer in females but not in males. It appears that the results of the subgroup analysis according to females and males was due to smoking and no smoking status as more men smoke than women, and it has been suggested that MDM2 SNP309 increases the risk of lung cancer in never smokers (MDM2 SNP309 expression and leads to an increased risk of lung cancer in females. This indicates that men and women have approximately the same prevalence of lung cancer although smoking status tends to be higher among men compared to women.According to the results of this meta-analysis, our main finding was that the  smokers ,23,40. YMDM2 SNP309 G allele frequency was found to be a risk factor in Asians. This result is consistent with previous studies (MDM2 SNP309 polymorphism was previously documented. However, the reason for the differential effects of the MDM2 polymorphism according to ethnicity is unclear. The differences in environment and genetic backgrounds may influence the association between the MDM2 SNP309 polymorphism and risk for lung cancer. Here, we must mention that, following subgroup analysis of Asian individuals, the result of our meta-analysis exhibited dissimilarity with Bai et al (The  studies ,18. The ai et al , which iai et al ,17,18. Tai et al  and thisHeterogeneity is inevitable in a meta-analysis ,42. We hOther possible limitations should be taken into account which contributed to the low statistical power of this meta-analysis. For instance, we only selected studies published in the electronic edition of the databases in English language and ignored the studies published in other languages, in paper version or not published at all. Publication bias may exist although Begg’s funnel plot and Egger’s test did not detect bias. Additionally, not all the included studies contained the complete data needed particularly for the subgroup analysis, thus we only analyzed the obtained data.MDM2 SNP309 GG genotype may increase the risk of lung cancer particularly in Asians, females and never smoking population. Considering the limitations of this meta-analysis, further studies with large sample sizes, using well-designed and more accurate methods of genotyping are warranted to confirm the association between MDM2 SNP309 and lung cancer risk.In conclusion, the current meta-analysis demonstrates that the


Glutathione S-transferases (GSTs) are multifunctional enzymes that play a key role in the detoxification of varieties of both endogenous products of oxidative stress and exogenous carcinogens.GSTM1 and 19 evaluated GSTT1. Crude odds ratios with corresponding 95% confidence intervals were used to estimate the association between GSTM1 and GSTT1 polymorphisms and risk of cervical neoplasia. Subgroup analyses were conducted by pathological history, ethnicity, source of DNA for genotyping, quality score, and matching variable.In this meta-analysis, twenty-five studies were identified by searching PubMed, EMBASE, ISI Web of Science and CBM databases: 23 evaluated GSTM1 and GSTT1 polymorphisms were associated with a significantly increased risk of cervical neoplasia . Subgroup analyses showed that the null genotype of GSTM1 increased the risk of cervical neoplasia in Asians, studies with DNA isolation from white blood cells and tissue samples, both high and low quality studies, and matched studies. In GSTM1-GSTT1 interaction analysis, individuals with dual null genotype were associated with a significantly increased risk of cervical neoplasia .The null genotypes of GSTM1 and GSTT1 polymorphisms, particularly GSTM1-GSTT1 interaction, may play critical roles in the development of cervical neoplasia. A conservative manner should be adopted to interpret these results because of obvious heterogeneity between-study, unadjusted data, and relatively small sample size in this meta-analysis. Well designed studies with larger sample size are of great value to confirm these results.These findings indicate that  Cervical cancer is the second most frequent cancer among women worldwide, with approximately 493,000 new cases diagnosed and 274,000 deaths occurring each year (2002 estimates) P53 (Pro72Arg) may represent a genetic marker for cervical carcinogenesis It is well established that human papilloma virus (HPV) infection is a necessary but insufficient event for the development of cervical cancer GSTM1 gene, is located on the short arm of chromosome 1 (1p13.3) GSTT1 gene, is locate on the long arm of chromosome 22 (22q11.23) GSTM1 and GSTT1 gene exhibit an inherited homozygous deletion polymorphism (null genotype) that is associated with an absence of enzyme activity. Individuals with homozygous deletion polymorphism are considered to be at increased risk for malignancies due to reduced efficiency in protection against environmental carcinogens Over the past decades, glutathione S-transferases (GSTs) genetic variants have been explored extensively as a predictive factor for cancer prognosis GSTM1 and GSTT1 polymorphisms and the risk of cervical neoplasia, and found that the combination of three factors  appeared significantly different frequency in cases and controls GSTM1 and GSTT1 homozygous deletion polymorphisms and risk of cervical neoplasia in diverse ethnicities In 1994, Warwick et al. explored for the first time the association between GSTM1 and GSTT1 polymorphisms on cervical neoplasia risk, we carried out a quantitative meta-analysis by combining data from all published case-control studies. Additionally, gene-gene and gene-environment interactions have also been examined in this meta-analysis.In order to provide strong evidence of the effects of GSTM1 and/or GSTT1 polymorphism and risk of cervical neoplasia; (b) presenting original data for the calculation of odds ratios (ORs) with corresponding 95% confidence intervals (95%CIs).We identified all publications by conducting computer-based searches of PubMed, EMBASE, ISI Web of Science, and CBM databases without language restrictions, using the following search algorithm:  and (“glutathione S-transferase” or “GST” or “GSTM” or “GSTM1” or “GSTT” or “GSTT1”) and (“polymorphism” or “polymorphisms” or “variant”). The literature search was performed up to Aug 2010. The inclusion criteria were: (a) case-control studies that investigated the association between GSTM1 and/or GSTT1 polymorphism (n = 13), no available data (n = 5) and review articles (n = 2). Additionally, we excluded two studies because the results were duplicated in subsequent publications GSTM1 polymorphism and risk of cervical neoplasia and 19 studies investigated the association between GSTT1 polymorphism and risk of cervical neoplasia.One hundred and fifty-four articles were identified by searching PubMed, EMBASE, ISI Web of Science and CBM databases. Eighty-four studies were excluded after screening the title or abstract . Then full-text articles were retrieved for assessment in detail. Forty-three were excluded with reasons for not cervical cancer (n = 23), no The groups of pathologic type were set according to the report by Klug et al. This study was approved by the ethics committee of Sichuan University. The data included in this study was taken from literatures, and thus written consent given by the patients was not needed.Two independent researchers (Gao and Pan) extracted raw data according to the inclusion criteria. The following information was collected from each study using a data extraction form: the surname of the first author, date of publication, country of origin, year of sample collection, ethnicity, characteristics of cases and controls, DNA source for genotyping, matching variables, number of cases and controls, genotype distribution of cases and controls, and quality control for genotyping assay. Additionally, we extracted, if available, the genotype frequency of cases and controls based on age (>40 or ≤40 years), smoking status (smoking or non-smoking) and HPV infection status (HPV positive or HPV negative). Given that there was no distribution of null/present heterozygote in each single study selected, the Hardy-Weinberg equilibrium (HWE) test could not be conducted. To ensure the accuracy of data extraction, the original extraction information was checked by Li, and discordant results were settled through discussion among the three authors.Three investigators  independently assessed the quality of included studies based on a predetermined rating scale  that wasGSTM1 and GSTT1 polymorphisms and risk of cervical neoplasia. Study-specific ORs comparing null genotype versus present genotype were combined using random-effects model (the DerSimonian and Laird) or fixed-effects model (the Mantel–Haenszel method), which was determined by the Q-test and I2 statistics P value for heterogeneity was ≤0.10 or I2≥50%, indicating a high extent of heterogeneity between studies, we used the DerSimonian and Laird method to evaluate the summary ORs. In contrast, if the P value for heterogeneity was >0.10 and I2<50%, indicating an absence of heterogeneity between studies We used crude ORs with corresponding 95% CIs as a measure of the association between GSTM1-GSTT1 interaction on cervical neoplasia compared with null/null versus present/present, null/null versus present/null, null/null versus null/present, null/present versus present/null, null/present versus present/present, and present/null versus present/present.Subgroup analyses were conducted by pathological history , ethnicity , source of DNA for genotyping , quality score (high versus low), matching according to age (matched versus unmatched), smoking status (smoking versus non-smoking) and HPV infection status (HPV positive versus HPV negative). Additionally, we evaluated the effect of the Logistic meta-regression was used to investigate possible sources of heterogeneity across studies. To determine the reliability of the outcomes in the meta-analysis, a sensitivity analysis was performed by exclusion an individual study each time. An evaluation of publication bias was carried out with funnel plot for visual inspection and Egger's regression asymmetry test The baseline characteristics of the included studies are shown in GSTM1 genotyping was extracted from white blood cells in 15 studies (62.5%). 17 studies (70.8%) mentioned genotyping quality control methods, mainly using an internal control. However, only six studies (25.0%) reported smoking status and only four studies (16.7%) detected HPV infection status.Totally, 23 studies met the inclusion criteria and were selected in this meta-analysis with 2,610 cases and 3,084 controls. Cases consisted of 32.5% patients with cervical cancer (histology not specified), 31.9% patients with SCC, 14.2% patients with HGL, 8.6% patients with LGL, 5.0% patients with SIL (unknown grade), 4.7% patients with both ICC and HGL and 3.0% patients with AC. Most of the controls (86.8%) were normal participants. There were sixteen studies of Asians, six studies of Caucasians, and two studies of mixed ethnicities that included more than one ethnicity. DNA used for GSTM1 polymorphism, most studies (68.4%) mentioned genotyping quality control methods, but only about 20% studies reported smoking status and HPV infection status.A total of 19 studies were included in the meta-analysis with 2,092 cases and 2,054 controls. Cases consisted of 27.1% patients with cervical cancer (histology not specified), 30.5% patients with SCC, 15.9% patients with HGL, 8.6% patients with LGL, 6.3% patients with SIL (unknown grade), 5.9% patients with both ICC and HGL and 5.8% patients with AC. Most of the controls (85.5%) were normal participants. Twelve studies were conducted in Asia; four in Europe; two in America and one in South America. Similar to GSTM1 polymorphism and cervical neoplasia risk are summarized in The evaluations of the association between GSTM1 polymorphism was associated with a significantly increased risk of cervical neoplasia when compared with present genotype . When stratified by pathologic types, significantly elevated risks were observed in unknown type of cervical cancer  and mixed group  but not in groups of SCC, HGL, LGL and AC. In the subgroup analysis by ethnicity, significantly increased risks were observed in Asian population  but not in Caucasian and mixed populations  and unknown type of cervical cancer , while the association was not observed in subgroup analyses according to ethnicity, DNA source, and quality criteria  . No signGSTM1 polymorphism and smoking on cervical neoplasia, and there were four literatures which investigated the impact of interaction between GSTT1 polymorphism and smoking on cervical neoplasia. The effect of interaction between GSTM1 polymorphism and HPV infection status on cervical neoplasia was reported in four studies, and the effect of interaction between GSTT1 polymorphism and HPV infection status on cervical neoplasia was reported in five studies. No increased risks were found in the interaction between GSTM1 and GSTT1 polymorphisms and environmental exposure  (There were six literatures which investigated the impact of interaction between  status)  and S5.I2 statistics were shown in GSTM1, I2 = 53.3%; for GSTT1, I2 = 59.1%) and subgroup analyses. We explored several possible sources of the between-study heterogeneity, including cancer type, ethnicity, sample size, DNA source for genotyping and quality score. However, none of these variables could explain the heterogeneity.The findings of Q-tests and P>0.05).To assess the effect of individual study on the overall meta-analysis estimate, we excluded one study at a time, and the exclusion of any single report did not alter the significance of the final decision, suggesting that the outcomes were robust. Funnel plot and Egger's test were used to assess publication bias of literatures on cervical neoplasia. No evidence of publication bias was observed in all comparison groups  are the most important parts of phase II superfamily of metabolism enzymes. In humans, there are several GST classes that were encoded by distinct gene families GSTM1 and GSTT1 polymorphisms have different effects on the risk of cervical neoplasia in different genetic backgrounds and environment which they exposed to. The major difference in the distribution of GSTM1 and GSTT1 polymorphisms has been reported among control groups in 2001. The frequency of GSTM1 null genotype was 53.1% (42.0–60.0%) in Caucasians, 52.9% (42.0–54.0%) in Asians, and 26.7% (16.0–36.0%) in Africans. The frequency of GSTT1 null genotype was 19.7% (13.0–26.0%) in Caucasians and 47.0% (35.0–52.0%) in Asians GSTM1 and GSTT1 polymorphisms and the risk of cervical neoplasia in Caucasian and mixed populations. Therefore, well-designed studies with thousands of sample size are of great value to confirm this finding in Caucasians and other ethnic populations.After subgroup analysis according to ethnicity, significantly increased risks were observed in Asian population but not in Caucasian and mixed populations. The possibilities of the conflicting results among diverse ethnicities may be that the GSTM1 and GSTT1 genotyping, the null genotype of GSTM1 significantly increased the cervical neoplasia risk in studies that the polymorphism was determined from white blood cells rather than from exfoliated cervical cells. The difference of studies with DNA isolation from exfoliated cervical cells tended to be significant (P = 0.057). It is likely that the potentially negative results were caused by small sample size with only 299 cases and 405 controls available in this meta-analysis. Another important issue is the source of cell used for DNA analysis. DNA isolation from different cell types may influence performance of genotyping, and eventually, lead to the conflicting results.When stratified based on the source of DNA for GSTM1 polymorphism was associated with an increased risk of cervical neoplasia in both high quality studies and low quality studies. However, there was lack of association between GSTT1 polymorphism and cervical neoplasia risk either in high quality studies or in low quality studies. These findings denote that GSTM1 plays much more important roles than GSTT1 in the development of cervical neoplasia.It is absolutely pivotal for a meta-analysis to assess the quality of literatures included. Currently, no standard quality score method was developed to evaluate observational case-control studies. We used a self-made rating scale for quality assessment, which was modified from previous studies GSTM1 and GSTT1 polymorphisms and smoking on the development of cervical neoplasia has been conducted in several studies GSTM1 and GSTT1 polymorphisms and cervical neoplasia in combination with smoking habit. There may be a high risk of false negative results due to insufficient statistical power with very limited subjects eligible in this meta-analysis .The hypothesis of cigarette smoking being a risk factor for cervical cancer was originally presented in 1977 GSTM1 and GSTT1 polymorphisms and cervical neoplasia risk in either HPV positive women or HPV negative women. The null result may be owing to limited relevant studies included in this meta-analysis. Thus, large-scale prospective cohort studies are needed to provide the best evidence for the impact of interaction of gene-environment on the risk of cervical neoplasia.Persistent HPV infections are known to be the major cause of cervical cancer GSTM1 and GSTT1 polymorphisms and various cancers, including brain tumors GSTM1 and GSTT1 polymorphisms and cervical cancer risk was published GSTM1 polymorphism but not GSTT1 polymorphism was associated with the risk of cervical cancer GSTM1 and GSTT1 polymorphisms and cervical intraepithelial neoplasia were also selected. Much more eligible studies, therefore, were included in this meta-analysis. Consistent with the results reported by Economopoulos et al., we found that the null genotype of GSTM1 polymorphism was associated with a significantly increased risk of cervical neoplasia. Inconsistent with the results reported by Economopoulos et al., we found an evidence of an association between GSTT1 polymorphism and the risk of cervical neoplasia with a borderline statistical significance. Larger sample size in this study may be responsible for the positive results. Our findings were in agreement with several previous reports. For example, Wang et al. reported that both GSTM1 and GSTT1 polymorphisms are associated with increased risk of hepatocellular carcinoma GSTM1 and GSTT1 null genotype carriers exhibited higher colorectal cancer risk in Caucasian population GSTM1 and GSTT1 polymorphisms did not increase a substantial risk of breast cancer GSTM1 and GSTT1 homozygous deletion polymorphisms may yield different effects on different types of cancers.Over the past decades, a large number of meta-analyses have been done to investigate the association between Our study has some limitations. Firstly, the between-study heterogeneity is a major problem in this meta-analysis because obvious heterogeneity was detected in overall analyses and also subgroup analyses. We explored several possible sources of heterogeneity, including cancer type, ethnicity, sample size, DNA source for genotyping and quality score. Unfortunately, we failed to find a bright reason for this variation, indicating that unknown confounding variables in single studies may have biased the findings. A conservative manner should, therefore, be adopted to interpret these results. Secondly, some potential confounding factors, such as age, sexual habits, and menopausal status can not be ruled out due to unadjusted data used. Finally, the sample size is relatively small in the meta-analysis, especially in some subgroup analyses.GSTM1 and GSTT1 polymorphisms were associated with a significantly increased risk of cervical neoplasia. In GSTM1-GSTT1 interaction analysis, individuals with dual null genotype were associated with a significantly increased risk of cervical neoplasia. In gene-environment interaction analysis, neither smoking status nor HPV infection status was associated with GSTM1 and GSTT1 polymorphisms. To ensure a precise estimate of the effect of GSTM1 and GSTT1 polymorphisms on cervical neoplasia risk, additional unbiased studies with larger sample size are needed. Such studies will not only elucidate the pivotal roles GSTM1 and GSTT1 polymorphisms playing in the development of cervical neoplasia, but also increase our understanding the etiology of cervical neoplasia.In summary, this meta-analysis indicates that the null genotypes of Figure S1Flow diagram of the literature search.(TIF)Click here for additional data file.Figure S2GSTM1 polymorphism in subgroup analysis according to ethnicity.Forest plot of cervical neoplasia risk of (TIF)Click here for additional data file.Figure S3GSTT1 polymorphism and risk of cervical neoplasia.Forest plot of association between (TIF)Click here for additional data file.Figure S4GSTM1-GSTT1 interaction (null/null versus present/present).Forest plot of (TIF)Click here for additional data file.Table S1Quality assessment for the included studies.(DOC)Click here for additional data file.Table S2Overview of literatures included in the meta-analysis.(DOC)Click here for additional data file.Table S3Characteristics of the included studies.(DOC)Click here for additional data file.Table S4GSTM1 polymorphism and cervical neoplasia risk.Summary odds ratios with confidence intervals between the (DOC)Click here for additional data file.Table S5GSTT1 polymorphism and cervical neoplasia risk.Summary odds ratios with confidence intervals between the (DOC)Click here for additional data file.Table S6GSTM1-GSTT1 interaction and cervical neoplasia risk.Summary odds ratios with confidence intervals between the (DOC)Click here for additional data file.


Background. Inflammation has a key role in migraine pathophysiology. Vitamin D is an effective anti-inflammatory agent. The aim of this study was to investigate the association between migraine and two vitamin D receptor (VDR) polymorphisms (TaqI and FokI) and also the relationship between VDR polymorphisms and headache severity. Methods. In this case-control study we assessed 103 patients with newly diagnosed migraine without aura and 100 healthy subjects. Patients filled headache impact test-6 (HIT-6) as a tool to assess headache severity. Results. Genotype frequencies of VDR were significantly different between control and migraine patients. Heterozygote genotypes (Ff and Tt) were statistically more frequent in the migraine patients than the control subjects both for TaqI gene  and FokI gene polymorphisms . Also f and t alleles were more frequent in the migraine patients. Total HIT-6 score was significantly different between FokI heterozygote and homozygote patients . Conclusions. In conclusion our results showed that TaqI and FokI gene polymorphisms are associated with migraine without aura in Iranians patients. Also headache severity in FokI heterozygote patients was significantly greater than in the homozygote patients. Migraine is a major cause of chronic headaches with a reported prevalence of about 17% in women and 6% in men. Migraine is clinically diagnosed by recurrent unilateral pulsatile headaches and may happen after motor or sensory symptoms. The headache in migraine patients could be accompanied by nausea, vomiting, phonophobia, and photophobia. So, these migraineurs will have a low quality of life and less efficacy at work. Migraine has been ranked as the 8th most debilitating disease .To find a comprehensive explanation for the underlying pathophysiology of migraine as a disease, attempts have come to form some theories which can somehow justify the heterogeneity of the symptoms. One of these hypotheses is the role of inflammation in physiopathology of migraine. It has been shown that inflammatory substances produced by mast cells, especially in meninges, can activate the trigeminal nerve which is a central event in the pain of migraine . Also, pOn the other hand vitamin D has important functions in lots of physiologic activities such as immune system regulation and resolution of inflammation . FurtherVitamin D is suggested to play a role in serotonin  and dopaVDR is a nuclear protein; VDR gene is located on chromosome 12q and has several polymorphisms. Four known single nucleotide polymorphisms at the 3′ end of this gene are FokI, TaqI, ApaI, and BmsI. The FokI polymorphism, also known as start codon polymorphism, is caused by replacement of C with T and makes the final protein shorter.The aim of this study was to find whether there is an association between two VDR polymorphisms (TaqI and FokI) and migraine without aura.This case-control study included 103 consecutive patients who were newly diagnosed as having migraine without aura, based on International Headache Society (IHS) criteria [Headache impact test-6 (HIT-6) questionnaire was filled out by all patients to assess headache severity. The HIT-6 questionnaire consists of six questions that show six dimensions: pain severity, role functioning, social functioning, vitality, emotional distress, and cognitive functioning. Each question has 5 available answers: never, rarely, sometimes, very often, and always. Choices have been scored between 6 and 13, respectively. The total score is between 36 and 78 .Two mL of peripheral blood was collected from each participant. Genomic DNA samples were extracted from peripheral whole blood, using the AccuPrep Genomic DNA Extraction kit  according to the manufacturer's protocol.NCBI data bank, and primers were designed by Beacon Designer 7.91 to flank the coding regions . The sequences of primers are shown in The single nucleotide polymorphisms (SNPs) rs2228570 and rs731236 were identified by the Genotyping was done by high-resolution melt (HRM) assay using a Rotor-Gene 6000 instrument .μL of final volume using the type-it HRM kit (Qiagen), HRM PCR buffer, HotStarTaq Plus DNA Polymerase, nucleotides and EvaGreen dye, and 30 ng DNA.PCR reactions were carried out in duplicate in 20 The PCR program consisted of an initial denaturation-activation step at 95°C for 5 min, followed by a 40-cycle program .Curves for each duplicate were checked on the shape and peak height to meet reproducibility.Normalized and temperature-shifted melting curves from HRM, suggestive of SNP, were distinguished, and the samples were subjected to direct sequencing.t-test was used for comparison of the quantitative variables between two groups.Differences in demographics, variables, and genotypes of the VDR polymorphism variants were evaluated using a chi-squared test. An independent The associations between VDR polymorphism and risk of migraine were estimated by computing odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression analyses and by using crude ORs. To prevent the overestimation by using OR, also relative risk (RR) was used to estimate the association between VDR polymorphism and risk of migraine.P value of less than 0.05 was considered statistically significant.The Hardy-Weinberg equilibrium (HWE) was tested by a goodness-of-fit chi-squared test to compare the observed genotype frequencies with the expected frequencies among controls. All statistical analyses were done with SPSS software . A two-tailed From 103 subjects with migraine without aura and 100 healthy subjects, DNA samples were analyzed for FokI rs2228570 and TaqI rs731236 polymorphisms. In the case and control group 82.6% and 78% of participants were female, respectively; and the difference was not statistically significant. Also there was no significant difference between the mean ages of case and control groups . Patients' characteristics are reported in P = 0.002) (P = 0.035) (P = 0.018) and FokI gene polymorphisms  (P = 0.001).The allele frequencies of F and f for the FokI gene in the study population were 356 (87.7%) and 50 (12.3%), respectively. Frequencies in the control group were in accordance with Hardy-Weinberg equilibrium. The f allele was more frequent in the migraine patients than the control subjects  . For the= 0.035) . The fre= 0.001) . MultiplP = 0.012).VDR haplotypes derived from FokI and TaqI polymorphisms were examined using combination of genotypes. Subjects heterozygous for more than one polymorphic site were not considered for haplotype frequency. The distribution of haplotype frequencies in patients and control groups is shown in P = 0.231 and 0.163 for FokI gene and P = 0.469 and 0.494 for TaqI gene, resp.). Further analysis in the migraine subjects showed that the distributions of FokI rs2228570 and TaqI rs731236 gene polymorphisms were not associated with the presence of a family history of migraine and also with presence of menstrual effect on the headache aggravation . Frequency of headache per month and total HIT-6 score between the homozygote and heterozygote patients are shown in The comparison of allele frequencies between males and females in the case and also control group showed that there is no significant difference in the alleles distribution according to the sex  subjects are more likely to have migraine than homozygotes (TT). In addition a significant association between FokI polymorphism heterozygotes (Ff) and migraine was shown. Furthermore we found a significantly higher HIT-6 score in the Ff genotype than in FF. Haplotype analysis showed that Tf increases the susceptibility to migraine. Logistic regression analysis indicated that Ff genotype in combination with Tt genotype is associated with a higher risk for the disease compared with the control than any other kind of genotype combination.There are a few studies about the relationship between vitamin D and headache with controversial results. A report by Wheeler indicated that 40 percent of people with migraine had low vitamin D levels; also people with deficiencies tend to have migraine at lower ages . A studyα-308G/A [Several lines of evidence showed the role of an inflammatory process in pathophysiology of migraine. For instance, some studies demonstrated an increase of proinflammatory cytokines such as IL-6, IL-2, CGRP, and TNF in migraine . Also soα-308G/A . Gu et aα-308G/A . Yilmaz α-308G/A .A role for vitamin D is suggested in many of physiologic and pathologic mechanisms. 25-Hydroxyvitamin D deficiency is associated with inflammation through its effects on the secretion of cytokines such as interleukin-1 (IL-1), IL-2, IL-6, IL-12, TNF .The contribution of mast cells in migraine pathophysiology is implied , and we There are some studies indicating the role of endothelial dysfunction in the pathophysiology of migraine. A relation between cardiovascular diseases which are associated with endothelial dysfunction and migraine has been found .Recent evidence has also linked migraine to a broader range of ischemic vascular disorders including cerebral ischemia stroke, angina, myocardial infarction, coronary revascularization, claudication, and cardiovascular mortality .Since vitamin D has improved several diseases accompanying endothelial dysfunction (ED) and migraine is also associated with ED, another hypothesis is that vitamin D plays a role in the improvement of ED in migraine –29.Recently, the relationship between polymorphisms of VDR, especially FokI and TaqI, and susceptibility to several diseases associated with inflammation such as diabetes, autoimmune diseases, and tuberculosis has been shown .Mohammadnejad et al. demonstrated that allele t is an allele of risk for developing type 1 diabetes mellitus (TIDM) in the Iranian population ; also a Karray et al. found that FokI polymorphisms were significantly associated with rheumatoid arthritis (RA) and Behçet's disease . PatientA meta-analysis showed that the ff genotype has significant marginal association with tuberculosis although TaqI polymorphisms did not have such relation .In nervous system diseases the role of VDR polymorphism is interesting because VDR is widely expressed in the human brain. Vitamin D may regulate inflammation in the brain. Lehmann et al. found that TaqI polymorphism accompanied Alzheimer's disease . HoweverThere is one study about migraine and VDR polymorphisms; Schürks et al. evaluated the association between 77 polymorphisms and migraine and demonstrated that VDR polymorphisms FokI and BsmI are not associated with migraine while TNF, CCR2, TGFB, NOS3, and IL9 polymorphisms can affect the susceptibility of having migraine . This stIn conclusion our study showed the association of TaqI and FokI polymorphisms with migraine without aura; also headache severity in FokI heterozygote patients was more significant than in the homozygote patients. Our results were obtained from a small sample size and included only migraine patients without aura; therefore this is a preliminary conclusion and provides little evidence for a causal association between migraine and VDR polymorphisms. As in some other case-control studies we could not obtain enough information about an individual's exposure status over time, an important drawback. Another limitation concerns the selection of controls: we could not choose all of our controls to be fully matched with cases. Validation by a larger studies, especially randomized controlled trials, and cohort studies from a more diverse ethnic population is needed to confirm our findings.


Many publications have evaluated the correlation between RET, PHOX2B polymorphisms and Hirschsprung's disease with conflicting results. We performed this meta-analysis to clarify the association of RET, PHOX2B polymorphisms with HSCR.We searched Pubmed, Elsevier Science Direct, China National Knowledge Infrastructure database, Chinese Biomedical database, Google scholar. The combined odds ratio (OR) with 95% CI was calculated to estimate the strength of the association. Heterogeneity and publication bias were also assessed.C versus A = 5.05,95%CI = 4.16–6.13; ORCC versus AA = 9.73, 95%CI = 5.94–15.94; ORCC/AC versus AA = 5.31, 95%CI = 3.27–6.82; ORCC versus AC/AA = 7.06,95%CI = 5.60–8.91.) But, for rs1800860, the GG/GA versus AA did not reach statistical association  and the G versus A, GG versus AA, GG versus GA/AA were 2.23 (1.60–3.11);4.56 (1.14–18.27); 2.38 (1.66–3.43) respectively. For rs2435357, the T versus C, TT versus CC, TT/TC versus CC and TT versus CC/TC were 4.53 (3.27–6.27); 11.44 (5.67–23.10); 4.04 (2.92–5.57), and 9.01(5.25–15.46).The single polymorphism of PHOX2B gene wasn't related to the risk for HSCR.In total, 16 studies concerning RET and 4 studies concerning PHOX2B were included in the meta-analysis. The effects of five polymorphisms of RET  and one polymorphism (rs28647582) of PHOX2B were evaluated. We found a significant correlation between RET polymorphisms and HSCR. For rs1800858, the overall ORs (95% CI) of the A versus G, AA versus GG, AA/AG versus GG and AA versus GG/AG were 3.81 (2.28–6.35); 8.36 (3.45–20.25); 3.59 (1.83–7.02); and 6.60 (3.66–11.89). For rs1800861, the comparison of subjects in the G versus T, GG versus TT, GG/TG versus TT and GG versus TT/TG were 2.85(1.81–4.47); 5.38(2.68–10.80); 3.07(2.17–4.34) and 4.14(1.84–9.30) respectively. For rs10900297, the comparison results showed statistically significant. (ORThis meta-analysis shows a significant association between RET polymorphisms and HSCR. Hirschsprung disease (HSCR) is a congenital malformation of the hindgut produced by a disruption in the neural crest cells (NCC) migration during embryonic development. This disorder results in an absence of intramural ganglion cells in the submucosal and myenteric plexuses producing a functional intestinal obstruction HSCR has a complex genetic etiology with several genes being described as associated with either isolated or syndromic forms, such as RET,EDNRB,GDNF,EDN3 and SOX10, NTN3, ECE1, PHOX2B RET locates in 10q11.2 and is composed of 21 exons. Three common SNPs in the coding region of RET, c135G>A , c1296A>G  and c2307T>G  lie in exon2, exon7 and exon13 respectivly We conducted a comprehensive literature search in Pubmed, Elsevier Science Direct, China National Knowledge Infrastructure database, Chinese Biomedical database and Google scholar from January 2003 to December 2012 using the following search terms : hirschsprung disease, hirschsprung's disease; polymorphism, genetic; RET; and PHOX2B. Moreover, the references of the selected papers were also checked by hand-search for other potential articles that possibly have been missed in the initial search. Only papers in Chinese and English were included.The inclusion and exclusion criteria were drew up on the basis of the discussion studies. Studies eligible for this meta-analysis had to fulfill (1) the design type of study was a case-control study;(2) the study had examined the associations between the RET, PHOX2B gene polymorphisms and HSCR;(3) the frequencies of genotypes in case and control groups could be collected;(4) controls derived from a population within the same geographic area and ethnic background as HSCR cases. The exclusion criteria were as follows : (1) researches that did not meet the inclusion criteria; (2) the study reported useless or dupicated data.All of the data were extracted independently by two reviewers (Chun-mei Liang and Dong-mei Ji) according to the prespecified selection criteria. Potential disagreements were resolved by consensus. The following characteristics were extracted: name of first author, year of publication, racial ancestry of the study participants, genotypes and sample size, the polymorphisms investigated in the studies, the genotyping method, type of study.2 statistic which measures the severe degree of heterogeneity. I2 value ranges from 0 to 100%  P<0.05 was considered to be representive of statistically significant publication bias).Allele frequencies of the RET and PHOX2B SNPs at genetic polymorphisms from the respective studies were determined by the allele counting method. All the statistical analyses were performed by Stata version 11.0 .We assessed Hardy–Weinberg equilibrium (HWE) for the controls in each study by the Chi-square test. The odds ratio (OR) and its 95% confidence interval (95% CI) were estimated for each study by fixed or random effect model. Heterogeneity among studies was measured using the Chi-square based Q statistic The process of selecting studies was showed in Totally, there were 4 studies In total, we identified nine studies On the basis of three studies Six studies Totally, five studies In all, five studies Moreover, we performed subgroup analyses by the race. The detailed results were showed in heterogeneity = 0.000; AA vs. AG/GG: OR = 5.91,95% CI = 2.55–13.69, Pheterogeneity = 0.000; AA/AG vs. GG: OR = 3.58,95% CI = 1.46–8.81, Pheterogeneity = 0.000; A vs. G: OR = 3.46, 95% CI = 1.73–6.95, Pheterogeneity = 0.000). However,sensitivity analysis showed that the studies by Du et al was the main origin of heterogeneity for rs1800858. The heterogeneity significantly decreased when this study was excluded(Pheterogeneity = 0.10 for GG vs. TT), while the value of pooled OR was not significantly altered without this studies ..P values of Egger's tests were more than 0.05,providing statistical evidences of funnel plots'summetry.The results of Egger's test suggested no publication bias , a congenital malformation characterized by intestinal obstruction and colonic distension in newborns, and constipation in adults, that occurs in 1 in 5000 live births Although the association between polymorphisms of RET, PHOX2B and HSCR risk has been reported by a number of studies, the conclusions remained controversial due to the inconsistent findings. For rs1800858 polymorphism, Phusantisampan et al GG/GA vs. AA = 3.77, 95% CI = 0.97–15.04, POR = 0.062), but comparisons of the remaining combinations were statistically significant. The reason there was no association between them may be because only two original studies were included into the meta-analysis. For this reason, more original studies regarding the association between rs1800860 gene polymorphism and HSCR are necessary for accurate results. In addition, we found no difference between cases and controls in the comparisons of all genotypes of rs28647582 in this meta-analysis, which indicated that the polymorphism of rs28647582 may not associate with the susceptibility of HSCR.Because the sample size was larger than previous ones, the meta-analysis reduced the probability that random error produced false-positive or false-negative association. We found a significant association between these gene polymorphisms  and HSCR demonstrating that the haplotype composited with more HSCR-risk alleles rendered the hosts more susceptible to HSCR. We failed to find an association in GG/GA versus AA genotype for rs1800860 polymorphism polymorphisms is significantly associated with an increased risk of HSCR, and the SNPs of rs28647582 may not relate to the susceptibility of HSCR. More work is needed to further investigate the association of the other RET SNPs with HSCR. Besides, future studies are recommended to identify the possible genetic interactions in this association.Supplement S1PRISMA 2009 Checklist.(DOC)Click here for additional data file.Supplement S2Forest plots about RET,PHOX2B gene polymorphisms and HSCR.(DOC)Click here for additional data file.Supplement S3Funnel plots about RET,PHOX2B gene.(DOC)Click here for additional data file.Supplement S4Sensitivity analysis after exclusion of three studies deviating from HWE on the association of rs1800858 and rs1800861 gene polymorphisms with HSCR risk.(DOC)Click here for additional data file.


MDR1), which encodes the major trans-membrane transporter P-glycoprotein (P-gp), was found to be associated with susceptibility to cancer and response to chemotherapy. The C3435T Polymorphism of MDR1 gene was correlated with expression levels and functions of P-gp. Here, we studied the association between MDR1 C3435T polymorphism and susceptibility to Hodgkin lymphoma (HL) and patient's response to ABVD chemotherapy regimen.The human multi-drug resistance gene  method. Data analysis was carried out using the statistical package SPSS version 17 to compute all descriptive statistics. Chi-square and Fisher exact tests were used to evaluate the genotype distribution and allele frequencies of the studied polymorphism.these studies revealed that the frequency of T allele was significantly higher in HL patients compared to the controls (P < 0.05). In addition, the frequency of CT and TT genotypes were also significantly higher in HL patients compared to the controls (P < 0.05). No association between C3435T polymorphism and response to ABVD was detected among HL patients (P > 0.05).MDR1 C3435T polymorphism might play a role in HL occurrence; however this polymorphism is not correlated with the clinical response to ABVD.these results suggest that  Lymphomas are heterogeneous group of hematological malignancies that arise from malignant transformation of immune cells and account for 17% of all cancers in teenagers, and around 10% of childhood cancers [Several modalities are available to improve the overall survival in HL patients including radiotherapy, chemotherapy or combination of both . HoweverMDR1 gene were found to be of clinical importance, since they can alter drug absorption, distribution and elimination [MDR1 C3435T polymorphism has been shown to affect the efficiency of chemotherapy in patients with lymphoproliferative diseases in a sample of the Europeoids of west Serbia [The multi-drug resistance (MDR) protein is a transporter that plays a primary role in drug resistance by affecting drug transport to cancer cells. MDR1 protein, called P-glycoprotein (P-gp), belongs to ATP-binding cassette superfamily . A numbemination . For exat Serbia .MDR1 C3435T polymorphism and NHL is well documented, the association between this polymorphism and HL has not been examined yet. In the present study, we investigated the association between the MDR1 C3435T polymorphism and the risk to develop HL, as well as the clinical response to ABVD chemotherapy regimen.While the association between the A total of 130 samples of paraffin-embedded tissue collected from HL patients were obtained from the Departments of Pathology at both Royal Medical Services and King Abdullah University Hospital. Patients included in the study are those of age more than 15-year old with HL, who received only ABVD regimen as initial chemotherapy. Patients were divided into two groups; complete response (n = 96) and relapsed disease (n = 34) according to International Workshop Criteria (IWC) .Complete response (CR) was defined as 1) complete disappearance of all detectable evidence of disease on computed tomography (CT), 2) all disease-related symptoms, 3) normalization of biochemical abnormalities, 4) normal bone marrow biopsy, and 5) regression of nodes on CT of more than 1.5 cm in their axial diameter to less than 1.5 cm, and nodes of 1.1-1.5 to less than 1 cm. Relapsed disease (RD) was defined as: 1) the appearance of any new lesion 2) or increase in the size of more than 50% of previously involved sites or nodes in patients who achieved CR or Cru (uncertain). CRu corresponds to CR criteria but with a residual mass more than 1.5 cm in greatest axial diameter that has regressed by more than 75% .Peripheral blood samples were collected from 120 healthy young volunteers as a control group from the same patient's geographical areas. Informed written consents were obtained from the participants in accordance with the requirements of the Institutional Review Boards of Jordan University of Science and Technology.DNA was extracted from paraffin embedded tissue samples using QIAamp DNA FFPE Tissue Kit  according to standard protocol provided by the manufacturer. Approximately, 3-5 sections of 5 μm thick were cut from each sample and used for DNA extraction. Venous blood samples were collected in EDTA tubes and obtained from young healthy control group. DNA was extracted from all blood samples using Promega wizard genomic DNA purification kit . DNA samples were stored at -20°C until used.et al. [The polymorphism C3435T was analyzed using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. Desired DNA target sequence (197) was amplified as described by Cascorbi et al.  using a Data analysis was carried out using the statistical package SPSS version 17 to compute all descriptive statistics. Chi-square and Fisher exact tests were used to evaluate the genotype distribution and allele frequencies of the studied polymorphism. A P value of < 0.05 was considered statistically significant. Hardy-Weinberg equilibrium was assessed using the chi-square test. The C3435T genotypes were found to be in Hardy- Weinberg equilibrium.A hundred and thirty patients diagnosed with HL, the median age is 30 years, were included in the study. Fifty five percent are males and 47.7% have early stages of HL and complaining of B-symptoms. Most of the patients (76.2%) received 6 cycles of ABVD regimen. Other baseline characteristics of the patients are shown in Table Sau3AI enzyme and remains as 197 bp fragment, while the wild C allele cuts into two fragments of 158 and 39 bp.As shown in Figure P value < 0.05) higher frequencies of both mutant T allele (65%) and TT homozygous mutant genotype (41%) compared to the control group. This indicates that the T allele in the C3435T polymorphism is associated with and HL occurrence.Results in Table P value > 0.05.No significant association between the C3435T genotypes  and alleles (C and T) with patient's baseline characteristics including patient's age, gender, specimen histology, stage of the disease and presence or absence of B-symptoms .To verify whether different baseline characteristics of the patients might contribute to chemotherapy response, complete remission and disease relapse were studied according to the following criteria: age, gender, specimen histology, disease stage and presence or absence of B-symptoms Table . None ofP value > 0.05).Table To identify possible correlation between the genotype and allele frequencies of the C3435T polymorphism and the progression free survival in relapsed group; patients were divided into two groups. The first include those having the relapse after one year of complete remission and the other group having the relapse during the first year of complete remission Table . HoweverMDR1 gene could affect patient's susceptibility to HL and/or modify its response to chemotherapeutic agents. The results suggest that C3435T polymorphism plays a role in susceptibility to HL but not its response to ABVD chemotherapy. We analyzed MDR1 C3435T polymorphism in DNA isolated from paraffin embedded tissues taken from patient's lymph nodes while the same polymorphism was analyzed in the controls from peripheral blood tissues. This might raise some concern that the DNA from the two tissues is not equivalent because mutations are common during cancer progression. However, unlike most other malignant tumors, HL is characterized by low number of malignant cells that are surrounded by many non-neoplastic lymphocytes .The results indicate approximately equal distribution of the C and T alleles of C3425T polymorphism in the Jordanian population. This distribution is similar to that of Japanese , CaucasiMDR1 polymorphisms such as C1236T and G2677T in exons 12 and 21, respectively. Thus, the contribution of those polymorphisms to susceptibility to HL observed in our study cannot be ruled out. In agreement with our results, Turgut, et al. [Several genetic and environmental factors such as exposure to pesticides, wood dusts and chemicals were found to be associated with development of HL . In here, et al.  found a , et al. . The TT , et al. , renal c, et al. . Further, et al.  and in c, et al. . Thus, a, et al.  showed tMDR1 C3435T variant was found to alter P-gp function and expression, which might affect the disease response by modifying the pharmacokinetics of anticancer drugs. Therefore, several studies have shown the effect of C3435T MDR1 variant on disease outcome. In our study, we investigated the effect of C3435T variant on HL outcome in patients who received ABVD regimen containing common P-gp substrates adriamycin and vinblastine. According to the current results, C3435T variant was not associated with HL outcome in two groups of patients one with complete remission and the other with relapse. However, previous reports have shown that the C3435T polymorphism alters the response in different cancers. For example, the wild type genotype CC was associated with better chemotherapy response in patients with NSCLC [A variety of mechanisms that may account for resistance of cancer cells to chemotherapy were described . The mosth NSCLC ,33 and ith NSCLC  and in pth NSCLC  comparedResults of this study show no significant association between HL response and patient's characteristics such as age, gender, HL stage, specimen histology and presence or absence of B-symptoms. In addition, the distribution of C3435T genotypes and alleles was not associated with patient's characteristics. Therefore, possibilities exist that other polymorphisms in the MDR1 gene might be involved in modulating HL response to drugs in the Jordanian population. Thus, scanning the MDR1 gene to search for common and new variants in the Jordanian population is important for future pharmacogenetic studies in this population.In conclusion, results of this study show that C3435T polymorphism is associated with susceptibility to HL in Jordanian population. However, this variant is not correlated with the drug response or clinical parameters in HL patients.The authors declare that they have no competing interests.NM, OK, OA, and AA carried out the molecular genetic studies, participated in the sequence alignment and drafted the manuscript. IOM participated in the sequence alignment. NM, OK, KA and OA participated in the design of the study and performed the statistical analysis. WH and IIM have participated in the study design and samples collection and preparation for perform the study. NM and KA helped to draft the manuscript. All authors read and approved the final manuscript.