The RTK/ERK pathway is associated with prostate cancer risk on the SNP level: A pooled analysis of 41 sets of data from case–control studies

Prostate cancer (PCa) is a malignant disease influencing numerous men worldwide every year. However, the exact pathogenesis and the genes, environment, and other factors involved have not been explained clearly. Some studies have proposed that cell signaling pathways might play a key role in the development and progression of PCa. According to our previous study, the RTK/ERK pathway containing nearly 40 genes was associated with PCa risk. On the basis of these genes, we conducted a meta-analysis with our own Chinese Consortium for Prostate Cancer Genetics (ChinaPCa) study and available studies in the databases to describe the association between the pathway and PCa on the SNP level. The results suggested that rs4764695/IGF1 (recessive model: pooled OR = 0.92, 95%CI = 0.852–0.994, P = 0.034; I² = 0%, P = 0.042; allele analysis: pooled OR = 0.915, 95%CI = 0.874–0.958, P = 0; I² = 0%, P = 0.424; codominant model: OR = 0.835, 95%CI = 0.762–0.916, P = 0; I² = 0%, P = 0.684) and rs1570360/VEGF (recessive model: OR = 0.596, 95%CI = 0.421–0.843, P = 0.003; I² = 23.9%, P = 0.269; codominant model: OR = 0.576, 95%CI = 0.404–0.820, P = 0.002; I² = 49.1%, P = 0.140) were significantly associated with PCa. In subgroup analysis, the relationship was also found in Caucasians for IGF1 (dominant model: OR = 0.834, 95%CI = 0.769–0.904, P = 0; allele analysis: OR = 0.908, 95%CI = 0.863–0.955, P = 0; AA vs CC: OR = 0.829, 95%CI = 0.750–0.916, P = 0; AC vs CC: OR = 0.837, 95%CI = 0.768–0.912, P = 0). In addition, in Asians (allele analysis: OR = 0.21, 95%CI = 0.168–0.262, P = 0) and Caucasians (recessive model: OR = 0.453, 95%CI: 0.240–0.855, P = 0.015; codominant model: OR = 0.464, 95%CI = 0.240–0.898, P = 0.023) for VEGF, the association was significant. The results indicated that rs4764695/IGF1 and rs1570360/VEGF might play a key role in the development and progression of PCa. On the SNP level, we suggest that the study gives us a new view of gene-pathway analysis and targeted therapy for PCa.     

Association of TLR and TREM-1 gene polymorphisms with risk of coronary artery disease in a Russian population

Atherosclerosis, manifesting itself as acute coronary syndrome, stroke, and peripheral arterial diseases, is a chronic progressive inflammatory disease which is driven by responses of both innate and adaptive immunity. Toll-like receptors (TLRs) and Triggering Receptor Expressed on Myeloid Cells-1 (TREM-1) are important effectors of the innate immune system, and polymorphisms within genes encoding them may increase risk of occurrence of various pathologies including cardiovascular disorders. Thus, we carried out a genetic association study on the sample of 702 consecutive Caucasian (Russian) patients with coronary artery disease (CAD) and 300 age-, sex-, and ethnicity-matched healthy controls. We revealed that the C/C genotype of the TLR1 rs5743551 polymorphism was significantly associated with a reduced risk of CAD according to the recessive model (OR = 0.41, 95% CI = 0.20–0.84, P = 0.017, adjusted by age and gender). Concerning TREM-1 gene polymorphisms, we found that A/A genotype of the rs2234237 polymorphism, the G/G genotype of the rs6910730 polymorphism, the C/C genotype of the rs9471535 polymorphism, and the T/T genotype of the rs4711668 polymorphism were significantly associated with elevated CAD risk according to the recessive model (OR = 5.52, 95% CI = 1.17–25.98, P = 0.011; OR = 4.28, 95% CI = 1.09–16.81, P = 0.021; OR = 5.55, 95% CI = 1.18–26.09, P = 0.011, and OR = 1.66, 95% CI = 1.10–2.52, P = 0.014, respectively, adjusted by age and gender). Conversely, the G allele of the rs1817537 polymorphism, the T allele of the rs2234246 polymorphism, and the T allele of the rs3804277 polymorphism significantly correlated with similarly decreased risk of CAD according to the dominant model (OR = 0.57, 95% CI = 0.40–0.81, P = 0.0013; OR = 0.59, 95% CI = 0.42–0.84, P = 0.003, and OR = 0.58, 95% CI = 0.41–0.81, P = 0.0014, respectively, adjusted by age and gender). We conclude that certain TLR and TREM-1 gene polymorphisms may be associated with CAD in Russian population; however, their significance as predictive and pathogenic markers of CAD should be interpreted with caution in other populations.     

Myeloperoxidase G-463A polymorphism and susceptibility to coronary artery disease: A meta-analysis

Published data on the association between the myeloperoxidase (MPO) G-463A polymorphism and coronary artery disease (CAD) are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis on this topic was performed. PubMed, EMBASE and Chinese national knowledge infrastructure were searched for studies regarding the association between the MPO G-463A polymorphism and CAD. A logistic regression analysis was used to estimate the genetic effect and the possible genetic model of action. Summary odds ratios (ORs) with their corresponding 95% confidence intervals (CIs) were calculated. There was strong evidence for an association between the MPO G-463A polymorphism and CAD. The genetic model of action was most likely to be co-dominant. Overall, the data showed that AA and GA genotypes were significantly associated with reduced risk of CAD (AA vs. GG: OR = 0.37, 95% CI = 0.17–0.78; GA vs. GG: OR = 0.73, 95% CI = 0.57–0.92). In subgroup analyses by study population and sources of controls, statistically significant results were observed in the Chinese population (AA vs. GG: OR = 0.21, 95% CI = 0.10–0.43; GA vs. GG: OR = 0.57, 95% CI =0.44–0.74) and in hospital-based control studies (AA vs. GG: OR = 0.20, 95% CI = 0.10–0.39; GA vs. GG: OR = 0.61, 95% CI = 0.48–0.77). This meta-analysis suggests that the MPO G-463A variant genotypes may be associated with decreased risk of CAD. However, given the limited number of studies and the potential biases, the influence of this polymorphism on CAD risk needs further investigation.     

Meta-analysis of genetic association of chromosome 9p21 with early-onset coronary artery disease

Purpose

A number of studies reported on associations of single nucleotide polymorphisms (SNPs) present in chromosome 9p21 with early-onset coronary artery disease (CAD). The present study was then undertaken to perform a meta-analysis of all the results published to date.

Methods

All studies of the 9p21 association with early-onset CAD that were published between 2007 and 2012 were retrieved from the PubMed database. RevMan 5.0 software was used to perform meta-analysis of the data that fulfilled the criteria for our meta-analysis. The effect size of four SNPs in the 9p21 region on early-onset CAD risk was assessed based on the odds ratios (ORs) with calculation of 95% confidence interval (CI).

Results

A total of 7123 subjects from 7 case–control studies were genotyped. Meta-analysis demonstrated disease association for rs2383207 (OR = 0.79, 95% CI 0.71–0.88, P < 0.0001), rs2383206 (OR = 1.17, 95% CI 1.10–1.25, P < 0.00001), rs10757278 (OR = 1.28, 95% CI 1.15–1.42, P < 0.00001), and rs10757274 (OR = 1.17, 95% CI 1.08–1.33, P = 0.02).

Conclusion

Genetic variation in the chromosome 9p21 region may contribute to the etiology of early-onset CAD although their effect size is rather small.     

Sex-specific association between X-linked Toll-like receptor 7 with the outcomes of hepatitis C virus infection

Toll-like receptor 7 (TLR7) senses hepatitis C virus (HCV) infection and drives the host specific innate and adaptive immune response. The aim of this study was to estimate the distributions of TLR7 single nucleotide polymorphisms (SNPs), including rs179019 and rs3853839, as well as the effect of TLR7 gene variants on TLR7 mRNA expression and cytokine production in response to TLR7 agonist in vitro. TLR7 SNP genotyping was performed among a Chinese sample population of 418 patients with persistent HCV infection, 317 patients with HCV spontaneous clearance, and 989 healthy controls. TLR7 mRNA expression and TLR7-specific IFN-α and IL-6 secretion in peripheral blood mononuclear cells, derived from 60 healthy individuals in vitro, were then quantified. We identified the association of TLR7 rs3853839C allele, haplotype CC and haplotype AC (rs179019/rs3853839) with protection against HCV persistence in Chinese females (OR = 0.49, 95% CI = 0.29–0.81, P = 0.01 for rs3853839 GC; OR = 0.29, 95% CI = 0.11–0.75, P = 0.01 for rs3853839 CC; OR = 0.51, 95% CI = 0.38–0.77, P < 0.01 for haplotype CC; OR = 0.29, 95% CI = 0.10–0.88, P = 0.03 for haplotype AC). In addition, the rs3853839 CC genotype among female carriers had significantly low TLR7 mRNA expression (P = 0.006 for GG vs. CC, P = 0.021 for GC vs. CC), along with decreased IFN-α (P = 0.002 for GG vs. CC, P = 0.021 for GC vs. CC) and increased antiviral IL-6 production (P = 0.002 for GG vs. CC, P = 0.030 for GC vs. CC), after treatment with Imiquimod in vitro. The cytokine profile among rs3853839 CC genotype female carriers may indicate a pronounced protective effect against persistent HCV infection. The functional polymorphism of TLR7 rs3853839C allele was found to be sex-specific and associated with protection against HCV persistence among Chinese females, which may be due to specific IFN-α and IL-6 secretion profiles.     

Association between the − 786T>C 1polymorphism in the promoter region of endothelial nitric oxide synthase (eNOS) and risk of coronary artery disease: A systematic review and meta-analysis

Background

A variety of studies have evaluated the association between the − 786T>C polymorphism in the promoter region of endothelial nitric oxide synthase (eNOS) and risk of coronary artery disease (CAD). However, the results remain conflicting. To better understand the role of eNOS − 786T>C polymorphism in CAD risk, we conducted a comprehensive systematic review and meta-analysis.

Methods

Case–control, cohort or cross-sectional studies evaluating the association between eNOS − 786T>C polymorphism and CAD risk were searched in electronic databases of PubMed, ISI Web of Knowledge, Medline, Embase and Google Scholar Search (up to January 2013). Overall and subgroup analyses were performed. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association between eNOS − 786T>C polymorphism and CAD risk. Statistical analysis was performed with Review Manager 5.0 and STATA12.0.

Results

Twenty-four studies were analyzed between 6192 CAD cases and 9281 healthy controls. The combined results of overall analysis showed significant positive associations between CAD risk and eNOS − 786T>C polymorphism in dominant model (OR = 1.45, 95% CI = 1.27–1.65), recessive model (OR = 1.37, 95% CI = 1.20–1.56), homozygote comparison (OR = 1.64, 95% CI = 1.31–2.04), heterozygote comparison (TC vs. TT, OR = 1.39, 95% CI = 1.23–1.57; CC vs. TC, OR = 1.20, 95% CI = 1.04–1.37) and allele comparison (OR = 1.35, 95% CI = 1.21–1.50). On subgroup analysis based on the ethnicity of population (Caucasians, Asians and others), significant differences were found in all genetic models for Caucasians, similar associations existed in Asians except heterozygote comparison (CC vs. TC). However, the associations were only found in dominant model, heterozygote comparison (TC vs. TT) and allele comparison for the populations named others.

Conclusions

Our investigations demonstrate the significant associations between eNOS − 786C>T polymorphism and CAD risk, and this polymorphism might become an early marker for the risk evaluation of CAD.     

CFH, VEGF, and PEDF genotypes and the response to intravitreous injection of bevacizumab for the treatment of age-related macular degeneration

We determined whether there is an association between complement factor H (CFH), high-temperature requirement A-1 (HTRA1), vascular endothelial growth factor (VEGF), and pigment epithelium-derived factor (PEDF) genotypes and the response to treatment with a single intravitreous injection of bevacizumab for age-related macular degeneration (AMD). Eighty-three patients with exudative AMD treated by bevacizumab injection were genotyped for three single nucleotide polymorphisms (SNPs; rs800292, rs1061170, rs1410996) in the CFH gene, a rs11200638-SNP in the HTRA1 gene, three SNPs (rs699947, rs1570360, rs2010963) in the VEGF gene, and four SNPs (rs12150053, rs12948385, rs9913583, rs1136287) in the PEDF gene using a TaqMan assay. The CT genotype (heterozygous) of CFH-rs1061170 was more frequently represented in nonresponders in vision than TT genotypes (nonrisk allele homozygous) at the time points of 1 and 3 months, while there was no CC genotype (risk allele homozygous) in our study cohort (p = 7.66 × 10⁻³, 7.83 × 10⁻³, respectively). VEGF-rs699947 was also associated with vision changes at 1 month and PEDF-rs1136287 at 3 months (p = 5.11 × 10⁻³, 2.05 × 10⁻², respectively). These variants may be utilized for genetic biomarkers to estimate visual outcomes in the response to intravitreal bevacizumab treatment for AMD.     

Association of interleukin-13 SNP rs20541 with allergic rhinitis risk: A meta-analysis

Studies investigating the association between interleukin-13 (IL-13) single nucleotide polymorphism (SNP) rs20541 and allergic rhinitis (AR) risk have reported conflicting results. The aim of the present study was to conduct a meta-analysis assessing the possible association of IL-13 SNP rs20541 with AR risk. Eight studies were included in the present meta-analysis (2153 cases and 3931 controls). The combined results based on all studies showed that IL-13 SNP rs20541 was associated with increased AR risk (Gln versus Arg: odds ratio (OR) = 1.18, 95% confidence interval (CI) = 1.08–1.30; Gln/Gln versus Arg/Arg: OR = 1.52, 95% CI = 1.20–1.92; Arg/Gln + Gln/Gln versus Arg/Arg: OR = 1.19, 95% CI = 1.06–1.33; Gln/Gln versus Arg/Gln + Arg/Arg: OR = 1.42, 95% CI = 1.13–1.79). When stratifying for race, IL-13 SNP rs20541 exhibited increased AR risk in Asians (Gln versus Arg: OR = 1.20, 95% CI = 1.06–1.36; Gln/Gln versus Arg/Arg: OR = 1.57, 95% CI = 1.17–2.12; Arg/Gln + Gln/Gln versus Arg/Arg: OR = 1.22, 95% CI = 1.04–1.44; Gln/Gln versus Arg/Gln + Arg/Arg: OR = 1.45, 95% CI = 1.09–1.93), while no significant association was detected in Caucasians (Gln versus Arg: OR = 1.28, 95% CI = 0.93 ~ 1.78; Gln/Gln versus Arg/Arg: OR = 1.42, 95% CI = 0.96–2.11; Arg/Gln + Gln/Gln versus Arg/Arg: OR = 1.35, 95% CI = 0.89–2.05; Gln/Gln versus Arg/Gln + Arg/Arg: OR = 1.37, 95% CI = 0.93–2.02). This meta-analysis supported that IL-13 SNP rs20541 was associated with AR, particularly in Asians.     

An obesity genetic risk score is associated with metabolic syndrome in Chinese children

Recent genome-wide association studies have identified several single nucleotide polymorphisms (SNPs) associated with body mass index (BMI)/obesity. In this study, we aim to examine the associations of obesity related loci with risk of metabolic syndrome (MetS) in a children population from China. A total of 431 children with MetS and 3046 controls were identified based on the modified ATPIII definition. 11 SNPs (FTO rs9939609, MC4R rs17782313, GNPDA2 rs10938397, BDNF rs6265, FAIM2 rs7138803, NPC1 rs1805081, SEC16B rs10913469, SH2B1 rs4788102, PCSK1rs6235, KCTD15 rs29941, BAT2 rs2844479) were genotyped by TaqMan 7900. Of 11 SNPs, GNPDA2 rs10938397, BDNF rs6265, and FAIM2 rs7138803 were nominally associated with risk of MetS (GNPDA2 rs10938397: odds ratio (OR) = 1.21, 95% confidence interval (CI) = 1.04–1.40, P = 0.016; BDNF rs6265: OR = 1.19, 95% CI = 1.03–1.39, P = 0.021; FAIM2 rs7138803: OR = 1.20, 95% CI = 1.02–1.40, P = 0.025); genetic risk score (GRS) was significantly associated with risk of MetS (OR = 1.09, 95% CI = 1.04–1.15, P = 5.26 × 10^− 4). After further adjustment for BMI, none of SNPs were associated with risk of MetS (all P > 0.05); the association between GRS and risk of MetS remained nominally (OR = 1.02, 95%CI = 0.96–1.08, P = 0.557). However, after correction for multiple testing, only GRS was statistically associated with risk of MetS in the model without adjustment for BMI. The present study demonstrated that there were nominal associations of GNPDA2 rs10938397, BDNF rs6265, and FAIM2 rs7138803 with risk of MetS. The SNPs in combination have a significant effect on risk of MetS among Chinese children. These associations above were mediated by adiposity.     

Multi-allelic haplotype association identifies novel information different from single-SNP analysis: A new protective haplotype in the LRP8 gene is against familial and early-onset CAD and MI

Our previous studies identified a functional SNP, R952Q in the LRP8 gene, that was associated with increased platelet activation and familial and early-onset coronary artery disease (CAD) and myocardial infarction (MI) in American and Italian Caucasian populations. In this study, we analyzed four additional SNPs near R952Q (rs7546246, rs2297660, rs3737983, rs5177) to identify a specific LRP8 SNP haplotype that is associated with familial and early-onset CAD and MI. We employed a case–control association design involving 381 premature CAD and MI probands and 560 controls in GeneQuest, 441 individuals from 22 large pedigrees in GeneQuest II, and 248 MI patients with family history and 308 controls in an Italian cohort. Like R952Q, LRP8 SNPs rs7546246, rs2297660, rs3737983, and rs5177 were significantly associated with early-onset CAD/MI in both population-based and family-based association studies in GeneQuest. The results were replicated in the GeneQuest II family-based population and the Italian population. We then carried out a haplotype analysis for all five SNPs including R952Q. One common haplotype (TCCGC) was significantly associated with CAD (P = 4.0 × 10^− 11) and MI (P = 6.5 × 10^− 12) in GeneQuest with odds ratios of 0.53 and 0.42, respectively. The results were replicated in the Italian cohort (P = 0.004, OR = 0.71). The sib-TDT analysis also showed significant association between the TCCGC haplotype and CAD in GeneQuest II (P = 0.001). These results suggest that a common LRP8 haplotype TCCGC confers a significant protective effect on the development of familial, early-onset CAD and/or MI.     

Vascular endothelial growth factor polymorphisms and risk of Alzheimer's disease: A meta-analysis

There were conflicting results about whether promoter polymorphisms (− 2578C/A, − 1154G/A) of vascular endothelial growth factor (VEGF) gene is a risk factor of Alzheimer's disease (AD). To determine the relationship between them, a meta-analysis is needed urgently. We searched all the reports about VEGF promoter polymorphisms (− 2578C/A, − 1154G/A) and AD risk from PubMed, Web of Science, Cochrane Collaboration and Google Scholar database for the period up to 1 August, 2012. A total of 7 studies were included in this meta-analysis. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated applying fixed or random effects models. There was no significant association between VEGF − 2578C/A polymorphisms and AD risk in all gene models (OR = 1.08, 95% CI = 0.94–1.23 for A vs. C; OR = 1.19, 95% CI = 0.89–1.59 for AA vs. CC; OR = 1.15, 95% CI = 0.91–1.45 for AA vs. CC + CA; OR = 1.11, 95% CI = 0.98–1.25 for AA + CA vs. CC). Similar results were provided in subgroup analysis by ethnicity. For the VEGF − 1154G/A polymorphisms, lack of an association was also found (A vs. G: OR = 0.89, 95% CI = 0.79–1.01; AA vs. GG: OR = 0.82, 95% CI = 0.62–1.08; AA vs. GA + GG: OR = 0.89, 95% CI = 0.68–1.16; AA + AG vs. GG: OR = 0.85, 95% CI = 0.72–1.00). Conclusively, the result of this meta-analysis suggested that VEGF promoter polymorphisms (− 2578C/A, − 1154G/A) might not contribute to the susceptibility of AD.     

Influence of interleukin-6 gene − 174G>C polymorphism on development of atherosclerosis: A meta-analysis of 50 studies involving 33,514 subjects

Increasing epidemiological studies have focused on the associations between interleukin-6 (IL-6) gene − 174G>C polymorphism and atherosclerotic diseases, but the results are still controversial. This meta-analysis was designed to identify whether this association exists. PubMed, Embase, Web of Science, Cochrane database, Clinicaltrials.gov and Current Controlled Trials, Chinese Clinical Trial Registry, CBMdisc, CNKI and Google Scholar were searched to get the genetic association studies. The crude odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were used to estimate the association between the IL-6 gene − 174G>C polymorphism and atherosclerosis ( AS ) risk. The subgroup analyses were made on the following: ethnicity, atherosclerotic diseases and source of controls. Finally, 50 studies (15,029 cases and 18,485 controls) were included in this meta-analysis. Overall, no significant association was found between the IL-6 gene − 174G>C polymorphism and AS risk (for C allele vs. G allele: OR = 1.02, 95% CI = 0.94–1.11, p = 0.64; for C/C vs. G/G: OR = 1.01, 95% CI = 0.85–1.21, p = 0.88; for C/C vs. C/G + G/G: OR = 0.97, 95% CI = 0.84–1.12, p = 0.68; for C/C + C/G vs. G/G: OR = 1.07, 95% CI = 0.97–1.17, p = 0.18). In the subgroup analyses, significant associations were found between the IL-6 gene − 174G>C polymorphism and AS in non-Caucasian group (for CC + CG vs. GG: OR = 1.22, 95% CI = 1.06–1.41, p = 0.005), other atherosclerotic diseases group (for C allele vs. G allele: OR = 0.75, 95% CI = 0.61–0.93, p = 0.008; for C/C vs. G/G: OR = 0.56, 95% CI = 0.38–0.81, p = 0.002; for C/C vs. C/G + G/G: OR = 0.60, 95% CI = 0.45–0.79, p = 0.0004) and population-based group (for C allele vs. G allele: OR = 1.09, 95% CI = 1.00–1.18, p = 0.04; for CC + CG vs. GG: OR = 1.15, 95% CI = 1.04–1.27, p = 0.005). In summary, the present meta-analysis suggests that the IL-6 gene − 174G C polymorphism is associated with the susceptibility to AS. However, due to the high heterogeneity in the meta-analysis, the results should be interpreted with caution.     

Hsa-miR-499 polymorphism (rs3746444) and cancer risk: A meta-analysis of 17 case–control studies

Introduction

MicroRNAs (miRNAs) are a family of endogenous, small and noncoding RNAs that negatively regulate gene expression by suppressing translation or degrading mRNAs. Recently, many studies investigated the association between hsa-miR-499 rs3746444 polymorphism and cancer risk, which showed inconclusive results.

Methodology/main results

We conducted a meta-analysis of 17 studies that included 7842 cancer cases and 8989 case-free controls and assessed the strength of the association, using odds ratios (ORs) with 95% confidence intervals (CIs). Overall, hsa-miR-499 rs3746444 polymorphism was associated with higher cancer risk in heterozygote model (AG vs AA, OR = 1.15, 95%CI = 1.01–1.30, P_{heterogeneity} < 0.001), dominant genetic model (GG/AG vs AA, OR = 1.18, 95% CI = 1.04–1.33, P_{heterogeneity} < 0.001) and allele contrast (G vs A, OR = 1.09, 95% CI = 1.01–1.18, P_{heterogeneity} = 0.021). In the stratified analyses, we observed that the GG/AG genotype might modulate breast cancer risk (OR = 1.13, 95% CI = 1.01–1.26, P_{heterogeneity} = 0.111) comparing with the AA genotype. Moreover, a significantly increased risk was found among Asian populations in heterozygote model (AG vs AA, OR = 1.23, 95% CI = 1.06–1.43, P_{heterogeneity} < 0.001), homozygote model (GG vs AA, OR = 1.22, 95% CI = 1.02–1.46, P_{heterogeneity} = 0.319), dominant model (GG/AG vs AA, OR = 1.25, 95% CI = 1.06–1.39, P_{heterogeneity} < 0.001) and allele contrast (G vs A, OR = 1.14, 95% CI = 1.04–1.25, P_{heterogeneity} = 0.021).

Conclusions

These findings supported that hsa-miR-499 rs3746444 polymorphism contributes to the susceptibility of cancers.     

The effect of XPD/ERCC2 Lys751Gln polymorphism on acute leukemia risk: A systematic review and meta-analysis

Aims

Epidemiological studies have assessed the association between xeroderma pigmentosum group D (XPD) Lys751Gln and acute leukemia risk with conflicting results. We performed this meta-analysis to derive a more precise estimation of the relationship. Pooled odds ratio (OR) with 95% confidence interval (95% CI) was used to assess the strength of the association.

Results

Ten published case–control studies including a total of 1494 cases and 2259 controls were identified. Overall, significant risk effects of Lys751Gln genotype was found under the dominant model (OR = 1.16; 95% CI = 1.01–1.34; P = 0.032). When stratified by clinical types, the variant genotype was associated with the acute myeloid leukemia (AML) risk under the heterozygote comparison (OR = 1.20; 95% CI = 1.00–1.43; P = 0.048), the homozygote comparison (OR = 1.35; 95% CI = 1.05–1.74; P = 0.019) and the dominant model (OR = 1.23; 95% CI = 1.04–1.45; P = 0.015), respectively. Furthermore, significantly increased risks were also pronounced in Caucasian AML patients (the homozygote comparison: OR = 1.38; 95% CI = 1.07–1.78; P = 0.013; the dominant model: OR = 1.23; 95% CI = 1.03–1.46; P = 0.020; and the recessive model: OR = 1.26; 95% CI = 1.00–1.60; P = 0.050). No evident heterogeneities were observed for the overall data under all genetic models. In addition, no statistical evidence for publication bias was found using the method of Begg's and Egger's tests.

Conclusion

This meta-analysis suggested that XPD Lys751Gln polymorphism might be a risk factor for AML and Caucasian acute leukemia patients.     

Genetic association of interleukin-10 promoter polymorphisms and susceptibility to diffuse large B-cell lymphoma: A meta-analysis

Published data on the association between interleukin-10 (IL-10) gene polymorphisms and diffuse large B-cell lymphoma (DLBCL) risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed, focusing on four major IL-10 gene variants in the promoter region: –3575T/A, –1082A/G, –819C/T and –592C/A. We applied the false discovery rate (FDR) method to adjust for multiple testing. A significant association between IL-10 –3575T/A polymorphism and the risk of DLBCL was observed in the pooled 10 case–control studies (A vs. T: OR = 1.16, 95% CI = 1.08–1.25, P < 0.0001; AA + TA vs. TT: OR = 1.20, 95% CI = 1.08–1.33, P = 0.0009; AA vs. TA + TT: OR = 1.25, 95% CI = 1.09–1.44, P = 0.001). The results indicated that carriers of –1082G allele (–1082GG/GA genotypes) had a nearly 30% increased risk of DLBCL, as compared with carriers of –1082AA genotype (GG + GA vs. AA: OR = 1.30, 95% CI = 1.08–1.57, P = 0.005). When P-values were not adjusted for multiple testing, the risk was significantly decreased among people with –592AA genotype (AA vs. AC + CC: OR = 0.63, 95% CI = 0.43–0.94, P = 0.02), while carriers with –819TT genotype also modestly weakened the DLBCL susceptibility at a marginal level of significance (TT vs. CT + CC: OR = 0.59, 95% CI = 0.35–0.99, P = 0.05). However, these associations were not significant after correction for multiple testing. This meta-analysis suggests that IL-10 –3575A allele confers a greater risk to DLBCL susceptibility, while –1082A/G polymorphism also has significant association with DLBCL risk. These results may help to further clarify the malignancy-risk gene signature of DLBCL, and thus have prognostic and predictive value especially for early-stage DLBCL.     

Tagging SNPs in the ERCC4 gene are associated with gastric cancer risk

ERCC4 plays an essential role in the nucleotide excision repair (NER) pathway, which is involved in the removal of a wide variety of DNA lesions. To determine whether the ERCC4 tagging SNPs (tSNPs) are associated with risk of gastric cancer, we conducted a hospital-based case-control study of 350 cases and 468 cancer-free controls. In the logistic regression (LR) analysis, we found a significantly decreased risk of gastric cancer associated with the rs744154 GC/CC genotypes [adjusted odds ratio (OR) = 0.56, 95% confidence interval (CI) = 0.42–0.75, false discovery rate (FDR) P = 0.003] compared with the wild-type GG genotype. Haplotype-based association study revealed that the CGC haplotype that containing the rs744154 C allele can decrease the risk of gastric cancer compared with the most common haplotype GGT (adjusted OR = 0.61, 95% CI = 0.46–0.81). Using the multifactor dimensionality reduction (MDR) analysis, we identified that the SNP rs744154 and smoking status were the best two predictive factors for gastric cancer with a testing accuracy of 55.76% and a perfect cross-validation consistency (CVC) of 10 (P = 0.001). Furthermore, the smokers with the rs744154 GC/CC genotypes showed a decreased risk of gastric cancer (adjusted OR = 0.55, 95% CI = 0.35–0.85) compared with the smokers with the GG genotype using multivariate LR analysis. The above findings consistently suggested that genetic variants in the ERCC4 gene may play a protective role in the etiology of gastric cancer, even in the smokers.     

Relationship between chemokine (C–X–C motif) ligand 12 gene variant (rs1746048) and coronary heart disease: Case–control study and meta-analysis

The goal of our study is to evaluate the contribution of CXCL12 rs1746048 (hg19, chr10:44775574) to the risk of CHD in Han Chinese, and to summarize its role in CHD through meta-analysis of existing studies among various ethnic groups. Significant association is observed between rs1746048-C and an increased risk of CHD in Han Chinese (χ² = 5.41, df = 1, P = 0.02). Post hoc analysis reveals an even stronger association of rs1746048 with the risk of CHD for subjects aged 65 years or older (genotype: χ² = 8.39, df = 2, P = 0.015; allele: χ2 = 9.13, df = 1, P = 0.003, odd ratio (OR) = 1.91, 95% confidential interval (CI) = 1.25–2.91). A break down analysis by gender shows that rs1746048 is likely a CHD risk factor under the recessive model in males (CC + CT versus TT: P = 0.05, χ² = 3.59, df = 1, OR = 1.72, 95% CI = 1.00–3.04). In addition, a meta-analysis of ten studies among over 107,000 individuals confirms that rs1746048 is a risk factor of CHD (P < 0.0001, OR = 1.12, 95% CI = 1.09–1.15) and this agrees with the findings of our case–control study in Han Chinese.     

Meta-analysis supports association of a functional SNP (rs1801133) in the MTHFR gene with Parkinson's disease

The MTHFR is a candidate risk gene for Parkinson's disease (PD), and a functional SNP (rs1801133) in the coding region of this gene has been investigated for the associations with the illness extensively among worldwide populations, but overall the results were inconsistent. Here, to assess the relationship between rs1801133 and risk of PD in general populations, we conducted a systematic meta-analysis by combining all available case–control samples in European and Asian populations, with a total of 1820 PD cases and 7530 healthy controls, and the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for rs1801133 and PD were calculated using the Mantel–Haenszel method with a fixed-effect model. Overall, rs1801133 was significantly associated with the risk of PD (allelic model, pooled OR = 1.212 for T allele, 95% CI = 1.097–1.340, p-value = 0.0002). When stratifying for ethnicity, significant association was also observed in European (allelic model, pooled OR = 1.187 for T allele, 95% CI = 1.058–1.332, p-value = 0.004) and Asian samples (allelic model, pooled OR = 1.293 for T allele, 95% CI = 1.058–1.580, p-value = 0.012) respectively. In addition, rs1801133 was also significantly associated with MTHFR mRNA expression in both CEU (European, p-value = 0.0149) and CHB (Chinese, p-value = 0.0178) HapMap populations. Collectively, our meta-analysis suggests that rs1801133 is significantly associated with susceptibility to PD in European and Asian populations, and MTHFR is likely an authentic risk gene for PD.     

Poly (AT) deletion/insertion polymorphism of the XPC gene contributes to urinary system cancer susceptibility: A meta-analysis

Numerous studies have investigated the association between xeroderma pigmentosum complementation group C (XPC) poly (AT) deletion/insertion (PAT −/+) polymorphism and cancer susceptibility; however, the findings are inconsistent. Therefore, we performed a meta-analysis based on 32 publications including 10,214 cases and 11,302 controls to acquire a more robust estimation of the relationship. We searched publications from MEDLINE, EMBASE and CBM which assessed the associations between XPC PAT −/+ polymorphism and cancer risk. We calculated pooled odds ratio (OR) and 95% confidence interval (CI) by using either fixed-effects or random-effects model. We found that individuals carrying the PAT +/+ genotype have significantly increased cancer risk (PAT +/+ vs. PAT −/−: OR = 1.18, 95% CI = 1.03–1.35 and recessive model: OR = 1.19, 95% CI = 1.06–1.33). Further stratification analysis showed a significantly increased risk for prostate cancer (PAT +/+ vs. PAT −/−: OR = 2.20, 95% CI = 1.39–3.48, recessive model: OR = 2.07, 95% CI = 1.33–3.23 and PAT + vs. PAT −: OR = 1.39, 95% CI = 1.12–1.71), bladder cancer (recessive model: OR = 1.33, 95% CI = 1.03–1.72), Caucasian ethnicity (recessive model: OR = 1.21, 95% CI = 1.02–1.43), population-based studies (recessive model: OR = 1.23, 95% CI = 1.05–1.43) and studies with relatively large sample size (PAT +/+ vs. PAT −/−: OR = 1.18, 95% CI = 1.04–1.35 and recessive model: OR = 1.20, 95% CI = 1.08–1.33). Despite some limitations, this meta-analysis established solid statistical evidence for the association between the XPC PAT +/+ genotype and cancer risk, especially for urinary system cancer, but this association warrants further validation in single large studies.     

Single nucleotide polymorphism in hMLH1 promoter and risk of tobacco-related oral carcinoma in high-risk Asian Indians

hMLH1 is a member of mismatch repair genes (MMR) that plays a crucial role in correcting replication errors, cell cycle arrest, apoptosis and oxidative stress. We explored the risk associated with hMLH1 − 93 A>G (rs 1800734) single nucleotide polymorphism (SNP) with the oral squamous cell carcinoma (OSCC) in Asian Indians. We genotyped 242 patients with tobacco-related OSCC and 205 healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The frequency of AA genotype was found to be significantly (P_c < 0.0006) lower in patients as compared to the controls (21.49% vs. 47.8%) while GG genotype showed significantly higher (P_c < 0.0006) prevalence in patients as compared to the healthy controls (41.32% vs. 13.66%). In logistic regression analysis AG (adjusted OR = 1.95, 95% CI = 0.72–5.26) and GG genotype (adjusted OR = 4.5, 95% CI = 1.54–13.16, P = 0.006) appeared susceptible when compared with the wild-type AA genotype. The allelic distribution showed that variant G allele is significantly higher (P_c < 0.0004) in patients and associated with increased risk (adjusted OR = 2.36, 95% CI = 1.33–4.19, P = 0.003) as compared to the wild-type A allele. Altogether, our results suggest that the hMLH1 − 93 A>G polymorphism is associated with the higher risk of tobacco-related OSCC in Asian Indians and could be useful in screening population at a higher risk.