Association between IL13 gene polymorphisms and susceptibility to cancer: A meta-analysis

Background/aims

Interleukin-13 (IL13) is an immunoregulatory cytokine which plays an important role in carcinogenesis through affecting tumor immunosurveillance. Many studies had reported the influence of IL13 rs1800925 and rs20541 polymorphisms on cancer risk, however, with inconclusive results. The aim of the present study was to conduct a meta-analysis to clarify the relationship.

Methods

Twenty studies including a total of 6713 cancer cases and 8693 controls for IL13 rs20541 polymorphism and 4081 cancer cases and 6202 controls for IL13 rs1800925 polymorphism were included in the meta-analysis. Data were extracted from these studies and odds ratios with corresponding 95% confidence intervals were computed to estimate the strength of the association.

Results

Overall, the IL13 rs20541 polymorphism were associated with significantly decreased cancer risk in all genetic models (AA vs. GG: OR = 0.82, 95%CI = 0.71–0.95; GA vs. GG: OR = 0.92, 95%CI = 0.85–0.99; GA/AA vs. GG: OR = 0.90, 95%CI = 0.85–0.97; AA vs. GG/GA: OR = 0.85, 95CI% = 0.74–0.98). In the stratified analyses, significant effects were found among European populations, studies with population-based controls and studies of glioma. No influence of the IL13 rs1800925 polymorphism on the overall cancer risk was observed. However, in the stratified analyses, we found the IL13 rs1800925 polymorphism was significantly associated with decreased risk for glioma (CT vs. TT: OR = 0.72, 95%CI = 0.55–0.93; CT/TT vs. TT: OR = 0.76, 95%CI = 0.62–0.89).

Conclusion

Our meta-analysis suggests that the IL13 rs20541 polymorphism contributes to susceptibility to cancer, especially for glioma; and the IL13 rs1800925 polymorphism may be associated with glioma risk.     

Relationship between CCR2-V64I polymorphism and cancer risk: A meta-analysis

Background and objectives

The role of CCR2-V64I polymorphism in various cancers has been reported in many studies. However, results from published studies on the association between CCR2-V64I polymorphism and cancer risk are conflicting. Therefore, we performed a meta-analysis to estimate the overall cancer risk associated with the polymorphism.

Methods

Electronic searches of PubMed and EMBASE were conducted for all publications on the association between this variant and cancer. Odds ratios (OR) with 95% confidence intervals (95% CI) were used to access the strength of this association.

Results

Sixteen studies with 2661 cancer patients and 5801 healthy controls were included. Overall, significant association was found between the CCR2-V64I polymorphism and cancer risk (OR = 1.84, 95% CI = 1.35–2.51, AA vs GA/GG, P = 0.37). In the subgroup analysis stratified by cancer types, there was a significant association between this polymorphism and bladder cancer (OR = 2.06, 95% CI = 1.02–4.15, AA vs GA/GG, P = 0.11), cervical cancer (OR = 3.34, 95% CI = 1.48–7.50, AA vs GG, P = 0.56), and oral cancer (OR = 2.04, 95% CI = 1.46–2.84, GA vs GG, P = 0.70). In the subgroup analysis stratified by ethnicities, an increased cancer risk was also found in Europeans (OR = 2.31, 95% CI = 1.45–3.68, AA vs GA/GG, P = 0.16) and Asians (OR = 1.88, 95% CI = 1.12–3.16, AA vs GA/GG, P = 0.92).

Conclusion

This meta-analysis suggested that CCR2-V64I polymorphism may contribute to an increased risk of cancer.     

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 CXCL12 G801A polymorphism and cancer risk: Evidence from 17 case‐control studies

CXCL12 has been implicated in human carcinogenesis, but the association between the most-studied G801A polymorphism (rs1801157) and the risk of various cancers was reported with inconclusive results. The aim of this study was to assess the association between the CXCL12 G801A polymorphism and cancer risk. A meta-analysis of 17 studies with 3048 cancer patients and 4522 controls was conducted to evaluate the strength of the association using odds ratio (OR) with its 95% confidence interval (CI). The overall results showed that the variant genotypes were associated with a significantly increased risk of all cancer types (OR = 1.38, 95%CI = 1.18–1.61 for GA versus GG, and OR = 1.36, 95%CI = 1.17–1.59 for GA/AA versus GG). In the stratified analyses, there was a significantly increased risk for the studies of breast cancer (OR = 1.64, 95% CI = 1.16–2.33 for AA versus GG, OR = 1.42, 95%CI = 1.18–1.71 for GA versus GG, and OR = 1.44, 95%CI = 1.21–1.72 for GA/AA versus GG) and lung cancer (OR = 2.86, 95% CI = 1.75–4.69 for AA versus GG, OR = 1.62, 95% CI = 1.20–2.18 for GA vs. GG, OR = 1.80, 95% CI = 1.36–2.39 for GA/AA versus GG, and OR = 2.24, 95%CI = 1.41–3.57 for AA versus GA/GG), which remained for the studies of Asian populations and hospital-based control sources. Although some modest bias could not be eliminated, this meta-analysis indicates that the CXCL12 G801A polymorphism is a low-penetrance risk factor for cancer development.     

Association of functional FEN1 genetic variants and haplotypes and breast cancer risk

Aim

As a tumor suppressor, FEN1 plays an essential role in preventing tumorigenesis. Two functional germline variants (-69G > A and 4150G > T) in the FEN1 gene have been associated with DNA damage levels in coke-oven workers and multiple cancer risk in general populations. However, it is still unknown how these genetic variants are involved in breast cancer susceptibility.

Methods

We investigated the association between these polymorphisms and breast cancer risk in two independent case–control sets consisted of a total of 1100 breast cancer cases and 1400 controls. The influence of these variations on FEN1 expression was also examined using breast normal tissues.

Results

It was found that the FEN1-69GG genotypes were significantly correlated to increased risk for developing breast cancer compared with the -69AA genotype in both sets [Jinan set: odds ratios (OR) = 1.41, 95% confidence interval (CI) = 1.20–1.65, P = 1.9×10^− 5; Huaian set: OR = 1.51, 95% CI = 1.22–1.86, P = 1.7×10^− 4]. Similar results were observed for 4150G > T polymorphism. The genotype–phenotype correlation analyses demonstrated that the -69G or 4150G allele carriers had more than 2-fold decreased FEN1 expression in breast tissues compared with -69A or 4150T carriers, suggesting that lower FEN1 expression may lead to higher risk for malignant transformation of breast cells.

Conclusion

Our findings highlight FEN1 as an important gene in human breast carcinogenesis and genetic variants in FEN1 confer susceptibility to breast cancer.     

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.     

Role of CYP1A2*1F polymorphism in cancer risk: Evidence from a meta-analysis of 46 case–control studies

Background

Emerging evidence showed that the common polymorphism (CYP1A2*1F, rs762551 C → A) in the promoter region of the CYP1A2 gene might be associated with susceptibility to cancer in humans. But individually published results were inconclusive. The aim of this meta-analysis is to investigate the association between CYP1A2*1F polymorphism and cancer risk.

Methods

The Pubmed, Embase, Web of Science and Chinese BioMedical databases were searched for all articles published up to September 1st, 2012. Statistical analyses were performed using the STATA 12.0 software.

Results

Forty-six case–control studies were included with a total of 22,993 cancer cases and 28,420 healthy controls. Meta-analysis results showed that the A allele of CYP1A2*1F polymorphism was associated with a decreased cancer risk (odds ratio [OR] = 0.92, 95% confidence interval [CI]: 0.87–0.98, P = 0.013). In the subgroup analysis by cancer types, the A allele of CYP1A2*1F polymorphism may increase the risk of breast cancer (OR = 1.05, 95% CI: 1.01–1.10, P = 0.024), and is also associated with a decreased risk of ovarian cancer (OR = 0.70, 95% CI: 0.54–0.89, P = 0.004). However, similar results were not found in lung, colorectal, bladder, endometrial, pancreatic and gastric cancers. Further subgroup analysis by ethnicity also showed a significant association between the A allele of CYP1A2*1F polymorphism and a decreased cancer risk among Caucasian populations (OR = 0.91, 95% CI: 0.84–0.98, P = 0.014); but no significant associations were observed among Asian populations.

Conclusions

Results from the current meta-analysis indicate that the A allele of CYP1A2*1F polymorphism may be associated with breast and ovarian cancer risk, especially among Caucasian populations.     

Current evidence on the relationship between five polymorphisms in the matrix metalloproteinases (MMP) gene and lung cancer risk: A meta-analysis

Purpose

Matrix metalloproteinase (MMP) 1, MMP2, MMP3 and MMP9 are important members of the MMP family. Recently, many studies have been carried out on the association between polymorphisms of MMP1-1607 1G/2G, MMP2-735 C/T, MMP2-1306 C/T, MMP3-1171 5A/6A and MMP9-1562 C/T and lung cancer risk. However the results of these studies remained inconclusive due to conflicting results from different case–control studies. To clarify these associations, we conducted a meta-analysis.

Methods

We conducted a comprehensive search in Medline, EMBASE, OVID and Chinese Biomedical Literature Database (date from Jan 2000 to Aug 2012). Overall and subgroup analysis by the ethnicity of study population was carried out. Odds ratio (OR) with 95% confidence interval (95%CI) was used to assess the strength of the association.

Results

There were 17 studies involving five polymorphic sites in four MMP genes. For MMP1-1607,increased lung cancer risk was found under dominant model (MMP1-1607 1G/2G: OR = 1.14, 95%CI = 1.03–1.26, P = 0.01), but not in the Caucasian population. For MMP2-1306 C/T, T polymorphism decreased lung cancer risk under dominant and recessive models (dominant, OR = 0.63, 95%CI = 0.46–0.88, P = 0.0006; recessive, OR = 0.61, 95%CI = 0.38–0.99, P = 0.04). For MMP9-1562 C/T, TT genotype decreased this risk under the recessive model (OR = 0.38, 95%CI = 0.19–0.75, P = 0.005), but not in the Asian population. For MMP2-735 C/T and MMP3-1171 5A/6A, there was no association between this polymorphism and lung cancer risk under the dominant and recessive models.

Conclusions

MMP1-1607 1G/2G polymorphism increased lung cancer risk in Asians. It was also found thatMMP2-1306 C/T polymorphism decreased lung cancer risk in Asians, while MMP9-1562 C/T polymorphism decreased lung cancer risk in Caucasians. No significant difference was found in any genotype of MMP2-735 C/T and MMP3-1171 5A/6A. Further studies with larger sample sizes should be carried out.     

Association between IL-4 polymorphism and acute rejection of solid organ allograft: A meta-analysis

Background

Cytokines have been implicated in the acute rejection of solid organ transplantation. Many studies have investigated the association between recipient or donor IL-4 polymorphism and acute rejection, with different studies reporting inconclusive results.

Methods

We searched PUBMED and EMBASE until June 2012 to identify eligible studies investigating the association between IL-4 polymorphism with acute rejection after solid organ transplantation. Statistical analysis was performed using STATA10.0.

Results

A total of 12 studies were included. Pooled ORs suggested 1) no significant association was detected between recipient or donor IL-4 − 590C/T polymorphism and acute rejection of solid allograft; 2) no significant association was detected between recipient IL-4 − 33C/T polymorphism and acute rejection of solid allograft; 3) when stratified by transplantation type, IL-4 − 590C/T polymorphism was associated with acute rejection of liver transplantation (T/T + C/T vs. C/C: OR = 0.36, 95%CI = 0.14–0.90); 4) significantly decreased risk of acute rejection was detected in recipient IL-4 − 590*T-negative/donor T-positive genotype pairs than all other recipient–donor IL-4 − 590T/C pairs (OR = 0.14, 95%CI = 0.03–0.66).

Conclusions

Our meta-analysis suggested that recipient IL-4 − 590C/T polymorphism was associated with acute rejection of liver transplantation, but nor renal or heart transplantation. It was also suggested that combined recipient IL-4 − 590*T-negative/donor T-positive genotype may suffer decreased risk of acute rejection of solid allograft. Further well-designed studies with larger sample size were required to verify our findings, with focus on the association of IL-4 polymorphism with acute rejection in patients with liver transplantation and studies investigating combined recipient–donor genotype.     

Association of glutathione S-transferase M1/T1 polymorphisms with susceptibility to vitiligo

Background

Some studies suggested that Glutathione S-transferases M1/T1(GSTM1/T1) null polymorphisms may be associated with the risk of vitiligo.

Aims

The purpose of this study is to further evaluate the association between GSTM1/T1 null polymorphisms and the susceptibility to vitiligo.

Methods

We carried out a retrieval of studies in the databases. Odds ratios (OR) and 95% confidence intervals (95% CIs) were used to assess the strength of this association. We analyzed the data using Stata 11.0.

Results

Six case–control studies including 1358 cases and 1673 controls were included in this meta-analysis. Our overall results showed the GSTM1 or GSTT1 null polymorphism was associated with vitiligo (GSTM1:OR = 1.59, 95% CI: 1.21–2.08, P = 0.001; GSTT1: OR = 1.30, 95% CI: 1.12–1.51, P = 0.001). In the subgroup analysis, the GSTM1 null polymorphism might be a genetic risk factor to vitiligo in East Asian (OR = 1.71, 95% CI: 1.12–2.63, P = 0.014) but not in the Mediterranean, however individuals with the GSTT1 null polymorphism in the Mediterranean (OR = 1.76, 95% CI: 1.15–2.71, P = 0.010) but not in East Asian have a greater predisposition to vitiligo. In addition there was also a significant trend toward an association with the combination of the GSTM1 null and GSTT1 null in either East Asians or Mediterraneans.

Conclusion

The GSTM1/T1 null polymorphisms may be associated with vitiligo. More studies are needed to confirm this conclusion.     

Single nucleotide polymorphism of CD40 in the 5′-untranslated region is associated with ischemic stroke

Objectives

Ischemic stroke is influenced by both environmental and genetic factors. The CD40/CD40L system is related to proinflammatory and prothrombogenic responses, which are involved in the pathophysiology of ischemic stroke. The aim of this study was to evaluate association between the CD40 -1C/T single nucleotide polymorphism (SNP) and ischemic stroke in a Chinese population.

Methods

We conducted a case–control study including 286 ischemic stroke patients and 336 controls. CD40 -1C/T SNP was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing methods, and evaluated its relevance to ischemic stroke susceptibility.

Results

Significantly increased ischemic stroke risk was found to be associated with the T allele of CD40 -1C/T (OR = 1.273, 95% CI = 1.016–1.594). The frequencies of CT and TT/CT genotypes of CD40 -1C/T in ischemic stroke patients were significantly higher than those of controls, respectively (for CT: OR = 2.350, 95% CI = 1.601–3.449; for TT/CT: OR = 2.148, 95% CI = 1.479–3.119). And, similar results were obtained after adjusting non-matched variables. We found that the frequency of carried T genotypes (TT and TT/CT) was significantly increased in patients with history of stroke compared with patients without (for TT: OR = 6.538, 95%CI = 1.655–25.833; for TT/CT: OR = 3.469, 95%CI = 1.031–11.670), respectively.

Conclusions

The findings suggested that the CD40 -1C/T polymorphism might contribute to the susceptibility to ischemic stroke in the Chinese population, and might be associated with history of previous stroke.     

Role of EGFR SNPs in survival of advanced lung adenocarcinoma patients treated with Gefitinib

Aim

As a novel molecularly targeting agent for non-small-cell lung cancer (NSCLC), Gefitinib can block its tyrosine kinase activity of the epidermal growth factor receptor (EGFR). Genetic variations in EGFR may affect its protein function or expression and lead to diverse outcomes in NSCLC patients after Gefitinib therapy. Therefore, this prospective study examined whether EGFR single nucleotide polymorphisms (SNPs) are associated with different survival time in advanced lung adenocarcinoma patients treated with Gefitinib.

Methods

One hundred and twenty-eight patients with stage IIIB or IV lung adenocarcinoma receiving Gefitinib target therapy between 2008 and 2010 were recruited in this study. Six EGFR haplotype-tagging SNPs were genotyped by the Sequenom MassArray system. Survival by different genotypes was compared using Kaplan–Meier methods. Cox proportional hazards models were applied to estimate the effect of prognostic factors on overall survival (OS) and progression-free survival (PFS).

Results

After the median 16.6 months of follow-up, the unfavorable EGFR rs2293347AA or GA genotype was significantly correlated with shorter OS (AA vs. GG: 2.0 vs. 21.0 months; hazard ratio (HR) = 2.44, 95% confidence interval (CI) = 1.06–5.56; P = 0.036; GA vs. GG: 15.0 vs. 21.0 months; HR = 1.75, 95%CI = 1.08–2.86, P = 0.025) compared with the favorable rs2293347GG genotype. The prognostic significance of EGFR rs4947492 polymorphism on OS also existed (GG carriers vs. AA carriers: median OS = 24.6 vs. 14.9 months, HR = 0.29, 95%CI = 0.10–0.83, P = 0.021). No significant associations were found among other EGFR SNPs and survival.

Conclusion

EGFR rs2293347 and rs4947492 SNPs might be potential predictive markers of OS in advanced lung adenocarcinoma patients treated with Gefitinib.     

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.     

Association of two ERCC4 tagSNPs with susceptibility to atrophic gastritis and gastric cancer in Chinese

Genetic polymorphisms in excision repair cross-complementing group 4 (ERCC4) may contribute to the risk of cancer development. However, there are few reports regarding to susceptibility to gastric cancer (GC) or its precursor, atrophic gastritis (AG). Thereby, we investigated the association between two tag single nucleotide polymorphisms (tagSNPs) rs6498486 and rs254942, which represents the majority of common SNPs of ERCC4 gene, and the risks of GC and AG development in a sex- and age-matched case–control designed study. We found that rs6498486 polymorphism was associated with a reduced AG risk in total population (for AC vs. AA: OR = 0.69, 95%CI = 0.52–0.94, P = 0.016; for AC/CC vs. AA: OR = 0.68, 95%CI = 0.51–0.92, P = 0.010) as well as in the subpopulation of youngers (age < 60 years) (for AC/CC vs. AA: OR = 0.67, 95%CI = 0.45–0.99, P = 0.048). For the rs254942 polymorphism, compared with the common TT genotype, the genotypes of CT and CT/CC were only observed to reduce AG risk in the subgroups of males (for CT vs. TT: OR = 0.64, 95%CI = 0.45–0.90, P = 0.012; for CT/CC vs. TT: OR = 0.66, 95%CI = 0.47–0.92, P = 0.016) and youngers (for CT vs. TT: OR = 0.72, 95%CI = 0.53–0.97, P = 0.035; for CT/CC vs. TT: OR = 0.74, 95%CI = 0.55–0.99, P = 0.045). However, no significant statistical association of the two SNPs with GC susceptibility was observed in the total population. Only rs6498486 AC and AC/CC genotypes were found to be marginally associated with a reduced GC risk in the subgroup of males (for AC vs. AA: OR = 0.69, 95%CI = 0.49–0.99, P = 0.043; for AC/CC vs. AA: OR = 0.71, 95%CI = 0.50–0.99, P = 0.046). Our findings suggested that the ERCC4 rs6498486 and rs254942 may be associated with AG risk. Further validation of our results in larger populations and additional studies evaluating their molecular function are required.     

Association between -251A>T polymorphism in the interleukin-8 gene and oral cancer risk: A meta-analysis

Background

Emerging evidence showed that the most common functional polymorphism (-251A>T, rs4073) in the promoter region of the interleukin-8 (IL-8) gene is involved in the regulation of the activities of interleukin-8, thus increasing an individual's susceptibility to oral cancer; but individually published results are inconclusive. The aim of this meta-analysis was to investigate the associations between IL-8 -251A>T polymorphism and oral cancer risk.

Methods

The PubMed, Embase, Web of Science and CBM databases were searched for all articles published up to October 1st, 2012 that addressed IL-8 -251A>T polymorphism and oral cancer risk. Statistical analyses were performed using STATA 12.0 software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

Results

Six case–control studies were included with a total of 1324 oral cancer cases and 1879 healthy controls. When all available studies were pooled into the meta-analysis, the results showed that the AA and AT genotypes of IL-8 -251A>T polymorphism were associated with increased risk of oral cancer (OR = 1.23, 95% CI: 1.03–1.46, P = 0.025; OR = 1.25, 95% CI: 1.07–1.47, P = 0.006; respectively). In the subgroup analysis by ethnicity, significant associations were observed between the AA and AT genotypes of IL-8 -251A>T polymorphism and increased risk of oral cancer among Caucasian populations (OR = 1.40, 95% CI: 1.14–1.72, P = 0.001; OR = 1.29, 95% CI: 1.06–1.57, P = 0.011; respectively). However, no statistically significant associations were found between IL-8 -251A>T polymorphism and oral cancer risk among Asian populations.

Conclusions

Results from the current meta-analysis indicate that the AA and AT genotypes of IL-8 -251A>T polymorphism might increase the risk of oral cancer, especially among Caucasian populations.     

Association of IL-6 − 174G > C and − 572C > G polymorphisms with risk of young ischemic stroke patients

Aim

To investigate the association between interleukin-6 (IL-6) − 174G > C and − 572C > G polymorphisms and risk for ischemic stroke (IS) in young patients.

Methods

We genotyped IL-6  − 174G > C and − 572C > G in a case–control study of 430 young IS patients and 461 control subjects. An unconditional multiple logistical regression model was used to calculate the effects of IL-6 − 174G > C and − 572C > G polymorphisms on IS risk.

Results

Higher body mass index, diabetes, hypertension, obesity, and smoking were associated with risk of ischemic stroke. Multivariate regression analyses showed that subjects carrying the − 174CC genotype (OR = 1.69, 95% CI = 1.16–2.57) and C allele (OR = 1.37, 95% CI = 1.09–1.67) had a small but significant increased risk of IS. Similarly, those carrying the − 572GG genotype (OR = 2.12, 95% CI = 1.18–3.82) and G allele (OR = 1.43, 95% CI = 1.14–1.83) had a moderate increased risk of IS. We found the − 174G > C and − 572C > G polymorphisms interact with hypertension and obesity.

Conclusion

Our results suggest that polymorphisms in IL-6 − 174G > C and − 572C > G are associated with IS risk in young patients, and that these polymorphisms interact with hypertension, obesity and etiologic subtypes. These findings could be helpful in identifying individuals at increased risk for developing IS.     

The effect of chemokine receptor gene polymorphisms (CCR2V64I,CCR5-59029G>A and CCR5Δ32) on renal allograft survival in Pakistani transplant patients

Background

Gene polymorphisms of the chemokine receptors CCR2 and CCR5 (CCR2V64I, CCR5-59029G>A and CCR5Δ32) have been shown to be associated with renal allograft rejection. The aim of this study was to investigate the association of these polymorphisms with allograft rejection among Pakistani transplant patients.

Method

A total of 606 renal transplant patients and an equal number of their donors were included in this study. DNA samples were used to amplify polymorphic regions of CCR2V64I, CCR5-59029G>A and CCR5Δ32 by polymerase chain reaction using sequence specific primers. The amplified products of CCRV64I and CCR5-59029G>A were digested with restriction enzymes (BsaB1 and Bsp12861) respectively. The CCR5Δ32 genotypes were determined by sizing the PCR amplicons. The association of these polymorphisms with the biopsy proven rejection and other clinical parameters was evaluated using the statistical software SPSS v.17.

Results

In this study, the G/G genotype of CCR2V64I was associated with a high frequency of allograft rejection (p = 0.009; OR = 2.14; 95% CI = 1.2–3.7). Rejection episode(s) in the GA + AA genotypes were found to be significantly lower as compared to the GG genotype (p = 0.009; OR = 0.4; 95% CI = 0.2–0.8). The Kaplan–Meier curve also indicated a reduced overall allograft survival for patients with the G/G genotype of CCR2V64I (59.2 ± 1.4 weeks, log p = 0.008). There was a significant association with rejection by female donors possessing the CCR2 GG genotype (p = 0.02; OR = 2.6; CI = 1.1–6.3) and male donors with the CCR5-59029 GG genotype (p = 0.004; OR = 1.7; CI = 1.03–3.01).

Conclusion

This study shows an association of the CCR2V64I (G/G) genotype with renal allograft rejection. However, no such association was found for the CCR5 gene polymorphisms. Therapeutic interventions such as blocking the CCR2 receptor (especially G polymorphism) may yield better survival of renal allograft in this patient group. Further, chemokine receptors may be added to the spectrum of the immunogenetic factors that are known to be associated with renal allograft rejection.     

Impact of MMP-3 and TIMP-3 gene polymorphisms on prostate cancer susceptibility in North Indian cohort

Purpose

Matrix metalloproteinases (MMPs) have been implicated in progression and metastases of different tumors. The balance between the MMPs and their natural inhibitors (tissue inhibitors of matrix metalloproteinases; TIMP) seem to be an important factor related to its role. The purpose of this study was to evaluate polymorphisms in the MMP-3 and TIMP-3 genes for their associations with prostate cancer (PCa) risk in North Indians.

Materials and methods

Genotypes were determined by PCR-RFLP (Polymerase Chain Reaction Restriction Fragment Length Polymorphism) method in 150 PCa patients and 200 age matched controls of similar ethnicity.

Results

We found significant association in the MMP-3(1171)5A/6A and TIMP-3 (1298) C/T polymorphism with PCa risk. Variant genotype (5A/5A) of MMP-3(1171)5A/6A polymorphism had a high PCa risk (p = 0.037, OR = 3.52, 95%CI = 1.08–11.5). Individuals with TIMP-3 (1298) CT genotype as well as T allele showed reduced risk of PCa (p < 0.001; OR = 0.31; 95%CI = 0.18–0.52, and p = 0.001; OR = 0.49; 95%CI = 0.32–0.75). This effect was even more evident in case of T allele carrier (CT + TT) (p < 0.001; OR = 0.36; 95%CI = 0.22–0.59). Overall no significant association was observed statistically in MMP-3 and TIMP-3 with any of the grading stages and smoking habits in PCa. Haplotype analysis of MMP-3 showed that A-5A-A was associated with three folds (OR = 3.06; 95%CI = 1.71–5.47; p < 0.001) increased risk in PCa patients.

Conclusion

This is the first reported association between polymorphisms in the MMP-3 and TIMP-3 gene and PCa risk and supports the hypothesis that the protease/antiprotease balance has an important role. Due to the small sample size further investigations need to be done to prove a statistical significant correlation between the MMP/TIMP expression and clinicopathological parameters.     

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.