Survivin promoter ?31G/C (rs9904341) polymorphism and cancer susceptibility: a meta-analysis

This study aimed to perform a meta-analysis to assess the association of survivin −31 G/C promoter polymorphism and cancer risk. Thirteen case–control studies identified through PubMed and published between 2007 and 2011 with a total of 3329 cancer cases and 3979 controls were included in this meta-analysis. Odds ratio (OR) and 95% confidence interval (95% CI) were used to investigate the strength of the association. Overall, the pooled analysis showed that survivin −31C allele was associated with 1.27 fold increased risk of cancer compared with the −31G allele (95% CI = 1.091–1.479; random model). Subgroup analyses based on type of cancer and ethnicity were also performed, and results indicated that survivin −31G/C polymorphism was not associated with risk of gastric cancer [OR = 2.879; 95% CI = 0.553–15.004) for CC vs.GG] and esophageal cancer [OR = 1.352; 95% CI = 0.494–3.699) for CC vs.GG]. Stratification on the basis of ethnicity showed that the risk due to −31C allele was significant only in Asian population [OR = 1.894; 95% CI = 1.206–2.974 for CC vs.GG]. The present meta-analysis suggests an important role of survivin −31 G/C polymorphism with cancer risk especially in Asian population. However, further studies with larger sample size are required to draw more comprehensive conclusions and provide more precise evidence in individual cancers.     

Association of a LSP1 gene rs3817198T>C polymorphism with breast cancer risk: evidence from 33,920 cases and 35,671 controls

Published data on the association between lymphocyte-specific protein 1 (LSP1) rs3817198T>C polymorphism and breast cancer risk are inconclusive. Hence, we conducted a meta-analysis of the LSP1 gene and risk of breast cancer to obtain the most reliable estimate of the association. PubMed, Embase and Web of Science databases were searched. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of the association between the LSP1 rs3817198T>C polymorphism and risk of breast cancer. A total of seven eligible studies including 33,920 cases and 35,671 controls based on the search criteria were involved in this meta-analysis. The distributions of genotypes in the controls were all in agreement with Hardy–Weinberg equilibrium. We observed that the LSP1 rs3817198T>C polymorphism was significantly correlated with breast cancer risk when all studies were pooled into the meta-analysis (the allele contrast model: OR = 1.06, 95% CI = 1.04–1.08; the homozygote codominant: OR = 1.14, 95% CI = 1.01–1.28). In the stratified analysis by ethnicity, significant association was observed in Caucasians for CC versus TT homozygote codominant model (OR = 1.25; 95% CI = 1.03–1.52) and for the recessive model (OR = 1.22; 95% CI = 1.02–1.47). There was significant association observed in Africans for CC versus TT homozygote codominant model (OR = 0.45; 95% CI = 0.22–0.92) and for the recessive model (OR = 0.43; 95% CI=0.22–0.88). Also, significant association was observed in mixed ethnicities for CC versus TT homozygote codominant model (OR = 1.12; 95% CI = 1.05–1.19). When stratified by study design, statistically significantly elevated risk was found in nested case–control studies (CC vs. TT: OR = 1.12, 95% CI = 1.05–1.19). But no significant association was observed for all comparison models between LSP1 rs3817198T>C polymorphism and breast cancer risk in hospital-based and people-based studies. When stratified by BRCA1 mutation carriers status, statistically significantly elevated risk was found in this meta-analysis (the allele contrast model: OR = 1.07, 95% CI = 1.01–1.14; the dominant model: OR = 1.09, 95% CI = 1.00–1.18). And significant association was found in the BRCA2 mutation carriers in the allele contrast (OR = 1.11, 95% CI = 1.03–1.20), the homozygote codominant (OR = 1.23, 95% CI = 1.04–1.47), the heterozygote codominant (OR = 1.12, 95% CI = 1.00–1.25) and the dominant models (OR = 1.14, 95% CI = 1.03–1.27). There was significant association between LSP1 rs3817198T>C polymorphism and breast cancer risk in BRCA1 and BRCA2 positive cohort in all comparison models (the allele contrast model: OR = 1.08, 95% CI = 1.03–1.13; CC vs. TT: OR = 1.16, 95% CI = 1.05–1.29; TC vs. TT: OR = 1.09, 95% CI = 1.01–1.16; the dominant model: OR = 1.10, 95% CI = 1.03–1.17; the recessive model: OR = 1.12, 95% CI = 1.01–1.23). In conclusion, this meta-analysis suggests that the LSP1 rs3817198T>C polymorphism is a low-penetrant risk factor for developing breast cancer but may not be in Africans.     

Association between paraoxonase 2 Ser311Cys polymorphism and ischemic stroke risk: a meta-analysis involving 5,008 subjects

Epidemiological studies have evaluated the association between paraoxonase 2 (PON2) Ser311Cys polymorphism and ischemic stroke risk which developed inconsistent conclusions. The aim of this study was to perform a meta-analysis to investigate a more authentic association between PON2 Ser311Cys polymorphism and ischemic stroke. Systematic searches in PUBMED, EMBASE, CBM, and CNKI databases were performed. Data analyses were carried out by Review Manager 5.1.2 and Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used for additive model (Cys/Cys vs. Ser/Ser), dominant model (Ser/Cys+Cys/Cys vs. Ser/Ser), recessive model (Cys/Cys vs. Ser/Cys+Ser/Ser), and allelic model (Cys allele vs. Ser allele), respectively. Publication bias was analyzed by Begg’s funnel plot and Egger’s test. A total of 7 studies including 2,046 cases and 2,962 controls were involved. Overall, no significant association was found between PON2 Ser311Cys polymorphism and ischemic stroke risk when all studies were pooled into the meta-analysis (for additive model: OR = 0.87, 95% CI = 0.67–1.14; for dominant model: OR = 1.05, 95% CI = 0.91–1.22; for recessive model: OR = 0.90, 95% CI = 0.77–1.05; and for allelic model: OR = 1.17, 95% CI = 0.86–1.59). In the subgroup analysis by ethnicity, significant association was found among Europeans (for recessive model: OR = 0.83, 95% CI = 0.69–0.99). However, due to the small number of studies included in subgroup analysis, the result for European population should be interpreted cautiously.     

XPA A23G polymorphism and susceptibility to cancer: a meta-analysis

Xeroderma pigmentosum group A (XPA) participates in modulating recognition of DNA damage during the DNA nucleotide excision repair process. The XPA A23G polymorphism has been investigated in case–control studies to evaluate the cancer risk attributed to the variant, but the results were conflicting. To clarify the effect of XPA A23G polymorphism in cancer risk, we conducted a meta-analysis that included 30 published case–control studies. Overall, no significant association of XPA A23G variant with cancer susceptibility was observed for any genetic model. However, significant association was observed for colorectal cancer (GG vs. AA: OR = 1.68, 95% CI = 1.15–2.44; dominant genetic model GG + AG vs. AA: OR = 1.54, 95% CI = 1.08–1.17), for breast cancer an increased but non-significant risk was found (GG vs. AA: OR = 1.27, 95% CI = 0.98–1.66; dominant genetic model GG + AG vs. AA: OR = 1.27, 95% CI = 0.99–1.63), and for head and neck cancer an increased risk was observed in recessive model (OR = 1.19, 95% CI = 1.02–1.38), whereas for lung cancer a significant reduced risk was observed (GG vs. AA: OR = 0.77, 95% CI = 0.66–0.90; dominant genetic model GG + AG vs. AA: OR = 0.76, 95% CI = 0.66–0.87), it’s noting that in Asian population the inverse association was more apparent. In addition, in Asian population for esophageal cancer a significant decreased risk was also found in dominant genetic model (OR = 0.55; 95% CI = 0.43–0.70) and for head and neck cancer an increased risk was observed in dominant genetic model (OR = 1.51, 95% CI = 1.03–2.23). The meta-analysis suggested that the XPA A23G G allele is a low-penetrant risk factor for cancer development.     

CYP2E1 Rsa I/Pst I polymorphism contributes to oral cancer susceptibility: a meta-analysis

Previous data on association between CYP2E1 Rsa I/Pst I polymorphism and oral cancer risk were controversial. To investigate the association between CYP2E1 Rsa I/Pst I polymorphism and oral cancer risk. We performed a meta-analysis to assess the relationship between oral cancer and genotype with English language until June 2010. Twelve published case–control studies of 1259 patients with oral cancer and 2262 controls were acquired. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association in codominant and dominant models. Overall, the pooled ORs indicated a significant association between CYP2E1 Rsa I/Pst I polymorphism and oral cancer risk (for c1/c2 vs. c1/c1: OR = 1.30, 95% CI = 1.04–1.62, P_{heterogeneity} = 0.57; for (c1/c2 + c2/c2) vs. c1/c1: OR = 1.32, 95% CI = 1.07–1.64, P_{heterogeneity} = 0.57, respectively). In subgroup analysis by race, the same significant risks were found among Asian (for c1/c2 vs. c1/c1: OR = 1.41, 95% CI = 1.05–1.91, P_{heterogeneity} = 0.92; for (c1/c2 + c2/c2) vs. c1/c1: OR = 1.43, 95% CI = 1.08–1.88, P_{heterogeneity} = 0.97, respectively). In conclusion, this meta-analysis demonstrates that CYP2E1 Rsa I/Pst I c2 allele may be a biomarker for oral cancer, especially among Asian populations.     

Common variant (rs9939609) in the<Emphasis Type="Italic"> FTO</Emphasis> gene is associated with metabolic syndrome

Recent genome-wide association studies have showed that common variant (rs9939609) in fat mass and obesity associated (FTO) gene was significantly associated with type 2 diabetes through an effect on human body mass index/obesity. Further studies have suggested that this variant was also involved in the development of metabolic syndrome (MetS). However, the results have been inconsistent. In this study, we performed a meta-analysis to clarify the association between rs9939609 polymorphism and the risk of MetS. Published literature from PubMed, EMBASE and other databases were searched. All studies assessing the association between rs9939609 polymorphism and the risk of MetS were identified. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed-effects model. Thirteen studies (8,370 cases and 23,156 controls) using NCEP ATPIII criteria for MetS were pooled with a meta-analysis. The overall result showed that there was a statistically significant association between rs9939609 polymorphism and MetS risk (OR = 1.11, 95% CI = 1.06–1.17). Subgroup analysis based on ethnicity showed that effect size was only statistically significant in Europeans (OR = 1.11, 95% CI = 1.05–1.16). Eight studies (1,256 cases and 2,551 controls) using IDF criteria for MetS were pooled with a meta-analysis. The overall analysis suggested that rs9939609 polymorphism was significantly associated with MetS risk (OR = 1.32, 95% CI = 1.13–1.54). Subgroup analysis stratified by ethnicity suggested that effect size was only statistically significant in Asians (OR = 1.33, 95% CI = 1.10–1.61). Our results suggested that FTO rs9939609 polymorphism was significantly associated with the increased risk of MetS in European and Asian populations. Mechanistic investigation is also needed to clarify the effect of FTO gene in the predisposition to MetS.     

TNF-308 gene polymorphism is associated with COPD risk among Asians: meta-analysis of data for 6,118 subjects

Chronic obstructive pulmonary disease (COPD) is a complex polygenic disease in which gene–environment interactions play a critical role in disease onset and progression. The gene encoding tumor necrosis factor (TNF) is one of several candidate loci for the pathogenesis of COPD and is highly polymorphic. A number of studies have investigated the association between the TNF-308 polymorphisms and COPD risk in different populations, and resulted in inconsistent results. A systematic review and meta-analysis of the published studies were performed to gain a clearer understanding of this association. The PubMed, Embase, Web of Science, and CNKI databases were searched for case–control studies published from 1966 to April 2009. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Twenty-four eligible studies, comprising 2,380 COPD cases and 3,738 controls, were included in the meta-analysis. The pooled result showed that the TNF-308 polymorphisms were significantly associated with an increased risk of COPD (OR = 1.335, 95% CI: 1.172–1.522, for allele A carriers versus G/G; OR = 1.330, 95% CI = 1.174–1.505, for allele A versus allele G). Subgroup analysis supported the results in the Asian populations, but not in the Caucasian populations. When the analysis was limited to only those studies in which the COPD cases and controls were smokers/ex-smokers, the pooled results supported the conclusion. This meta-analysis suggested that the TNF-308 A allele is a more significant risk factor for developing COPD among Asian populations, but not among Caucasians.     

Association between ATM 5557G>A polymorphism and breast cancer risk: a meta-analysis

Epidemiological studies have evaluated the association between ATM 5557G>A (p.D1853N) polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the relationship, we performed this meta-analysis. Systematic searches of PubMed and Medline databases were performed. A total of nine studies included 3155 cases and 2752 controls were identified. When all nine studies were pooled into the meta-analysis, there was no evidence for significant association between 5557G>A mutation and breast cancer risk(for G/A vs. G/G: OR = 1.05, 95% CI = 0.83–1.34; for A/A vs. G/G: OR = 0.77, 95% CI = 0.58–1.03; for dominant model: OR = 1.04, 95% CI = 0.82–1.31; for recessive model: OR = 0.87, 95% CI = 0.69–1.09). In the subgroup analyses by family history and ethnicity, significant associations were found among Amerindians (for G/A vs. G/G: OR = 2.19, 95% CI = 1.38–3.47; for dominant model: OR = 2.15, 95% CI = 1.37–3.38). In summary, the meta-analysis suggest that ATM 5557G>A polymorphism is associated with increased breast cancer risk among Amerindians. However, due to the small subjects included in analysis and the selection bias existed in some studies, the results for Amerindians should be interpreted with caution.     

Current evidences on vascular endothelial growth factor polymorphisms and breast cancer susceptibility

Several polymorphisms of vascular endothelial growth factor (VEGF) such as 936 C/T, −2578 C/A, −406 C/T, and −1154 G/A polymorphism have been identified. Published data on the association between VEGF polymorphisms and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Crude OR with 95% CI was used to assess the strength of association between them. For VEGF 936C/T polymorphism, a total of 10 studies including 7,685 cases and 7,915 controls were involved in this meta-analysis. Overall, no significant associations were found between VEGF 936C/T polymorphism and breast cancer risk when all studies pooled into the meta-analysis (TC vs. CC: OR = 0.904, 95% CI = 0.797–1.024; TT vs. CC: OR = 0.974, 95% CI = 0.786–1.205; dominant model: OR = 0.911, 95% CI = 0.811–1.024; and recessive model: OR = 0.991, 95% CI = 0.801–1.226). In the subgroup analysis by ethnicity, still no significant associations were found for all comparison models. For −2578 C/A, −406 C/T, and −1154 G/A polymorphism, there were too limited data to perform a meta-analysis. In conclusion, this meta-analysis suggests that the VEGF 936C/T polymorphism may be not associated with breast cancer development. However, large sample and representative population-based studies with homogeneous breast cancer patients and well matched controls are warranted to confirm this finding.     

TNF-308 gene polymorphism and tuberculosis susceptibility: a meta-analysis involving 18 studies

A number of studies have investigated the association between TNF-308 (rs1800629 G/A) polymorphisms and the susceptibility towards tuberculosis (TB) in different populations. However, many of these studies provided inconsistent results. In this study, a systematic review and meta-analysis of the published studies was performed to gain a clearer understanding of this association. The PubMed, Embase, Web of Science and CNKI databases were searched for case–control studies published up to Jan 2011, we used no lower date limit. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. A total of 18 publications from 2001 to 2010, involving 2584 TB cases and 3817 controls were included. Overall, for the A allele carriers (G/A + A/A) vs. homozygote GG, the pooled OR was 1.03 (95% CI = 0.89–1.19; P = 0.912 for heterogeneity). For the allele A vs. allele G, the pooled OR was 1.07 (95% CI = 0.93–1.22; P = 0.013 for heterogeneity). In the stratified analysis by ethnicity, among Asians significant risk was found for allele A vs. allele G (OR = 1.22, 95% CI = 1.02–1.47; P = 0.152 for heterogeneity), no significant risks were found among Caucasians. This meta-analysis indicated that the TNF-308 polymorphism was not associated with the risk of TB in the total population, however the significant risk for TNF-308 A allele was found among Asians not Caucasians.     

Association between the XRCC3 polymorphisms and breast cancer risk: meta-analysis based on case–control studies

The previous published data on the association between X-ray repair cross-complementing group 3 (XRCC3) T241M, A4541G, and A17893G polymorphisms and breast cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between breast cancer and XRCC3 T241M (21,910 cases and 23,961 controls), A4541G (9,633 cases and 10,994 controls), and A17893G polymorphisms (10,761 cases and 12,235 controls) in different inheritance models. When all the eligible studies were pooled into the meta-analysis of XRCC3 T241M polymorphism, significantly increased risk of breast cancer was observed in recessive model (odds' ratio [OR] = 1.10, 95% confidence interval [CI] = 1.04–1.16) and in additive model (OR = 1.10, 95% CI = 1.03–1.16). No significant association was found between A4541G polymorphism and breast cancer risk. When all the eligible studies were pooled into the meta-analysis of XRCC3 A17893G polymorphism, no significant association was found in any genetic model. Additionally, when one study was deleted in the sensitive analysis, the results of XRCC3 A17893G were changed in the additive model (OR = 0.90, 95% CI = 0.82–0.99) and dominant model (OR = 0.94, 95% CI = 0.89–0.99). In summary, this meta-analysis indicates that T241M polymorphism show an increased breast cancer risk and A17893G polymorphism may be associated with decreased breast cancer risk. A study with the larger sample size is needed to further evaluated gene-environment interaction on XRCC3 T241M, A4541G, and A17893G polymorphisms and breast cancer risk.     

Quantitative assessment of the effect of MTHFR polymorphisms on the risk of lung carcinoma

Published studies on the relationships between 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and lung cancer risk have been conflicting. To derive a more precise estimation of the relationship, a meta-analysis was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between MTHFR C677T and A1298C polymorphisms and lung cancer risk. A total of 15 studies including 10,753 cases and 11,275 controls described C677T genotypes, among which 11 articles totalling 6,161 cases and 7,684 controls described A1298C genotypes, were also involved in this meta-analysis. Overall, no significantly elevated lung cancer risk was found in any genetic models when all studies were pooled. For C677T polymorphism: (TT vs. CC: OR = 1.17, 95% CI = 0.97–1.42; TC vs. CC: OR = 1.06, 95% CI = 0.94–1.20; dominant model: OR = 1.09, 95% CI = 0.96–1.24; and recessive model: OR = 1.08, 95% CI = 0.95–1.24); for A1298C polymorphism: (CC vs. AA: OR = 1.04, 95% CI = 0.91–1.19; AC vs. AA: OR = 0.98, 95% CI = 0.91–1.06; dominant model: OR = 0.99, 95% CI = 0.92–1.06; and recessive model: OR = 1.05, 95% CI = 0.92–1.20). In the subgroup analyses, the results showed that 677T varients could decrease lung cancer risk in female (OR = 0.63, 95% CI = 0.41–0.95, P-value = 0.03, 677CC as reference). No evidence of any associations of MTHFR A1298C polymorphism with lung cancer was found in overall or subgroup analyses. Our meta-analysis supports that the common polymorphisms of C677T and A1298C in MTHFR gene are not susceptibility gene for lung cancer from currently available evidence.     

Association of IL-10-1082 promoter polymorphism with susceptibility to gastric cancer: evidence from 22 case–control studies

Evidence suggested that interleukin-10 (IL-10) may be involved in the etiology of gastric cancer (GC). However, epidemiological studies on the association between IL-10-1082 promoter polymorphism and GC risk are still ambiguous. To quantitatively summarize the evidence for such a relationship, we performed a meta-analysis. Systemic searches of the PubMed and Medline databases were performed, with the last report up to July 2011. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. 22 independent studies including 4,289 cases and 5,965 controls were involved in this meta-analysis. Obvious association was found when all studies were pooled into the meta-analysis (A vs. G: OR = 0.489, 95% CI = 0.335–0.713, P < 0.001). In the subgroup analysis by ethnicity, we observed significant associations in Asians (A vs. G: OR = 0.651, 95% CI = 0.506–0.838, P = 0.001; AA vs. GG: OR = 0.482, 95% CI = 0.328–0.709, P < 0.001; AA/AG vs. GG: OR = 0.711, 95% CI = 0.527–0.959, P = 0.025; AA vs. AG/GG: OR = 0.701, 95% CI = 0.520–0.944, P = 0.019) and Caucasians (A vs. G: OR = 0.365, 95% CI = 0.140–0.949, P = 0.039), but not in Latino population. When stratified analysis by control sources, our results indicated that A allele decreased approximately 48% risk among population-based studies (A vs. G: OR = 0.524, 95% CI = 0.374–0.733, P < 0.001). Taken together, this meta-analysis suggests that IL-10-1082 polymorphism is associated with GC risk.     

The association between the mannose-binding lectin codon 54 polymorphism and systemic lupus erythematosus: a meta-analysis update

The aim of this study was to determine whether the functional mannose-binding lectin (MBL2) exon 1 codon 54 polymorphism (rs1800450) confers susceptibility to systemic lupus erythematosus (SLE) in ethnically different populations. A meta-analysis was conducted on the MBL2 codon 54 polymorphism across 21 comparative studies. Meta-analysis showed an association between the MBL2 codon 54 B allele and SLE in all study subjects [odds ratio (OR) = 1.298, 95% confidence interval (CI) = 1.154–1.459, P = 1.4 × 10⁻⁵]. Analysis after stratification by ethnicity indicated that the MBL2 codon 54 B allele is significantly associated with SLE in Europeans, Asian, and Africans (OR = 1.246, 95% CI = 1.062–1.462, P = 0.007; OR = 1.268, 95% CI = 1.049–1.532, P = 0.014; OR = 1.939, 95% CI = 1.269–2.962, P = 0.002, respectively). However, African Americans had a much lower prevalence of the T allele (5.8%) than any other populations studied, whereas Asians had the highest prevalence (16.2%). This meta-analysis confirms that the MBL2 codon 54 polymorphism is associated with SLE susceptibility in different ethnic groups, and that its prevalence is ethnicity dependent.     

ICAM‐1 and MKL‐1 polymorphisms impose considerable impacts on coronary heart disease occurrence

This study was aimed to explore the correlation of intercellular adhesion molecule‐1 (ICAM‐1) K469E and megakaryoblastic leukaemia factor‐1 (MKL‐1) ?184C/T polymorphisms with the susceptibility to coronary heart disease (CHD) in the Chinese Han population. 100 CHD patients and 91 healthy people that had no blood connection with each other were enrolled in this case‐control study. ICAM‐1 and MKL‐1 polymorphisms were genotyped by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) approach. Multiple logistic regression was used to analyse the correlation between polymorphisms of ICAM‐1 and MKL‐1 and CHD susceptibility. Differences of genotype and allele frequencies of the two SNPs between case and control groups were analysed by chi‐square test. Odds ratios (ORs) and 95% confidence intervals (CIs) were indicated relative susceptibility of CHD. The distributions of ICAM‐1 and MKL‐1 polymorphisms in each group conformed to Hardy‐Weinberg equilibrium (HWE). After adjusting for traditional risk factors, the TT genotype frequency of MKL‐1 ?184C/T polymorphism was found significantly higher in case group than in control group (P < .05). Meanwhile, T allele frequency increased in case group compared with control group, and the differences had statistical significance (P = .04, OR = 2.34, 95% CI = 1.34‐5.26). Logistic regression analysis in this study proved that smoking, hypertension, diabetes and triglyceride (TG) were all risk factors for CHD ICAM‐1 K469E polymorphism has no association with the onset of CHD. But MKL‐1 ?184C/T polymorphism is associated with the risk of CHD and T allele might be a susceptibility factor for CHD.     

MDM2 SNP309 polymorphism and breast cancer risk: a meta-analysis

The mouse double minute 2 (MDM2) gene encodes a phosphoprotein that interacts with P53 and negatively regulates its activity. SNP309 polymorphism (T-G) in the promoter of MDM2 gene has been reported to be associated with enhanced MDM2 expression and tumor development. Many published studies have evaluated the association between MDM2 SNP309 polymorphism and breast cancer risk. However, the results were inconsistent. We combined and analyzed the data from 19 case–control studies including 14,450 cases and 13,382 controls. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association between MDM2 SNP309 polymorphism and breast cancer risk. No significant association was found in all genetic models in overall population. However, in subgroup analysis by ethnicity (4 studies in Asian group, 13 studies in European group, 2 studies of mixed population which were separated into 2 European population group and 2 African population group), we found an increased breast cancer susceptibility for GT versus TT (OR = 1.31, 95% CI = 1.03–1.67) in Asian population and for GT versus TT (OR = 1.31, 95% CI = 1.03–1.66) in African population. When stratified by family history status (5 studies in familial breast cancer group, 5 studies in sporadic breast cancer group), homozygous subjects of sporadic breast cases carrying the T309G G allele exhibited elevated breast cancer risk (OR = 1.35, 95% CI = 1.00–1.82), whereas heterozygous carriers did not show significant association with breast cancer risk for GT vs. TT (OR = 1.26, 95% CI = 0.84–1.87). Our meta–analysis suggests that MDM2 SNP309 polymorphism may increase the risk to breast cancer in Asian and African population.     

Combined analysis of the association between p73 G4C14-to-A4T14 polymorphisms and cancer risk

P73 is a structural and functional homologue of p53, and plays an important role in regulating cell cycle and apoptosis. A potentially functional polymorphism (designated as p73 G4C14-to-A4T14) has been identified in a region in exon 2 of the p73 gene, which may theoretically form a stem-loop structure and thereby affect p73 expression. Several investigations have reported the correlation between p73 G4C14-to-A4T14 polymorphism and cancer risk. However, the results are inconclusive. To further assess the association between p73 polymorphism and cancer risk, we performed meta-analysis of the data sets obtained from 26 individual studies involving 8,148 cancer patients and 8,150 controls. The association between p73 G4C14-to-A4T14 polymorphism and cancer risk was determined by crude odd ratios (OR) with 95% CI (confidential interval). AT-allele carriers were found to have a significantly increased risk of cervical cancer (AT/GC vs. GC/GC, OR = 1.63, 95% CI = 1.14–2.33; AT/AT + AT/GC vs. GC/GC, OR = 1.49, 95% CI = 1.05–2.10), colorectal cancer (AT/AT vs. AT/GC + GC/GC, OR = 1.98, 95% CI = 1.25–3.12), head and neck cancer (AT/AT + AT/GC vs. GC/GC, OR = 1.44, 95% CI = 1.06–1.96) and other cancers (AT/AT vs. GC/GC, OR = 1.78, 95% CI = 1.24–2.57; AT/AT vs. AT/GC + GC/GC, OR = 1.80, 95% CI = 1.26–2.56). In the stratified analysis of ethnicity, a significantly elevated cancer risk was found in Caucasians (AT/AT + AT/GC vs. GC/GC, OR = 1.18, 95% CI = 1.08–1.30; allele AT vs. allele GC, OR = 1.15, 95% CI = 1.06–1.24). No significant association of p73 polymorphism with the cancer risk of smoking was detected by stratified analysis by smoking status. Together, our data suggest that the p73 G4C14-to-A4T14 may be a risk factor of cancer especially in Caucasians.     

CXCL12 G801A polymorphism and breast cancer risk: a meta-analysis

The G801A polymorphism in the CXCL12 gene has been implicated in breast cancer risk. However, the published findings are inconsistent. We therefore performed a meta-analysis to investigate this relationship. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Five published case–control studies, including 1,058 breast cancer cases and 1,023 controls were identified. No study had a deviation from the Hardy–Weinberg equilibrium (HWE) in controls. We found that the CXCL12 G801A (rs1801157) polymorphism was associated with a significantly increased risk of breast cancer risk when all studies were pooled into the meta-analysis (codomiant model: AA versus GG, OR = 1.64, 95% CI = 1.16–2.33; GA versus GG, OR = 1.42, 95% CI = 1.18–1.71; dominant model: AA/GA versus GG, OR = 1.44, 95% CI = 1.21–1.72). Furthermore, Egger’s test did not show any evidence of publication bias (P > 0.05 for the dominant model). In conclusion, the results suggest that the CXCL12 G801A polymorphism may be a low-penetrant risk factor for developing breast cancer.     

Vitamin D receptor ApaI,TaqI, BsmI,and FokI polymorphisms and psoriasis susceptibility: a meta-analysis

The aim of this study was to explore whether vitamin D receptor (VDR) polymorphisms confer susceptibility to psoriasis. Meta-analyses were conducted on the associations between the VDR ApaI, TaqI, BsmI, and FokI polymorphisms and psoriasis. Nine relevant studies on VDR polymorphisms and psoriasis were included in this meta-analysis, which involved 742 psoriasis patients and 715 controls. Meta-analysis indicated an association between the VDR ApaI A allele and psoriasis in Turkish studies (OR = 0.684, 95% CI = 0.475–0.985, p = 0.041). Meta-analysis indicated an association between the BsmI B allele and psoriasis in Asians (OR = 0.636, 95% CI = 0.411–0.984, p = 0.041), and showed a significant association between the FF and ff genotypes of the FokI polymorphism and psoriasis in all study subjects and in Turkish studies (OR = 2.028, 95% CI = 1.194–3.446, p = 0.009; OR = 3.582, 95% CI = 1.602–8.009, p = 0.002). This meta-analysis suggests that the VDR ApaI polymorphism confers susceptibility to psoriasis in the Turkish population. In addition, associations were found between the BsmI polymorphism and susceptibility to psoriasis in Asians and between the Fok I polymorphism and psoriasis in the Turkish population.     

Association of C47T polymorphism in <Emphasis Type="Italic">SOD2</Emphasis> gene with coronary artery disease: a case–control study and a meta-analysis

Oxidative damage promotes atherosclerosis. SOD2 is an important antioxidant enzyme. A case–control study and a meta-analysis were performed to assess the association of C47T polymorphism in SOD2 gene with premature, late-onset and overall coronary artery disease (CAD) risk. A hospital-based case–control study was conducted with 269 premature CAD cases, 278 late-onset CAD cases and 299 healthy controls. Polymerase chain reaction (PCR) and Pyrosequencing were used to detect the polymorphism. Multinomial logistic regression model was performed to estimate odds ratio (OR) with 95% confidence intervals (CIs) and adjust potential confounders. A meta-analysis was performed using eight outcomes including our result. Fixed or random effect pooled measure was selected on the basis of homogeneity test among studies. Heterogeneity among studies was evaluated using I ². Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was estimated using Peters’s linear regression test. In our case–control study, compared with the TT as the reference, the mutant genotype of CC + TC was significantly associated with a reduced premature CAD risk both in univariate (OR = 0.60, 95% CI = 0.41–0.87) and multivariate (OR = 0.59, 95% CI = 0.40–0.87) logistic regressions, but not with late-onset CAD risk. After excluding one article that deviated from Hardy–Weinberg equilibrium in controls, this meta-analysis showed a significant association of the C allele with reduced risk of CAD in dominant (FEM: OR = 0.69, 95% CI = 0.61–0.78), recessive (OR = 0.64, 95% CI = 0.50–0.82), and codominant (FEM: OR = 0.73, 95% CI = 0.65–0.80) models. Our study suggested that the mutant genotype of CC + TC was significantly associated with a reduced CAD risk.