• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.479-483
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• 2016

Breast cancer is the first or second leading cancer among females across the globe. A large number of studies have been conducted to assess any relationship between vitamin D receptor (VDR) gene polymorphisms and breast cancer development. Epidemiological studies have indicated that ethnic traits exhibited by a group of people with a common ancestry and culture, alter the link between VDR gene and breast cancer. It has been hypothesized that VDR polymorphisms have the capacity to impact both on incidence of breast cancer occurrence and to predict its outcome. A survey was here conducted to assess and compare the impact of vitamin D receptor gene polymorphisms Fok1, Bsm1, Taq1, Apa1 and poly (A) on development of breast cancer. Information was obtained from electronic databases including PubMed and Google Scholar for articles published during the period from 1996 to 2015. This search was achieved by using the terms "genetics", "breast cancer", "VDR gene", "polymorphisms". However, due to inconsistent results, no conclusive statements could be presented about the significance of the VDR genotype as far as the development of breast carcinoma is concerned.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.10009-10013
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• 2014

Background: Vitamin D receptor (VDR) gene has been a subject of extensive pharmacogenetic research recently. Association studies between different types of cancers including prostate cancer (PCa) and VDR gene polymorphism have also been conducted. The objective of this study was to find possible associations between PCa and VDR gene polymorphisms in the Pakistani population. Materials and Methods: A total of 162 subjects, including prostate cancer patients and controls, were genotyped for Apa I, Taq I and Fok I polymorphisms in the VDR gene using allele specific PCR, PCR-RFLP and direct DNA sequencing. Allelic frequencies were tested for Hardy-Weinberg equilibrium and associations between the genetic markers and PCa were calculated using logistic regression. Results: Apa I CC genotype was found to have strongest association with PCa risk, and "A" genotype was found to have protective effect. Fok I and Taq I did not have appreciable levels of association with PCa, although Taq I "TC" heterozygotes seemed to have some protective effect. Similarly the "C" allele of Fok I also seemed to have protective effect. Conclusions: To our knowledge, this is the first report showing association between VDR gene polymorphisms and PCa in Pakistan. Our findings may be somewhat skewed because of small sample size and tendency of consanguineous marriages in Pakistani society; nevertheless, it shows the trend of association and protective effects of certain VDR gene polymorphisms against PCa.

• IMMUNE NETWORK
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• v.11 no.5
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• pp.253-257
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• 2011

Background: The active metabolite (1, 25- dihydroxycholecalciferol) of vitamin D (25-hydroxycholecalciferol) leads to activation of macrophages and deficiency of vitamin D seems to be involved in the risk of tuberculosis. The effects of vitamin D are exerted by interaction with the vitamin D receptor (VDR) and may be influenced by polymorphism in the VDR gene. In this study, variation in the VDR gene was investigated in Korean population with tuberculosis. Methods: We typed three VDR polymorphisms of restriction endonuclease sites for TaqI, BsmI and FokI in 155 patients with tuberculosis and 105 healthy volunteers. Results: The frequencies of FokI genotypes determined from TB patients were 29.13% for FF, 56.31% for Ff, and 14.56% for ff. We observed 1.4-fold increased prevalence of the Ff genotype in TB patients compared with normal healthy groups (p=0.0857). However, there was no significant association between the genotype groups, TB patient and normal control, for FokI polymorphism. There was also no significant association between VDR gene and tuberculosis in another polymorphism (BsmI and TaqI). Conclusion: Three polymorphisms (TaqI, BsmI and FokI) in the VDR gene do not appear to be responsible for host susceptibility to human tuberculosis in Korean population.

• Nutrition Research and Practice
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• v.5 no.5
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• pp.464-470
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• 2011

Growing evidence suggests an elevated risk for colorectal neoplasia among individuals with low levels of vitamin D, the biological actions of which are mediated by the vitamin D receptor (VDR). To investigate the association among vitamin D status, VDR polymorphisms (FokI, and BsmI), and colorectal adenoma, we conducted a meta-analysis of nine studies of circulating levels of 25-hydroxyvitamin D (25(OH)D) and five studies of FokI or BsmI polymorphisms in relation to colorectal adenomas. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were pooled using a random-effects model. A total of 3398 coloreetal adenomas for 25(OH)D and 1754 colorectal adenomas for VDR were included in the meta-analysis. We identified a significant inverse association between colorectal adenoma (combined RR, 0.93; 95% CI, 0.87-0.98 per 10 ng/mL increase in 25(OH)D levels). When we examined FokI and BsmI polymorphisms in the meta-analysis, we found no association for either FokI (combined RR, 1.00; 95% CI, 0.95-1.06) or BsmI (combined RR, 0.99; 95% CI, 0.93-1.05) in the additive model. These data suggest an inverse association between circulating 25(OH)D levels and colorectal adenoma risk.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1255-1262
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• 2014

Background: The aim of the study was to investigate any associations between benign prostate hyperplasia (BPH) and single nucleotide polymorphisms (SNPs) in the VDR gene (FokI, BsmI, ApaI and Taq${\alpha}$I loci) and the CYP17 gene (MspA1I locus), as well as TA repeat polymorphism in SRD5A2 gene among Lebanese men. Materials and Methods: DNA extracted from blood of 68 subjects with confirmed BPH and 79 age-matched controls was subjected to PCR/PCR-restriction fragment length polymorphism analysis. The odds ra=tio (OR) of having a genotype and the relative risk (RR) of developing BPH for having the genotype were calculated and the alleles were designated risk-bearing or protective. Results: Our data indicated that the A and B alleles of the VDR ApaI and BsmI SNPs were highly associated with increased risk of BPH (p=0.0168 and 0.0002, respectively). Moreover, 63% of the controls compared to 43% of the subjects with BPH were homozygous for none of the risk-bearing alleles (p=0.0123) whereas 60% of the controls and 28% of the subjects with BPH were homozygous for two or more protective alleles (p<0.0001). Conclusions: For the first time, our study demonstrated that ApaI and BsmI of the VDR gene are associated with risk of BPH among Lebanese men. Our study also indicated that overall polymorphism profile of all the genes involved in prostate physiology could be a better predictor of BPH risk.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.2019-2026
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• 2015

Much interest has been drawn to possible associations between vitamin D receptor (VDR) gene polymorphisms and colorectal cancer risk in conjunction with potentially protective effects of calcium and vitamin D. In a study of 685 cases of colorectal cancer and 778 community controls in Japan, we examined the associations of the FokI, BsmI, ApaI, and TaqI polymorphisms with colorectal cancer risk and effect modification by dietary calcium and vitamin D. Genotypes were determined by the PCR-RFLP method. The ApaI polymorphism seemed to be associated with a decreased risk of colorectal cancer, particularly of rectal cancer. The adjusted odds ratio of colorectal cancer for the ApaI AA and Aa genotypes combined versus the aa genotype was 0.83 (95% confidence interval [CI] 0.67-1.02), and the corresponding value for rectal cancer was 0.75 (95%CI 0.56-0.99). A decreased risk of colorectal cancer for the ApaI AA and Aa genotypes combined was more evident in individuals with high calcium intake (interaction p=0.055). The FokI polymorphism seemed to be associated with a decreased risk of colon cancer among those with high vitamin D intake (interaction p=0.09). The BsmI and TaqI polymorphisms were unrelated to colorectal cancer risk, and the null associations were not modified by calcium or vitamin D intake. In conclusion, the ApaI polymorphism may be associated with a decreased risk of colorectal cancer in Japanese, dependent on dietary calcium intake.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3359-3362
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• 2014

Increasing attention is being devoted to the mechanisms by which cells receive signals and then translate these into decisions for growth, death, or migration. Recent findings have presented significant breakthroughs in developing a deeper understanding of the activation or repression of target genes and proteins in response to various stimuli and of how they are assembled during signal transduction in cancer cells. Detailed mechanistic insights have unveiled new maps of linear and integrated signal transduction cascades, but the multifaceted nature of the pathways remains unclear. Although new layers of information are being added regarding mechanisms underlying ovarian cancer and how polymorphisms in VDR gene influence its development, the findings of this research must be sequentially collected and re-interpreted. We divide this multi-component review into different segments: how vitamin D modulates molecular network in ovarian cancer cells, how ovarian cancer is controlled by tumor suppressors and oncogenic miRNAs and finally how vitamin D signaling regulates miRNA expression. Intra/inter-population variability is insufficiently studied and a better understanding of genetics of population will be helpful in getting a step closer to personalized medicine.

• Environmental Analysis Health and Toxicology
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• v.21 no.1 s.52
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• pp.27-34
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• 2006

Numerous studies reported the significant association between genetic polymorphisms in the vitamin D receptor (VDR) gene and various bone phenotypes such as bone mineral density (BMD) and bone quality, although conflicting results were produced. The objective of this study was to investigate the association between a TaqI RFLP in the VDR gene and calcaneal BMD in Korean vegetarian men, and its interaction with nutrition status as an environmental factor. BUA (broadband ultrasound attenuation), SOS (sound of speed) and stiffness index of the calcaneus were measured using an ultrasound bone densitometer in 266 Korean men (age: $mean{\pm}SD;\;50.9{\pm}12.0$ year), and a TaqI RFLP in the VDR gene analysed by PCR-RFLP method. In total subjects, the distribution of TT, Tt and tt genotypes occurred with frequencies of 90.8%, 8.8% and 0.4%, respectively. There were no significant associations between this polymorphism and osteopenia-osteoporosis or several bone phenotypes in our subjects irrespectively of nutrition status (P>0.05). Therefore, our results suggest that a TaqI RFLP in the vitamin D receptor gene does not contribute to the susceptibility to the calcaneal BMD in Korean men.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.847-853
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• 2014

There is a lot of debate on the relationship between vitamin D receptor polymorphisms and risk of breast cancer. Herein, we quantitatively analyzed the published case-control studies on this relationship by meta-analysis, performing a bibliographic search from Pubmed and CNKI up to July 31, 2013. The included case-control studies for Fok1, Bsm1, Taq1, Apa1, Cdx2 and Poly-A were 16, 19, 20, 10, 4, 6, respectively. Crude and adjusted odd ratios and 95% confidence intervals were calculated to present and compare the strength of any associations. The results of combined analyses indicated that Fok1, Bsm1, Apa1, Cdx2 and Poly-A were not significantly associated with the risk of breast cancer. In contrast, the tt genotype of Taq1 was a modest risk factor for breast cancer development (tt vs. TT: OR = 1.21, 95% CI: 1.01-1.44). To further confirm the above results, adjusted effects for the six polymorphisms were pooled based on adjusted ORs reported in the original studies. Adjusted ORs of Fok1, Apa1, Cdx2 and Poly-A were similar to the crude ORs. However, Bsm1 and Taq1 showed inconsistent results. For Bsm1, OR for BB vs. bb was 0.85, 95% CI: 0.74-0.98; for Taq1, OR for tt vs. TT was 1.03, 95% CI: 0.92-1.15, and not associated with risk. Subgroup analyses for crude ORs showed some association between Bsm1, Taq1 and breast cancer in Caucasians only, but for adjusted ORs, no associations were found. This meta-analysis suggests that the roles that Fok1, Apa1, Cdx2 and Poly-A polymorphisms play in breast cancer risk are negligible, with Bsm1 and Taq1 as possible exceptions. To be conservative, we still assumed that they may play a modest role in determining breast cancer risk. Further studies are needed to validate our findings.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4441-4444
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• 2012

Background: Polymorphisms of the Taq I gene have been associated with prostate cancer risk. Methods:We applied a fixed-effects model to combine odds ratios (ORs) and 95% confidence intervals (95% CI). The Egger's test was carried out to evaluate potential publication bias. Results: A total of 10 case-control studies enrolling 1,141 prostate cancer patients and 1,685 controls were included in this meta-analysis. Compared with the T allele, the OR for the C allele was 0.81 (0.70-0.94). The ORs for CT and CC+CT genotypes were 0.86 (0.74-1.01) and 0.84 (0.73-0.97) compared to wide type genotype (homozygote TT). Conclusions: The present meta-analysis suggests that the TF gene Taq I polymorphism may reduce the prostate cancer risk in Asian populations.