Vitamin D Receptor Cdx-2 Polymorphism and Premenopausal Breast Cancer Risk in Southern Pakistani Patients

Background

Vitamin D3 is a secoster oid that exerts its effect by binding to its nuclear receptor called vitamin D receptor (VDR), inducing apoptosis and thereby inhibiting cell proliferation in cancer cells. The VDR receptor, located in the nucleus, is known to regulate the functions of over 200 genes. Various allelic forms of hVDR have been discovered that increase susceptibility to various cancers. The VDR-Cdx2 polymorphism, located in the promoter region of exon 1e in the VDR gene, influences the functional activity of the receptor, since the hVDR lacks consensus TATA and CAAT boxes. The current investigation examines the association between VDR-Cdx2 polymorphism and breast cancer in premenopausal females from Southern Pakistan.

Methods

We conducted a case control study on 264 subjects (103 cases and 161 controls) who were recruited from a tertiary hospital located in Karachi, Pakistan. Genomic DNA was extracted from peripheral blood using a commercial kit method, and the VDR-Cdx2 polymorphism was genotyped using tetraprimer amplification refractory mutation system polymerase chain reaction (T-ARMS-PCR) method. Pearson chi square test was used to assess the association between VDR-Cdx2 genotype and breast cancer while genotype distribution in controls was evaluated by Hardy-Weinberg equilibrium (HWE). Breast cancer risk was calculated using odds ratios and 95% confidence intervals.

Results

The genotype distribution in the control group was in HWE (p > 0.05) for the VDR-Cdx2 polymorphism. A non-significant association was observed between VDR cdx2 polymorphism and breast cancer, however the GG genotype was at risk (OR = 1.832, 95% CI = 0.695–4.828) of developing breast cancer.

Conclusion

The GG genotype of Cdx2-VDR gene polymorphism may increase the risk of developing breast cancer in young female patients in South Pakistan. Further investigations examining additional single nucleotide polymorphisms (SNPs) in VDR are required to assess their relationships with breast cancer.     

Association of Vitamin D Receptor BsmI Gene Polymorphism with Risk of Tuberculosis: A Meta-Analysis of 15 Studies

Background

Genetic variations in vitamin D receptor (VDR) may contribute to tuberculosis (TB) risk. Many studies have investigated the association between VDR BsmI gene polymorphism and TB risk, but yielded inconclusive results.

Methodology/Principal Findings

We performed a comprehensive meta-analysis of 15 publications with a total of 2309 cases and 3568 controls. We assessed the strength of the association between VDR BsmI gene polymorphism and TB risk and performed sub-group analyses by ethnicity, sample size and Hardy–Weinberg equilibrium (HWE). We found a statistically significant correlation between VDR BsmI gene polymorphism and decreased TB risk in four comparison models: allele model (b vs. B: OR = 0.78, 95% CI = 0.67, 0.89; P_{heterogeneity} = 0.004), homozygote model (bb vs. BB: OR = 0.61, 95% CI = 0.43, 0.87; P_{heterogeneity} = 0.001), recessive model (bb vs. Bb+BB: OR = 0.70, 95% CI = 0.56, 0.88; P_{heterogeneity} = 0.005) and dominant model (bb+Bb vs. BB: OR = 0.77, 95% CI = 0.61, 0.97; P_{heterogeneity} = 0.010), especially in studies based on Asian population. Sub-group analyses also revealed that there was a statistically decreased TB risk in “small” studies (<500 participants) and studies with P_HWE>0.5. Meta-regression and stratification analysis both showed that the ethnicity and sample size contributed to heterogeneity.

Conclusions

This meta-analysis suggests that VDR BsmI gene polymorphism is associated with a significant decreased TB risk, especially in Asian population.     

Association between Vitamin D Receptor Gene Polymorphisms and Breast Cancer Risk: A Meta-Analysis of 39 Studies

Background

The associations between vitamin D receptor (VDR) gene polymorphisms and breast cancer risk were comprehensively investigated to clarify issues that remain controversial.

Methodology/Principal Findings

An electronic search was conducted of several databases, including PubMed, the Cochrane library, Web of Science, EMBASE, CBM and CNKI, for papers that describe the association between Fok1, poly-A repeat, Bsm1, Taq1 or Apa1 polymorphisms of the VDR gene and breast cancer risk. Summary odds ratios and 95% confidence intervals (CI) were estimated based on a fixed-effect model (FEM) or random-effect model (REM), depending on the absence or presence of significant heterogeneity. A total of 39 studies met the inclusion criteria. A meta-analysis of high-quality studies showed that the Fok1 polymorphism of the VDR gene was associated with an increased risk of breast cancer (ff vs. Ff+FF, OR: 1.09, 95%CI: 1.02 to 1.16, p = 0.007). No significant associations were observed between the other polymorphisms and breast cancer risk. No positive results were detected by pooling the results of all relevant studies.

Conclusion

A meta-analysis of high-quality studies demonstrated that the Fok1 polymorphism of the VDR gene was closely associated with breast cancer risk.     

The Role of the rs1544410 Polymorphism of Vitamin D Receptor Gene in Breast Cancer Susceptibility

This study was devised to investigate the genetic effect modification of the BsmI polymorphism associated with the susceptibility to breast cancer. Case–control studies of the BsmI polymorphism and breast cancer were searched. A total of 17 eligible publications were included in our final analysis. Pooled ORs and 95 % CIs were obtained by means of fixed effects model. The general and stratified analyses according to ethnicity showed that the association between the BsmI polymorphism and the risk of breast cancer was not statistically significant. However, the subgroup of the hospital-based studies was found to confer protection against the disease (OR_BBvs.bb = 0.83, 95 % CI = 0.71–0.97, P _h = 0.571; OR_BBvs.Bb+bb = 0.86, 95 % CI = 0.74–1.00, P _h = 0.903; OR_{allele B vs. allele b} = 0.92, 95 % CI = 0.86–0.99, P _h = 0.337). Our results suggested that the presence of the BsmI polymorphism may contribute to the susceptibility of breast cancer. It is necessary that future large-scale studies should be conducted to further confirm the association between the BsmI polymorphism and breast cancer risk.     

FokI Polymorphism in the Vitamin D Receptor Gene (VDR) and Its Association with Lumbar Spine Pathologies in the Italian Population: A Case-Control Study

Alterations in vitamin D homeostasis, mainly involving its nuclear receptor (VDR), could have a role in the pathophysiology of the spine. The association between VDR polymorphisms and spine disorders has been analyzed in different ethnic groups, focusing on the functional FokI polymorphism. However, so far, inconsistent findings were reported. The aims of this study were to evaluate, in the Italian white population, the VDR FokI polymorphism frequencies distribution in subjects with clearly defined lumbar spinal pathologies compared to asymptomatic controls and to analyze the interplay of genetic and conventional risk factors. Using a case-control design, 267 patients with spinal disorders and 220 asymptomatic controls were enrolled, evaluating their exposition to putative risk factors. Patients’ clinical assessment was performed by Magnetic Resonance Imaging. FokI polymorphism (rs2228570) was detected by PCR-RFLP. Genotypes were designated by a lowercase letter (f allele, T nucleotide) for the presence of the restriction site and by a capital letter (F allele, C nucleotide) for its absence. Family history, higher age and BMI, exposure to vibration, physical job demand, smoking habit and lower practice of leisure physical activity were associated with spinal disorders. The FF genotype and F allele represented approximately 2-fold risk factors to develop discopathies and/or osteochondrosis concomitant with disc herniation, while f allele was protective. In conclusion, the link we observed between VDR FokI variants and specific lumbar spine pathologies suggests that spinal tissue degeneration is influenced by the genetic background. Future studies should evaluate the signaling pathways involving alterations in VDR and influencing the development and/or progression of spine disorders.     

The Association of Vitamin D Receptor Polymorphisms with Multiple Sclerosis in a Case-Control Study from Kuwait

Vitamin D deficiency is associated with several diseases including multiple sclerosis (MS). Several factors influence vitamin D levels and its optimal multi-function maintenance. Our objective was to assess quantifiable variables influencing vitamin D level and metabolism in MS patients from Kuwait. In a case-control study involving 50 MS patients, and 50 healthy control individuals for which plasma vitamin D levels, supplement use, vitamin D receptor (VDR) variants, and skin pigmentation indices were ascertained; we found overall vitamin D levels to be deficient in both groups, and supplement use to be common practice. VDR variants TaqI and BsmI associated with MS risk, and ApaI associated with low disease progression. VDR variant FokI associated with higher vitamin D levels in both groups. We conclude that several quantifiable variables related to vitamin D associate with MS suggesting a possible clinical immuno-modulatory application of vitamin D for MS patients in Kuwait.     

MICB基因多态性与乳腺癌的易感关联性研究

目的:研究海南汉族人群MICB等位基因的多态性与乳腺癌易感性之间的关联性。方法:采用PCRSSP(PCR sequence-specific primers)和PCR-SBT(PCR sequence-based typing)方法对样本MICB等位基因的多态性进行检测。结果:乳腺癌患者中检出14种MICB等位基因;和对照组相比较,MICB*002和MICB*014等位基因在乳腺癌患者组分布频率较少,MICB*002和MICB*014等位基因可能对乳腺癌不易感(MICB*002:OR=0.31,95%CI:0.19-0.51,Pc0.05;MICB*014:OR=0.32,95%CI:0.17-0.60,Pc0.05)。MICB*016和MICB*003等位基因在乳腺癌患者组分布较多;MICB*016和MICB*003等位基因可能对乳腺癌易感(MICB*016:OR=10.68,95%CI:2.52-45.28,Pc0.05;MICB*003:OR=3.57,95%CI:1.34-9.49,Pc0.05);MICB*002/002和MICB*014/014基因型可能对乳腺癌不易感(MICB*002/002:OR=0.12,95%CI:0.04-0.36,Pc0.05;MICB*014/014:OR=0.30,95%CI:0.10-0.89,Pc0.05)。结论:MICB等位基因的多态性与乳腺癌的易感性之间存在关联性。     

A Common Polymorphism near the ESR1 Gene Is Associated with Risk of Breast Cancer: Evidence from a Case-Control Study and a Meta-Analysis

Background

Genome-wide association studies have reported that a polymorphism near the estrogen receptor gene (ESR1) (rs2046210) is associated with a risk of breast cancer, with the A allele conferring an increased risk. However, considering the controversial results from more recent replicated studies, we conducted a case-control study in an independent Chinese Han population and a meta-analysis to clarify the association of this polymorphism with breast cancer risk.

Method and Findings

A hospital-based case-control study including 461 cases and 537 controls from a Chinese Han population was conducted initially, and this study showed that the rs2046210 A allele was significantly associated with breast cancer risk, with an OR of 1.32 (95% CI  = 1.10–1.59). Subsequently, a meta-analysis integrating the current study and previous publications with a total of 53,379 cases and 55,493 controls was performed to further confirm our findings. Similarly, a significant association between this polymorphism and breast cancer risk was also observed in the overall population especially among Asians, with ORs for per A allele of 1.14 (95% CI  = 1.10–1.18) in the overall population and 1.27 (95% CI  = 1.23–1.31) in the Asian population.

Conclusion

Our results provide strong evidence to support that the common polymorphism near the ESR1 gene, rs2046210, is associated with an increased risk of breast cancer in Asian and European populations but not in Africans, although the biological mechanisms need to be further investigated.     

Genetic Polymorphisms in Vitamin D Metabolism and Signaling Genes and Risk of Breast Cancer: A Nested Case-Control Study

Genetic polymorphisms in vitamin D metabolism and signaling genes have been inconsistently associated with risk of breast cancer, though few studies have examined SNPs in vitamin D-related genes other than the vitamin D receptor (VDR) gene and particularly have not examined the association with the retinoid X receptor alpha (RXRA) gene which may be a key vitamin D pathway gene. We conducted a nested case-control study of 734 cases and 1435 individually matched controls from a population-based prospective cohort study, the Northern Sweden Mammary Screening Cohort. Tag and functional SNPs were genotyped for the VDR, cytochrome p450 24A1 (CYP24A1), and RXRA genes. We also genotyped specific SNPs in four other genes related to vitamin D metabolism and signaling (GC/VDBP, CYP2R1, DHCR7, and CYP27B1). SNPs in the CYP2R1, DHCR7, and VDBP gene regions that were associated with circulating 25(OH)D concentration in GWAS were also associated with plasma 25(OH)D in our study (p-trend <0.005). After taking into account the false discovery rate, these SNPs were not significantly associated with breast cancer risk, nor were any of the other SNPs or haplotypes in VDR, RXRA, and CYP24A1. We observed no statistically significant associations between polymorphisms or haplotypes in key vitamin D-related genes and risk of breast cancer. These results, combined with the observation in this cohort and most other prospective studies of no association of circulating 25(OH)D with breast cancer risk, do not support an association between vitamin D and breast cancer risk.     

Association between 1p11-rs11249433 Polymorphism and Breast Cancer Susceptibility: Evidence from 15 Case-Control Studies

Genome-wide association studies have identified SNP rs11249433 at chromosome 1p11 as a new breast cancer (BC) susceptibility locus in populations of European descent. Since then, the relationship between 1p11- rs11249433 and breast cancer has been reported in various ethnic groups; however, these studies have yielded inconsistent results. To investigate this inconsistency, we performed a meta-analysis of 15 studies involving a total of 90,154 cases and 137,238 controls for 1p11-rs11249433 polymorphism to evaluate its effect on genetic susceptibility for breast cancer. An overall random effects odds ratio of 1.09 (95% CI: 1.06-1.12, P<10^-5) was found for rs11249433-G variant. Significant results were also observed for heterozygous (OR=1.09, 95% CI: 1.05-1.12, P<10^-5) and homozygote (OR=1.14, 95% CI: 1.08-1.21, P<10^-5). There was strong evidence of heterogeneity, which largely disappeared after stratification by ethnicity. After stratified by ethnicity, significant associations were found among Caucasians. However, no significant associations were detected among East Asian and African populations. In addition, we found that rs11249433 polymorphism on 1p11 confer risk, exclusively for ER-positive tumors with per-allele OR of 1.13 (95% CI: 1.08-1.18; P <10^-5) compared to ER-negative tumors of 1.01 (95% CI: 0.98-1.04; P=0.49). Similar results were also observed when stratified by PR status. Our findings demonstrated that rs11249433-G allele is a risk-conferring factor for the development of breast cancer, especially in Caucasians.     

Vitamin D Receptor Gene FOKI Polymorphism Contributes to Increasing the Risk of HIV-Negative Tuberculosis: Evidence from a Meta-Analysis

BackgroundVitamin D receptor (VDR) gene FokI polymorphism have been studied in relation to tuberculosis (TB) in many populations and provided inconsistent results. In this study, we carried out a meta-analysis to derive a more reliable assessment on FokI polymorphism and the risk of HIV-negative TB.MethodsThe Embase, PubMed, and Cochrane Library databases were used to undertake a comprehensive systematic literature review of all current published VDR gene FOKI association studies aimed at the risk of TB up to June 30, 2015. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were used to measure the strength of the models.ResultsA total of 14 studies (1,668 cases and 1,893 controls) were retrieved in the meta-analysis. The pooled OR was 1.60 (95% = 1.28–1.97, P<0.001; I ² = 29.5%, and P = 0.141 for heterogeneity) in the best genetic model (recessive model: ff vs. fF+FF). In the subgroup analysis by ethnicities, a significantly increased risk was found in the Asian group (OR = 1.82, 95% CI = 1.42–2.33, P<0.001; I ² = 31.0%, and P = 0.150 for heterogeneity) in the recessive model. Similarly, significant associations were also found in the polymerase chain reaction-restriction fragment length polymorphism group, high-quality studies, and the population based or hospital based groups. Moderate heterogeneity was found in this study.ConclusionOur results suggested that VDR FokI polymorphism contributes to increasing the risk of TB in HIV-negative individuals, especially in the Asian region. Further studies on this topic in other races are expected to be conducted in future.     

Vitamin D Receptor Gene Polymorphisms on the Risk of Tuberculosis,a Meta-Analysis of 29 Case-Control Studies

The relationship of four potentially functional polymorphisms of the vitamin D receptor (VDR) gene, ApaI, BsmI, FokI and TaqI , with tuberculosis susceptibility were considered. The aim of this meta-analysis was to explore the association between the four polymorphisms and tuberculosis risk in different ethnic backgrounds. Eligible case-control studies that were catalogued before April 1^st 2013 were enrolled, and the heterogeneity between the studies was evaluated using a χ² based Q-test. Fixed and random effect models were built to evaluate the association of the four polymorphisms with the risk of tuberculosis, and the association between the four polymorphisms and tuberculosis was expressed as the odds ratio (OR) and 95% confidence interval (CI). Finally, twenty nine qualified studies were enrolled for this meta-analysis that included 6179 tuberculosis cases and 6585 healthy controls. The variant homozygote genotype of the FokI polymorphism was associated with a significantly increased risk of tuberculosis when compared to the heterozygote and wild type homozygote genotypes in the Chinese population (ff vs. Ff+FF: OR_recessive=1.97, 95%CI: 1.32-2.93, P _bonferroni=0.0032; heterogeneity test: χ²=0.24, P=0.62). For European subjects, the homozygote and heterozygote genotypes of the BsmI polymorphism were associated with a significantly decreased risk of tuberculosis when compared to the wild type homozygote (bb+Bb vs. BB: OR_dominant=0.41, 95%CI, 0.22-0.76, P _bonferroni=0.02; heterogeneity test: χ²=2.59, P=0.11). Based on the above results, we conclude that variants of the VDR gene that are homozygous for the FokI polymorphism might be more susceptible to tuberculosis in Chinese. Furthermore, larger sample studies are warranted to confirm the protective effects of BsmI variants on tuberculosis in the Europeans.     

Genetic Variants in Vitamin D Pathway Genes and Risk of Pancreas Cancer; Results from a Population-Based Case-Control Study in Ontario,Canada

Recent studies of 25-hydroxyvitamin D (25(OH)D) levels and pancreas cancer have suggested a potential role of the vitamin D pathway in the etiology of this fatal disease. Variants in vitamin-D related genes are known to affect 25(OH)D levels and function and it is unknown if these variants may influence pancreatic cancer risk. The association between 87 single nucleotide polymorphisms (SNPs) in 11 genes was evaluated within the Ontario Pancreas Cancer Study, a population-based case-control study. Pancreatic cancer cases with pathology confirmed adenocarcinoma were identified from the Ontario Cancer Registry (n = 628) and controls were identified through random digit dialing (n = 1193). Age and sex adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated by multivariate logistic regression. SNPs in the CYP24A1, CYP2R1, calcium sensing receptor (CASR), vitamin D binding protein (GC), retinoid X receptor-alpha (RXRA) and megalin (LRP2) genes were significantly associated with pancreas cancer risk. For example, pancreas cancer risk was inversely associated with CYP2R1 rs10741657 (AA versus GG, OR = 0.70; 95%CI: 0.51–0.95) and positively with CYP24A1 rs6127119 (TT versus CC. OR = 1.94; 95%CI: 1.28–2.94). None of the associations were statistically significant after adjustment for multiple comparisons. Vitamin D pathway gene variants may be associated with pancreas cancer risk and future studies are needed to understand the possible role of vitamin D in tumorigenesis and may have implications for cancer-prevention strategies.     

Association between Alcohol Consumption and Pancreatic Cancer Risk: A Case-Control Study

Purpose

Evidence is inconsistent regarding alcohol and pancreatic cancer risk, although heavy drinking may increase risk.

Methods

A population-based case-control study was conducted using 345 pancreas cancer cases diagnosed 2011–2012 and 1,285 frequency-matched controls from Ontario, Canada. Logistic regression was used to evaluate alcohol consumption and pancreatic cancer risk; data was also stratified by sex and smoking status to assess interaction.

Results

Alcohol consumption was not associated with pancreatic cancer risk (age-adjusted odds ratio=0.78, 95% CI: 0.58, 1.05 for 1 - 3 drinks/week; age-adjusted odds ratio=0.86, 95% CI: 0.63, 1.17 for 4 - 20 drinks/week), however there was a non-significant increased risk for heavy drinkers consuming ≥21 drinks/week (age-adjusted odds ratio=1.35, 95% CI: 0.81, 2.27). Cigarette smoking modified the alcohol-cancer relationship; among current smokers, heavy alcohol consumption was associated with a significantly increased pancreatic cancer risk (age-adjusted odds ratio=4.04, 95% CI: 1.58, 10.37), whereas this significant association with heavy drinking was not observed among non-smokers (age-adjusted odds ratio=2.01, 95% CI: 0.50, 8.18). Furthermore, light – moderate alcohol intake was associated with increased pancreas cancer risk among current smokers.

Conclusions

While alcohol was not significantly associated with pancreatic cancer risk, smoking status modified this relationship such that among current smokers, alcohol intake was associated with a greater than two-fold increased risk of pancreatic cancer. The results should be interpreted with caution due to small sample sizes within subgroups and correction for multiple comparisons should be considered. These findings should be replicated in larger studies where more precise estimates of risk can be obtained.     

Association between MCP-1 -2518A/G Polymorphism and Cancer Risk: Evidence from 19 Case-Control Studies

Background

Single nucleotide polymorphisms (SNPs) may affect the development of diseases. The -2518A/G polymorphism in the regulatory region of the monocyte chemo-attractant protein-1 (MCP-1) gene has been reported to be associated with cancer risk. However, the results of previous studies were inconsistent. Therefore, we performed a meta-analysis to obtain a more precise estimation of the relationship between the -2518A/G polymorphism and cancer risk.

Methodology/Principal Findings

We performed a meta-analysis, including 4,162 cases and 5,173 controls, to evaluate the strength of the association between the −2518A/G polymorphism and cancer risk. Odds ratio (OR) and 95% confidence intervals (95% CIs) were used to assess the strength of association. Overall, the results indicated that the −2518A/G polymorphism was not statistically associated with cancer risk. However, sub-group analysis revealed that individuals with GG genotypes showed an increased risk of cancer in digestive system compared with carriers of the A allele (GG vs. AA: OR = 1.43, 95%CI = 1.05–1.96, P_{heterogeneity} = 0.08; GG vs. AG/AA: OR = 1.29, 95%CI = 1.02–1.64, P_{heterogeneity} = 0.14). In addition, the increased risk of GG genotype was also observed in Caucasians (GG vs. AG/AA: OR = 1.81, 95%CI = 1.10–2.96, P_{heterogeneity} = 0.02).

Conclusion

This meta-analysis suggests that the MCP-1 −2518A/G polymorphism may have some relation to digestive system cancer susceptibility or cancer development in Caucasian. Large-scale and well-designed case-control studies are needed to validate the findings.     

Lack of Association between Insulin Receptor Substrate2 rs1805097 Polymorphism and the Risk of Colorectal and Breast Cancer: A Meta-Analysis

Background

Insulin receptor substrate-2 (IRS-2), a signaling adaptor protein, was involved in two cancer-related pathways (the phosphatidylinositol 3′-kinase (PI3K) and the extracellular signal-regulated kinase (ERK) pathways). Several studies have evaluated the association between IRS2 rs1805097 (G>A) polymorphisms and the risk of colorectal and breast cancer. However, the results were inconsistent.

Methodology/Principal Findings

A meta-analysis of seven published case-control studies (4 studies with 4798 cases and 5478 controls for colorectal cancer and 3 studies with 2108 cases and 2507 controls for breast cancer) were conducted to assess the strength of association using crude odd ratios (ORs) with 95% confidence intervals (CIs). For colorectal cancer, no obvious associations were found for all genetic models (homozygote comparison OR = 0.96, 95%CI 0.85–1.08, P_{heterogeneity} = 0.97; heterozygote comparison: OR = 0.91, 95%CI 0.73–1.13, P_{heterogeneity}<0.01; dominant model: OR = 0.92, 95%CI 0.80–1.06, P_{heterogeneity} = 0.05; recessive model: OR = 1.02, 95%CI 0.91–1.14, P_{heterogeneity} = 0.60). In the subgroup analysis by ethnicity, control source and consistency of frequency with Hardy-Weinberg equilibrium (HWE), still no significant associations were observed. For breast cancer, also no obvious associations were found for all genetic models (homozygote comparison: OR = 0.95, 95%CI 0.71–1.26, P_{heterogeneity} = 0.10; heterozygote comparison: OR = 1.00, 95%CI 0.89–1.14, P_{heterogeneity} = 0.71; dominant model: OR = 0.98, 95%CI 0.87–1.10, P_{heterogeneity} = 0.55; recessive model: OR = 0.95, 95%CI 0.72–1.25, P_{heterogeneity} = 0.07). We performed subgroup analyses by sample size and did not find an association.

Conclusions

This meta-analysis indicated that IRS2 rs1805097polymorphism was not associated with colorectal and breast cancer risk.     

Association between Gene Polymorphism of Manganese Superoxide Dismutase and Prostate Cancer Risk

Manganese superoxide dismutase (MnSOD) is the most effective antioxidant enzyme in mitochondria and protects cells from reactive oxygen species‐induced oxidative damage. The aim of this study was to investigate the association between MnSOD Ala‐9Val gene polymorphism and prostate cancer (PCa) risk in Turkish men with prostate cancer. 33 patients with PCa and 81 control individuals were included in the study. We observed an association between MnSOD Ala/Ala frequency and a higher PCa risk. In addition, we found that the increased risk of early‐onset PCa (under age of 65) in the men homozygous for Ala allele was higher than the men homozygous for Val allele. However, we determined that MnSOD Ala‐9Val genotype was not associated with the aggressiveness of the disease. The results of our study suggest that MnSOD Ala/Ala genotype may influence on early‐onset of PCa patients, but no effect on subsequent development of the disease in Turkish men. However, our study has a limitation that is small numbers of individuals for cases and controls. Therefore, the presented study limited our statistical power to fully investigate the gene polymorphism on cancer risk. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:213‐218, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21472     

Vitamin D Receptor Gene Polymorphisms and Prognosis of Breast Cancer among African-American and Hispanic Women

Background

Vitamin D plays a role in cancer development and acts through the vitamin D receptor (VDR). Although African-Americans have the lowest levels of serum vitamin D, there is a dearth of information on VDR gene polymorphisms and breast cancer among African-Americans and Hispanics. This study examines whether VDR gene polymorphisms are associated with breast cancer in these cohorts.

Methods

Blood was collected from 232 breast cancer patients (Cases) and 349 non-cancer subjects (Controls). Genotyping for four polymorphic variants of VDR (FokI, BsmI, TaqI and ApaI) was performed using the PCR-RFLP method.

Results

An increased association of the VDR-Fok1 f allele with breast cancer was observed in African-Americans (OR = 1.9, p = 0.07). Furthermore, the FbTA, FbtA and fbtA haplotypes were associated with breast cancer among African-Americans (p<0.05). Latinas were more likely to have the VDR-ApaI alleles (Aa or aa) (p = 0.008). The VDR-ApaI aa genotype was significantly associated with poorly-differentiated breast tumors (p = 0.04) in combined Cases. Kaplan-Meier survival analysis showed decreased 5-year disease-free-survival (DFS) in breast cancer patients who had the VDR-Fok1 FF genotype (p<0.05). The Cox regression with multivariate analysis revealed the independent predictor value of the VDR-FokI polymorphism for DFS. The other three variants of VDR (BsmI, TaqI and ApaI) were not associated with disease outcome.

Conclusions

VDR haplotypes are associated with breast cancer in African-Americans, but not in Hispanic/Latinas. The VDR-FokI FF genotype is linked with poor prognosis in African-American women with breast cancer.