LDLR as a candidate gene of CHD has been intensively studied. The goal of our study is to evaluate the overall contribution of LDLR rs2228671 polymorphism to the risk of CHD by combining the genotyping data from multiple case-control studies. Our meta-analysis is involved with 8 case-control studies among 7588 cases and 9711 controls to test the association between LDLR rs2228671 polymorphism and CHD. In addition, we performed a case-control study of LDLR rs2228671 polymorphism with the risk of CHD in Chinese population. Our meta-analysis showed that rs2228671-T allele was significantly associated with a reduced risk of CHD  = 0.83, and 95% confidence interval (95% CI) = 0.75–0.92). However, rs2228671-T allele frequency was rare (1%) and was not associated with CHD in Han Chinese (P = 0.49), suggesting an ethnic difference of LDLR rs2228671 polymorphism. Meta-analysis has established rs2228671 as a protective factor of CHD in Europeans. The lack of association in Chinese reflects an ethnic difference of this genetic variant between Chinese and European populations.Low density lipoprotein receptor (LDLR) can regulate cholesterol metabolism by removing the excess low density lipoprotein cholesterol (LDL-C) in blood. Since cholesterol metabolism is often disrupted in coronary heart disease (CHD),  Coronary heart disease (CHD) is a complex disease caused by an insufficient blood flow inside the coronary vessels . The blo LDLR gene mutations can lead to deficiency or abnormality of LDLR in the cell membrane surface and thus disrupt lipid metabolism [ LDLR gene mutations are known to cause familial hypercholesterolemia (FH) [ LDLR gene mutations were significantly associated with the abnormal blood lipid levels and CHD [ LDLR polymorphisms, rs2228671 was associated with LDL-C levels and CHD in German and British populations [ LDLR rs2228671 with CHD in Italians and Germans [CHD is caused by both environmental and genetic factors . Variatitabolism . LDLR gemia (FH)  that is mia (FH) . Recent  and CHD , 9. Amonulations –14. Howe Germans , 16. LDLR rs2228671 polymorphism with CHD among 17299 individuals in 8 studies.Meta-analysis is able to combine and review the results from previous studies , 18. MetLDLR” or “low density lipoprotein receptor” or “rs2228671” and “polymorphism” or “genetic association.” The inclusion criteria for the studies involved in this meta-analysis met the following criteria: (1) case-control study about LDLR rs2228671 polymorphism; (2) case-control study with genotyping or allelic information, or odd ratio (OR) with 95% confidential interval (CI).We systematically search available studies from 2003 to 2013 in PubMed (English), CNKI, and Wanfang (Chinese). Keywords were “coronary heart disease” or “coronary artery disease” or “myocardial infarction” combined with “Data included in this meta-analysis was extracted independently from all studies using the same standard protocol by two reviewers (HY and YH). The inclusion criteria of our meta-analysis were as follows: first author's name, publication year, ethnicity, numbers of cases and controls, genotype distribution, and OR with 95% CI.The study protocol was approved by the ethical committee of School of Medicine, Ningbo University. A total of 162 cases and 113 controls were recruited in this study from the Affiliated Hospital of Ningbo University. All the participants in this study have signed the informed consent forms. All the 275 individuals underwent coronary angiography and were categorized into CHD patients and non-CHD controls according to our previous descriptions . All theGenomic DNA was isolated from peripheral blood lymphocytes using standard phenol-chloroform method and then was stored in TE buffer. All DNA samples were amplified by polymerase chain reaction (PCR). PCR was denatured at 94°C for 15 s, followed by 45 cycles of denaturation at 94°C for 20 s, annealing for 30 s at 56°C, extension at 72°C for 1 min, and a final extension at 72°C for 3 min. DNA amplification and genotyping was performed on the SEQUENOM Mass-ARRAY iPLEX platform according to the manufacturer's instructions [P value of 0.05 or lower was defined to be statistically significant.Hardy-Weinberg equilibrium (HWE) was examined by the Arlequin program (version 3.5) . The difWe systematically searched in PubMed, CNKI, and Wanfang from 2003 to 2013, and selected a total of 57 literatures after removing the duplicated publications . AccordiP > 0.05), indicating that our case-control study had a well-characterized random sampling. Our case-control study suggested that LDLR rs2228671-T allele was rare in Chinese population , and this agrees with the frequency in HapMap Chinese Han in Beijing (CHB) population (0–2%). No significant difference in the genotype distribution between CHD cases and non-CHD controls are revealed in all samples . In addition, no heterogeneity among the studies was included in this meta-analysis  in the 3′-untranslated region (3′-UTR) and rs2228671 in second exon [ LDLR gene were closely related to both LDL-C and CHD [ LDLR were reported to be associated with baseline lipids in American population [Aberrant LDLR level in blood can cause abnormal cholesterol metabolism . As the diseases , 16, 27.diabetes  and hypediabetes  that alsond exon . SNPs in and CHD . Rs14330pulation . The T aP = 0.0005). Furthermore, rs2228671-T allele frequencies in the meta-analysis among German, British, and Italian populations were 7–12.2% that is similar to 10% in HapMap CEU population. However, rs2228671-T allele frequency is 0% in HapMap CHB population and 0.9% in the controls of our study. Due to the rare allele of LDLR rs2228671 in our samples, the power of our case-control study was only 5.1%, in contrast of 100% in the present meta-analysis. This suggests that a lack of association in our case-control study may largely be explained by the insufficient power for this rare polymorphism and the small sample size. Future investigation on other common LDLR polymorphisms is worth being performed in a large Chinese cohort.Our meta-analysis among 17299 individuals showed that rs2228671-T allele reduced the risk of coronary heart disease in the combined samples from German, British, Italian, and Chinese populations  [P = 0.0005). This suggests rs2228671 and rs1122608 might exert different contributions to the risk of CHD.Human= 0.148) , in cont LDLR gene in Chinese population.There were several limitations in our study as follows. Firstly, most of the involved individuals in our meta-analysis were Europeans; thus our result might not be applied to other populations such as Chinese. Secondly, although we had no evidence of the publication bias in our meta-analysis, we cannot exclude the possibility of existing potential bias upon reporting the studies without significant association results. Last but not least, the power of our case-control study in Chinese is only 5.1%. The negative result of rs2228671 might not represent for other variants of LDLR rs2228671-T allele is a protective factor of CHD in Europeans. However, the case-control study showed no significant association of LDLR rs2228671 with CHD in Han Chinese population.In conclusion, the meta-analysis demonstrated that the


Xeroderma Pigmentosum group C (XPC) gene polymorphisms and gastric cancer risk reported inconsistent results. We performed a meta-analysis to summarize the possible association.Reduced DNA repair capacities due to inherited polymorphisms may increase the susceptibility to cancers including gastric cancer. Previous studies investigating the association between XPC polymorphisms and gastric cancer risk were identified by searching electronic databases PubMed, EMBASE, Cochrane library, and Chinese Biomedical Literature database (CBM). The association between XPC polymorphisms and gastric cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).All studies published up to January 2014 on the association between Six studies with 1,355 gastric cancer cases and 2,573 controls were finally included in the meta-analysis. With respect to Lys939Gln polymorphism, we did not observe a significant association when all studies were pooled into the meta-analysis. When stratified by ethnicity, source of control, and study quality, statistical significant association was not detected in all subgroups. With respect to Ala499Val and PAT−/+polymorphisms, we also did not observe any significant association with gastric cancer risk in the pooled analysis.XPC polymorphisms  did not contribute to gastric cancer risk. Considering the limited sample size and ethnicity included in the meta-analysis, further larger scaled and well-designed studies are needed to confirm our results.This meta-analysis based on current evidences suggested that the http://www.diagnosticpathology.diagnomx.eu/vs/1485880312555069The virtual slide(s) for this article can be found here:  Gastric cancer is one of the most common cancers and cancer related deaths are highly prevalent worldwide . The devxeroderma pigmentosum complementation group C (XPC) is one of the eight core genes  in the nuclear excision repair (NER) pathway of the DNA repairing system. XPC binds to HR23B and forms the XPC-HR23B complex, which is involved in the DNA damage recognition and DNA repair initiation in the NER pathway [XPC gene, which encodes a 940-amino acid protein, spans 33 kb on chromosome 3p25 and contains 16 exons and 15 introns [XPC gene region (http://www.ncbi.nlm.nih.gov/projects/SNP). Among all the identified SNPs, three common polymorphisms have been extensively studied: (a) a substitution of alanine for valine in codon 499 , in the interaction domain of XPC with hHRAD23; (b) an A to C transversion in exon 15 resulting in a lysine-to-glutamine transition at position 939 , located in the interaction domain with TFIIH; and (c) a poly AT region on intron 9 (PAT−/+). It was reported that the variant alleles of the three polymorphisms in the XPC genes correlated with relatively high DNA adduct levels in lymphocyte DNA, indicating that these polymorphisms were associated with decreased DNA repair capacity [XPC gene polymorphisms and cancer susceptibility.The DNA repairing system, which was composed of many DNA repair genes, plays an important role in removing damaged genes, maintaining the genomic integrity and preventing carcinogenesis. The  pathway -7, and t pathway . The XPCcapacity ,11. TherXPC gene polymorphisms  to gastric cancer risk have been a research focus in scientific community and have drawn increasing attention. Several original studies have reported the role of XPC polymorphisms in gastric cancer risk [To date, the cer risk -17, but cer risk , especiaWe conducted a comprehensive literature search in PubMed, EMBASE, Cochrane library, and Chinese Biomedical Literature (CBM) databases up to January 01, 2014 using the following search strategy: (“gastric cancer”) and . There was no restriction on time period, sample size, population, language, or type of report. All eligible studies were retrieved and their references were checked for other relevant studies. The literature retrieval was performed in duplication by two authors independently (Qiliu Peng and Yu Lu). When multiple publications reported on the same or overlapping data, we chose the most recent or largest population.XPC polymorphisms and gastric cancer; (2) had an odds ratio (OR) with 95% confidence interval (CI) or other available data for estimating OR (95% CI); and (3) the control population did not contain malignant tumor patients. Studies were excluded if one of the following existed: (1) no control population; (2) duplicate of previous publication; and (3) insufficient information for data extraction.Studies were considered if they met the following inclusion criteria: (1) case–control or cohort studies which evaluated the association between Information was extracted by two authors independently according to the inclusion criteria listed above. Data extracted from eligible studies included the first author, publication year, ethnicity, country, genotyping methods, matching criteria, source of control, gastric cancer ascertainment, total numbers of cases and controls and genotype frequencies of cases and controls. Ethnic backgrounds were categorized as Caucasian, Asian. To ensure the accuracy of the information extracted, the two authors checked the data extraction results and reached consensus on all of the items. If different results generated, they would check the data again and have a discussion to come to an agreement. If these two authors could not reach a consensus, another author (Xue Qin) was consulted to resolve the dispute.The quality of eligible studies was assessed independently by two authors (Qiliu Peng and Xianjun Lao) according to a set of predefined criteria Table  modifiedXPC polymorphisms and gastric cancer risk. The pooled ORs were performed for co-dominant genetic models, dominant genetic model, and recessive genetic model, respectively. Heterogeneity among studies was checked by the chi-square-based Q-test and I2 statistics [Q < 0.1 or I2 ≥ 50%, indicating the presence of heterogeneity, a random-effects model (the DerSimonian and Laird method) was used to estimate the summary ORs [Q ≥ 0.1 and I2 < 50%, indicating the absence of heterogeneity, the fixed-effects model (the Mantel–Haenszel method) was used [Crude odds ratios (ORs) with their 95% confidence intervals (CIs) were used to assess the strength of association between the atistics ,21. If tmary ORs ; otherwiwas used . Subgrouwas used . If publwas used . The disBased on the search criteria, seven potential relevant studies were identified. One of these articles was excluded because it contained overlapping data . Manual XPC Lys939Gln polymorphism and gastric cancer risk were present in Table XPC Lys939Gln polymorphism and gastric cancer risk when all the eligible studies were pooled into the meta-analysis .The main results of meta-analysis of XPC Val499Arg polymorphism and gastric cancer risk were summarized in Table XPC Val499Arg polymorphism and gastric cancer risk when all the eligible studies were pooled into the meta-analysis . In addition, no significant heterogeneity was found in the pooled analysis . We did not perform subgroup analysis because of the limited number of studies available for XPC Val499Arg polymorphism.The main results of meta-analysis of XPC PAT−/+polymorphism and gastric cancer risk were summarized in Table XPC PAT−/+polymorphism and gastric cancer risk when all the eligible studies were pooled into the meta-analysis  + (+/−) vs. (−/−): OR = 0.896, 95% CI = 0.724–1.111, P = 0.317; (+/+) vs. (+/−) + (−/−): OR = 1.141, 95% CI = 0.871-1.495, P = 0.338). Moreover, statistical significant heterogeneity was also not found in the pooled analysis. We also did not perform subgroup analysis because only two studies were available for XPC PAT−/+polymorphism.The results of meta-analysis of A single study involved in the meta-analysis was deleted each time to reflect the influence of the individual data-set to the pooled OR, and the corresponding pooled OR was not materially altered Figure , indicatXPC Lys939Gln and XPC Val499Arg polymorphisms. The shape of the funnel plot did not reveal any evidence of obvious asymmetry. Then, the Egger’s test was used to provide statistical evidence of funnel plot symmetry. The results still did not suggest any evidence of publication bias for XPC Lys939Gln  and XPC Val499Arg . We did not carry out Begger’s funnel plot and Egger’s test for XPC PAT−/+polymorphism because only two studies were available for this polymorphism.Begger’s funnel plot and Egger’s test were performed to assess the publication bias of the included studies for XPC polymorphisms  and gastric cancer risk have provided inconsistent results, and most of these studies involved no more than a few hundred gastric cancer cases, which is too few to assess any genetic effects reliably. Meta-analysis has been recognized as an important way to detect the effect of selected genetic polymorphisms on disease risk precisely and to identify potential important sources of between-study heterogeneity. Hence, we performed this meta-analysis including all published studies to investigate the association between the XPC polymorphisms and gastric cancer risk. To the best of our knowledge, this is the first comprehensive meta-analysis of genetics studies on the association between XPC polymorphisms and gastric cancer risk. Our results suggested that the XPC polymorphisms  were not associated with gastric cancer risk when all studies were pooled together. In subgroup analyses stratified by ethnicity, source of control, and study quality, statistical significant association was also not observed in all subgroups.Previous studies evaluating the association between XPC genes may increase gastric cancer susceptibility by causing a severe depression of NER and consequently altering DNA repair activity [XPC polymorphisms and gastric cancer risk was observed in the pooled analysis and subgroup analyses, which was inconsistent with the hypothesis above. Several potential concerns should be discussed for the non-significant associations between XPC polymorphisms and gastric cancer susceptibility. First, gastric cancer is a multi-factorial disease resulting from complex interactions between environmental and genetic factors [XPC polymorphisms in gastric cancer development. Second, there are eight core genes  in the NER pathway of the DNA repairing system, variants in these genes may interfere with each other in associated functions. This could cover the true associations of XPC gene polymorphisms with gastric cancer. Therefore, other variants as gastric cancer risk factors should be induced as co-variants to determine their true effects. The lack of considering above confounding factors might affect the significance of their results. Moreover, the null result may be due to the limited number of studies included in the meta-analysis, which had insufficient statistical power to detect a slight effect or may have generated a fluctuated risk estimate. Therefore, the negative results of the association between XPC polymorphisms and gastric cancer risk should be interpreted with caution.DNA repair mechanisms are important pathways in the removal of DNA adducts from damaged genomic sites and play crucial roles in the carcinogenesis of cancers . XPC is activity . However factors ,30. It iXPC Val499Arg and XPC PAT−/+polymorphisms, the number of studies included was relatively small, not having enough statistical power to investigate a real association of the polymorphisms with gastric cancer susceptibility. However, our meta-analysis also had some advantages. First, a substantial number of cases and controls were pooled from different studies, which significantly increased the statistical power compared with the individual studies. Second, no heterogeneity and publication bias was detected in our meta-analysis, indicating that the pooled results were precise and reliable.Some limitations of this meta-analysis should be acknowledged. First, only published studies were included in the meta-analysis. It is possible that some related unpublished studies that might meet the inclusion criteria were missed; therefore, publication bias may have been present, even though statistical analysis indicated this not to be the case. Second, our results were based on unadjusted estimates and a more precise analysis could be conducted if more individual data were available; this would allow for adjustment by other covariates such as the quantity of salty food consumption, drinking, smoking and Helicobacter pylori infection; Third, in the pooled analyses for XPC polymorphisms  may not contribute to gastric cancer risk. However, it is necessary to conduct large sample studies using standardized unbiased genotyping methods, homogeneous gastric cancer patients, and well-matched controls. Moreover, gene–gene and gene–environment interactions should also be considered in the analysis. Such studies taking these factors into account may eventually lead to our better, comprehensive understanding of the association between the XPC polymorphisms and gastric cancer risk.In conclusion, the result of this meta-analysis based on current evidences suggests that the HWE: Hardy–Weinberg equilibrium; XPC: Xeroderma Pigmentosum group C; NER: Nuclear excision repair; SNP: Single nucleotide polymorphism; OR: Odds ratio; CI: Confidence interval.The authors declare that they have no competing interest.QP, XQ performed the literature search, data extraction, statistical analysis and drafted the manuscript. QP, YL, XL, CM, and RL participated in data extraction. SL, XQ, ZC supervised the literature search, data extraction, statistical analysis and drafted the manuscript. All authors read and approved the final manuscript.


High levels (> 200 µg/L) of inorganic arsenic in drinking water are known to be a cause of human lung cancer, but the evidence at lower levels is uncertain. We have sought the epidemiological studies that have examined the dose-response relationship between arsenic levels in drinking water and the risk of lung cancer over a range that includes both high and low levels of arsenic. Regression analysis, based on six studies identified from an electronic search, examined the relationship between the log of the relative risk and the log of the arsenic exposure over a range of 1–1000 µg/L. The best-fitting continuous meta-regression model was sought and found to be a no-constant linear-quadratic analysis where both the risk and the exposure had been logarithmically transformed. This yielded both a statistically significant positive coefficient for the quadratic term and a statistically significant negative coefficient for the linear term. Sub-analyses by study design yielded results that were similar for both ecological studies and non-ecological studies. Statistically significant X-intercepts consistently found no increased level of risk at approximately 100–150 µg/L arsenic. Inorganic arsenic in drinking water occurs naturally from the earth’s crust and anthropogenically as a byproduct of some industrial processes and uses. While human arsenic exposure can be air-borne or food-borne , the biggest cancer health threat from inorganic arsenic in the environment is from drinking water . OrganicExposure to inorganic arsenic through drinking water causes bladder, skin, and lung cancers and has been classified as being carcinogenic to humans by the International Agency for Research against Cancer  and as aLung cancer risk from exposures to arsenic in the hundreds of µg/L range but not below 100 µg/L has been consistently found. The dose-response pattern transitioning from relatively low risk at low exposure levels to high risks at high exposure levels is unknown. The purpose of this analysis is to examine across this low to high concentration range. The dose-response patterns might be evident in the assembly of the data while not otherwise evident in the examination of single studies. Furthermore, we additionally wish to examine whether such patterns are consistent across study designs. We have assembled the published literature on lung cancer and drinking water arsenic levels and examined the risk over the spectrum of exposure—from about 1 ppb (1 µg/L) to 1 ppm (1000 µg/L). This range was chosen since some publications have suggested that there is a carcinogenic threshold in the 100 µg/L to 200 µg/L range ,17. SuchA search of electronic literature bases  was conducted in August 2015 using the keywords “drinking water arsenic”, “lung cancer”, and “epidemiology”. There was no restriction on geography or on language. This yielded 202 citations from 1981 through 2015. Their titles and/or abstracts were reviewed. Reviews were examined to identify primary studies that might have been missed. Subsequent analyses of previously published studies were also sought. The preliminary search was for studies with risk estimates at various exposure levels including low exposures. The selection was then restricted to studies that reported lung cancer risks in a defined study population of males and females combined, used drinking water arsenic level in units of µg/L as the exposure metric, and had both a reference population with lung cancer at low arsenic exposure as well as additional study populations at both low and high arsenic exposure with high exposure being defined here as greater than 100 µg/L. The most recent data presentations for each study were used in our analyses . The search sought ecological, case-control, and cohort studies and was updated on 13 August 2015. There was no restriction on country of study or language of publication. We used the study populations as defined by the authors. All studies had been designed to assess the relationship between drinking water arsenic level and lung cancer incidence or mortality. Incidence cases came either from local and national cancer registries, or hospital records. Mortality cases came from vital statistics records at the national, state, or local level.All exposure measurements are for arsenic (As) water concentration given in micrograms arsenic per liter (ug As/L) drinking water, equivalent to parts per billion (ppb). Exposures are expressed as either mean or population-weighted mean where feasible; otherwise, mid-range or highest exposures were used. Arsenic exposure data were log-transformed to log arsenic (Log As) as the exposure metric for analyses of individual studies since the exposure range covered three orders of magnitude. In the meta-regression analysis, the exposure metric was transformed to Log [(As − Ref) +1] due to the requirements of the analysis, where As was the arsenic water concentration for the study population in the particular study and Ref was the arsenic water concentration (µg/L) for the reference group in the particular study. Studies produced outcomes of lung cancer risk as standardized mortality ratios (SMR) in ecological studies, odds ratios (OR) in case-control studies, and incidence relative risks (RR) in a cohort study. Relative risks or risk ratios were developed for the ecological studies using the SMR in the lowest exposure group as the reference risk and presented as the ratio of the SMR in the specific exposure strata to the SMR in the reference exposure strata. Similarly, the risk ratios for the case-control and cohort studies used the odds ratios or adjusted relative risks with the lowest exposure group as the reference risk. p  for the model at a two-tailed significance level of 5%. Log Arsenic is retained as the expression of exposure rather than Arsenic, as the AIC goodness-of-fit statistic in the all studies model was smaller when Log Arsenic was used (−0.468) than when Arsenic was used (−0.248). For each individual study, the data were displayed on a scatter plot with log risk ratio (Log RR) as the dependent variable and log arsenic (Log As) as the independent variable. A visual examination revealed a non-linear pattern with an upward curve at higher exposure levels. A variety of non-linear models  were examined for their fits to the data with the most consistent pattern seen for a linear-quadratic model. The AIC goodness-of-fit was used to assist in model selection. Each study population was examined for a goodness-of-fit to a linear-quadratic regression model performed in Microsoft Excel  with a pp-value for each of the coefficients where a two-tailed significance level is set at 5%.For a pooled regression analysis, the data from all studies were similarly displayed. A linear-quadratic regression model was performed utilizing each data point from each study population in the analysis for all studies. For the pooled regression analyses by study design, the data were limited to those of the studies meeting that specific study design. Log of the risk ratio (Log RR) was the dependent variable, and log arsenic (Log As) was the independent variable in the regressions performed, yielding a set of coefficients with a Models were examined for their statistical significance  and for the coefficients of the linear and quadratic terms with their statistical significance. Where the constant term was not statistically significant, the regressions were run in a no-constant model. For the meta-regression analyses, the data were organized by study and analyzed using a linear-quadratic meta-regression model as a series of subsets of data, one set for each study. Meta-regression analyses were conducted using the “metareg” function in STATA, 13.2 . The dati.e., not above the reference level. Thus, at arsenic (As − Ref) = 0 µg/L, log [(As − Ref) + 1] is log (1) or zero on the logarithmic scale. The reference point waszeroed out, and, when the constant term in the regression was not significant, a no-constant model was run. The independent (exposure) variable was transformed to log [(As − Ref) + 1] in order to examine the pattern of the change in risk as the exposure level increased above the reference exposure level. The (As − Ref) in the transformation accommodates the differences in reference levels among the studies and provided a common starting point, and the (+1) in the transformation accommodated for the exposure variable being a logarithmic function and for the fact that log (zero) would be undefined. The net effect of the transformation was that each model began at the starting point of no increased lung cancer risk at no increased arsenic exposure, ith specific randomness that varies between studies. Here p-values for the coefficients of the linear and quadratic term coefficients were obtained, as were p-values (p > F) from the joint test of the null hypothesis, i.e., that the coefficients of intercept, the point at which increased risk is zero , was calculated as the antilog of the ratio of the coefficients (−linear/quadratic) and is quite similar to the no-increase risk level for the data.We conducted a random effects meta-regression model that addressed these aspects, written as d errors . The hetcomputed . Meta-reThe initial search identified 20 studies for consideration, six of which met the specific study parameters. Four studies were excluded because the exposure media were not drinking water arsenic levels—soil or sediment , toenailThese 6 studies included three studies from Chile ,38,39, tet al. (2006)  so that, when (As − Ref) is zero, [(As − Ref) + 1] is 1 and log [(As − Ref) + 1] is zero. Thus, the model begins at no increased lung cancer risk and at no increased arsenic exposure level.p > F) to the no-constant linear-quadratic regression model for all study populations, for study populations from ecological studies, and for study populations from non-ecological studies. Additionally, the data yield a good fit for study populations from the case-control studies and from the cohort study. The regression for the cohort study is a simple no-constant linear-quadratic regression model, as a random effect analysis, would have no meaning for a single study. The meta-regression analyses (Eq. 1) reveal that the data, after controlling for study population and including the uncertainty estimate of the log RR [SE (Log RR)], yield an excellent fit  of < 0.01. Both the analysis of the study populations in the case-control studies and the study population in the cohort study had quadratic terms with statistically significant positive (~0.17 · 0.02) coefficients, linear terms with negative (~−0.365 · 0.016) coefficients that was statistically significant only for the cohort study, and a good goodness-of-fit  of < 0.05. The primary model, which included all study populations and all study designs, yielded a quadratic term (~0.21) with a statistically significant positive coefficient and a linear term (~0.46) with a statistically significant negative coefficient. Sub-analyses were conducted by study design. The sub-analyses for study populations in ecological studies and for study populations in non-ecological studies yielded similar results, having similar positive statistically significant coefficients for the quadratic term (0.21 · 0.03) coefficient, similar negative coefficients for the linear terms (~0.45 · 0.08), and an excellent goodness-of-fit  in the coefficients for the linear term than for the coefficients for the quadratic terms. The study heterogeneity measure The linear coefficients are all seen to be negative and similar, with three out of five being statistically significantly negative, and the quadratic coefficients are all seen to be positive and similar, with five out of five being statistically significantly positive. Thus, the standard pattern is an excellent fit to a no-constant linear-quadratic model with a statistically significant positive coefficient for the quadratic term and a variably statistically significant negative coefficient for the linear term. intercepts of the models, i.e., the non-zero increased arsenic exposure level at which Log RR = zero and RR = 1.0, were obtained. Overall, the all-study populations analysis yielded a Xintercept of 136 µg/L. The Xintercept for the ecological studies was 159 µg/L, while that for the non-ecological studies was 118 µg/L. The Xintercept for the case-control studies was 98 µg/L, while that for the cohort study was 207 µg/L. Each Xintercept was statistically significant with its 95% CI not including zero. The interval between 0 and Xintercept can be interpreted as approximately the range of an increased level of arsenic exposure for which the model would not predict an increase in the risk of lung cancer. The Xp < 0.01) fit to the model with statistically significant positive coefficients for the quadratic term. The coefficient for the linear term is negative in each model and is statistically significant in the overall model. The regression for the cohort study shows a good (p < 0.05) fit to the model with a statistically significant positive coefficient for the quadratic term and also a statistically significant negative coefficient for the linear term. The coefficient for the quadratic term is similar in all the analyses, and the coefficient for the linear term in the analysis of the cohort study is more greatly negative than that of the others. The regression results based on the ecological studies are not different from the results based on the non-ecological studies.The data from the studies on arsenic ingestion and lung cancer, grouped by study design, are each found to fit similar no-constant linear-quadratic log-log meta-regression models. All the meta-regressions show an excellent , below which there is, with a range of uncertainty, no evidence of an increased risk of lung cancer, nor is there evidence of a negative, or hermetic (J-shaped), response.Other systematic reviews have excluded ecological studies from their meta-analyses on the basis that non-ecological (case-control and cohort) studies have stronger or more efficient study designs as they have individualized data on exposures and confounders ,45. In cet al. (2000) study group entered the analyses based on the mean village well water arsenic level rather than the median [et al. (2000) study was the only one to have a reference exposure that was not approximately 1–10 µg/L [intercept of 153 µg/L. The definition of the study populations, the exposure strata, and the risk estimates generally followed those of the authors. The exception is that the villages of the Morales e median . The Mor–10 µg/L . The allintercepts that ranged between 100 and 165 µg/L. These alternative analyses included the data from their first publication instead of the data from the most recent presentation when individual studies were either dropped or used the data from their first publication instead of the data from the most recent presentation, and when studies were grouped by geographical area, data source , presumed nutritional status, or highest exposure. The Xintercept, when including studies, were limited to those with exposure > 500 µg/L was 135.6 µg/L. As a sensitivity analysis, the meta-regression was run with a variety of inclusion assumptions and found to yield XWhether arsenic is a “threshold” carcinogen or not has been debated for decades. The U.S. EPA held a roundtable on this topic in 1995 and reached no conclusion . Later, et al. (2005) [et al. (2013) [et al. (2013) [Snow . (2005)  focused . (2013)  focused . (2013)  providedThe linear-quadratic models demonstrated here are not inconsistent with current thinking on these nonlinear MOA processes underlying arsenic carcinogenicity. et al. (2008) [There are some limitations with our linear-quadratic model. It was based on the assumption that a single analytic model would express an exposure-outcome relationship in a continuous model across the full exposure range. It may be that a segmental model with two segments would fit the data better, since the biological model proposed (cellular toxicity followed by cellular proliferation) would not necessitate the same process or dose-response pattern in both exposure ranges. Further analyses could include the extension of a hockey-stick model or a step function in the meta-regression framework with a robust estimation of such a hooked pattern using non-parametric regression approaches. In fact, US EPA (2005) cancer guidelines specifically encourage investigators to contemplate dual modes of action in any dose response assessment when sufficient data on MOA and tumor observations are available . Unfortu. (2008)  for the An alternative interpretation of our model might be that the ingestion of inorganic arsenic stimulates both anti-carcinogenic responses (linear and negative) and pro-carcinogenic responses (quadratic and positive). At some exposure levels, the pro-carcinogenic responses would be greater than the anti-carcinogenic response, leading to the observed effects. Additional efforts would need to be made to explore this speculation and seek a mechanistic basis. vs. females or for smokers vs. non-smokers. Other sources of arsenic exposure, such as dietary or occupational, have not been included. These analyses intrinsically have assumed that within each study the daily water intake is independent of the arsenic water concentration, though the population water consumption may differ between studies. Most of these study populations have been nutritionally sufficient, and issues of nutritional deficiency and arsenic metabolism are also not included. As it is based on the studies that cover the full exposure range, it has not included those studies that are limited to the low exposure range. Further, these analyses apply only to the carcinogenic risk pattern for lung cancer and not for other adverse effects of inorganic arsenic ingestion, such as cardiovascular, endocrine/metabolic, and reproductive aspects. The carcinogenic risk pattern for bladder cancer has been assessed elsewhere  [These analyses are able to assess the overarching hypothesis on the shape of the dose-response curve for lung cancer over the range of low to high water arsenic concentration exposures. They are not able to distinguish difference in risk or risk pattern for males ., 2014) .i.e., case-control and cohort studies). All analyses yielded statistically significant Xintercepts that generally indicate no increased risk at exposures below about 100–150 µg/L for lung cancer over the low through high arsenic exposure range.We have conducted a systematic review of the epidemiological literature on drinking water arsenic levels and lung cancer and an analysis of their data. We examined the fit to a wide range of continuous models and found overall, and by study design, that the lung cancer data best fit a linear-quadratic model with a statistically significant positive quadratic coefficient and a negative linear coefficient that was statistically significant in the overall model. Importantly, we found that an analysis of the data from the ecological studies was as informative and with similar results as an analysis of the data from the non-ecological studies (


STAT3) and the risk of gastric cancer. In the present study, a case-control study was conducted in which rs2293152 and rs744166 polymorphisms in STAT3 were analyzed in 209 Chinese patients with gastric cancer and 294 cancer-free controls. The genotypes were determined by polymerase chain reaction restriction fragment length polymorphism method. For the rs744166 polymorphism, the TC genotype  and CC genotype  were associated with a decreased risk of gastric cancer compared to the TT genotype. However, rs2293152 did not show any difference in gastric cancer risk between patients and controls in the CG/CC genotype compared to the GG genotype. Besides, the SNP effects were additive to the effects of environmental factors without any interaction between them in the susceptibility to gastric cancer. Collectively, rs744166 polymorphism might be significantly associated with a decreased risk of gastric cancer in a Chinese population. Additionally, polymorphisms in STAT3, along with environmental factors, might be associated with the development of gastric cancer.The aim of this study was to explore the association between polymorphisms in signal transducer and activator of transcription protein 3 ( In recent years, gastric cancer (GC) incidence rates have decreased substantially in most parts of the world. However, GC was still the fourth most common malignancy worldwide, with approximately 989,600 new cases, particularly in Eastern Asian countries, such as China , 2. It iα, and VEGF [ Helicobacter pylori (H. pylori) CagA protein activated the STAT3 signaling pathway in gastric cells, providing a potential mechanism by which chronic H. pylori infection promotes the development of GC [Signal transducer and activator of transcription 3 (STAT3) is a key transcription factor of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway , 5. The and VEGF , 5, 7, 8and VEGF –12. Receand VEGF , 13–17. nt of GC , 19.STAT3 is located on chromosomal region 17q21. To date, single-nucleotide polymorphisms (SNPs) in STAT3 have shown significant associations with cervical cancer, nonsmall cell lung cancer, leukemia, prostate cancer, and hepatocellular cancer [ STAT3 SNPs are significantly associated with susceptibility of Crohn's disease [ STAT3 polymorphisms and GC risk until now.r cancer –24. Ferg disease . To our  STAT3 polymorphisms and susceptibility of GC, as well as discussing potential environmental factors.In this case-control study we aim to evaluate the associations betweenA case-control study was conducted using a Chinese study population of 209 GC patients and 294 controls. All patients, based on pathologic diagnosis, were recruited from the Third Affiliated Hospital of Harbin Medical University. For the frequency-matched controls on age and sex, 154 healthy individuals were recruited from Harbin Center for Disease Control, as well as 140 cancer-free patients who were chosen from the neurology department at the Fourth Affiliated Hospital of Harbin Medical University as controls. All cases and controls had completed a face-to-face questionnaire. A 5 mL sample of venous blood was collected from each subject following the interview. Cases and controls with incomplete questionnaires, as well as non-GC patients, were excluded from this study. Informed consent was obtained from all subjects and the protocol was approved by the Human Research and Ethics Committee of Harbin Medical University.Demographic and habit related data such as age, gender, smoking (including cigarette and pipe) and drinking history, family history of cancer, and frequency of food consumption were collected using a structured questionnaire. We defined smokers as those who smoked more than one cigarette/pipe per day for at least half a year. Likewise, drinkers were defined as those who consumed two or more alcoholic drinks per week for at least half a year. For family history, it referred to first and second degree relatives .Genomic DNA was extracted from whole blood using a QIAamp DNA Blood Mini Kit . DNA purity and concentrations were determined by spectrophotometric measurement of absorbance at 260/280 nm.STAT3 gene polymorphisms were reviewed based on previously published literature which identified functional effects or associations with disease. Minor allele frequency (MAF) of ≥5% in the Asian population, parameters set by the SNP database of the National Center for Biotechnology Information, were also reviewed. Ultimately, rs2293152 (G>C) and rs744166 (T>C) polymorphisms were selected. STAT3 rs2293152 and rs744166 were digested by restriction enzymes AciI and AluI (New England BioLabs), respectively, 5 units for 16 h at 37°C, followed by electrophoresis on a 2% agarose gel.Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was implemented to determine the genotypes. The PCR primers were designed using Primer Premier 5.0 software. For rs2293152, the primer sequences were 5′-TAGAGGCTTCCTTTTGTTCCG-3′ (forward) and 5′-CCAGTTGTCTTTCATCCC-3′ (reverse) that generated the 356-bp fragment. For rs744166, the primer sequences were 5′-GAGTACAAACCCTGAACC-3′ (forward) and 5′-GACTTGGTGACTGACTGAA-3′ (reverse) that generated the 301-bp fragment. Amplification was performed under the following conditions: an initial denaturation for 5 min at 95°C, followed by 30 cycles of denaturation at 95°C for 30 s, annealing at 56°C for 30 s, and extension at 72°C for 30 s, followed by a final extension at 72°C for 7 min. The amplified fragments ofWe used the common genotype homozygotes, the rare genotype homozygotes, and the heterozygous of the polymorphisms (rs2293152 and rs744166) for direct sequencing.χ2) test was used to evaluate Hardy-Weinberg equilibrium (HWE), as well as comparing the genotype and allele frequencies between groups. The associations between genetic polymorphisms and the risk of GC were estimated by computing the odds ratios (ORs) and their 95% confidence intervals (CIs) from unconditional univariate and multivariate logistic regression analyses. We evaluated the interactions between genetic polymorphisms and environmental factors on the risk of GC with four types of ORs . Reference groups consisted of individuals who were not exposed to environmental factors and lacked genetic variants. ORe compares the risk of GC based on the level of exposure to environmental factors; ORg is the odds ratio for the association between the genetic variant with the risk of GC; OReg is the odds ratio for the combined effect of both genetic variants and environmental factors; ORi is the odds ratio of interactions of genetic variants and environmental factors. ; ORi < 1 indicated a negative interaction (antagonism); ORi = 1 indicated that there was no interaction.) A P value of <0.05 was considered statistically significant. All tests were two-sided, and all statistical analyses were conducted with SAS 9.1 .A chi-square (P > 0.05). However, smoking and drinking were overrepresented in the cases compared to the controls (P < 0.001), and cases with family history of cancer were more frequent than controls (P < 0.001).This case-control study enrolled 209 GC patients and 294 cancer-free controls. The demographic information on study subjects are shown in P = 0.233 for rs2293152 and P = 0.851 for rs744166). The genotype distributions of these two SNP loci in the cases and controls are presented in  STAT3 rs744166 were 9.1% (TT), 42.6% (TC), and 48.3% (CC) in the cases and 36.4% (TT), 48.3% (TC), and 15.3% (CC) in control subjects (P = 0.01). Additionally, STAT3 rs744166 showed a statistically significant association in further logistic regression analysis. Compared to the TT genotype carriers, the TC genotype  and CC genotype  carriers were both less frequent among cases than controls, suggesting a dominant effect of the C allele. Overall, C carriers (either TC or CC) were associated with a lower GC risk when compared to those carrying the TT genotype . Conversely, the genotype and allele frequencies of locus rs2293152 did not show a significant difference between GC cases and controls.In our study population, the alleles at rs2293152 and rs744166 loci were in HWE , but not in subjects less than 60 years old. Additionally, TC+CC genotypes were associated with a decreased risk of GC in male subjects , whereas the association was not statistically significant in female subjects. When stratified by smoking status, the C carriers were found to be significantly associated with GC  compared to the TT genotype carriers in smokers. Likewise, drinkers with C carriers showed a significantly decreased risk of GC , compared to those carrying the TT genotype. Stratification by family history of cancer revealed a significant association of TC+CC genotypes and the risk of GC  in subjects without family history of cancer, whereas the association was not statistically significant in subjects with family history of cancer. Conversely, we observed no statistical significance between the rs2293152 gene polymorphism and the risk of GC (data not show).We further evaluated the association between genotypes of these two selected SNPs ofic model . Stratifeg = 0.25 and 95% CI = 0.13–0.48; fresh fruit: OReg = 0.34 and 95% CI = 0.19–0.61). Consumption of seafood (≥average 2 times/week) and using a refrigerator to store food were associated with a decreased risk of GC in subjects with a C allele or TT genotype. On the contrary, long-term irregular eating habits were associated with an increased risk of GC. Additionally, no statistically significant interactions or combination effects were observed between consumption of pork, preference for hot food, and the rs744166 polymorphism on GC risk. Moreover, the combination effects of rs2293152 and environmental factors are almost identical to rs744166  and fresh fruit (≥average 2 times/week) and the TC+CC genotypes were observed  [ STAT3 rs744166 as a susceptible loci of ankylosing spondylitis  in a population of white European ancestry from the UK, USA, Canada, and Australia [Recently, increasing evidence shows that polymorphisms of thediseases , 31–33. ustralia . Moreoveustralia . These fustralia . Yet, otustralia , 33 and  STAT3 polymorphism may play an important role in males with GC. Smoking, which generates reactive oxygen species production and induces DNA adducts that may lead to mutations and thus the initiation of carcinogenesis, has been confirmed to be an independent risk factor of GC [ STAT3 and smoking and drinking is not clear. It is likely that smoking and drinking might significantly induce STAT3 expression, and it is possible that the C allele of rs744166 leads to a higher basal expression level of STAT3 under unnormal circumstances. Therefore, the subjects carrying the C allele of rs744166 might not have decreased GC risk under normal conditions but might have a reduced risk when exposed to tobacco and alcohol that might induce STAT3 expression in response.Furthermore, our present study revealed a decreased effect with the C allele of rs744166 in subgroups of males, smokers, and drinkers. Stratified analysis suggested that the association between the C allele of rs744166 and the risk of GC was more profound in males than females. A previous study reported that noncardia cancer was more common in males than females by a ratio of approximately 2 : 1, and gastric cardia cancer had a ratio of nearly 4.1 : 1 in a Chinese population . Our dator of GC , 37. Meaor of GC , 39. In Interestingly, we found that the influence of C allele of rs744166 disappeared in the subjects with family history, although it existed in all study subjects. Positive family history was reported as a strong and consistent risk factor for GC due to the combination result of a number of alleles , 41. The STAT3 gene polymorphisms and environmental factors for the risk of GC; further studies are needed to confirm this phenomena and a mechanistic explanation for our findings needs to be explored.Single SNPs in low-penetrance genes are unlikely to significantly affect susceptibility to cancer, but combination effects may exist , 43. In  H. pylori is an independent risk factor for GC that we did not explore due to ethical considerations. These related issues will need to be addressed in our future studies.Some limitations in our study need to be addressed. First, the relatively small sample size may reduce the statistical power in stratified analysis. The second limitation was an inevitable recall bias during data collection in regard to environmental factors, although measures were taken to minimize this bias. Third, we adopted a frequency questionnaire to collect information about dietary intake that did not take into consideration the amounts of food being consumed. Therefore, the questionnaire had limited power to detect precise gene-dietary interactions. Finally, STAT3 rs744166 is associated with decreased GC risk in a Chinese population. The minor C allele of rs744166 may correlate with STAT3 expression and thus exert a protective effect on GC development. Additional large-scale, well-designed studies that include environmental factors are required to further validate the role of STAT3 gene polymorphisms in GC risk.In conclusion, our data provided the first evidence that the C allele of


KCNJ11) gene have a key role in insulin secretion and is of substantial interest as a candidate gene for type 2 diabetes (T2D). The current work was performed to delineate the genetic influence of KCNJ11 polymorphisms on risk of T2D in South Indian population through case-control association study along with systematic review and meta-analysis.Potassium inwardly rectifying channel, subfamily J, member 11  and copy number variations (CNV) on the risk of T2D. In addition a systematic review and meta-analysis for KCNJ11 rs5219 was conducted in 3,831 cases and 3,543 controls from 5 published reports from South-Asian population by searching various databases. Odds ratio with 95% confidence interval (CI) was used to assess the association strength. Cochran's Q, I2 statistics were used to study heterogeneity between the eligible studies.A case-control study of 400 T2D cases and controls of South Indian origin were performed to analyze the association of KCNJ11 rs5215, C-G-C-C haplotype and two loci analysis (rs5219 vs rs1800467) showed a significant association with T2D but CNV analysis did not show significant variation between T2D cases and control subjects. Lower age of disease onset (P = 0.04) and higher body mass index (BMI) (P = 0.04) were associated with rs5219 TT genotype in T2D patients. The meta-analysis of KCNJ11 rs5219 on South Asian population showed no association on susceptibility to T2D with an overall pooled OR = 0.98, 95% CI = 0.83–1.16. Stratification analysis showed East Asian population and global population were associated with T2D when compared to South Asians.KCNJ11 rs5219 is not independently associated with T2D in South-Indian population and our meta-analysis suggests that KCNJ11 polymorphism (rs5219) is associated with risk of T2D in East Asian population and global population but this outcome could not be replicated in South Asian sub groups. Potassium inwardly rectifying channel, subfamily J, member11 (KCNJ11) subunits linked to four high affinity sulfonylurea receptor  subunit KCNJ11 has attracted considerable interest in recent years as candidate gene for Type 2 diabetes (T2D) and has a reported 180 single nucleotide polymorphisms (SNPs) in NCBI  database for humans. KCNJ11 polymorphisms rs5219 (E23K), rs1800467 (L270V), rs5215 (V337I), rs41282930 (S385C) are four common missense polymorphisms that have been observed in KCNJ11 gene and has shown to influence the risk of T2D in multiple studies including recent large scale genetic studies KCNJ11 rs5219 (C/T) variant association with T2D KCNJ11 rs5219 (C/T) polymorphism and the susceptibility to T2D in Caucasian subjects in vitro experiments have revealed that Kir6.2 with K23 type allele showed an increased threshold of ATP concentration for the release of insulin KCNJ11 T23 allele KCNJ11 polymorphism (rs5219) with T2D is less explored in non-Caucasian populations. Reports from earlier studies have shown that KCNJ11 polymorphism (rs5219) appears fairly common in Asian subjects and to a lesser degree in individuals of African descent. In this population, small and medium size studies were performed and contradictory results were reported for the association of this variant with T2D KCNJ11 polymorphism (rs5219) and T2D in South Asian populations, as has been performed in East Asian and Caucasian populations. Global meta-analyses undertaken so far on KCNJ11 polymorphism (rs5219) have collected all the studies and this may not be suitable for Asians and Caucasians as they may differ in their genetic predisposition to T2D KCNJ11 polymorphisms and CNV for T2D risk in a large South Indian population. A systematic review and meta-analysis of KCNJ11 rs5219 gene polymorphism on all available studies from South Asian populations was also performed and we compared our results with the meta-analysis of East Asian population and global population to explore the possibilities of ethnic differences in relation to KCNJ11 polymorphism (rs5219) and T2D risk.Insulin secretion induced by glucose comprises of an intricate network of regulatory mechanisms involving glucose metabolism by pancreatic β-cell and electrical activity controlled by ion channels of plasma membrane. A key role of ATP-sensitive potassium (KATP) channel is to control insulin secretion by glucose and to pair metabolism of glucose with electrical activity of the membrane The study was approved by the institutional review board, Kasturba Hospital ethical committee of Manipal University and we obtained written informed consent from all the study participants.The study involved a total of 400 unrelated individuals as cases and 400 controls of South Indian origin recruited from the Kasturba Hospital, Manipal and Mangalore, Karnataka state, India. The cases and control subjects were recruited on the basis of our inclusion criteria. For cases (a) clinically diagnosed T2D patients as defined by world health organization (WHO) criteria (b) disease onset age>30 years (c) belonging to South Indian origin. For controls (a) fasting glucose <126 mg/dl and glycated hemoglobin (HbA1c) <6.0% (b) no history of diabetes in the first and second degree relatives (c) age>40 years (d) belonging to South Indian origin.The general anthropometric parameters considered for the study includes height (m), weight (kg), which were done as per standardized protocols, and BMI was calculated. Biochemical measurements including levels of glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), total cholesterol (TC), Low density lipoprotein (LDL) cholesterol, High density lipoprotein (HDL) cholesterol, and triglycerides (TG) were determined by following manufacturer's instructions using Hitachi 912 auto-analyzer . HbA1c levels were estimated in whole blood using Cobas integra 512 clinical chemistry auto-analyzer following manufacturer's instructions.KCNJ11 polymorphisms  was carried out using tetra primer amplification refractory mutation system (TETRA-ARMS). This method uses two primer sets in which the outer primers are specific to amplify a larger fragment of DNA containing the SNP and the inner allele specific primers are specific to amplify two different alleles in a single polymerase chain reaction (PCR). The differing sizes of amplicon representing the presence of alleles were resolved on agarose gel electrophoresis. Online primer design program by Ye et al., (2001) (http://cedar.genetics.soton.ac.uk) was used to design the primers 2;10 mM 50 mMKCl; Tris HCl, pH 8.8; 0.1% Triton X-100), and 1 U of Taq polymerase . PCR condition includes initial denaturation of 95°C for 5 minutes, 35 cycles of 95°C for 30 seconds, 64°C for 45 seconds and 72°C for 45 seconds and a final extension of 72°C for 10 minutes. Primer sequences and amplicon size are given in The Genomic DNA was extracted from peripheral blood by conventional phenol-chloroform method KCNJ11 gene of T2D and control subjects. 2−ΔΔCt method was used for relative quantification of CNVs Quantitative real time PCR (qPCR) was used to detect CNVs in http://www.ncbi.nlm.nih.gov/projects/SNP/) Quanto version 1.2.4  was used for sample size calculation using minor allele frequency data from dbSNP database (KCNJ11polymorphism (rs5219) and T2D in PubMed, Scopus, Science direct and Embase for all relevant articles pertaining to South Asian and East Asian population. The keywords for searching included Kir6.2/potassium inwardly rectifying channel, subfamily J, member 11/KCNJ11 rs5219/in combination withKCNJ11 and T2D and T2D in South Asia/India/Pakistan. We searched for all possible combination of keywords one at a time. All articles published till November 2013 was included. To further identify eligible studies, reference lists from the retrieved articles were examined. Potentially relevant articles from PubMed were extracted using “Related Articles” option.A broad search was performed for reports on KCNJ11 polymorphism (rs5219) with T2D, 4) study design should conform to cases vs controls, 5) study should provide allelic frequencies, genotypic frequencies and their distribution in cases and controls and odds ratio (OR) with 95% CI, 6) study should use World Health Organization Criteria (WHO) or American Diabetes Association criteria (ADA) for diagnosis of T2D patients, 7) non-diabetic individuals as controls should be included and 8) method of genotyping used should be explained or linked to a reference. We have excluded studies for 1) overlapping and insufficient data and 2) family based and case only studies or review articles. Guidelines from meta-analysis of observation studies in epidemiology (MOOSE) group was followed to extract the following information: name of first author, year of publication, ethnic background of study subjects, work plan, criteria followed for diagnosis of T2D, source of control, mean age of case and controls, method of genotyping, single nucleotide polymorphisms studied, P value for Hardy Weinberg Equilibrium test (HWE), allelic and genotypic frequency and their distribution in cases and controls, adjusted odds ratio (OR)and 95% CI. Supplementary materials if available were scanned for data extraction. The studies were reviewed by two independent reviewers and disagreements concerning inclusion/exclusion of studies or risk estimates were resolved by consensus. Cohen's kappa coefficient was used to assess the agreement between the reviewers for inclusion/exclusion of studies Published manuscripts which met the following criteria were selected: 1) study participants must be from South Asian countries, 2) study should be published in peer reviewed journals with original data, 3) study should investigate the association of Newcastle-Ottawa scale (NOS) was used to assess methodological quality of the included nonrandomized studies. Three major parameters were taken into consideration to evaluate the quality: 1) selection of groups of the studies 2) comparability 3) assessment of the outcome or exposure. The maximum score could be 9 points for each study representing the highest methodological quality KCNJ11 polymorphism (rs5219) and T2D with its corresponding 95% CI. For every allele OR of the risk allele  was compared between cases and controls. To assess for heterogeneity within and between the eligible studies, Cochran's Q-statistic which followed a chi-square distribution with k−1 degrees of freedom (df) was utilized. P<0.05 was regarded as statistically significant 2 statistic was reported as a measure of heterogeneity in odds ratio between the studies included in the meta-analysis. An I2 value of <25% indicates low heterogeneity, 25–50%moderate heterogeneity, 50–75% high heterogeneity and>75% extreme heterogeneity 2) was reported as a measure of between study variance. The smaller the value of τ2, the smaller is the variance. Sensitivity analysis was performed to evaluate the weight of each individual study on the pooled OR. All analyses were performed with MetaXL1.3 tool for meta-analysis in Microsoft excel.We used OR as the measure of association between A total of 400 T2D subjects and 400 control subjects of South Indian origin were enrolled for this study. KCNJ11 variants  only rs5215 variant showed statistically significant association with T2D susceptibility. We observed a considerable difference in the distribution pattern of TT genotype of rs5215 between T2D subjects and controls (22.2% vs 11.2%) and this SNP showed a significant increased risk with T2D  under an co-dominant model and we observed a synergistic protective effect in recessive model with an OR = 0.42, 95% CI = 0.28–0.62, P = 0.0001 . However two-locus analysis between rs5219 and rs1800467 showed a considerable collective effect on T2D. For this analysis the study subjects were grouped into two groups based on the genotypes of rs5219 variant: C/C subjects and C/T+T/T subjects. In the presence of C/C genotype the rs1800467 variant showed an increased susceptibility to T2D with an OR = 1.62, 95%CI = 1.03–2.53 P = 0.03. Where as in the presence of C/T+T/T genotype the rs1800467 variant showed an insignificant risk with an OR = 0.96, 95%CI = 0.65–1.4 P = 0.83 .KCNJ11 loci  was tested using UNPHASED which is a program that uses an algorithm to obtain a maximum Likelihood estimates of case and control haplotype frequency under an alternative and null hypothesis are summarized in The association of haplotypes of four KCNJ11polymorphisms  on T2D related quantitative traits  using ANOCVA with univariate general linear regression model to adjust for age, sex and BMI as covariates. KCNJ11rs5219 T/T genotype showed an increased BMI  and an early age of disease onset  in T2D subjects. KCNJ11 rs1800467 G/G genotype showed an increased TC level  in T2D subjects when compared to other two genotypes  and T2D by searching 4 databases . Relevant titles and summaries were identified and 115 were chosen from 210 articles after removing duplicates, reviews and letters. Of the 115 articles we only included case reports, drug response studies, functional studies of KCNJ11 gene and prospective studies. 72 articles were retrieved for detailed evaluation out of which 58 articles were discarded as the study population was different and 10 articles did not analyze KCNJ11 polymorphism (rs5219) with T2D. The remaining 4 articles in addition to the present study were included in the final qualitative analysis  under random effects model in South-Asian population showed no association . When stratification analysis was done only for the Indian subgroup within the South-Asian population we observed an insignificant risk of KCNJ11 rs5219 on T2D susceptibility . However, when we pooled our data with the other 4 studies we observed a significant association of the KCNJ11 polymorphism (rs5219)   . Our resWhen we performed sensitivity analysis to evaluate the weight of each individual study on the pooled OR by sequential removal of individual studies, there was no one study that could significantly affect the pooled OR .KCNJ11 has a decisive function in insulin secretion from pancreatic β cells, thus making it a potential susceptibility gene for T2D. Large studies of susceptibility gene polymorphisms can offer insight into the association between candidate genes and polymorphisms. KCNJ11 polymorphisms rs5219 (E23K), rs1800467 (L270V), rs5215 (V337I), rs41282930 (S385C) are the most widely studied. Until now, association of these variants with T2D has been fully investigated only in European populations. Previous reports have shown that individuals may be predisposed to the development of T2D if they carry risk alleles which may predispose to impaired insulin secretion and insulin resistance KCNJ11 polymorphism (rs5219) and T2D in Caucasian populations KCNJ11 with T2D KCNJ11 polymorphism (rs5219) with T2D in Caucasians with an overall risk allele KCNJ11 polymorphism (rs5219) and T2D gave contradictory results in Asian populations. Considering functional importance of the gene and since there are a) very few studies explaining the role of KCNJ11 polymorphisms (rs5219 (E23K), rs1800467 (L270V), rs5215 (V337I), rs41282930 (S385C)) in South Asian population, b) no reported large scale GWAS studies and c) lack of comprehensive meta-analysis, we have performed a case–control association study with 400 T2D cases and 400 controls and a systematic review and meta-analysis to provide an assessment of the risk association between KCNJ11 polymorphism (rs5219) and T2D in South Asian population. Five studies were included in the current meta-analysis (including our present study) with 3,831 cases and 3,543 controls. Our case-control association study established that among all the SNPs we evaluated, KCNJ11 polymorphism (rs5215) was only one that was associated with risk of T2D in South Indian population. The important finding of the study is that rs5219, rs41282930, rs1800467 are not independently associated with T2D. However, they showed a statistically significant association with susceptibility to T2D as two-loci (rs5219 and rs1800467) and haplotype (C-G-C-C). According to our knowledge this is the first report in South-Asian populations revealing the possible relation between the two loci (rs5219 and rs1800467) and the susceptibility of T2D. Genome analysis of KCNJ11 gene from UCSC genome browser (http://genome.ucsc.edu/) suggested presence of CNV within exon 2 encompassing rs5219 SNP. Therefore, we analyzed CNVs in this region which suggested absence of any such change in majority of samples but however two T2D samples in a total of 50 T2D samples and 50 control samples did show copy number loss, relevance of such a change remains to be clearly understood. Our meta-analysis of South Asian population also showed no significant association of KCNJ11 polymorphism (rs5219) with risk of T2D. The minor allele frequency (MAF) of control subjects in South Asians (0.28) is much lower than that of East Asians (0.37). Thus a considerable difference in MAF between East Asians and South Asians substantiates the compelling contribution of KCNJ11 polymorphism (rs5219) to T2D. To dissect the consequence of ethnic differences on susceptibility to T2D with respect to this variant we compared the results of our meta-analysis to previous meta-analyses of East Asian and global populations by Yang et al., 2012 and Gong et al., 2012KCNJ11 rs5219 gene polymorphism is not an independent risk factor for T2D but in combination with rs1800467 exhibits a risk to the development of T2D in South Indians. Our meta-analysis results also showed no association of KCNJ11 polymorphism (rs5219) with risk of T2D in South Asian population with an increased overall risk in East Asian and global population, the influence of ethnicity on predisposition to T2D is further confirmed. Since the associations what we have observed in the present study are at a statistical level, more of independent case-control association studies are required to validate these findings in South Asian populations. Further gene-gene interactions and gene-environment interactions should be considered to gain deeper understanding of the genetics of T2D in general and role of KCNJ11 in particular to the onset of T2D.Protein encoded by Table S1List of primer sequences and amplicon size for the SNPs in the study. Abbreviations: FOP- Forward outer primer (5′-3′), ROP-Reverse outer primer (5′-3′), FIP- Forward inner primer, RIP-Reverse inner primer.(DOCX)Click here for additional data file.Table S2Study quality based on the Newcastle-Ottawa scale.(DOCX)Click here for additional data file.Checklist S1(DOCX)Click here for additional data file.


Although family studies have shown that male lower urinary tract symptoms (LUTS) are highly heritable, no systematic review exists of genetic polymorphisms tested for association with LUTS.To systematically review and meta-analyze studies assessing candidate polymorphisms/genes tested for an association with LUTS, and to assess the strength, consistency, and potential for bias among pooled associations.A systematic search of the PubMed and HuGE databases as well as abstracts of major urologic meetings was performed through to January 2013. Case-control studies reporting genetic associations in men with LUTS were included. Reviewers independently and in duplicate screened titles, abstracts, and full texts to determine eligibility, abstracted data, and assessed the credibility of pooled associations according to the interim Venice criteria. Authors were contacted for clarifications if needed. Meta-analyses were performed for variants assessed in more than two studies.ACE, ELAC2, GSTM1, TERT, and VDR). The heterogeneity was high in three of these meta-analyses. The rs731236 variant of the vitamin D receptor had a protective effect for LUTS  with moderate heterogeneity (I2 = 27.2%). No evidence for publication bias was identified. Limitations include wide-ranging phenotype definitions for LUTS and limited power in most meta-analyses to detect smaller effect sizes.We identified 74 eligible studies containing data on 70 different genes. A total of 35 meta-analyses were performed with statistical significance in five  remains weak. In pooled analyses, only the rs731236 variant of the vitamin D receptor has moderate epidemiologic credibility as a risk factor for LUTS. Early reports identified very large excess risks for the surgical treatment of LUTS among men with so-called familial BPH Twin studies provide estimates of heritability that are less confounded by environmental or lifestyle factors that may be shared within families. In a study of 256 twin pairs enrolled in the US military, heritability was estimated at 49% using a case definition corresponding to diagnosis and/or treatment for BPH Many of the studies available for this review aimed primarily to explore the molecular genetics of prostate cancer rather than LUTS, but they included men with and without LUTS as separate subgroups of controls. It remains unclear whether LUTS or BPH might be risk factors for prostate cancer. There is conflicting data regarding any association of a diagnosis of LUTS/BPH with a subsequent diagnosis of prostate cancer With pharmaceutical options for the prevention of prostate cancer and LUTS The aim of this systematic review was to assess which candidate polymorphisms and/or candidate genes had been tested for an association with LUTS in men, and to assess the strength, consistency, and potential for bias among pooled associations.22.1The review protocol was prospectively registered (PROSPERO 2011: CRD42012001985). We prespecified inclusion of both case-control and cross-sectional designs, with both population-based samples and other sampling methods. We included association studies testing for any genetic polymorphism at the nucleotide level including single nucleotide polymorphisms (SNPs), deletions, duplications, and copy-number variants but excluded larger microscopic variants at the karyotype level.For LUTS, there are no gold standard diagnostic methods because these are largely symptomatic diagnoses. We therefore expected to accept case definitions or criteria for LUTS as specified within each study, recognizing there would be heterogeneity in definitions across studies. We planned to include case definitions based on validated symptom questionnaires, clinical evaluation, or urodynamics. After conducting initial searches, we expanded this to case definitions based on care seeking, including the use of relevant medications  or a history of relevant surgery including transurethral resection of the prostate. We excluded studies using solely histologic BPH or clinical BPE case definitions where LUTS were not an inclusion criterion, for example studies based on samples of asymptomatic men undergoing prostate cancer screening. We considered the population of interest as men ≥18 yr of age.2.2(polymorphism OR SNP OR CNV OR “copy number variation” OR mutation OR genetic OR chromosome OR VNTR OR InDel OR microsatellite) AND (“benign prostatic enlargement” OR BPE OR “benign prostatic hyperplasia” OR “bladder outflow obstruction” OR BPH OR nocturia OR LUTS OR incontinence OR urgency OR “overactive bladder” OR “Lower Urinary Tract Symptoms”[Mesh] OR “Urinary Incontinence”[MeSH] OR “enuresis”[Mesh]) NOT mitral NOT carcinoma[Title] NOT cancer[Title] NOT We combined searches from PubMed, HuGE Navigator, and an extensive selection of urologic conference reports. We searched PubMed up to January 2013 without language restrictions, using a combination of genetic and phenotype keywords and Medical Subject Headings (MeSH) terms: We searched HuGE Navigator, also through to January 2013, using the following phenotype indexing terms: .In addition we searched conference abstracts for annual meetings of the American Urological Association, European Association of Urology, International Urogynecological Association, and International Continence Society from 2005 to 2012.2.3We developed standardized data forms, and conducted pilot screening and data extraction training exercises to achieve a high level of consensus between reviewers. All screening and data extraction was performed independently and in duplicate by methodologically trained reviewers. Reviewers screened study reports by first screening titles and abstracts to select papers for full-text assessment and then screening full-text papers to confirm eligibility of the articles. Screening discrepancies were resolved by discussion and adjudication. We hand-searched reference lists of all included articles, applying the same standardized screening process. When more than one published or unpublished report was identified for the same association in the same study population, we included the paper or abstract with the largest sample size.We contacted study authors by e-mail for clarifications, additional information about methodology, and for additional subgroup analyses where necessary. Data extracted included information on the setting for each study, details of the sampling strategy and sampled populations , the overall sample size and proportion genotyped, the outcome assessments used and phenotypic definitions, the genotyping method used, and the genotyping quality control methods applied. Where possible we extracted or requested from authors full genotype frequencies among both cases and controls.2.4Q test and the I2 statistic as measures of between-study heterogeneity. We retested for departure from the Hardy-Weinberg equilibrium among controls. We assessed the risk of bias in phenotype definitions, genotyping, and population stratification. We used the Harbord For polymorphisms assessed in at least two studies for the same phenotype, we conducted meta-analyses using the “metan” package . For meta-analyses with only two studies, or for three or more studies and low heterogeneity, we used fixed effects models but otherwise used random effects models. In the absence of a clear rationale supporting any specific model of inheritance, we used the allelic association test, corresponding to codominant modes of inheritance for all polymorphisms. We assessed the credibility of pooled associations using the interim Venice criteria 3We screened 1025 abstracts and retrieved 191 full texts . A totalp < 0.05) , and of those only the rs731236 polymorphism of VDR could be assigned moderate epidemiological credibility (Quantitative syntheses were possible for 35 polymorphisms in or near 24 genes . Only 5 dibility . The oth3.12 = 91.9%)  . Followi3.2ELAC2 was one of the earliest candidates as a prostate cancer risk SNP n = 71), and accordingly, the association was assigned weak credibility. Analysis of a different SNP, rs4792311, in ELAC2 in the same four studies showed nonsignificant results in all samples and no significant pooled association  . The gene encodes a cytoplasmic glutathione S-transferase, involved in the detoxification of a range of compounds including potential carcinogens. Current evidence suggests the null allele is significantly associated with prostate cancer = 74.3%) . Althoug3.4TERT have been identified as prostate cancer risk SNPs in recent GWAS 2 = 87.1%)  . Again, 3.52 = 27.2%) (n = 409), and no apparent sources of bias in the primary studies, conferring moderate epidemiological credibility. One other SNP, in near perfect linkage disequilibrium, in the same gene (rs1544410) demonstrated a near significant effect in a random effects pooled analysis of Japanese, Thai, and Indian populations  with moderate heterogeneity (I2 = 45.9%). In a prespecified analysis restricted to the two East Asian populations, the pooled effect size was large , with no heterogeneity, suggesting the possibility of an effect specific to East Asian populations. Other SNPs tested in the same gene (rs7975232 and rs10735810) showed no significant pooled effects.Low vitamin D can be considered one component of the metabolic syndrome. Low vitamin D levels decrease prostate apoptosis and are associated with BPH = 27.2%) . Uniquel3.6p values all >0.1) for any individual meta-analysis. However across the field as a whole, we observed a number of phenomena consistent with potential publication bias and selective reporting. The most studied polymorphism, the CAG repeat in the androgen receptor, provides a salient example. We included nine case-control studies, of which all but one contributed to meta-analysis. This meta-analysis demonstrates a marked Proteus effect Most of the possible meta-analyses included fewer than five studies, providing low power for conventional measures of funnel plot asymmetry. Consequently, the Harbord test demonstrated no evidence of small study bias or publication bias , are the following: Chris Chapple is a speaker, consultant, and paid investigator for Astellas Pharma, Allergan, Recordati, and Pfizer. Vik Khullar is a speaker, consultant, and paid investigator for Astellas Pharma, Allergan, and Pfizer. Jori Pesonen has received unrestricted grant funding and/or travel expenses from Pfizer, Novartis, and Ferring Pharma.Funding/Support and role of the sponsor: The study was supported by grants from the International Continence Society and the UK Medical Research Council, but neither body organization any involvement in analysis or preparation of the manuscript. The work of Kari A.O. Tikkinen was supported by unrestricted grants from the Finnish Cultural Foundation and the Finnish Medical Foundation. The work of Marjo-Riitta Järvelin was supported by an unrestricted grant from the Academy of Finland. The work of Phillip Bennett and Vik Khullar is supported by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Imperial College Healthcare NHS Trust and Imperial College London.Acknowledgment statement: The authors would like to thank the following people who provided additional information about primary studies: Oluyemi Akinloye, Yoshitaka Aoki, Basu Banerjee, Vanderlei Biolchi, Goran Brajuskovic, William Catalona, Ivana da Cruz, Nejat Dalay, Edward Giovannucci, Sezgin Gunes, Fouad Habib, Tomonori Habuchi, Jaakko Kaprio, Bart Kiemeney, Kevin McVary, Rama Mittal, Brasil Silva Neto, Leonardo Oliveira Reis, Katsushi Shibata, Manuela Simoni, Ranbir Sobti, and Teuvo Tammela.


OPG rs3102735 T>C, rs2073618 G>C, RANK rs1805034 T>C, RANKL rs9533156 T>C and rs2277438 A>G were determined by ligation detection reaction method. Our findings suggested that RANK rs1805034 T>C is associated with the susceptibility of ESCC, which is more evident in male and elder (≥63) patients. Our study provides the first evidence that functional polymorphisms RANK rs1805034 T>C may be an indicator for individual susceptibility to ESCC. However, further larger studies among different ethnic populations are warranted to verify our conclusion.Esophageal cancer remains the sixth leading cause of cancer associated death and eighth most common cancer worldwide. Genetic factors, such as single nucleotide polymorphisms (SNPs), may contribute to the carcinogenesis of esophageal cancer. Here, we conducted a hospital based case-control study to evaluate the genetic susceptibility of functional SNPs on the development of esophageal cancer. A total of 629 esophageal squamous cell carcinoma (ESCC) cases and 686 controls were enrolled for this study. The  Essentially, esophageal cancer is the 6Neu (ERBB2). RANKL blockade effectively attenuated the formation of mammary tumors and pulmonary metastasis in the MMTV-Neu transgenic mouse model Recently, the osteoprotegerin (OPG), its binding protein–the receptor activator of NF-κB (RANK) and RANK ligand (RANKL) have been implicated with the pathogenesis of breast cancer OPG) with the susceptibility to develop breast cancer has been reported RANK, RANKL and OPG. In a hospital-based case-control study, we performed genotyping analyses of the five miRNA SNPs in 629 ESCC cases and 686 controls in a Chinese population.Genetic variations in genes encoding RANK, RANKL and OPG were found to affect the rheumatoid arthritis This hospital-based case-control study was approved by the Review Board of Jiangsu University . All subjects provided written informed consent to be included in the study. We have complied with the World Medical Association Declaration of Helsinki regarding ethical conduct of research involving human subjects and/or animals.A total of 1,315 participants consisting of 629 esophageal cancer patients and 686 non-cancer controls frequency-matched to the cases with regard to age (±5 years) and sex were enrolled in this study . All patEach subject was personally questioned by experienced interviewers using a 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. “Smokers” subgroup included individuals who smoked one cigarette per day for >1 year. Subjects who consumed ≥3 alcoholic drinks a week for >6 months were subdivided into “alcohol drinkers” category.Genomic DNA was isolated from peripheral blood using QIAamp DNA Blood Mini Kit  as reported previously OPG rs3102735 T>C, rs2073618 G>C, RANK rs1805034 T>C, RANKL rs9533156 T>C and rs2277438 A>G variants between the cases and controls were evaluated using the χ2 test. The associations between the five SNPs and risk of ESCC were assessed by computing the ORs and their 95% CIs using logistic regression analyses for crude ORs and adjusted ORs when adjusting for age, sex, tobacco smoking and alcohol 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 .Variations of demographic characteristics, selected variables, and genotypes of the χ2 tests. Notably, significant difference exists on both tobacco smoking and alcohol drinking status between the ESCC patients and the controls (p<0.001).Characteristics of cases and controls included in the study are summarized in OPG rs3102735 C>T, OPG rs2073618 G>C, RANK rs1805034 T>C, RANKL rs9533156 T>C and RANKL rs2277438 A>G, respectively. The concordance rates of repeated analyses reached 100%. As for the Minor Allele Frequency (MAF), there was no significant difference between our controls and database of Chinese subjects for all five SNPs. The observed genotype frequencies for OPG rs3102735 C>T, OPG rs2073618 G>C, RANK rs1805034 T>C, RANKL rs9533156 T>C and RANKL rs2277438 A>G polymorphisms in the controls were in HWE (The primary information for five genotyped SNPs was shown in ectively).RANK rs1805034 T>C were 45.9% (TT), 42.9% (TC) and 11.2% (CC) in the case patients and 50.5% (TT), 41.8% (TC) and 7.7% (CC) in the control subjects. In the recessive model, when the RANK rs1805034 TT/TC genotypes were used as the reference group, the CC homozygote genotype was associated with a significantly increased risk for ESCC . When the RANK rs1805034 TT homozygote genotype was used as the reference group, the TC genotype was not associated with the risk of ESCC , but the CC genotype was associated with the risk of ECSS . In the dominant model, the RANK rs1805034 CC variant was associated with the risk of ESCC as compared with the TT genotype .OPG rs3102735 C>T, OPG rs2073618 G>C, RANKL rs9533156 T>C, RANKL rs2277438 A>G polymorphisms and the risk of ECSS   . Likewise, in elder patients (≥63 years old), RANK rs1805034 T>C polymorphism was also associated with a significantly increased risk of ESCC   .OPG rs3102735 C>T, OPG rs2073618 G>C, RANK rs1805034 T>C, RANKL rs9533156 T>C and RANKL rs2277438 A>G polymorphisms with risk of ESCC in a Chinese population. Our multivariable logistic analyses demonstrated that RANK rs1805034 T>C genotype has an increased risk of ESCC. Significant association with increased risk of ESCC was noticed among male patients and elder patients (≥63 years old). To our knowledge, this is the first study demonstrating a significant association between the RANK rs1805034 T>C genotype with the susceptibility of ESCC.In this hospital-based case-control study of ESCC, we investigated the association of RANK locus and/or functionally related genes, such as RANKL, have also been reported to be associated with rheumatoid arthritis OPG/RANK/RANKL gene polymorphisms with carcinogenesis. Several studies demonstrated additional loci to be associated with breast cancer including the chromosomal region 8q24 for OPG gene OPG gene has been reported to be associated with the susceptibility of breast cancer in Caucasian population RANK (rs7226991) was associated with a breast cancer risk OPG was initially derived from an expressed sequence tag of a fetal rat intestine cDNA library encoding a 401-amino-acid polypeptide RANK rs1805034 C was 0.286 among 686 control subjects in Chinese population, which is lower than that of European (0.438) and African American (0.478), but similar with the Japanese population (0.311). However, interestingly, another study reported the frequency of RANK rs1805034 C was 0.476 in Han population from North China, which differs our finding in cohort from East China, suggesting the ethnical impact could also be interfered with regional environmental factors (http://www.ncbi.nlm.nih.gov/projects/SNP/snp_ref.cgi? rs = 1805034). Using Power and Sample Size Calculation , considering RANK rs1805034 T>C mutant alleles, the power of our analysis (α = 0.05) was 0.946 in 629 ESCC cases and 686 control subjects with adjusted OR 1.52. In male subgroup, the power of our analysis was 0.995 among 434 cases and 438 control subjects, with the adjusted OR 1.89. In elder cohort (≥63), the power of analysis (α = 0.05) was 0.962 among 314 cases and 312 controls with adjusted OR 1.84. The current study has revealed the association with increased risk of ESCC among male patients and elder patients (≥63 years old), which was in consistent with the previous report. In a retrospective study involving 74,854 ESCC patients from North China, the prevalence among males was higher than that among females, similar to our findings. Moreover, this study demonstrated that although the prevalence significantly declined, the median age-of-onset of ESCC postponed Among different ethnic cohorts, the frequencies of genetic polymorphisms vary drastically. Our study demonstrated that the frequency of RANK rs1805034 T>C is associated with the susceptibility of ESCC. We acknowledge there are several limitations in this study that need to be addressed. First of all, the study subjects were all recruited from several local medical centers within same area, which may not completely represent the general Chinese population, especially when diverse regional environmental factors exist. Secondly, the detailed information regarding cancer metastasis and survival were not provided as the follow-up study is still ongoing, which hinders further analyses of the impact of these SNP polymorphisms on the ESCC progression and prognosis. Lastly, as the epidemiologic complexities of esophageal cancer are vast, rendering screening and prevention limited at best. The association between nutrition factors, exposure to fungal toxins or N-nitroso-compound in food and risk of ESCC is not studied. Further studies among different regions or ethnic populations with diverse nutrition conditions, and supplemented with functional analyses, are warranted to verify our findings.In conclusion, our study provides with the evidence that functional polymorphism of