Statin drugs are highly effective in lowering blood concentrations of LDL-cholesterol, with concomitant reduction in risk of major cardiovascular events. Although statins are generally regarded as safe and well-tolerated, some users develop muscle symptoms that are mostly mild but in rare cases can lead to life-threatening rhabdomyolysis. The SEARCH genome-wide association study, which has been independently replicated, found a significant association between the rs4149056 (c.521T>C) single-nucleotide polymorphism (SNP) in the SLCO1B1 gene, and myopathy in individuals taking 80 mg simvastatin per day, with an odds ratio of 4.5 per rs4149056 C allele. The purpose of this paper is to assemble evidence relating to the analytical validity, clinical validity and clinical utility of using SLCO1B1 rs4149056 genotyping to inform choice and dose of statin treatment, with the aim of minimising statin-induced myopathy and increasing adherence to therapy. Genotyping assays for the rs4149056 SNP appear to be robust and accurate, though direct evidence for the performance of array-based platforms in genotyping individual SNPs was not found. Using data from the SEARCH study, calculated values for the clinical sensitivity, specificity, positive- and negative-predictive values of a test for the C allele to predict definite or incipient myopathy during 5 years of 80 mg/day simvastatin use were 70.4%, 73.7%, 4.1% and 99.4% respectively. There is a need for studies comparing the clinical validity of SLCO1B1 rs4149056 genotyping with risk scores for myopathy based on other factors such as racial background, statin type and dose, gender, body mass index, co-medications and co-morbidities. No direct evidence was found for clinical utility of statin prescription guided by SLCO1B1 genotype. A recent network meta-analysis of placebo-controlled trials and head-to-head trials comparing different statin types found small or non-significant differences in rates of adverse muscle events, and no clear dose relationship.,,,,Several studies have implicated high-dose simvastatin (≥40 mg) in risk of myopathy: an incidence of approximately 0.4%-1% for definite myopathy and 0.1% for rhabdomyolysis has been reported for intensive therapy with 80 mg simvastatin.The reasons for the discrepancies among studies on statin dose and type are not clear. The differing problems associated with clinical trials and observational studies have already been mentioned. Large prospective trials directly comparing statins at equipotent doses in well-defined patient populations, and with standardised definitions for myopathy, will probably be required to resolve the question.A range of risk factors have been reported for statin-associated myopathy, including female gender , low body mass index, older age, intense physical exercise, comorbidities such as hypothyroidism, and – most importantly – interactions with other drugs such as amiodarone and fibrates.SLCO1B1 gene encoding organic anion transporting polypeptide 1 (OATP1B1), a membrane transporter that facilitates hepatic uptake of statins.SLCO1B1 that is in near-complete linkage disequilibrium with a functional SNP, rs4149056 (c.521T>C). At this locus, the wild-type T allele encodes valine while the minor C allele encodes alanine. The association between the rs4149056 (c.521T>C) C allele and simvastatin-induced myopathy has been independently replicated by subsequent studies.,,,In 2008, a genome-wide association study (the SEARCH Study) found an association between myopathy on high-dose (80 mg) simvastatin and a polymorphism in the ,SLCO1B1*5 , *15, *16 and *17.The frequency of the C allele is less than 3% in some African populations, 10%-20% in European and Middle Eastern populations, 10%-15% in East Asian populations, 5%-10% in South/West Asian populations, and over 20% in some populations from South and Central America.,The rs4149056 polymorphism has been shown to influence statin pharmacokinetics in all of these haplotypes: in studies on simvastatin, CC homozygotes (0%-6% of patients), with the lowest OATP1B1 activity, had higher plasma exposure to active simvastatin acid than TT homozygotes (55%-88% of patients); TC heterozygotes (11%-36% of patients) had intermediate exposure.,,,,The effect of rs4149056 on statin pharmacokinetics also varies with statin type. Relative to the wild-type TT genotype, homozygosity for the C allele increases the observed plasma area under the curve by 221% for active simvastatin acid, 162%-191% for pitavastatin, 144% for atorvastatin, 57%-130% for pravastatin, 62%-117% for rosuvastatin and 19% for fluvastatin.SLCO1B1 SNPs and simvastatin-induced myopathy, but in haplotypes with rs4149056 there was an association of borderline significance (P=0.03) between the G allele of the functional variant rs2306283 (c.388A>G) and lower risk of myopathy.,The SEARCH genome-wide association study found no evidence for significant associations between other SLCO1B1 rs4149056 variant and simvastatin-induced myopathy has led to suggestions that SLCO1B1 genotyping might be used clinically (together with other risk factors) to guide choice and/or dose of statin therapy, with the aim of reducing risk of myopathy and improving adherence to therapy.,SLCO1B1 polymorphisms on the efficacy of statin therapy is inconclusive.,,,,SLCO1B1 genotype  on LDL-c reduction and no significant effect on vascular outcomes.,The evidence for an association between the SLCO1B1 genotyping in the context of simvastatin therapy is already undertaken in some US institutions.Vanderbilt University Medical Center is piloting a pre-emptive pharmacogenomic strategy in 10,000 patients at high risk of coronary events.SLCO1B1 SNP genotyping is included within some direct-to-consumer testing services.The rs4149056 variant can be tested on its own by a PCR-based SNP assay, or multiplexed on an array-based platform.,,Coronary heart disease is a major cause of morbidity and mortality in the industrialised world and, increasingly, in low- and middle-income countries. Introduced in the late 1980s, statins have become the most important pharmaceutical intervention for primary and secondary prevention of this condition, decreasing cardiovascular events by approximately 25%.,Although the frequency of statin-related myopathy is low, particularly for severe or life-threatening symptoms and at standard doses, the very high usage of statins means that the number of individuals affected by definite or incipient myopathy may be substantial: approximately 108,000 if an overall 0.3% risk is assumed for standard-dose therapy. However, accurate estimation is very difficult, for the reasons discussed above. Concerns about myopathy contribute to non-adherence to statin therapy,FDA dosing recommendation: In 2011, the FDA published a safety announcement recommending limiting the use of high dose (80 mg) simvastatin because of increased risk of muscle damage, which “appears to be higher during the first year of treatment, is often the result of interactions with other drugs, and is frequently associated with a genetic predisposition towards simvastatin-related myopathy” (http://www.fda.gov/Drugs/DrugSafety/ucm256581.htm). The announcement states that “simvastatin 80 mg should be used only in patients who have been taking this dose for 12 months or more without evidence of muscle injury (myopathy). Simvastatin 80 mg should not be started in new patients, including patients already taking lower doses of the drug.” The announcement also lists contraindications for simvastatin in combination with 11 other drugs, and dose limitations for simvastatin in combination with a further 6 drugs.Final conclusions and Recommendations of the National Lipid Association Statin Safety Assessment Task Force (2006)ACC/AHA/NHLBI Clinical Advisory on Use and Safety of Statins (2002)SLCO1B1 and Simvastatin-Induced Myopathy The Clinical Pharmacogenomics Implementation Consortium Guideline for (2012)SLCO1B1 variants. It recommends that prescribing physicians should be alerted to the FDA advice on avoiding high-dose simvastatin, and on contraindications for simvastatin prescription. If rs4149056 genotype is available and simvastatin is not contraindicated, the physician should consider adjusting simvastatin therapy according to the patient’s risk as indicated by their genotype: TT genotype : Avoid 80 mg dose unless already tolerated 12 months. Prescribe desired starting dose and adjust doses based on disease-specific guidelines. TC genotype (intermediate myopathy risk): Avoid 80 mg dose. Consider a lower dose; if suboptimal efficacy, consider an alternative statin. CC genotype (high myopathy risk): Avoid 80 mg dose. Prescribe a lower dose or consider an alternative statin; consider routine CK surveillance. The guideline also includes a decision support algorithm.Analytic validitySLCO1B1 locus is not stated specifically by Pulley et al, but it is not listed among loci displaying lower-than-average concordance. The manufacturer’s technical data sheet for the VeraCode ADME array assay claims 99.8% reproducibility between runs and 99.8% concordance with Sanger sequencing or whole-genome genotyping (http://www.illumina.com/documents/products/datasheets/datasheet_veracode_adme_core_panel.pdf).Pulley et al. have published evidence regarding the test performance of the Illumina VeraCode ADME microarray panel, which assays 184 pharmacogenetic variants in 34 genes and is genotyped by a specific version of Illumina’s GoldenGate® assay.For the Affymetrix DMET™ Plus array and proprietary DMET™ Plus genotyping assay, the manufacturer claims sample concordance to reference of ≥99.5%, reproducibility of ≥99.8% and sample pass rate of >95% (http://www.affymetrix.com/estore/browse/products.jsp?productId=131412#1_1).SLCO1B1 SNP analysis, including PCR-based TaqMan assays for single SNPsSLCO1B1 exons,,,,,Other published papers report a variety of assay methods for Clinical validitySLCO1B1 rs4149056 C allele comes from the SEARCH study of patients with prior myocardial infarction who were taking 80 mg simvastatin.-9) for CC homozygotes relative to TT homozygotes. An even stronger association was found between the C allele and “definite” myopathy (OR for CC vs TT 27.2 [CI 6.8-109.2]). The cumulative risk of myopathy over five years of treatment with 80 mg simvastatin was estimated to be approximately 18% for CC homozygotes, 3% for TC heterozygotes and 0.6% for TT homozygotes, with 80% of the risk occurring during the first year of treatment, and 60% of myopathy cases on 80 mg simvastatin attributable to the rs4149056 variant. Importantly, the association between the C allele and myopathy was replicated in the large Heart Protection Study (HPS) of patients on 40 mg simvastatin, though with a smaller odds ratio of 2.6 per allele .The strongest support for an association of statin-induced myopathy with the Significant associations between the C allele at rs4149056 and simvastatin-associated myopathy (variously defined) have also been reported in a retrospective case-control study of lipid clinic outpatients,aTaken from discussion of the STRENGTH study data by Wilke et al.,,,,,,,Table 2 also summarises results from recent studies on the effects of rs4149056 genotype on myopathy with other statins .From calculated values presented for the SEARCH study for the cumulative risk of myopathy associated with taking 80 mg simvastatin daily over 5 years  is 42% in women and 38% in men. In calibration analysis, the model was found to be reasonably well calibrated, but to over-estimate myopathy risk slightly in older age groups. In general, tests with an AUROC of less than 75% are not considered clinically useful,SLCO1B1 genotype could be shown to increase the AUROC of Qstatin significantly (at least for simvastatin), this would be an important contribution towards demonstrating good clinical validity for a combined test.Despite the high attributable risk for the SLCO1B1 genotype to inform statin therapy  results in net clinical benefit to patients: lower rates of myopathy together with adequate efficacy and acceptability of alternative treatment(s).Direct demonstration of clinical utility would require evidence that using ,SLCO1B1 genotype. Now that the FDA advises avoiding 80 mg simvastatin in all patients except those already tolerant for at least 12 months, it may be difficult to demonstrate clinical utility for a test-and-treat prescribing strategy at lower simvastatin doses.Although genotype-directed prescribing advice for simvastatin is currently offered at two institutions,SLCO1B1 C allele. For example, fluvastatin, pravastatin and lovastatin may all have adequate efficacy if low potency is acceptable  who are more likely to be able to tolerate higher-dose simvastatin, especially if they are at high risk of major coronary events (and assuming that higher doses do not cause other adverse effects).SLCO1B1 C allele.,SLCO1B1 genotype may be particularly useful to inform prescribing and on-therapy safety monitoring if statins are to be used in conjunction with other drugs, and during the first year of therapy when the absolute risk of myopathy is highest.In view of the clinical benefits that have been demonstrated for intensive statin therapy,SLCO1B1 has been found to be associated with uptake or clearance of other drugs including irinotecan and lopinavir, and there are reports that other SLCO1B1 variants are associated with risk of gallstone disease, hypertension and coronary artery disease.SLCO1B1 genotype with clinical phenotypes other than response to statins have yet to be independently replicated.SLCO1B1 genotyping are likely to be few.Westbrook et al. have pointed out the potential consequences, for both patients and clinicians, of incidental findings resulting from testing with pharmacogenetic SNP arrays.The designers of the PREDICT project at Vanderbilt University Medical Center (VUMC) have undertaken pilot work to assess patients’ understanding and acceptance of use of pharmacogenomic tests in prescribing.Costs and cost-effectivenessSLCO1B1 genotyping in the context of statin prescription. Statin switching has cost implications if the switch is from generic simvastatin to a more expensive branded alternative such as Crestor® (rosuvastatin). However the overall cost implications of switching are likely to be small in comparison to other  factors affecting statin prescription.No specific information was found relating to health-economic evaluation of In a general discussion, the VUMC PREDICT group have set out the financial, organisational and professional commitment required to establish and run their pharmacogenomic prescription advice framework linked to patients’ electronic medical records.SLCO1B1 rs4149056 genotyping and the lack, to date, of studies investigating the clinical validity of combining SLCO1B1 genotype with other risk factors for myopathy such as those included in the Qstatin risk score. The possibly protective effect of the rs2306283 (c.388A>G) G allele on statin-induced myopathy may merit further investigation, particularly in haplotypes where it occurs with the rs4149056 C allele .The most important current gap in the evidence base is the lack of direct evidence on clinical outcomes resulting from prescribing decisions guided by Clarification is also needed on the relationship between risk of statin-induced myopathy and statin type and dose, and on whether the association between the rs4149056 polymorphism and risk of myopathy is specific for high-dose simvastatin, as current evidence suggests.SLCO1B1.A further important deficiency is the lack of studies on population groups with ancestries other than white European. Allele frequencies at rs4149056 are known to vary in different populations but the effect of this variation on clinical outcome is not yet clear.


MS4A4A, CD2AP, EPHA1 and CD33. Meta-analyses of this and a previously published GWAS revealed significant association at ABCA7 and MS4A, independent evidence for association of CD2AP, CD33 and EPHA1 and an opposing yet significant association of a variant near ARID5B. In this study, we genotyped five variants  in a large , independent dataset comprising six case-control series from the USA and Europe. We performed meta-analyses of the association of these variants with LOAD and tested for association using logistic regression adjusted by age-at-diagnosis, gender, and APOE ε4 dosage.A recently published genome-wide association study (GWAS) of late-onset Alzheimer's disease (LOAD) revealed genome-wide significant association of variants in or near EPHA1  and CD33 , with odds ratios comparable to those previously reported. Although the two ARID5B variants (rs2588969 and rs494288) showed significant association with LOAD in meta-analysis of our dataset , the associations did not survive adjustment for covariates . We had insufficient evidence in our data to support the association of the CD2AP variant .We found no significant evidence of series heterogeneity. Associations with LOAD were successfully replicated for EPHA1 and CD33 variants with LOAD risk: addition of our data to the results previously reported  increased the strength of evidence for these variants, providing impressive p-values of 2.1 × 10-15 (EPHA1) and 1.8 × 10-13 (CD33).Our data overwhelmingly support the association of  APOE ε4 allele as a risk factor for late-onset Alzheimer's disease (LOAD) in 1993 [CLU, PICALM , and CR1 with LOAD, which were consistently replicated in multiple large, independent case-control studies [BIN1 was reported [Following the identification of the  in 1993 ,3 identi studies . Subsequreported -19. Theset al. [et al. [APOE, CLU, PICALM, and CR1, the meta-analyses revealed association at ABCA7 (p = 5 × 10-21), MS4A6A (p = 1.2 × 10-16), MS4A4E (p = 1.1 × 10-10), EPHA1 (p = 6 × 10-10), CD2AP (p = 8.6 × 10-9) and CD33 (p = 1.6 × 10-9). In addition, the two datasets revealed opposing association  of the variant near ARID5B (rs2588969) with LOAD, suggesting potential heterogeneity at this locus. In this study, we genotyped the variants identified at the CD2AP, EPHA1, and CD33 loci in our independent case-control dataset comprising six case-control series . To assess the opposing associations at the ARID5B locus, we also genotyped the two ARID5B variants included in the Hollingworth et al. study. Genotypes from our follow-up case-control series (Mayo 2) for variants in ABCA7, MS4A6A and MA4A4E were included in Stage 3 of the Hollingworth et al. study, so we have not included these three variants in this study. We have performed meta-analyses of five variants  in our six case-control series, which showed no significant series heterogeneity. Furthermore, we have performed logistic regression analysis of our pooled series adjusting for covariates. Finally, we have used a Fisher's combined test to evaluate the significance of the association of these five variants in our data combined with the data in the Hollingworth et al. and Naj et al. studies.Two recently published companion studies by Hollingworth et al.  and Naj  [et al.  performeCD2AP; rs9349407, EPHA1; rs11767557, ARID5B; rs2588969 and rs4948288, CD33; rs3865444) in our independent follow-up case-control series (Mayo2) from three North American and three European Caucasian series. Detailed information about these samples is shown in Table et al. study and have not been included in any of the published LOAD GWAS. The Mayo2 dataset included in the Hollingworth et al. publication only included genotypes for ABCA7, MS4A6A and MA4A4E.We genotyped five variants  and by Hollingworth et al. (OR = 0.90). As shown in Figure ARID5B variants  with ORs comparable to those reported by Hollingworth et al.  and in the opposing direction to those reported by Naj et al. for rs2588969 . As shown in Figure CD2AP  or CD33  in our meta-analyses. Breslow-Day tests provided no significant evidence that the ORs for any of these variants were heterogeneous among our series , as shown in Figure CD2AP (rs9349407) where the estimated percentage of variation due to heterogeneity across studies (I2) was 25.1% (95% CI 0%-70%) suggesting the presence of some heterogeneity for that variant.Meta-analyses of allelic association in the six Mayo2 series performed using a DerSimonian-Laird random effects model Figure  revealedAPOE ε 4 dosage in logistic regression analyses of all five variants in each of the six Mayo2 series; in our analysis of all Mayo2 series combined, series was included as an additional covariate. Table EPHA1 , CD33  and CD2AP  loci. However, the associations of the ARID5B variants were no longer significant following adjustment for covariates  suggesting that these associations may be dependent upon the series, age-at-diagnosis/entry, sex and/or APOE ε 4 dosage of the individual.To adjust for important covariates, we included age-at-diagnosis/entry, sex and CD2AP: p = 6.5 × 10-11, EPHA1: p = 2.1 × 10-15, ARID5B rs2588969: p = 2.3 × 10-9, ARID5B rs4948288: p = 4.0 × 10-4, CD33: p = 1.8 × 10-13).In order to estimate the overall association of these five variants in our data combined with the previously published associations, we used Fisher's method to combine the p-values for all associations (Table EPHA1 (p = 5 × 10-4) and rs3865444, which is located 373 bp upstream of CD33 (p = 0.049). The ORs we observed in our meta-analyses  were comparable to those reported by both Naj et al.  and by Hollingworth et al.  such that the estimated p-values for association of these variants in all data  were an impressive 2.1 × 10-15 for EPHA1 and 1.8 × 10-13 for CD33.We report here successful replication of the association of two variants with LOAD in a large , independent case-control study; rs11767557, which is located 3 kb upstream of ARID5B variants rs2588969  and rs4948288  with a direction of association consistent with that reported by Hollingworth et al. , the associations did not survive adjustment for age-at-diagnosis/entry, sex and APOE ε 4 status . This covariate-dependent association could explain the opposing association reported by Naj et al. in their discovery (OR = 0.88) and replication (OR = 1.05) datasets for rs2588969; the only ARID5B variant they tested. Therefore, while estimation of the p-values for association of the ARID5B variants in all datasets combined were highly significant , interpretation of these associations should be treated with caution and should take into account the age-at-diagnosis/entry, sex and APOE ε 4 dosage of the populations. Finally, although the estimated p-value for association of rs9349407 (located in intron 1of CD2AP) in all datasets was 6.5 × 10-11, there was no evidence for association of this variant in our dataset alone .Although our meta-analyses showed successful replication of the association of the CD2AP (MAF = 0.27).Our Mayo2 collection of case-control series studies provided a total of 2,634 LOAD and 4,201 controls. Combining across studies to perform global tests of significance for additive genotypic trend tests gave us 80% power to detect ORs ranging from 1.17 (or 0.855) for variants with a minor allele frequency (MAF) of 0.2 to 1.13 (or 0.883) for variants with a MAF of 0.45 in controls. The study provided approximately 60% power to detect the OR of 1.11 that we report for EPHA1 and CD33 variants represent excellent candidates for targeted deep sequencing or high density genotyping in order to define the locus further, followed by subsequent functional studies of nearby genes to elucidate the mechanism behind these associations. With the exception of rs9349407, which lies within intron 1of CD2AP, all of these variants lie within intergenic regions but for ease of the reader, we have thus far only referred to the nearest gene for each variant. This by no means signifies that these variants  are assumed to affect the expression or function of the nearest gene but may affect other nearby genes. Until it is known which gene underlies these associations, all nearby genes should be included in follow-up functional investigation  block within which a truly functional variant may reside. Our results indicate that the ABCA7, BIN1, CD33, CLU, CR1, EPHA1, GAB2, LOC651924, MS4A6A/4E and PICALM), eight of which are currently ranked in the top ten (after APOE) on AlzGene. This recent success in replicating genetic association highlights the utility of multiple, large case-control follow-up studies to confirm the novel associations reported by large GWAS, thus confirming them as good candidate genes for functional follow-up studies.Taken along with our previous publications ,18,20,21Approval was obtained from the ethics committee or institutional review board of each institution responsible for the ascertainment and collection of samples. Written informed consent was obtained for all individuals that participated in this study.et al., the same subject/sample ascertainment methodology was followed. The ARUK series included here are from Bristol, Leeds, Manchester, Nottingham, Oxford and Southampton. Since the Manchester cohort only consisted of LOAD cases, the Manchester cases were combined with subjects in the Nottingham series.The Mayo2 case-control series consisted of Caucasian subjects from the United States ascertained at the Mayo Clinic Jacksonville, Mayo Clinic Rochester, or through the Mayo Clinic Brain Bank. Additional Caucasian subjects from Europe were obtained from Norway , Poland ® SNP Genotyping Assays in an ABI PRISM® 7900HT Sequence Detection System with 384-Well Block Module from Applied Biosystems, California, USA. The genotype data was analyzed using the SDS software version 2.2.3 .All genotyping was performed at the Mayo Clinic in Jacksonville using TaqManhttp://pngu.mgh.harvard.edu/purcell/plink/) was used to perform logistic regression analysis under an additive model adjusting for age-at-diagnosis, sex and APOE ε 4 dose as covariates. In our analysis of all series combined, series was included as an additional covariate. Since genotype counts were not reported for series included in the Naj et al. or Hollingworth et al. studies, we employed a Fisher combined test to combine p-values across series. Power calculations, based on a Mantel-Haenszel chi-square test that pooled across six different study groups, were obtained to estimate the detectable odds ratios for an ordinal effect using a range of minor allele frequencies spanning those expected from the candidate variants.Meta-analysis of allelic association and Breslow-Day tests were performed using StatsDirect v2.5.8 software. Meta-analyses were performed using the results from each individual case-control series. Summary ORs and 95% CI were calculated using the DerSimonian and Laird (1986) random-effects model . BreslowABCA7: ATP-binding cassette, sub-family A (ABC1), member 7; AD: Alzheimer's disease; ADGC: Alzheimer's disease Genetic Consortium; APOE: apolipoprotein E; ARID5B: AT rich interactive domain 5B (MRF1-like); ARUK: Alzheimer's Research United Kingdom; BIN1: bridging integrator 1; Bp: base pair; CD2AP: CD2-associated protein; CD33: CD33 molecule; CI: confidence interval; CLU: clusterin; CR1: complement component (3 b/4 b) receptor 1 (Knops blood group); EPHA1: EPH receptor A1; GAB2: GRB2-associated binding protein 2; GERAD: Genetic and Environmental Risk in Alzheimer's Disease Consortium; GWAS: genome-wide association study; kb: kilobases; LD: linkage disequibrium; LOAD: late-onset Alzheimer's disease; MAF: minor allele frequency; MS4A4A: membrane-spanning 4-domains, subfamily A, member 4; OR: odds ratio; PICALM: phosphatidylinositol binding clathrin assembly protein; SD: standard deviation.The authors declare that they have no competing interests.Study concept and design: MMC and SGY. Sample Collection and Diagnosis: ARUK, DWD, JOA, MB, NRG-R, RCP, SBS, and ZKW. Genotyping: MMC and TAH. DNA Sample Preparation: GDB, ML and ZFG. Analysis and interpretation of data: JEC, KM, MMC, OB, SGY and VSP. Drafting of the manuscript: MMC and OB. Critical revision of the manuscript for important intellectual content: KM, MMC, OB, SGY and VSP. Study supervision: KM, MMC and SGY. All authors have read and approve the final manuscript.Table S1. Genes located within 100 kb of the five variants tested in this study. Chr, chromosome. Base pair positions (bp) are relative to the NCBI Human Genome build 36.1. The position of the variant relative to the gene is given as 5' (upstream from the gene's transcription start site) or 3' (downstream from the gene's last exon). Distance indicates the number of base pairs from the variant position to the gene's nearest exon.Click here for file


To explore the association between transforming growth factor-beta1 (TGF-β1) T869C polymorphism and risk of ischemic stroke (IS) by performing a meta-analysis based on published articles.Systematic electronic searches of PubMed, Science Direct, BIOSIS Previews, Chinese Biomedical Database, Chinese National Knowledge Infrastructure, and WANFANG Database were performed. The strength of the association was calculated by pooled odds ratios (ORs) with 95% confidence intervals (95%CIs). Subgroup analysis was conducted to explore potential sources of heterogeneity. Sensitivity analysis was performed to elucidate the stability of the outcomes. Publication bias was evaluated by Begg’s funnel plot and Egger’s test.A total of 6 studies involving 1701 cases were included. The overall estimates did not show any significant association between TGF-β1 T869C polymorphism and risk of IS under all genetic models . Similar lacking associations were observed in subgroup analysis based on ethnicity and source of controls. When stratified by study design, significant increased association of IS risk was found in cohort studies under genetic models except recessive model, whereas in case-control studies a significant decreased risk was detected under heterozygote comparison. However, after correction for multiple testing, the associations were observed to be null significant in both cohort and case-control subgroups among all genetic models.This meta-analysis suggested that current epidemiological studies of TGF-β1 T869C polymorphism are too inconsistent to draw a conclusion on the association with IS susceptibility. Given the small sample size and remarkable between-study heterogeneity, further well-designed prospective large-scale studies are warranted. Stroke is a leading cause of death and adult long-term disability worldwide, and remains as an enormous burden for society due to lack of illustrated etiology and effective treatments TGF-β1 is a pleiotropic cytokine with potent anti-inflammation property, and has been considered as an essential risk factor in the inflammatory process of IS by involving in the pathophysiological progresses of such as hypertension, atherosclerosis and lipid metabolisms To date, several studies have been performed to investigate the association between T869C polymorphism of TGF-β1 gene and risk of IS. However, the results remain controversial http://sinomed.imicams.ac.cn/index.jsp), Chinese National Knowledge Infrastructure(http://dlib3.cnki.net/kns50/), and WANFANG Database (http://g.wanfangdata.com.cn/). Other relevant studies were also conducted by hand searching of the references of selected articles and the abstracts presented at related conferences. Languages were limited to English and Chinese. Search terms included the following key words: (“transforming growth factor beta-1″ OR “TGFβ1” OR “TGF-β1”) and  and . If more than one geographic or ethnic group were included in one publication, each group was treated separately. The last search was updated on 10th March 2013.This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria The inclusion criteria for identified studies were as follows: (1)evaluating the association between TGF-β1 T869C polymorphism and IS risk;(2)using a case-control, cohort, nested case-control, case-cohort, or cross-sectional study with either population-based or hospital-based design; (3)reporting sufficient available genotype distribution data in both cases and controls for calculating OR and 95%CI; (4) diagnosis of IS should be confirmed by computed tomographic(CT) or magnetic resonance imaging(MRI); and (5) genotype distribution in control group must be consistent with Hardy–Weinberg equilibrium (HWE). Studies were excluded if one of the following existed: (1) not relevant to TGF-β1 T869C polymorphism or IS; (2) genotype frequencies or numbers not reported; (3) the design based on family or sibling pairs; and (4) reviews, abstracts or animal studies. For studies with overlapped data by the same research group, the most recent or complete one was extracted. When detailed data were not reported, authors were contacted to obtain the relevant information.Data were reviewed and extracted by 2 independent investigators (Peng and Li). Any disagreement was resolved by discussion and consensus with a third reviewer (Chen). The following data from eligible studies were extracted: the first author, publication year, country (ethnicity), study design, diagnostic criteria of IS, genotyping method, allele numbers and genotype frequencies in cases and controls.The quality of included studies was evaluated independently using Newcastle-Ottawa Scale (NOS) http://biostat.mc.vanderbilt.edu/twiki/bin/view/Main/PowerSampleSize) to prove whether the selected studies could offer adequate power. HWE of genotype distribution in the controls of eligible studies was calculated using an online program (http://ihg2.helmholtz-muenchen.de/cgi-bin/hw/hwa1.pl), and P value<0.05 suggested no deviation. The strength of association between TGF-β1 T869C polymorphism and IS risk was assessed by crude ORs with corresponding 95%CIs under the following five genetic models: the allele comparison(C vs. T), the homozygote comparison (CC vs. TT), the heterozygote comparison (CT vs. TT), the dominant model (CC+CT vs. TT), and the recessive model (CC vs. CT+TT). The significance of OR was determined by the Z-test, and P value<0.05 was accounted as statistically significant. The degree of heterogeneity between studies was detected by the Q-test and I2-statistics Q <0.10 or I2>50% suggested significant heterogeneity existed. The pooled estimate was combined by a random-effect model(DerSimonian-Laird method) Before this meta-analysis, power analysis was performed using the PS program, with remarkable between-study heterogeneities ; thus a To explore the sources of heterogeneity, further subgroup analyses by ethnicity, source of controls, and study design were performed respectively. Similarly, lacking significant associations were revealed in the subgroup of Asians and population-based studies, yet still with significant heterogeneity among all contrasts. As for non-Asians or hospital-based studies, we were unable to draw a conclusion since both of the two stratifications included only one study. When stSensitivity analysis was performed to examine the stability of the results. The corresponding pooled ORs were not significantly altered after excluding each eligible study at a time (data not shown).The shape of the Begg’s funnel plot showed no asymmetric visually (figure not shown), and the result of Egger’s test detected no statistical evidence of publication bias among studies  .It is well-established that inflammation and IS are interrelated. TGF-β1 is a multifactorial inflammatory cytokine involving in many inflammation processes as well as the development of IS. The expression of plasma TGF-β1 protein is predominantly under genetic control and modified by several common SNPs in this gene, and T869C polymorphism has been indicated to be associated with elevated serum TGF-β1 level. Several epidemiological studies investigated the association between T869C polymorphism and susceptibility to IS, yet with conflicting results. Therefore, we conducted this meta-analysis combining all eligible published studies to draw a more precise conclusion.Our overall estimates did not observed any significant association between TGF-β1 T869C polymorphism and risk of IS under all contrasts, as well as in subgroup analysis by ethnicity or source of controls. However, since there was only one study included in non-Asian and hospital-based group, these results may not be valid. In subgroup analysis based on study design, significant but contradictory results were found between case-control and cohort studies. Likewise, since there were only two studies included in cohort group, and one of which was hospital-based source in controls, we may run the risk of chance bias. Moreover, after correction for multiple testing, the associations were observed to be null significant in both cohort and case-control subgroups among all genetic models. Due to these discrepancies, we were unable to draw a solid conclusion on the association between T869C polymorphism and the risk of IS.Obvious evidences of between-study heterogeneities existed among all comparison models. Although the heterogeneity was almost removed when stratified by study design, remarkable heterogeneity still existed after stratification based on ethnicity or source of controls, suggesting that all above confounders should be taken into consideration. In addition, other factors such as gender distribution, subtype of IS, genotyping methods, as well as clinical characteristics such as smoking, alcohol drinking, family history of stroke, diabetes mellitus, hypertension, dyslipidemia, cardiac diseases and so on, might also account for the potential sources of heterogeneity. However, we failed to perform further subgroup analysis or meta-regression analysis based on these factors owing to limited information of original studies.To our knowledge, the present study is the first meta-analysis concerning relationship between TGFβ1 gene T869C polymorphism and susceptibility to IS. Genotype distribution in all controls did not deviate from HWE, reassuring the representation of control samples. The result of NOS indicated that the methodological quality we adopted was of credibility. Moreover, sensitivity analysis did not significantly alter in overall and subgroup results under all genetic models; In addition, results from Begg’s funnel plot and Egger’s test indicated no evidence of publication bias. In addition, we conducted multiple testing to adjust for multiple comparisons which can reduce the type I error rate. Taken together, the outcomes we obtained were relatively reliable and stable.Nevertheless, several limitations of the current study should be acknowledged. Firstly, the sample size of included studies was respectively small, attributing to a smaller amount for further subgroup analysis. Although meta-analysis has the benefit to overcome this limitation and may generate more precise results, the combined sample sizes in our study were still inadequate to detect the association between T869C polymorphism and IS risk because power calculation for the pooled sample sizes was less than 80%, which might attenuate the statistical power to detect a slight effect and increase the chance of opportunity bias.Secondly, significant heterogeneity was observed among all genetic models. However, lacking detailed information of individual studies limited our further subgroup analysis or meta-regression to adjust potential confounders, which may result in obscure estimates.Thirdly, although we performed a systematic searching strategy to identify eligible studies, there was still probability that few studies so called “grey literatures” were not included. In addition, since we restricted literatures published in English or Chinese language, potential eligible studies written in other languages would also be neglected.Fourthly, our current study only focused on one variation in TGF-β1 gene, without considering the role of other SNPs in this gene nor precluding the potential interactions such as linkage disequilibrium or haplotype analysis between them, which might mask its real genetic effect towards IS susceptibility.Last but not the least, IS is a complex multifactorial disease related to both genetic and environmental factors, such as climate, diet, life style and economic status, etc. However, our results were based on unadjusted estimates since most of original studies did not take such gene-environmental interactions into account.In summary, this meta-analysis suggested that current epidemiological studies of TGF-β1 T869C polymorphism are too inconsistent to draw a conclusion on the association with IS susceptibility. However, given the limitations above, more well-designed prospective large-scale studies with different ethnicities considering both genetic and environmental factors are warranted in future.Figure S1Forest plot of all genetic models for association between TGF-β1 T869C polymorphism and IS risk.(TIF)Click here for additional data file.Checklist S1PRISMA 2009 Checklist.(DOC)Click here for additional data file.


SLC6A4) polymorphism and FD was explored.Although familial clustering of functional dyspepsia (FD) has been reported, the role of genetics in the susceptibility to FD is still not well understood. In the present study, the association between serotonin transporter (SERT) gene , was then evaluated, and logistic regression analysis was used to test all variables.Subjects were divided into either a postprandial distress syndrome (PDS) group or an epigastric pain syndrome (EPS) group according to the Rome III criteria. The healthy controls were those who had visited a hospital for an annual health check-up. The presence of the 5-HTTLPR genotype distribution was 448 SS, 174 SL, and 24 LL in controls and 30 SS, 20 SL, and 3 LL in FD subjects. No significant correlation was found between the 5-HTTLPR genotype and FD. When the genotypes and subtypes of FD were exploratory evaluated, the SL genotype was significantly associated with PDS  compared to the SS genotype adjusted for sex and age. Comparison of the SS genotype with the SL/LL genotype also showed a significant association of genotype with PDS .The 5-HTTLPR L allele may influence the susceptibility to PDS.The present results suggest that  Helicobacter pylori infection, smoking, and psychological disturbances, have also been reported, the data are inconclusive  adjusted for sex and age (Table P = 0.009) , which are widely used as antidepressants. Although SSRIs have been reported to have a benefit in IBS , few tri5-HTTLPR L allele may be associated with PDS. Based on in vitro studies of 5-HTTLPR polymorphism function, excessive transcription of SERT in 5-HTTLPR L allele would be expected to lead to higher 5-HT reuptake activity and decreased levels of 5-HT in the synaptic cleft [The results of the present study suggest the hypothesis that the ic cleft , which iThe secreted 5-HT affects at least 30 subtypes of 7 main subclasses of serotonergic receptors that cause various effects on the gut or brain. There are several reports about the association between specific serotonergic receptors and dyspepsia. We have reported that the 5HT1A agonist tandospirone improved abdominal symptom scores, including upper abdominal pain and discomfort . On the 5-HTTLPR polymorphism have been investigated in a report concerning IBS. However, there are many conflicting results [Some reports seem to support our hypothesis, but there are several conflicting results. Therefore, the role of SERT functional differences in the gut is still unclear. The physiological effects on gut function of  results .5-HTTLPR polymorphism. Yeo et al. reported a significant association between D-IBS and 5-HTTLPR SS genotype in females [Some studies have reported a sex relation in  females . A simil females . However5-HTTLPR L allele may influence the susceptibility to PDS in a Japanese population. This is the first report that shows the possibility of a significant association between PDS and 5-HTTLPR polymorphism. FD is a complex and heterogeneous disorder, and it is known that FD is not caused by a single gene. Additional studies with a further larger sample and different polymorphisms are mandatory to identify the genetic background that influences susceptibility to FD.We have exploratory shown that 5-HTTLPR - 5-HT transporter gene linked polymorphic region; GERD: gastroesophageal reflux disease; IBS- irritable bowel syndrome; PDS: postprandial distress syndrome; EPS: epigastric pain syndrome; EGD - esophagogastroduodenoscopy; US - ultrasonography; OR: odds ratio; CI: confidence interval.FD: functional dyspepsia; 5-HT: 5-hydroxytryptamin (serotonin); SERT - serotonin transporter; The authors declare that they have no competing interests.FT analyzed the data and wrote the paper. TO participated in the design of the study, and wrote part of the paper. SN, together with JS, JT, TT and KH, obtained the samples and the data. TM supervised the research project and the drafting of the manuscript. HM was responsible for the conception of the study and designed the study. All authors approved of the final manuscript prior to submission.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2350/12/88/prepub


MMP) 2, MMP3, and MMP9 genes, respectively, have been found to be functional and may contribute to head and neck carcinogenesis. However, the results of case-control studies examining associations between MMP polymorphisms and head and neck cancer (HNC) risk remain inconclusive. Therefore, we performed a meta-analysis to further evaluate the role of these polymorphisms in HNC development.The 1306 C>T, 1171 5A>6A, and 1562C>T polymorphisms of matrix metalloproteinase  and 95% confidence intervals (CIs) were used to assess the association between these polymorphisms and HNC risk.We searched PubMed, ISI Web of Knowledge, MEDLINE, Embase, and Google Scholar to identify all published case-control studies of MMP2-1306 C>T polymorphism, significant associations were observed under three genetic models both in overall comparison and in a hospital-based subgroup, and in oral cavity cancer and nasopharyngeal cancer under dominant model as well. For MMP3-1171 5A>6A and MMP9-1562 C>T polymorphisms, no association was found in overall comparison; however, in subgroup analyses based on ethnicity and tumor site, significant associations were detected between the MMP3-1171 5A>6A polymorphism and HNC risk in a European population and pharyngeal/laryngeal cancer under two genetic contrasts.Thirteen studies were included in this meta-analysis. For MMP2-1306 C>T polymorphism is associated with HNC risk, as is the MMP3-1171 5A>6A polymorphism specifically in some subgroups. Further studies with larger sample sizes are warranted.This meta-analysis suggests that the  Head and neck cancer (HNC), which includes cancers of the oral cavity, pharynx, hypopharynx, and larynx, is one of the most common cancers worldwide Studies have demonstrated that Matrix metalloproteinases (MMPs) may play an important role in HNC development MMP2, MMP3, and MMP9 are three important members of the MMP family. MMP2 (gelatinase- A), located on chromosome 16q13–q21, digests gelatin (denatured collagen), type IV collagen, and some bioactive molecules, such as growth factor-binding proteins and growth factor receptors MMP3 (stromelysin-1), located on chromosome 11q22.2–22.3, can lyse the collagen present in the basal membrane and induces the synthesis of other MMPs such as MMP1 and MMP9MMP9 (gelatinase B) is the most complex member of the MMPs family in terms of domain structure. It is capable of degrading decorin, elastin, fibrillin, laminin, gelatin, and types IV, V, XI, and XVI collagen MMP2, MMP3, and MMP9 has been found to associate with the development of cancer, including HNC MMP2, MMP3, and MMP9 genes have been well described. Previous researchers reported that these polymorphisms play critical roles in the regulation of MMP gene transcription. MMP2 -1306 C>T (rs243865), which contains a C to T transition at −1306, is associated with high transcriptional activity of the MMP2 gene MMP3 -1171 5A>6A (rs3025058), which is characterized by the insertion or deletion of a single adenosine at position −1171, could alter MMP3 transcription levels MMP9 -1562 C>T (rs3918242), which includes a C>T transition at position −1562 near the upstream transcription initiation site, also influences the MMP9 transcriptional levels Several polymorphisms in the promoter regions of the MMP2, MMP3 and MMP9 polymorphisms with HNC risk conducted between January 2000 and June 2012. We used the following key words:Using key words search in the PubMed, Web of Knowledge, MEDLINE, Embase, and Google Scholar electronic databases and search engines, we identified all eligible case-control studies of the associations of “MMP”, “matrix metalloproteinase”, “collagenase”, “gelatinase”, “matrilysin” or “PUMP” and “head and neck cancer”, “oral cancer”, “pharyngeal cancer”, “hypopharyngeal cancer” or “laryngeal cancer” and “polymorphism”, “variant”, “genotype” or “SNP”. After performing the electronic key word searches, we manually reviewed the references of the search results to identify additional evaluable studies. We contacted authors directly for important data that were not reported in original articles. Abstracts, unpublished reports, and articles not written in English were not included.The following details were extracted from each article included in the meta-analysis: first author, publication year, ethnicity of the study population (categorized as Asian and European), the number of cases and controls, and genotype distribution, genotyping methods, allele frequency, and so on. To minimize bias and improve reliability, two investigators extracted the data independently and reached a consensus on all items (the details of each study) via discussion.MMP2, MMP3, and MMP9 polymorphisms and HNC risk, (3) had sufficient available data to calculate an odds ratio (OR) with a 95% confidence interval (CI) and P- value, and (4) were published in English.Studies were included if they: (1) were case-control studies, (2) assessed the associations between Studies were excluded if they: (1) had insufficient information about genotype frequency or number, (2) if the same population was evaluated in two or more studies, only the most recent or the one with the largest study population was included in this meta-analysis.MMP polymorphisms and HNC risk using ORs and 95% CIs. The significance of pooled ORs was estimated via a Z test . Heterogeneity between studies was assessed via Cochran’s chi-square Q statistic test. A random- effects model was used when the P value for heterogeneity was less than 0.05, which indicated obvious heterogeneity of the data; otherwise, a fixed-effects model was used. Heterogeneity across studies was also detected using an I2 test. As a guide, I2 values of <25% were considered low, I2 values of 25 to 75% were considered moderate, and I2 values of >75% were considered high MMP2, MMP3, and MMP9 polymorphisms and the risk of HNC were evaluated using a recessive genetic model (BB versus AB+AA), dominant genetic model (BB+AB versus AA), and allele contrast model , respectively . In addition to overall comparison, subgroup analyses based on the ethnicity of each study population and the source of the control subjects were also performed using different genetic models. Furthermore, sensitivity analyses were performed to reflect the influence of the individual dataset on the pooled ORs by sequential removing each eligible study. Finally, we assessed the publication bias using Begg’s funnel plot and Egger’s test. Additionally, the Hardy–-Weinberg equilibrium (HWE) was calculated via a chi-square test at a significance level of α <0.05. All P values were two-sided, and all statistical analyses were performed using STATA 12.0 software .We evaluated the association of MMP2, MMP3, and MMP9 polymorphisms and HNC risk; 2 had insufficient data for further analysis; 4 were review articles; and one was a commentary. Zhou MMP2, MMP3, and MMP9 polymorphisms in a case–-control study of two independent populations. Each population was regarded as a separate study. Consequently, 13 studies of the association of MMP2, MMP3, and MMP9 polymorphisms with the risk of HNC were ultimately included in this mata-analysis ; in the population-based subgroup ; in the oral cavity cancer ; and in the nasopharyngeal cancer . However, in subgroup analyses based on ethnicity and tumor site, the MMP3-1171 5A>6A polymorphism was significantly associated with HNC risk in Europeans  and in pharyngeal/laryngeal cancers , but the MMP3-1171 5A>6A polymorphism was not significantly associated with HNC risk in Asians, in oral cavity cancer and in nasopharyngeal cancer using three genetic models . Furthermore, in subgroup analysis based on tumor site, no significant association was detected either in oral cavity cancer or in nasopharyngeal cancer.MMP2-1306 C>T polymorphism, no significant heterogeneity was found either in overall comparison  or in subgroup analyses using three genetic models  and the allele contrast model . However, heterogeneity was eliminated in the European population after stratifying by ethnicity . Also, in subgroup analyses based on the source of control subjects, heterogeneity significantly decreased in the population-based subgroups . For the MMP9-1562 C>T, significant heterogeneity was detected using the dominant model. However, when the study by Vairaktaris and colleagues In specific comparisons, the data from two of the three polymorphisms were hetergeneous. For the c models . For theMMP2-1306 C>T, the results demonstrated that the significance of pooled ORs was undetectable after excluding the studies MMP3-1171 5A>6A and MMP9-1562 C>T, the significance of the pooled ORs was not materially altered by exclusion of any individual study .For all the three polymorphisms, the shapes of the Begg’s funnel plots in all genetic models did not show any evidence of obvious asymmetry. MMP2-1306 C>T polymorphism was significantly associated with HNC risk both in overall comparison and in subgroup analyses based on the source of the controls and tumor sites. In contrast, no association was observed between either MMP3-1171 5A>6A or MMP9-1562 C>T polymorphism and HNC risk in overall comparison; however, in subgroup analyses based on ethnicity and tumor site, significant associations were found between the MMP3-1171 5A>6A polymorphism and HNC risk in Europeans and pharyngeal/laryngeal cancer under two genetic contrasts. Our findings indicate that MMP2-1306 C>T polymorphism might modulate risk of HNC, so does the MMP3-1171 5A>6A polymorphism in some subgroups.In this meta-analysis, the MMP2-1306 C>T polymorphism, which contains a C>T transition at the −1306 position upstream of the transcriptional site, can abolish Sp1-binding site and downregulate transcriptional activity. Previous studies have shown that MMP2 gene expression was significantly lower in individuals with the T allele than in individuals with the C allele MMP2 overexpression was associated with the development and aggressiveness of a variety of malignancies including HNC, as most patients in the studies included in our meta-analysis carried the C allele but not the T allele.The MMP2-1306 C>T polymorphism and its expression level with the risk of HNC vs. 76%; P<0.05). Moreover, they also found that MMP2 expression in HNC cells containing the CC genotype was significantly higher than that in cells with the CT genotype. Similarly, in a study of the association of the MMP2-1306 C>T polymorphism with the risk of oral squamous cell carcinoma (OSCC) For example, O-Charoenrat and colleagues assessed the association of the MMP3-1171 5A>6A polymorphism, functional analysis in vitro showed that the 5A allele had approximately 2-fold higher promoter activity than the 6A allele. This finding implies that the 5A allele is responsible for increased MMP3 transcriptional levels and contributes to the carcinogenesis of most malignancies. Several groups have evaluated the association between MMP3-1171 5A>6A polymorphism and the risk of HNC; however, the results of these studies remain inconsistent. Chaudhary and colleagues found that the 5A allele might play an important role in the susceptibility to HNC, as individuals with 5A/5A genotype had nearly two fold risk of HNC (OR = 1.94) when compared to controls MMP3-1171 5A>6A polymorphism and HNC risk was found, which is consistent with the findings of this meta-analysis MMP3-1171 5A>6A polymorphism was significantly associated with risk of HNC in Europeans when the study population was stratified by ethnicity, thereby indicating that the discrepancies in the aforementioned results may be attributed to diverse genetic backgrounds and different environmental factors in different populations. Future studies with larger samples are warranted to further evaluate the role of the MMP3-1171 5A>6A polymorphism in HNC risk in different populations.For the MMP9-1562 C>T polymorphism, which is located at position 1562 bp upstream of the transcriptional start site and contains either C or T, has been shown to influence the transcriptional activity of the MMP9 gene. Zhang and colleagues performed transient transfection and DNA-protein interaction assays and found that T allele-associated promoter activity was higher than the C allele-associated promoter activity owing to the binding of a transcriptional repressor MMP9 plays an important role in head and neck carcinogenesis and MMP9 is frequently overexpressed in HNC, our meta-analysis indicated no significant association between the MMP9-1562 C>T polymorphism and HNC risk, suggesting that MMP9 expression might influence HNC progression via mechanisms other than regulation by the MMP9-1562 C>T polymorphism. Several other factors, such as interleukin-1, tumor necrosis factor α, and oncogenes, may also regulate MMP9 expression The Some heterogeneity factors between studies that could limit the strengths of the meta-analysis should be addressed. First, ethnicity was one of the most important factors that could lead to heterogeneity because of the diverse genetic backgrounds and environmental factors in different ethnicities. Second, tumor site was another reason for the heterogeneity between studies as HNC have quite different origins of organs, different histological subtypes, different etiology and different biological behavior. For example, tobacco use and alcohol consumption play important roles in oral cavity cancer, while viral infection is the major risk factor for oropharyngeal and nasopharyngeal cancer. Thus, different risk factors for different tumor sites may explain why the same polymorphism may play different roles in different subgroups of HNC. Furthermore, the source of the controls was another factor that could lead to heterogeneity. Population-based controls could be more reliable than hospital-based controls because the genotype distributions in hospital-based controls may be deviated from normal. Thus, population-based study design for individual subgroups of HNC is needed for future studies.MMP3-1171 5A>6A polymorphism and HNC risk in Europeans. Although significant association was detected, the statistical power could have been limited. Second, if more detailed information about age, sex, alcohol consumption, tobacco smoking and/or HPV status had been available in the original studies, a more accurate OR would have been estimated after further stratification. Third, evaluating the association between MMP polymorphisms and HNC risk using linkage disequilibrium (LD) would have been more powerful. However, few studies performed haplotype analysis of these three MMPs. Additionally, publication bias may have occurred because we included only published studies in the meta-analysis, although it was not detected via a statistical test. Despite these limitations, however, the statistical power of the analysis could have been significantly increased as the cases and controls were pooled from different studies. Therefore, our results from this meta-analysis might be more reliable than those of individual studies.Since this is a pooled analysis, we thus have had relatively higher study power for the evaluation of such associations. In addition, we have performed stratified analysis by tumor sites in this meta-analysis, while our analysis by different tumor sites might minimize the issue of the confounding effect from mixed tumor sites. Although this analysis had such strengths, it also had some limitations. First, the number of eligible studies included in this meta-analysis was limited, and the sample size of each study was relatively small, especially in stratified analyses. For example, there were only two studies examined the association between the MMP2-1306 C>T polymorphism is associated with the risk of HNC, as is the MMP3-1171 5A>6A polymorphism specifically in some subgroups. However, the MMP9-1562 C>T polymorphism is not associated with HNC risk. Further studies with larger samples are warranted to further evaluate the association between MMP polymorphisms and HNC risk.In conclusion, this meta-analysis suggests that the Table S1PRISMA 2009 Checklist.(PDF)Click here for additional data file.


TERT) rs2736098, was recently reported to be associated with lung cancer risk in Caucasians. In addition, many studies have investigated the role of this polymorphism in the etiology of cancer of various organs. Nevertheless, the results of related case-control studies remain inconsistent.A common genetic variant, telomerase reverse transcriptase  cases and 627 cancer-free controls was conducted. Furthermore, to investigate the association between rs2736098 and cancer risk, a meta-analysis based on previously published studies and our case-control study was also performed.P = 0.028; AA vs. GG: OR = 1.48, 95% CI = 1.05–2.09, P = 0.025). Additionally, this association was stronger among adenocarcinoma cases . In the meta-analysis, a borderline significant association between the rs2736098 polymorphism and overall cancer risk was observed , and further stratifications demonstrated a moderately increased risk for lung and bladder cancer, Asian ethnicity and hospital-based studies.Multivariate logistic regression demonstrated that individuals carrying the A allele or the AA genotype exhibited a significantly elevated risk of NSCLC compared with those carrying the G allele or GG genotype (A vs. G: OR = 1.21, 95% CI = 1.02–1.43, Our results suggest that the rs2736098 polymorphism may contribute to the risk of lung cancer, especially adenocarcinoma, in the Chinese population. In addition, the current meta-analysis indicates that this genetic variant is only weakly associated with overall cancer risk. However, the rs2736098 polymorphism may affect individual susceptibility to lung and bladder cancer. Further studies are needed to validate our findings. Worldwide, lung cancer was the leading cause of cancer deaths in males and the second leading cause of cancer deaths in females in 2008. The geographical and temporal patterns of lung cancer incidence are largely determined by tobacco consumption. Lung cancer rates are increasing in countries such as China and several other countries in Asia and Africa, where the smoking prevalence continues to either increase or show signs of stability TERT) and cleft lip and palate trans-membrane 1-like (CLPTM1L). TERT protein is the telomerase catalytic subunit that elongates telomeres and serves as a key regulator of telomerase activity. Telomeres, consisting of TTAGGG repeats that undergo shortening with each cell replication cycle, have long been known to be essential for the preservation of chromosomal integrity TERT gene , are involved in the susceptibility of many tumor types The development of lung cancer appears to be the result of a complex interaction between environmental exposures and genetic factors. Recently, independent genome-wide association studies (GWAS) TERT rs2736098, which is located on chromosome 5p15.33, was recently identified as a susceptibility locus for lung cancer in a combined analysis of Icelandic and European sample sets TERT A variant genotype is associated with a significantly increased risk of lung cancer A common genetic variant, TERT rs2736098 polymorphism and cancer risk, a meta-analysis based on previously published studies and our case-control study was also performed.Furthermore, many studies have investigated the role of this polymorphism in the etiology of cancer of various organs, including the bladder, liver, and breast To exclude the possible effects of ethnicity, all subjects in this study were genetically unrelated ethnic Han Chinese. The cases included 539 newly diagnosed NSCLC patients who were admitted to the Qilu Hospital of Shandong University  between 2010 and 2012. Of these NSCLC patients, 293 patients had adenocarcinomas (ADC) and 246 had squamous cell carcinomas (SQC). Meanwhile, 627 cancer-free controls were selected from the same hospital and were frequency-matched to cases by age and sex. Subjects who were relatives or had histories of malignancy and other major diseases were excluded from this study. In addition, a structured questionnaire was completed for each case and control by a trained interviewer to collect demographic data and other relevant information, including age, sex, and smoking status. Those individuals who smoked <1 cigarette per day and for <1 year were defined as nonsmokers; otherwise, the patients were considered smokers. All participants were given an explanation of the study, and written informed consent was obtained from each participant. This study was conducted under the approval of the Ethics Committees of Qilu Hospital affiliated to Shandong University.TERT SNP rs2736098 was genotyped using the TaqMan methodology in 96-well plates and read with the Sequence Detection Software  on an Applied Biosystems (ABI) 7500 Real-Time PCR System.Blood samples were collected from all participants at the time of recruitment. Genomic DNA was extracted from peripheral blood obtained from each participant using the DNA Extraction Kit (Tiangen Biotech (Beijing) Co., Ltd.) according to the manufacturer's protocol. The 2 test was employed to evaluate the differences in the distributions of selected characteristics between the cases and controls. The goodness-of-fit χ2 test was adopted to assess Hardy-Weinberg equilibrium (HWE) in the controls. Multivariate logistic regression analysis was used to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) for the effect of rs2736098 polymorphism on NSCLC risk. In addition, stratified analyses by histological types were further performed to evaluate the role of rs2736098 in NSCLC risk. All statistical tests were two-sided, and statistical significance was accepted as P<0.05.The Pearson χTERT rs2736098 polymorphism and cancer risk, a meta-analysis based on previously published studies and our case-control study was performed. We searched the PubMed and ISI Web of Science databases for all articles on the association between the TERT rs2736098 polymorphism and cancer risk (last search update 5th June 2013). The following search terms were used in isolation and in combination with one another: “telomerase reverse transcriptase or TERT or 5p15.33”, “polymorphism or variant or variation”, and “cancer or carcinoma or tumor”. The search was limited to English language papers and human studies. In addition, we screened the reference lists for all included studies, reviews and meta-analyses. When multiple publications reported on the same or overlapping data, we selected the most recent publication with the most subjects. Studies included in our meta-analysis had to meet the following inclusion criteria: (1) evaluation of the TERT rs2736098 polymorphism and cancer risk; (2) a case-control design; (3) sufficient genotype data for the calculation of odds ratios (OR) with 95% confidence intervals (CIs); and (4) written in English. The major reasons for exclusion of studies included (1) the lack of a control group; (2) duplicates of previous publications; (3) reviews, comments or editorials; and (4) a lack of usable data on genotype frequencies.To further investigate the association between the Two investigators (Wu H and Wang Y) extracted information from all eligible publications independently according to the inclusion criteria listed above. Disagreements were resolved by discussion until consensus was achieved on every item. In the present study, the following characteristics were collected: the first author's last name, the year of publication, the country of origin, ethnicity, cancer type, the source of the control groups , the genotyping method, and the frequencies of genotypes in cases and controls. For studies including subjects of different ethnic groups, genotype frequencies and other information were extracted separately for each ethnic group whenever possible TERT rs2736098 polymorphism and cancer risk was evaluated by the odds ratios (ORs) with 95% confidence intervals (CIs). The pooled ORs were calculated for homozygote comparison (AA vs. GG), heterozygote comparison (AG vs. GG), the dominant genetic model (AA+AG vs. GG), the recessive genetic model (AA vs. AG+GG), and the additive genetic model (2*AA+AG vs. 2*GG+AG). Stratified analyses were performed by cancer type , ethnicity and source of the controls. The evaluation of the meta-analysis results included an examination of the heterogeneity, an analysis of the sensitivity, and an examination for publication bias. Heterogeneity was checked by the chi-square-based Q-test P<0.05, then the pooled ORs were calculated using the random effects model (the DerSimonian and Laird method) P>0.05, the fixed-effects model was selected (the Mantel–Haenszel method) 2I statistic to efficiently test for heterogeneity, with 2I<25%, 25–75% and >75% representing low, moderate and high degrees of inconsistency, respectively P<0.05 was considered a significant publication bias) We first assessed the Hardy-Weinberg equilibrium (HWE) for the controls in each study. The strength of the association between the P = 0.403) and age (P = 0.688) between the case and control groups. Males represented 79.7% of the control group and 77.7% of the case group. Of the 539 NSCLC cases, 293 (54.4%) were adenocarcinomas, and 246 (45.6%) were squamous cell carcinomas. Approximately 51.8% of cases were smokers, compared with 43.1% of controls (P = 0.003).The characteristics of the cases and controls are presented in TERT rs2736098 polymorphism and NSCLC risk are shown in P = 0.361). The multivariate logistic regression model demonstrated that individuals carrying the A allele or AA genotype exhibited a significantly elevated risk of NSCLC compared with those carrying the G allele or GG genotype, after adjusting for age, gender and smoking status .Data for the genotype frequencies and the association between the TERT rs2736098 polymorphism and NSCLC risk was further examined by stratifying the subjects according to tumor histology. When analyzed according to the histological type, the effect of the TERT rs2736098 polymorphism on the NSCLC risk was significant for adenocarcinomas , but not for squamous cell carcinomas  ( The association between the  0.487)  .P<0.05) TERT rs2736098 polymorphism and overall cancer risk in the homozygote comparison , recessive genetic model  and additive genetic model   , but no TERT rs2736098 polymorphism and the risk of HCC or other cancers. When stratified by ethnicity, significantly increased risk was observed in the Asian population  in all genetic models tested, with the exception of the heterozygote comparison . Nevertheless, no significant association was observed in the European population. In the subgroup analysis by the source of controls, significantly increased risk was observed in hospital-based studies  but was not observed in population-based studies. The main results of this meta-analysis and the heterogeneity test are presented in In the subgroup analysis according to cancer type, significantly increased risk was observed in lung cancer  and bladder cancer . However, no evidence of association was observed in any genetic model between the hetP. = 0.001, I2 = 63.0%; AA+AG vs. GG: het.P = 0.010, I2 = 54.3%; AA vs. AG+GG: hetP. = 0.002, I2 = 61.3%; 2*AA+AG vs. 2*GG+AG: hetP. = 0.001, I2 = 64.8%). However, the heterogeneity decreased markedly after stratification, especially in the subgroups of lung cancer  and bladder cancer . When stratified by ethnicity, heterogeneity was not observed in the subgroups of Asian and European populations   .hetP. = 0.158, I2 = 30.3%; dominant model: OR = 1.12, 95%CI = 1.05–1.20, hetP. = 0.119, I2 = 35.0%; additive model: OR = 1.14, 95%CI = 1.09–1.19, hetP. = 0.142, I2 = 32.1%). Furthermore, none of the pooled ORs was significantly affected by any single study, suggesting that the results of this meta-analysis were relatively stable.In the sensitivity analyses, the influence of each study on the pooled OR was checked individually by repeating the meta-analysis while omitting each study. Although the genotype distributions of the control groups in the studies by Gago-Dominguez et al. Egger'sP = 0.795 for AA vs. GG; Egger'sP = 0.220 for AG vs. GG; Egger'sP = 0.123 for dominant model; Egger'sP = 0.913 for recessive model and Egger'sP = 0.290 for additive model) (Begg's funnel plot and Egger's test were conducted to assess the publication bias of the literatures. As shown in e model) . The resTERT rs2736098 polymorphism with the risk for NSCLC in a Chinese Han population. Furthermore, to derive a more precise estimation of the association between this polymorphism and cancer risk, a meta-analysis based on previously published studies and our case-control study was also performed. Our multivariate logistic regression model demonstrated that individuals carrying the A allele or AA genotype exhibited a significantly elevated risk of NSCLC compared with those carrying the G allele or GG genotypes after adjusting for age, gender and smoking status. In the subgroup analysis by histological type, increased cancer risk was observed in adenocarcinomas but not squamous cell carcinomas under the homozygote comparison and the additive genetic model. In addition, the TERT rs2736098 variant A allele showed a marginally significant association with overall cancer risk.In this study, we examined the association of the TERT rs2736098 polymorphism is mapped to a region of chromosome 5p15.33. The chromosome 5p15.33 locus contains two well-known genes, telomerase reverse transcriptase (TERT) and cleft lip and palate trans-membrane 1-like (CLPTM1L), which have been implicated in carcinogenesis. Telomerase is expressed in most tumors from virtually all types of cancers, including those of the lung. Telomerase is a relatively specific cancer target, as normal body cells express little or no telomerase for most of their lifespan TERT, is one of the most frequent genetic events in early stages of non-small-cell lung cancer TERT SNP has been shown to be associated with telomere length The TERT rs2736098 polymorphism at 5p15.33 and the risk of HCC. In two population-based case-control studies conducted separately among non-Hispanic whites (NHW) and Asian populations, the TERT rs2736098 polymorphism exhibited a significant association with bladder cancer risk among non-Hispanic whites. However, an association of similar magnitude was not observed in the Asian population TERT rs2736098 polymorphism at 5p15.33 was associated with breast cancer risk. However, in stratified analysis, this variant exhibited evidence of being associated with a reduced risk of breast cancer among individuals with a family history of breast cancer. Although it is difficult to explain the controversial results in these studies, different genetic backgrounds, cancer types and study designs may contribute to the discrepancies. Interestingly, our case-control study demonstrated that the AA homozygote in TERT rs2736098 exhibited a significantly increased risk of developing NSCLC , especially adenocarcinoma , compared with those who carry the GG genotype. The homozygous AA alleles may be correlated with increased lung adenocarcinoma susceptibility. The results of our case-control study support 5p15.33 (TERT-CLPTM1L) as a susceptibility region for lung cancer in the Chinese population TERT has been observed between adenocarcinoma and other histological carcinomas of lung cancer Many studies have investigated the role of this polymorphism in the etiology of cancer of various organs, including the bladder, liver, and breast, among others. However, the results of related published case-control studies remain inconsistent TERT rs2736098 polymorphism were more likely to exhibit an increased cancer risk among Asians but not among Europeans, possibly because of the differences in genetic backgrounds among different populations. Another plausible hypothesis suggests that the TERT rs2736098 polymorphism, a synonymous single nucleotide polymorphism, is only a marker SNP of other functional variants in TERT or other nearby genes. However, this hypothesis remains to be tested. In addition, different study designs and inadequate adjustments for confounding factors might explain, to some extent, the inconsistent results in different cancer types and different populations. The evaluation of heterogeneity, influence analysis, and publication bias confirmed the reliability of the meta-analysis.In the current meta-analysis, a borderline significant association between this polymorphism and cancer risk was observed in the overall analysis, with obvious between-study heterogeneity. However, when stratified by tumor sites, the subgroups of lung cancer and bladder cancer failed to exhibit heterogeneity, suggesting that different tumor sites might be a potential source of heterogeneity. Similarly, after stratifying by ethnicity, heterogeneity was largely reduced in both Asian and European populations, suggesting that ethnicity could partly explain the heterogeneity. Therefore, it may be presumed that the heterogeneity exists mainly owing to differences of ethnicity and tumor types. Furthermore, in the subgroup analysis by ethnicity, we found that individuals carrying the A allele or AA and AA/AG genotypes of the Some limitations should be addressed in interpreting the results of our case-control study and meta-analysis. First, the sample size of our case-control study was relatively small. Therefore, well-designed population-based studies with large sample sizes and detailed exposure information are needed to further confirm our findings. Additionally, the meta-analysis was based on unadjusted estimates. A more precise analysis should be conducted if more detailed individual data are available, which will allow for an adjusted estimate. Further, in the subgroup analysis stratified by cancer type, the number of studies and subjects analyzed was small, and caution should be taken in interpreting these results. It might be difficult to make a concrete conclusion because few studies were included in the subgroups. Despite these limitations, our meta-analysis also had some advantages. First, significant data were extracted from the related published case-control studies. Second, all studies included in this meta-analysis were case-control investigations and contained available genotype frequencies, which met our inclusion criteria very well.TERT rs2736098 polymorphism identified in the 5p15.33 region in Caucasians may also predispose to lung cancer, especially adenocarcinomas, in the Chinese population. Moreover, meta-analysis by tumor type suggested that this genetic variant may modify individual susceptibility to lung and bladder cancer. Further studies are required to validate these findings and explain the inconsistent results in different ethnicities and cancer types.In conclusion, we found that the Checklist S1PRISMA checklist.(DOC)Click here for additional data file.Figure S1Flow diagram of the study selection procedure.(TIF)Click here for additional data file.Figure S2Begg's funnel plot for publication bias (AA vs. GG).(TIF)Click here for additional data file.Figure S3Begg's funnel plot for publication bias (recessive model).(TIF)Click here for additional data file.


Our results demonstrated that hsa-miR-34b/c rs4938723 CC genotype had a decreased risk of ESCC. The association was evident among patients who never drinking. Hsa-miR-423 rs6505162 C>A might associated with a significantly increased risk of ESCC in patients who smoking. These findings indicated that functional polymorphisms hsa-miR-34b/c rs4938723 T>C and hsa-miR-423 rs6505162 C>A might alter individual susceptibility to ESCC. However, our results were obtained with a limited sample size. Future larger studies with other ethnic populations are required to confirm current findings.Esophageal cancer is the eighth most common cancer and sixth leading cause of cancer associated death worldwide. Besides environmental risk factors, genetic factors might play an important role in the esophageal cancer carcinogenesis. We conducted a hospital based case–control study to evaluate the genetic susceptibility of functional single nucleotide polymorphisms (SNPs) in the microRNAs on the development of esophageal cancer. A total of 629 esophageal squamous cell carcinoma (ESCC) cases and 686 controls were recruited for this study. The  MicroRNAs (miRNAs) are tiny noncoding RNAs that act as posttranscriptional gene regulatory elements Genetic factors, such as single nucleotide polymorphisms (SNPs), may contribute to carcinogenesis Hsa-miR-34b/c rs4938723 polymorphism is located within the CpG island of pri-miR-34b/c, and might be the predicted binding site for GATA-X transcription factors Hsa-miR-34b/c rs4938723 T>C polymorphism was associated with the risk of nasopharyngeal carcinoma Members of the miR-34 family are direct p53 targets, and their expression is directly induced by p53 in response to DNA damage or oncogenic stress hsa-miR-34b/c rs4938723 T>C, pri-miR-124-1 rs531564 C>G, pre-miR-125a rs12975333 G>T and hsa-miR-423 rs6505162 C>A were also associated with the risk of different types of cancers. The rs531564 C>G SNP in pri-miR-124-1 was associated with an increased risk of bladder cancer pre-miR-125a rs12975333 G>T polymorphism was a founder mutation specific to the Antwerp area and associated with high risk for breast cancer Hsa-miR-423 rs6505162 C>A polymorphism was associated with reduced breast cancer risk Hsa-miR-423 rs6505162 C>A polymorphism was also significantly associated with both the overall survival and the recurrence-free survival of colorectal cancer Besides miR-196a2 rs11614913 T>C, miR-146a rs2910164 C>G, miR-499 rs3746444 T>C, miR-26a-1 rs7372209 C>T and miR-27a rs895819 T>C SNPs and esophageal squamous cell carcinoma (ESCC) risk in 380 cancer cases and 380 controls miR-196a2 rs11614913 T>C might contribute to decreased ESCC risk among women patients and patients who never smoking or drinking hsa-miR-34b/c rs4938723 T>C, pri-miR-124-1 rs531564 C>G, pre-miR-125a rs12975333 G>T and hsa-miR-423 rs6505162 C>A genotypes and ESCC risk. We performed genotyping analyses for the four miRNA SNPs with 629 ESCC cases and 686 controls in a Chinese population.We previously investigated This hospital-based case-control study was approved by the Review Board of Jiangsu University . We have complied with the World Medical Association Declaration of Helsinki regarding ethical conduct of research involving human subjects and/or animals. All subjects provided written informed consent to be included in the study.629 subjects with esophageal cancer were consecutively recruited from the Affiliated People’s Hospital of Jiangsu University and Affiliated Hospital of Jiangsu University  between October 2008 and December 2010. Diagnosis was done by biopsy and all cases of esophageal cancer were ESCC. The exclusion criteria were patients who previously had: cancer; any metastasized cancer; radiotherapy or chemotherapy. The 686 controls were patients without cancer frequency-matched to the cases with regard to age (±5 years) and sex recruited from the two hospitals mentioned above during the same time period. Most of the controls were admitted to the hospitals for the treatment of trauma.Each subject was personally questioned by trained interviewers using a pre-tested questionnaire to obtain information on demographic data  and related risk factors . After the interview, 2-mL samples of venous blood were collected from each subject. Individuals who smoked one cigarette per day for >1 year were defined as “smokers”. Subjects who consumed ≥3 alcoholic drinks a week for >6 months were considered to be “alcohol drinkers”.Blood samples were collected from patients using Vacutainers and transferred to tubes lined with ethylenediamine tetra-acetic acid (EDTA). Genomic DNA was isolated from whole blood with the QIAamp DNA Blood Mini Kit  hsa-miR-34b/c rs4938723 T>C, pri-miR-124-1 rs531564 C>G, pre-miR-125a rs12975333 G>T and hsa-miR-423 rs6505162 C>A variants between the cases and controls were evaluated using student t test and the χ2 test. The associations between the four SNPs and risk of ESCC were estimated by computing the ORs and their 95% CIs using logistic regression analyses for crude ORs and adjusted ORs when adjusting for age, sex, smoking and drinking status. The Hardy-Weinberg equilibrium (HWE) was tested by a goodness-of-fit χ2 test to compare the observed genotype frequencies to the expected ones among the control subjects. All statistical analyses were performed with SAS 9.1.3 .Differences in the distributions of demographic characteristics, selected variables, and genotypes of the χ2 tests . As shown in p < 0.001), and drinking rate was higher in ESCC patients than in control subjects (p < 0.001). The primary information for four genotyped SNPs was in hsa-miR-34b/c rs4938723 T>C, pri-miR-124-1 rs531564 C>G and hsa-miR-423 rs6505162 C>A polymorphisms in the controls were in HWE  except pre-miR-125a rs12975333 G>T (not available) (Characteristics of cases and controls included in the study are summarized in ailable) .hsa-miR-34b/c rs4938723 T>C, pri-miR-124-1 rs531564 C>G, pre-miR-125a rs12975333 G>T and hsa-miR-423 rs6505162 C>A in the cases and the controls are shown in hsa-miR-34b/c rs4938723 T>C were 46.2% (TT), 46.3% (TC), and 7.5% (CC) in the case patients and 46.1% (TT), 43.1% (TC), and 10.8% (CC) in the control subjects, and the difference was not statistically significant (p = 0.101). In the recessive model, when the hsa-miR-34b/c rs4938723 TT/TC genotypes were used as the reference group, the CC homozygote genotype was associated with a statistically significantly decreased risk for ESCC . When the hsa-miR-34b/c rs4938723 TT homozygote genotype was used as the reference group, the TC genotype was not associated with the risk for ESCC ; the CC genotype was not associated with the risk for ESCC . In the dominant model, the hsa-miR-34b/c rs4938723 TC/CC variants were not associated with the risk for ESCC, compared with the hsa-miR-34b/c rs4938723 TT genotype  (The genotype distributions of = 0.853) .pri-miR-124-1 rs531564 C>G and hsa-miR-423 rs6505162 C>A polymorphisms and the risk of ESCC    . In pati= 0.012) .hsa-miR-34b/c rs4938723 T>C, pri-miR-124-1 rs531564 C>G, pre-miR-125a rs12975333 G>T and hsa-miR-423 rs6505162 C>A with risk of ESCC in a high risk Chinese population. Our multivariable logistic analysis revealed that hsa-miR-34b/c rs4938723 CC genotype had a decreased risk of ESCC. The association was evident among patients who never drinking. Hsa-miR-423 rs6505162 C>A might associated with a significantly increased risk of ESCC in patients who smoking.In this hospital-based case-control study of ESCC, we investigated the associations of hsa-miR-34b/c rs4938723 T>C SNP is located within the CpG island of pri-miR-34b/c and may affect a predicted GATA-X transcription factor binding Hsa-miR-34b/c rs4938723 T>C polymorphism was associated with the risk of nasopharyngeal carcinoma Hsa-miR-423 rs6505162 C>A polymorphism was associated with reduced breast cancer risk hsa-miR-34b/c rs4938723 CC genotype had a decreased risk of ESCC among patients who never drinking, hsa-miR-423 rs6505162 C>A might associated with a significantly increased risk of ESCC in patients who smoking, indicating gene-environment interaction.It is well known that members of the miR-34 family expression is directly induced by p53 in response to DNA damage or oncogenic stress hsa-miR-34b/c rs4938723 C was 0.324 among 686 control subjects, which is slightly higher than that of Japanese population (0.261) and similar to that of European population (0.310) and Sub-Saharan African population (0.305). The allele frequency of hsa-miR-423 rs6505162 A was 0.188 among 686 control subjects, which is in accordance with that of Chinese population (0.200) and Japanese population (0.178). But the allele frequency is significantly lower than that of European population (0.575) and Sub-Saharan African population (0.783) .The frequencies of genetic polymorphisms often vary between ethnic groups. In the present Chinese study, the allele frequency of http://biostat.mc.vanderbilt.edu/twiki/bin/view/Main/PowerSampleSize), considering hsa-miR-34b/c rs4938723 T>C mutant alleles in the control group, OR, ESCC samples and control samples, the power of our analysis (α = 0.05) was 0.929 in 600 ESCC cases and 673 controls with adjusted OR 0.65. The power of our analysis (α = 0.05) was 0.962 in 404 ESCC cases and 519 controls with adjusted OR 0.57 in non- drinking subgroup. For hsa-miR-423 rs6505162 C>A, the power of our analysis (α = 0.05) was 1.000 in 263 ESCC cases and 179 controls with adjusted OR 4.94 in smoking subgroup.Using Power and Sample Size Calculation (PS, version 3.0, 2009, In this case-control study, several limitations need to be addressed. Firstly, the patients and controls were enrolled from hospitals and may not represent the general population. Secondly, statistical power of our study was limited the especially in stratification analyses, it is better that the control group being larger than the case group; therefore it is possible to have a more statistical power. Thirdly, detailed information on cancer metastasis and survival were not recruited till now, which restricted further analyses on the role of the four polymorphisms in ESCC progression and prognosis. Finally, the information about viral infections and immune parameters was not available, which restricted the power of our analyses.hsa-miR-34b/c rs4938723 T>C and hsa-miR-423 rs6505162 C>A might alter individual susceptibility to ESCC. Future larger studies with other ethnic populations and functional analysis are required to confirm current findings.In conclusion, our study provides evidence that functional polymorphisms