Review and meta-analysis on vitamin D receptor polymorphisms and cancer risk

Vitamin D in Cancer Prevention and Treatment: A Review of Epidemiological, Preclinical, and Cellular Studies

BACKGROUND

Inhibition of human carcinomas has previously been linked to vitamin D due to its effects on cancer cell proliferation, migration, angiogenesis, and apoptosis induction. The anticancer activity of vitamin D has been confirmed by several studies, which have shown that increased cancer incidence is associated with decreased vitamin D and that dietary supplementation of vitamin D slows down the growth of xenografted tumors in mice. Vitamin D inhibits the growth of cancer cells by the induction of apoptosis as well as by arresting the cells at the G0/G1 (or) G2/M phase of the cell cycle. Aim and Key Scientific Concepts of the Review: The purpose of this article is to thoroughly review the existing information and discuss and debate to conclude whether vitamin D could be used as an agent to prevent/treat cancers. The existing empirical data have demonstrated that vitamin D can also work in the absence of vitamin D receptors (VDRs), indicating the presence of multiple mechanisms of action for this sunshine vitamin. Polymorphism in the VDR is known to play a key role in tumor cell metastasis and drug resistance. Although there is evidence that vitamin D has both therapeutic and cancer-preventive properties, numerous uncertainties and concerns regarding its use in cancer treatment still exist. These include (a) increased calcium levels in individuals receiving therapeutic doses of vitamin D to suppress the growth of cancer cells; (b) hyperglycemia induction in certain vitamin D-treated study participants; (c) a dearth of evidence showing preventive or therapeutic benefits of cancer in clinical trials; (d) very weak support from proof-of-principle studies; and (e) the inability of vitamin D alone to treat advanced cancers. Addressing these concerns, more potent and less toxic vitamin D analogs have been created, and these are presently undergoing clinical trial evaluation. To provide key information regarding the functions of vitamin D and VDRs, this review provided details of significant advancements in the functional analysis of vitamin D and its analogs and VDR polymorphisms associated with cancers.

Association between vitamin D receptor polymorphism and breast cancer in women: An umbrella review of meta-analyses of observational investigations

This study aimed to conduct an umbrella review of meta-analyses to synthesize the existing evidence regarding the relationship between vitamin D receptor (VDR) polymorphism and breast cancer (BC) risk. A comprehensive search was performed across multiple databases, including Embase, PubMed, Scopus, the Cochrane Database of Systematic Reviews, and the Web of Science. The investigation included 17 meta-analyses for the BsmI polymorphism, 6 for the Cdx2 polymorphism, and 6 for the Poly (A) polymorphism. Among the 119 datasets analyzed, only 6 (5 %) reported statistically significant outcomes (p < 0.05), comprising 2 comparisons for VDR BsmI polymorphism (3 %), 1 for VDR Cdx-2 polymorphism (4 %), and 3 for VDR Poly (A) polymorphism (14 %), across various genetic models. Notably, significant heterogeneity was observed in 82 comparisons, and publication bias was detected in 16 comparisons. Furthermore, a substantial proportion (86 %) of the included studies exhibited critically low methodological quality. In conclusion, our findings suggest that VDR polymorphism (BsmI, Cdx-2, and Poly (A)) is not strongly associated with BC risk in the general population.

Vitamin D deficiency and the vitamin D receptor (VDR) gene polymorphism rs2228570 (FokI) are associated with an increased susceptibility to hypertension among the Bangladeshi population

Vitamin D receptor (VDR) gene is implicated in hypertension vulnerability due to its role in regulating the renin-angiotensin system (RAS) and blood pressure. In this case-control study, a carefully selected cohort of 111 hypertensive individuals and 100 healthy controls underwent serum analysis using HPLC to measure 25-hydroxy vitamin D levels. Polymorphic variations in the VDR gene were detected and characterized using the PCR-RFLP method. At first, lower 25-hydroxy vitamin D levels were observed in hypertensive individuals compared to controls (p<0.001). The genotype frequency of the VDR gene TaqI showed no significant difference between cases and controls (p>0.05). Similarly, no significant difference was found in the VDR gene BsmI genotype frequency between hypertensive patients and controls (p>0.05). However, a statistically significant distinction was observed in the VDR gene FokI genotype frequency between cases and controls (p<0.01). The odds ratios for FokI genotypes (CC, CT, TT, and CT+TT) were 1.0, 0.590, 1.566, and 0.963, respectively. Furthermore, serum 25-hydroxy vitamin D levels were significantly higher in control subjects compared to hypertensive patients across all genotypes of VDR (p<0.001). Hypertensive patients, excluding those with the FokI VDR gene CC genotype, exhibited significantly higher systolic blood pressure levels compared to the control group (p<0.05). Similarly, hypertensive subjects displayed elevated diastolic blood pressure levels compared to the control group (p<0.001). Overall, the results suggest the presence of a potential inverse correlation between serum 25-hydroxy vitamin D levels and hypertension. The association analysis conducted indicated that there is no significant association between TaqI and bsmI genotypic variants and the risk of developing hypertension. However, it was observed that VDR gene polymorphisms do have a clear association with hypertension susceptibility, as evidenced by the significantly higher occurrence of FokI genotypic variants in hypertensive patients. Our study therefore introduces the possibility of utilizing 25-hydroxy vitamin D deficiency and VDR gene polymorphisms as a biomarker for hypertension.

Vitamin D intake and gastric cancer in Viet Nam: a case-control study

Background

Most recent laboratory studies have suggested a promising role of vitamin D and its analogs as novel chemotherapeutic agents for cancer treatment. However, epidemiological evidence, especially regarding the effects of vitamin D on gastric cancer is still inconsistent.

Objectives

Our research aimed to evaluate the associations between vitamin D intake and the risk of developing gastric cancer through a case-control study in North Vietnam.

Methods

We accessed databases of the previous completed case-control studies to derive 1182 incident gastric cancer cases and 2995 hospital controls selected from hospitals in Hanoi from 2003 to 2019. Vitamin D intake was computed by multiplying the food frequency intake with nutrient content based on the Viet Nam Food Composition Tables. Data were collected through face-to-face interviews by trained interviewers using the validated semi-quantitative food frequency and demographic lifestyle questionnaires. The odds ratio and 95% confidence interval (OR and 95%CI) were estimated using unconditional logistic regression analysis.

Results

We observed a continual decline in gastric cancer risk according to the level-up of vitamin D intake in both genders, men, and women [Fifth vs. bottom quintile, OR, 95%CI: 0.68 (0.53, 0.86), OR, 95%CI: 0.72 (0.53, 0.97), OR, 95%CI: 0.58 (0.38, 0.89), respectively. Per increment quintile, the statistically significant decreased risk was seen by 7% in men and 13% in women. The significant inverse association between vitamin D intake remained in the subgroups of ever and never tobacco smoking; negative and positive H. pylori infection.

Conclusion

The findings suggested that sufficient vitamin D intake was associated with a lower risk of Gastric Cancer in the Vietnamese population.

The relationship between VDR polymorphisms and keratinocyte carcinomas: a systematic review and meta-analysis

Aim: To perform a meta-analysis to assess the association between common VDR polymorphisms (Fok1, Taq1, Apa1, Bsm1) and keratinocyte carcinomas (KCs) susceptibility. Methods & materials: databases were searched up to November 2021. Odds ratios (OR) with 95% CIs were evaluated in the association. Results: This meta-analysis included seven articles. KC (and its subtypes) risks are found to be associated with Fok1 (BCC: ff vs FF+Ff: OR = 2.13, 95% CI = 1.14-3.97; SCC: ff vs FF+Ff: OR = 1.54, 95% CI = 1.09-2.18) and Taq1 (BCC: Tt vs TT: OR = 1.99, 95% CI = 1.35-2.93; tt vs TT: OR = 2.09, 95% CI = 1.27-3.43; Tt +tt vs TT: OR = 2.02, 95% CI = 1.41-2.90) polymorphisms. Conclusion: This study suggests that the Fok1 f allele and the Taq1 t allele are associated with increased susceptibility to KC and its subtypes.

Association between vitamin D deficiency and prostate cancer: Prospective case-control study

Objective:

We aimed to find out the association of low serum vitamin D levels with the incidence of prostate cancer through a prospective case-control study.

Material and methods:

This study was carried out in the tertiary care hospital (India). All newly diagnosed patients of prostate cancer and age-matched controls were included. Serum vitamin D levels were measured in all of them. Vitamin D status (ng/mL) was classified as severe deficiency <10, moderate deficiency 10–<30, normal 30–100, and toxicity >100. Normality of the data was tested by the Kolmogorov–Smirnov test, statistical analysis was done with Statistical Package for the Social Sciences version 26.0, p-value of <0.05 was considered significant.

Results:

In our study, 320 cases and 320 controls were included. The mean vitamin D levels in cases and controls were 15.71 ± 6.5 (ng/mL) and 17.63 ± 4.54 (ng/mL), respectively, ( p-Value <0.01). Patients with severe vitamin D deficiency (73.58%) had a Gleason score ⩾8 on biopsy and 79.24% of them had a serum prostate specific antigen (PSA) level >20 ng/mL.

Conclusion:

We had concluded that there was no significant association between vitamin D deficiency and increased risk of prostate cancer, although patients with higher-grade prostate cancer and with higher PSA level had severe vitamin D deficiency.

Level of evidence:

Not applicable for this multicentre audit.

Vitamin D and Hypoxia: Points of Interplay in Cancer

Vitamin D is a hormone that, through its action, elicits a broad spectrum of physiological responses ranging from classic to nonclassical actions such as bone morphogenesis and immune function. In parallel, many studies describe the antiproliferative, proapoptotic, antiangiogenic effects of calcitriol (the active hormonal form) that contribute to its anticancer activity. Additionally, epidemiological data signify the inverse correlation between vitamin D levels and cancer risk. On the contrary, tumors possess several adaptive mechanisms that enable them to evade the anticancer effects of calcitriol. Such maladaptive processes are often a characteristic of the cancer microenvironment, which in solid tumors is frequently hypoxic and elicits the overexpression of Hypoxia-Inducible Factors (HIFs). HIF-mediated signaling not only contributes to cancer cell survival and proliferation but also confers resistance to anticancer agents. Taking into consideration that calcitriol intertwines with signaling events elicited by the hypoxic status cells, this review examines their interplay in cellular signaling to give the opportunity to better understand their relationship in cancer development and their prospect for the treatment of cancer.

Indoor tanning: Evidence surrounding advertised health claims

Indoor tanning continues to remain common, despite evidence of an increased risk of skin cancer from artificial ultraviolet (UV) radiation. In the hopes of gaining customers, the tanning bed industry has marketed health benefits of indoor tanning such as increased vitamin D production, development of a base tan, enhanced mood, and treatment of certain dermatologic conditions. To better educate their patients, providers need a comprehensive reference reviewing the evidence that support or oppose these claims. In this work, we conducted an evidence-based review of the literature to identify and grade studies that investigate health claims related to UV exposure. Results indicate that there is little evidence to support each of these proposed health benefits. Tanning beds emit primarily UVA radiation, which is relatively ineffective at activating vitamin D or mood enhancing pathways, and the effects are minimal in regard to tanning beds generating a protective base tan or treating dermatologic conditions compared with the increased risk of skin cancer. Health care providers must continue to warn and educate patients about the misleading information propagated by the tanning bed industry as well as about the dangers of artificial UV radiation.

Vitamin D receptor gene polymorphisms and its interactions with environmental factors on renal cell carcinoma risk

Aims

We designed a case-control study to investigate the effect of vitamin D receptor gene (VDR) gene single nucleotide polymorphisms (SNPs) and possible gene- environment interaction on the susceptibility of renal cell carcinoma (RCC).

Methods

Generalized multifactor dimensionality reduction (GMDR) was used to find out the interaction combinations between SNPs and environmental factors, including gene- gene synergy and gene environment synergy effect. Logistic regression was used to analyze the correlation between the four SNPs in VDR gene and RCC, and the significant interaction combinations found by GMDR model were analyzed by hierarchical analysis.

Results

The genotype distribution of the control group was in accordance with Hardy- Weinberg equilibrium. Logistic regression analysis showed that the risk of RCC in VDR-rs7975232 A allele carriers was significantly higher than that of CC genotype carriers (CA + AA vs. CC), adjusted OR (95 % CI) = 1.75 (1.26–2.28). We used GMDR model to screen the best synergistic model between the four SNPs of VDR gene and smoking and drinking. We found a significant two locus model (P = 0.0010) involving rs7975232 and smoking. The cross- validation consistency of the two- locus model was 10/ 10, and the accuracy was 60.72 %. Compared with non-smokers with rs7975232 -CA or AA genotype, smokers with rs7975232 -CC genotype had the highest risk of RCC, or (95 % CI) = 2.23 (1.42–3.09), after adjustment for covariates.

Conclusions

We found that the A allele of rs7975232 within VDR gene, interaction between rs7975232 and smoking were all associated with increased RCC risk.

Association Between Vitamin D Exposure and Head and Neck Cancer: A Systematic Review With Meta-Analysis

Background

Vitamin D deficiency is a well-described preventable cause of many cancers; the association of vitamin D use with the development of head and neck cancer (HNC) is not clear. We aim to conduct a systematic review of the studies assessing the relation between vitamin D exposure and the prevention and prognosis of the HNC using meta-analysis.

Methods

PubMed, EMBASE, Cochrane Library, Web of Science up to 1 January 2021, and reference lists of related studies were searched. We extracted observational studies reporting the association between vitamin D (vitamin D receptor gene polymorphisms, 25-hydroxyvitamin D concentrations, and vitamin D intake) and the outcomes of interest (HNC incidence and HNC mortality) in HNC patients aged 18 or older. Fixed effects models were used to calculate pooled effect sizes and 95% confidence intervals (CIs) by RevMan (version 5.3).

Results

Sixteen studies with a total of 81,908 participants were enrolled in our meta-analysis. Based on the pooled genomic analysis, comparing with participants with the genotypes of Ff + FF or FF, the pooled odds ratio (OR) of participants with the genotype of ff was 0.77 (95% CI: 0.61 to 0.97) and 0.75 (0.58 to 0.97), respectively. A similar trend was noted when comparing tt with Tt + TT or TT, in which OR (95% CI) was 0.70 (0.55 to 0.90) and 0.72 (0.55 to 0.95). No significant association was identified between BsmI polymorphism and HNC. Furthermore, the OR of HNC incidence was 0.77 (0.65 to 0.92) for participants with vitamin D intake over the ones with a regular diet. High concentrations of circulated 25-hydroxyvitamin D (25-OHD) significantly decreased by 32% of HNC incidence (OR (95% CI): 0.68 (0.59 to 0.78)) and increased HNC survival (pooled hazard ratio 1.13, 1.05 to 1.22) during a 4-5 years follow-up. High concentrations of circulating 25-OHD in patients with HNC led to a decreased risk of mortality to 0.75 (0.60 to 0.94) as the follow-up extends to 8-12 years.

Conclusions

Elevated activities of vitamin D by diet intake, genomic polymorphisms, or circulated 25-OHD may protect people from HNC and improve the prognosis of patients with HNC.

Systematic Review Registration

PROSPERO, identifier CRD42020176002 (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=176002).

Vitamin D receptor gene polymorphisms and risk of hepatocellular carcinoma in hepatitis C-related liver cirrhosis

Background

HCV is a major risk factor for HCC; however, the exact mechanism of hepatocarcinogenesis is still not fully understood. Host genetic factors have been reported to play a significant role. Experimental studies support the tumor inhibitory effect of vitamin D on HCC cells. Several single nucleotide polymorphisms (SNPs) have been depicted in the vitamin D receptor (VDR) gene. We aimed to assess whether any of these polymorphisms could be significantly associated with increased risk of HCC.

Results

This study was conducted on 76 patients with HCV-related liver cirrhosis (48 patients had HCC on top of cirrhosis, and the other 28 had liver cirrhosis only). All patients underwent full medical history assessment, clinical examination, laboratory investigations, abdominal ultrasonography, and genotyping of the VDR gene. HCC patients had a significantly higher frequency of ApaI CC genotype compared with those patients without HCC. There is no statistically significant difference between the studied groups at any TaqI genotypes, but the carriage of the ApaI CC genotype had a significant association with liver disease severity in both patients groups compared with ApaI CA/AA genotypes. The carriage of the ApaI CC genotype was an independent predictor for HCC in HCV-related liver cirrhosis.

Conclusions

VDR ApaI polymorphism is significantly associated with the development of HCC; thus, ApaI CC genotype could be used as an important molecular marker to predict the risk of HCC in patients with HCV-related liver cirrhosis.

Ethnicity as modifier of risk for Vitamin D receptors polymorphisms: Comprehensive meta-analysis of all cancer sites

Vitamin D receptors polymorphisms are found to be associated with several cancers. Since their prevalence vary across ethnicities and ethnicity itself seems to influence the cancer risk, a comprehensive meta-analysis was performed to investigate the role of VDR Fok1, Bsm1, Taq1, Apa1, Cdx2 and cancer risk at specific organ sites. Odds ratios, calculated with random-effects models, summarized one-hundred-ninety-two independent studies for twenty-two cancer sites. Evidence was provided that Fok1, Bsm1, Cdx2, Apa1 and Taq1 are linked to cancer susceptibility for colorectal, lung, ovarian, skin, multiple myeloma and brain cancer. Stratifying by ethnicity, some differences were found, partially explained by minor allele frequency (MAF), for colorectal cancer, ovarian and prostate cancer in Caucasian and prostate cancer in Asian populations. In summary, ethnicity may be a modifier of cancer risk, in particular for hormone dependent cancers and it should be considered evaluating the effect of VDR on cancer risk.

Vitamin D Receptor Polymorphisms and Non-Melanoma Skin Cancer Risk: A Case-Control Study

Exposure to sunlight is the major source of vitamin D and the main environmental cause of non-melanocytic skin cancers. Vitamin D, partly mediated through the vitamin D receptor (VDR), has potential therapeutic applications in skin cancer. The aim of this study was to investigate the association of BsmI and ApaI VDR polymorphisms among patients with non-melanoma cancers and controls. An observational case-control study was conducted in a sample of 154 subjects. We observed no significant effects between these polymorphisms and skin cancer risk. When stratified for gender, GG and AG BsmI polymorphisms significantly increased the risk of basal cell carcinomas in males. In relation to ApaI, all three polymorphisms significantly increased the risk of basal cell carcinoma in males. When stratified for age, we found that being 70 years of age or younger was a protective factor against both skin cancers. Being a female and 70 years old or younger was a protective factor for basal cell carcinoma. A comparison of the frequencies of the VDR genotypes in patients older than 70 years vs. 70 years or younger also revealed age-dependent variations in patients with non-melanoma skin cancer. Our study suggests a role for VDR polymorphisms in non-melanoma skin cancer development.

Prognostic role of vitamin D receptor in breast cancer: a systematic review and meta-analysis

Background

A higher vitamin D intake improves the prognosis of early stage breast cancer (BC) patients. We hypothesized that vitamin D intake should refer to vitamin D receptor (VDR) expression. In order to prove this hypothesis, we first intend to evaluate the correlation between VDR expression and prognosis of BC patients using meta-analysis.

Methods

Literatures from PubMed, Embase, and the Cochrane Library (last update by May 20, 2020) were retrieved to find studies assessing the prognostic role of VDR in BC. The hazard ratios (HRs) for patients’ survival were extracted for pooled analyses. Subgroup analysis, sensitivity analysis and meta-regression were performed to explore the sources of heterogeneity.

Results

Seven articles containing eight studies with 2503 patients were enrolled. The results from the pooled analyses showed that the VDR expression generally had no relationship with BC patients’ overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and progression-free survival (PFS) (P > 0.05). Because only the number of studies exploring the relationship between VDR expression and OS is greater than five and there is heterogeneity, we explored the sources of heterogeneity of these studies. Subgroup analyses showed that the VDR expression in the nucleus had no relationship with OS, but high total VDR expression in the nucleus and cytoplasm was related to a better OS (pooled HR = 0.41; 95% CI = 0.18–0.95; P = 0.038). In addition, in subgroup of studies using cut-off values other than ‘immunoreactive score (IRS)>5’ and ‘IRS > 25′, high VDR expression was associated with a better OS (pooled HR = 0.47; 95% CI = 0.30–0.74; P = 0.001). Sensitivity analysis showed that the result pattern was not obviously affected by any single study. Meta-regression showed that the source of heterogeneity was not country (P = 0.657), pathological type (P = 0.614), molecular type (P = 0.423), staining location (P = 0.481), or cut-off value (P = 0.509).

Conclusions

The protein expression level of VDR in entire BC cells evaluated by immunohistochemistry is related to the OS of BC patients. It is expected that a more individualized vitamin D intake and a more accurate prognosis assessment can be recommended for BC patients based on the VDR expression. Of course, more preclinical and clinical studies are needed.

Vitamin D Receptor Polymorphisms and Cancer

Increasing scientific evidence supports the link between vitamin D and cancer risk. The active metabolite 1,25(OH)2D exerts its activity by binding to the vitamin D receptor (VDR), an intracellular receptor that mediates transcriptional activation and repression of target genes. The binding of 1,25(OH)2D to VDR is able to regulate hundreds of different genes. VDR is active in virtually all tissues including the colon, breast, lung, ovary, bone, kidney, parathyroid gland, pancreatic b-cells, monocytes, T lymphocytes, melanocytes, keratinocytes, and also cancer cells.The relevance of VDR gene restriction fragment length polymorphisms for various types of cancer has been investigated by a great number of studies.We have carried out a systematic review of the literature to analyze the relevance of more VDR polymorphisms (Fok1, Bsm1, Taq1, Apa1, and Cdx2) for individual malignancies considering ethnicity as a key factor for heterogeneity.Up to December 2018, we identified 176 independent studies with data to assess the risk of breast, prostate, colorectal, skin (melanoma and non-melanoma skin cancer), lung, ovarian, kidney, bladder, gallbladder, esophageal, thyroid, head and neck, liver and pancreatic cancer, oral squamous cell carcinoma, non-Hodgkin lymphoma, multiple myeloma and sarcoma.Significant associations with VDR polymorphisms have been reported for prostate (Fok1, Bsm1, Taq1, Apa1, Cdx2), breast (Fok1, Bsm1, Taq1, Apa1, CdX2), colorectal (Fok1, Bsm1, Taq1, Apa1), and skin cancer (Fok1, Bsm1, Taq1). Very few studies reported risk estimates for the other cancer sites.Conflicting data have been reported for most malignancies, and at present, it is still not possible to make any definitive statements about the importance of the VDR genotype for cancer risk. It seems probable that other factors such as ethnicity, phenotype, 25(OH)D plasma levels, and UV radiation exposure play a role as confounding factors and introduce heterogeneity.To conclude, there is some indication that VDR polymorphisms may modulate the risk of some cancer sites and in future studies VDR genetic variation should be integrated also with assessment of vitamin D status and stratified by ethnicity.

Anticancer activity of vitamin D – molecular mechanisms

A large number of studies have pointed to the relations between blood levels of 25-hydroxy vitamin D with cancer incidence and survival. The phenomenon of the multidirectional activity of vitamin D is possibly due to the presence of VDR in most nonskeletal human cells, including cancer cells. A wide range of the genes regulated by VDR are related with cell proliferation, apoptosis, differentiation, angiogenesis and metastasis. In some preclinical studies, colon, lung and BC have all demonstrated downregulation of VDR expression as compared to normal cells, and well-differentiated tumors have shown more VDR expression when compared to their poorly differentiated counterparts. Generally, higher tumor VDR expression has been noted as correlating with better prognosis in cancer patients. However, vitamin D pathway genetic polymorphisms also may influence cancer risk. VDR polymorphisms have received the most attention, but this influence has also been observed in genes related to vitamin D metabolism or signalling, such as: CYP27B1, CYP24A1, VDBP or RXRA. Even though the associations between most of them and cancers were not significant, some studies show that VDR polymorphisms may be a better or poor prognostic factor to assess the risk of cancer. The aim of this paper was to present the molecular pathways affected by vitamin D, which are included in carcinogenesis. The literature survey comprised of research compiled from mostly the last five years and it proves vitamin D as the most phenomenal among other vitamins.

BRCA1 and VDR gene polymorphisms are associated with prostate cancer risk in Mexican men

Prostate cancer (PC) is a polygenic disease with broad differences across ethnicities. BRCA1/2 and VDR have exhibited a featured genetic contribution to PC development in European populations. Nonetheless, its contribution in Latino populations specifically among Mexican men, where 70% of PC cases are detected in advanced stages, is still unknown. The contribution of seven polymorphisms in BRCA1/2 and VDR genes to PC susceptibility was evaluated in 370 incident PC cases and 759 age-matched (±5 years) controls belonging to the Mexican population. Based on Gleason score at diagnosis, PC cases were classified as well-differentiated PC (Gleason <7) and moderate or poorly differentiated PC (Gleason ≥7). Age at diagnosis was used to divided PC cases in earlier (<60 years) and late-onset PC (≥60 years). Prostate and breast cancer family histories were obtained through interview. Our results provided evidences about the contribution of BRCA1-rs1799966 (OR_{CC genotype}  = 2.30; 95% confidence interval [CI] = 1.36-3.91) to the moderate or poorly differentiated PC risk, independently of the family history of prostate, breast or ovary cancer. Further, VDR-rs2238135-G allele was associated with early-onset PC (OR_{G allele}  = 2.05; 95% CI = 1.06-3.95), and marginally with moderate or poorly differentiated PC risk. The present study revealed the crucial role of BRCA1 in PC aggressiveness risk, outstanding the gender imbalance regarding the breast cancer risk in women.

Genetic associations of vitamin D receptor polymorphisms with advanced liver fibrosis and response to pegylated interferon-based therapy in chronic hepatitis C

Vitamin D receptor (VDR) modulates host immune responses to infections such as hepatitis C virus (HCV) infection, including interferon signaling. This study aimed to investigate the associations of VDR polymorphisms with advanced liver fibrosis and response to pegylated interferon (PEG-IFN)-based therapy in patients with chronic HCV infection. In total, 554 Thai patients with chronic HCV infection treated with a PEG-IFN-based regimen were enrolled. Six single-nucleotide polymorphisms (SNPs) were genotyped: the IL28B C > T (rs12979860) SNP and five VDR SNPs, comprising FokI T > C (rs2228570), BsmI C > T (rs1544410), Tru9I G > A (rs757343), ApaI C > A (rs7975232), and TaqI A > G (rs731236). In total, 334 patients (60.3%) achieved sustained virological response (SVR), and 255 patients (46%) were infected with HCV genotype 1. The bAt (CCA) haplotype, consisting of the BsmI rs1544410 C, ApaI rs7975232 C, and TaqI rs731236 A alleles, was associated with poor response (in terms of lack of an SVR) to PEG-IFN-based therapy. The IL28B rs12979860 CT/TT genotypes (OR = 3.44, 95% CI [2.12–5.58], p < 0.001), bAt haplotype (OR = 2.02, 95% CI [1.04–3.91], p = 0.03), pre-treatment serum HCV RNA (logIU/mL; OR = 1.73, 95% CI [1.31–2.28], p < 0.001), advanced liver fibrosis (OR = 1.68, 95% CI [1.10–2.58], p = 0.02), and HCV genotype 1 (OR = 1.59, 95% CI [1.07–2.37], p = 0.02) independently predicted poor response. Patients with the bAt haplotype were more likely to have poor response compared to patients with other haplotypes (41.4% vs 21.9%, p = 0.03). The FokI rs2228570 TT/TC genotypes (OR = 1.63, 95% CI [1.06–2.51], p = 0.03) and age ≥55 years (OR = 2.25; 95% CI [1.54–3.32], p < 0.001) were independently associated with advanced liver fibrosis, assessed based on FIB-4 score >3.25. VDR polymorphisms were not associated with pre-treatment serum HCV RNA. In Thai patients with chronic HCV infection, the bAt haplotype is associated with poor response to PEG-IFN-based therapy, and the FokI rs2228570 TT/TC genotypes are risk factors for advanced liver fibrosis.

Association of vitamin D receptor gene polymorphisms with osteosarcoma risk and prognosis

OBJECTIVE

Through its receptor (VDR), vitamin D3 plays an important role in a wide variety of cellular processes. Polymorphisms in VDR gene have been linked to risk of various cancers and their prognoses. We conducted a case-control study to analyze he relationship of VDR gene polymorphisms with the occurrence and prognosis of osteosarcoma.

METHODS

Fifty-eight osteosarcoma patients and 75 healthy controls were included in the study. Single nucleotide change polymorphisms (SNPs) in Cdx2, FokI, BsmI, ApaI and TaqI regions of VDR gene were examined with SNaPshot mini-sequencing technique. Allele and genotype frequencies in patients and controls were compared. The association of polymorphic genotypes with osteosarcoma was evaluated. The relationship of the presence of polymorphism to prognostic parameters and survival rates were also analyzed.

RESULTS

Allele and genotype frequencies of Cdx2, FokI, BsmI, ApaI and TaqI regions in VDR gene were found to be similar in patients and controls. Polymorphisms in these regions were not associated with osteosarcoma risk. In patients having Cdx2 polymorphic allele, tumor volume was greater (p:0.041), metastasis was more common (p:0.042) and histopathological response to chemotherapy was worse (p:0.044). Good histopathological response was significantly higher in patients with BsmI homozygous polymorphism (p:0.037). In the presence of heterozygous Cdx2 and homozygous a higher three-year overall survival rate was found, while there was a higher event-free survival rate in patients with ApaI polymorphisms.

CONCLUSION

Our results suggested that although polymorphisms of VDR gene are not related to the development of osteosarcoma, they may be important for prognosis. Understanding the effect of VDR polymorphisms on osteosarcoma will be important in identifying new prognostic parameters and new targets for treatment.

Relationship between vitamin D receptor gene polymorphisms and anemia in postmenopausal Vietnamese women

Background: Both in vitro and in vivo studies have shown that calcitriol, the active form of vitamin D, is involved in hematopoiesis. Vitamin D receptor (VDR) gene has been suggested as one of the candidate genes for anemia. Objective: Investigate relationship between anemia and the commonly studied polymorphisms of VDR gene (FokI, BsmI, ApaI and TaqI) in terms of genotype and haplotype in Vietnamese. Methods: A case-control study including 132 postmenopausal women without chronic kidney diseases was designed to investigate the relationship between VDR polymorphism and anemia. Four single nucleotide polymorphisms (SNPs) FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) were typed by polymerase chain reaction and restriction fragment length polymorphism method. Results: Genotype distributions of four SNPs were in Hardy-Weinberg equilibrium in both anemia and control groups. The SNPs at the 3’end of the VDR gene (BsmI, ApaI and TaqI) exhibited a strong linkage disequilibrium. There was no significant association between anemia and VDR polymorphism in terms of allele, genotype, and haplotype in the analyses unadjusted or adjusted for the covariates (age, body mass index, educational level, serum ferritin, iron and albumin). Conclusion: VDR gene did not influence anemia in postmenopausal women without chronic kidney disease. For further study on the association between VDR gene and anemia, the use of larger sample size, a prospective study design, and additional markers would enhance the reliability and validity of findings.

Polymorphisms of VDR gene and risk of gastric cardiac adenocarcinoma in Chinese population

Vitamin D receptor (VDR) gene polymorphisms have been reported to increase susceptibility to some malignant tumors, yet the effect on gastric cardiac adenocarcinoma susceptibility remains unknown. Here, we conducted a hospital-based case-control study to examine the correlation of single nucleotide polymorphisms of VDR rs2107301T>C, rs2228570C>T, rs1989969C>T and rs11568820 G>A and gastric cardiac adenocarcinoma susceptibility. A total 330 cases and 608 controls were enrolled in the study. Using ligation detection reaction, we found that the variant alleles of the four polymorphisms were not associated with risk of gastric cardiac adenocarcinoma. Further stratified analyses showed that there was an increased risk associated with VDR rs1989969 polymorphism among patients who were drinking or aged <60. The haplotypes VDR T_rs2107301T_rs2228570C_rs1989969G_rs11568820 reduced the susceptibility. This study demonstrated that VDR rs1989969 polymorphism was involved in the carcinogenesis of gastric cardiac adenocarcinoma, especially increased the risk in the younger and alcohol drinking Chinese population.

Association of Vitamin D receptor Fok I polymorphism with the risk of prostate cancer: a meta-analysis

Several previous studies have been reported to examine the association between Vitamin D receptor (VDR) gene Fok I polymorphism and susceptibility to prostate cancer (PCa), however the results remain inconclusive. To provide a relatively comprehensive account of the association, we searched PubMed, Embase, CNKI, and Wanfang for eligible studies and carry out this meta-analysis. A total of 27 case-control studies with 10,486 cases and 10,400 controls were included. In the overall analysis, Fok I polymorphism was not significantly associated with the susceptibility to PCa. Subgroup analyses showed that significantly association was existed in Caucasian population, the subgroup of population-based controls and the stratified group with advanced tumor.These results indicate that the VDR Fok I polymorphism might be capable of causing PCa susceptibility and could be a promising target to forecast the PCa risk for clinical practice. However further well-designed epidemiologic studies are needed to confirm this conclusion.

Vitamin D and VDR in Gynecological Cancers-A Systematic Review

In recent years, a vast amount of studies have centered on the role of vitamin D in the pathogenesis of certain types of cancers such as breast, colorectal and lung cancer. Increasing evidence suggests that vitamin D and its receptor play a crucial role in the development of gynecological cancers. In this review, we systematically analyzed the effect of vitamin D and the vitamin D receptor on endometrial, ovarian, cervical, vulvar and vaginal cancer. Our literature research shows that vitamin D levels and vitamin-D-related pathways affect the risk of gynecological cancers. Numerous ecological studies give evidence on the inverse relationship between UVB exposure and gynecological cancer risk. However, epidemiologic research is still inconclusive for endometrial and ovarian cancer and insufficient for rarer types of gynecological cancers. The vitamin D receptor (VDR) is upregulated in all gynecological cancers, indicating its influence on cancer etiology. The VDR polymorphism FokI (rs2228570) seems to increase the risk of ovarian cancer. Other nuclear receptors, such as the RXR, also influence gynecological cancers. Although there is limited knowledge on the role of the VDR/RXR on the survival of endometrial, cervical, vulvar or vaginal cancer patients, some studies showed that both receptors influence survival. Therefore, we suggest that further studies should focus on the vitamin D- and its hetero dimer receptor RXR in gynecological cancers.

Calcitriol induces cell senescence of kidney cancer through JMJD3 mediated histone demethylation

Calcitriol, also known as 1,25-dihydroxyvitamin D3 (1,25(OH)₂VD₃), is a biologically active form of vitamin D and has a wide range of anticancer activity against various cancer cell lines. However, the mechanism of calcitriol remains to be further studied. In this study, the biological effect and epigenetic regulation of calcitriol on kidney cancer cells were investigated. Calcitriol can significantly inhibit cell proliferation of kidney cancer cell lines 786-O (P<0.05). Calcitriol also induced cell apoptosis and senescence of 786-O and ACHN (P<0.05). Calcitriol can increase the expression of histone demethylase JMJD3 and cell senescence marker p16INK4A (P<0.05). Knockdown of JMJD3 decreased p16INK4A upregulation after calcitriol treatment (P<0.05), and also reduced calcitriol-induced cell senescence (P<0.05). This study reveals a new mechanism of anticancer activity of calcitriol by showing that histone demethylase JMJD3 induced by calcitriol increases p16INK4A expression and cell senescence. Therefore, these results provide new strategy for treatment and prevention of kidney cancer.

Association of vitamin D receptor gene polymorphisms with breast cancer risk in an Egyptian population

This study aimed to explore whether genetic polymorphisms in vitamin D receptor are correlated to the breast cancer prevalence in an Egyptian population. Polymerase chain reaction-restriction fragment polymorphism was used to genotype three frequently analyzed vitamin D receptor gene single-nucleotide polymorphisms (rs1544410, rs7975232, and rs731236) and were identified by sequencing analysis. This is the first study that recorded a new single-nucleotide polymorphism in ApaI genotype within an Egyptian population and was registered with the accession number KY859868. The authors found that TC in rs731236, and TG in KY859868 single-nucleotide polymorphism showed significant distribution differences with an increased risk of breast cancer ( p < 0.05, odds ratio = 3.71, 95% confidence interval: 1.04-13.28 and p < 0.001, odds ratio = 7.05, 95% confidence interval: 2.02-24, respectively) compared with the wild-type TT genotype carriers in both single-nucleotide polymorphisms. In addition, the distribution frequencies of haplotypes ACT, GTT, and ATT in the patients group were significant, where ATT haplotype was associated with the highest breast cancer risk among all other haplotypes in the patients group ( p = 0.0023, odds ratio = 1.72, 95% confidence interval: 1.24-2.437). In conclusion, vitamin D receptors ApaI and TaqI confer high breast cancer susceptibility, particularly in Egyptians females carrying haplotype ATT. However, further studies focusing on the vitamin D receptor variants and haplotypes effects on vitamin D and vitamin D receptor concentrations, activities, and functionalities are needed.

Vitamin D Levels, Vitamin D Receptor Polymorphisms, and Inflammatory Cytokines in Aromatase Inhibitor-Induced Arthralgias: An Analysis of CCTG MA.27

BACKGROUND

Approximately half of women taking aromatase inhibitor (AI) therapy develop AI-induced arthralgia (AIA), and many might discontinue AI therapy because of the pain. Using plasma samples from the MA.27 study, we assessed several factors potentially associated with AIA.

PATIENTS AND METHODS

MA.27 is a phase III adjuvant trial comparing 2 AIs, exemestane versus anastrozole. Within an 893-participant nested case-control AIA genome-wide association study, we nested a 72 AIA case-144 control assessment of vitamin D plasma concentrations, corrected for seasonal and geographic variation. We also examined 9 baseline inflammatory cytokines: interleukin (IL)-1β, IL-6, tumor necrosis factor-α, interferon (IFN)γ, IL-10, IL-12p70, IL-17, IL-23, and chemokine ligand (CCL)-20. Finally, we analyzed the multivariate effects of baseline factors: vitamin D level, previously identified musculoskeletal single nucleotide polymorphisms, age, body mass index, and vitamin D receptor (VDR) Fok-I variant genotype on AIA development.

RESULTS

Changes in vitamin D from baseline to 6 months were not significantly different between cases and controls. Elevated inflammatory cytokine levels were not associated with development of AIA. The multivariate model included no clinical factors associated with AIA. However, women with the VDR Fok-I variant genotype were more likely to have a lower IL-1β level (P = .0091) and less likely to develop AIA after 6 months of AI compared with those with the wild type VDR (P < .0001).

CONCLUSION

In this nested case-control correlative study, vitamin D levels were not significantly associated with development of AIA; however, patients with the Fok-I VDR variant genotype were more likely to have a significant reduction in IL-1β level, and less likely to develop AIA.

Updated analysis of vitamin D receptor gene FokI polymorphism and prostate cancer susceptibility

INTRODUCTION

Polymorphisms of the vitamin D receptor (VDR) gene have been investigated in various case-control studies to evaluate prostate cancer susceptibility; however, published data on the association between vitamin D receptor gene FokI polymorphism and prostate cancer risk are inconclusive.

MATERIAL AND METHODS

To assess the impact of vitamin D receptor gene FokI polymorphism, we performed a meta-analysis of eligible studies including 9,720 patients and 9,710 control subjects.

RESULTS

The overall results indicated no obvious association of this variant on prostate cancer risk. However, in subgroup analysis by ethnicity, positive associations existed in Caucasian descendents for allelic contrast (OR = 1.03, 95% CI: 1.00-1.06, p_{heterogeneity} = 0.552, p = 0.026) and the dominant genetic model (OR = 1.03, 95% CI: 1.00-1.05, p_{heterogeneity} = 0.856, p = 0.032). In the subgroup analysis by tumor stage, there was a significant association between this variant and advanced prostate cancer under the recessive genetic model (OR = 1.15, 95% CI: 1.01-1.32, p_{heterogeneity} = 0.469, p = 0.032). In the subgroup analysis by source of control, association of the VDR FokI polymorphism and prostate cancer susceptibility was also found in population-based studies under homozygote comparison and the recessive genetic model.

CONCLUSIONS

The VDR FokI polymorphism may contribute to the risk of developing prostate cancer in Caucasian and population-based studies. Further large, well-designed studies are warranted to confirm this conclusion in more detail.

Genetic variation in the vitamin D related pathway and breast cancer risk in women of African ancestry in the root consortium

The vitamin D related pathway has been evaluated in carcinogenesis but its genetic contribution remains poorly understood. We examined single-nucleotide polymorphisms (SNPs) in the vitamin D related pathway genes using data from a genome-wide association study (GWAS) of breast cancer in the African Diaspora that included 3,686 participants (1,657 cases). Pathway- and gene-level analyses were conducted using the adaptive rank truncated product test. Odds ratios (OR) and 95% confidence intervals (CI) were estimated at SNP-level. After stringent Bonferroni corrections, we observed no significant association between variants in the vitamin D pathway and breast cancer risk at the pathway-, gene-, or SNP-level. In addition, no association was found for either the reported signals from GWASs of vitamin D related traits, or the SNPs within vitamin D receptor (VDR) binding regions. Furthermore, a decrease in genetically predicted 25(OH)D levels by Mendelian randomization was not associated with breast cancer (p = 0.23). However, an association for breast cancer with the pigment synthesis/metabolism pathway almost approached significance (pathway-level p = 0.08), driven primarily by a nonsense SNP rs41302073 in TYRP1, with an OR of 1.54 (95% CI = 1.24-1.91, p_adj  = 0.007). In conclusion, we found no evidence to support an association between vitamin D status and breast cancer risk in women of African ancestry, suggesting that vitamin D is unlikely to have significant effect on breast carcinogenesis. Interestingly, TYRP1 might be related to breast cancer through a non-vitamin D relevant mechanism but further studies are needed.

Vitamin D and K signaling pathways in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary liver malignancy, and is now the six most common in between malignancies. Early diagnosis of HCC with prompt treatment increases the opportunity of patients to survive. With the advances in understanding the molecular biology of HCC, new therapeutic strategies to treat HCC have emerged. There is a growing consensus that vitamins are important for the control of various cancers. Biochemical evidence clearly indicates that HCC cells are responsive to the inhibitory effect of vitamin D, vitamin D analogues and vitamin K. In this review, we summarize the mechanisms used by vitamin D and K to influence the development of HCC and the latest development of vitamin analogues for potential HCC therapy.

THE INVOLVEMENT OF VDR PROMOTER METHYLATION, CDX-2 VDR POLYMORPHISM AND VITAMIN D LEVELS IN MALE INFERTILITY

INTRODUCTION

Vitamin D (VD) levels were correlated with different health conditions, including reproductive disorders in males. Vitamin D action is mediated through vitamin D receptor (VDR), which acts as a transcription factor. VDR gene promoter is embedded in a GC-rich island. The VDR gene has been shown to have several polymorphisms that affect the receptor function.

AIM

To examine the relationship between Cdx-2 polymorphism (rs17883968), the methylation status of VDR's promoter and serum levels of 25-hydroxyvitamin D in male infertility.

PATIENTS AND METHODS

A total of 69 infertile men and 37 age-matched controls were enrolled in this study. Vitamin D level assessments were detected using the electrochemiluminescent method. Cdx-2 VDR polymorphism identification was performed by PCR on DNA samples from blood, followed by restriction. Methylation of VDR gene promoter was assessed by qMS-PCR using bisulfite-treated DNA from fresh sperm.

RESULTS

Vitamin D levels was found to be significantly decreased in infertile groups compared the controls (p=0.0279). The GG genotype was found in a higher percentage in controls and the AA genotype was higher in infertile group (p=0.0056). Infertile homozygote (GG) and heterozygote (GA) individuals had significantly higher vitamin D levels than AA homozygote. Methylation is higher in individuals with lower vitamin D levels and AA genotype is characterized by higher methylation values.

CONCLUSION

The results provide new insights of Cdx-2 polymorphism is involved in vitamin D deficiency, highlighting the important role of epigenetic modification of vitamin D receptor and male infertility along with the genetic context.

Vitamin D Receptor (VDR) Polymorphisms in Pediatric Patients Presenting With Hodgkin's Lymphoma

Vitamin D receptor (VDR) polymorphisms are found more commonly in some tumor types than in healthy individuals, suggesting that some polymorphisms (Cdx2, Fok1, Bsm1, Apa1, Taq1) contribute to tumor development. There is no previous report on VDR polymorphism in Hodgkin's lymphoma (HL) patients. VDR polymorphism patterns in 95 pediatric HL cases with 100 healthy controls were compared. No statistically significant difference was found between the patient group and control group in terms of Cdx2, Fok1, Bsm1, Apa1, and Taq1 polymorphisms (P>0.5). Our findings suggest that VDR polymorphisms may not play a role in HL development.

Association between genetic variation within vitamin D receptor-DNA binding sites and risk of basal cell carcinoma

An increasing number of studies have reported a protective association between vitamin D and cancer risk. The vitamin D endocrine system regulates transcriptional programs involved in inflammation, cell growth and differentiation through the binding of vitamin D receptor (VDR) to specific VDR elements. However, limited attention has been given to the role of variation within VDR binding sites in the development of basal cell carcinoma (BCC). Across 2,776 previously identified VDR binding sites, we identified 2,540 independent single-nucleotide polymorphisms (SNPs) and examined their associations with BCC risk in a genome-wide association meta-analysis totaling 17,187 BCC cases and 287,054 controls from two data sets. After multiple testing corrections, we identified two SNPs at new loci (rs16917546 at 10q21.1: odds ratio (OR) = 1.06, p = 3.16 × 10^-7 and rs79824801 at 12q13.3: OR = 1.10, p = 1.88 × 10^-5 ) for the first time as independently related to BCC risk in meta-analysis; and both SNPs were nominally significant in two data sets. In addition, the SNP rs3769823 within VDR binding site at a previously reported BCC susceptibility locus (2q33.1, rs13014235) also exhibited a significant association (OR = 1.12, p = 3.99 × 10^-18 ). A mutually adjusted model suggested that rs3769823 explained the signal in this region. Our findings support the hypothesis that inherited common variation in VDR binding sites affects the development of BCC.

Bile salt receptor TGR5 is highly expressed in esophageal adenocarcinoma and precancerous lesions with significantly worse overall survival and gender differences

Bile acid reflux in the esophagus plays an important role in the carcinogenesis of esophageal adenocarcinoma (EAC). The G-protein coupled bile acid receptor (TGR5) has been associated with the development of gastrointestinal cancer. However, little is known regarding the role of TGR5 in esophageal carcinoma and precancerous lesions. We analyzed genomic DNA from 116 EACs for copy number aberrations via Affymetrix SNP6.0 microarrays. The TGR5 gene locus was amplified in 12.7% (14/116) of the EACs. The TGR5 protein expression was also assessed using immunohistochemistry from tissue microarrays, including Barrett’s esophagus (BE), low-(LGD) and high-grade dysplasia (HGD), columnar cell metaplasia (CM), squamous epithelium (SE), EAC and squamous cell carcinoma. The TGR5 protein was highly expressed in 71% of EAC (75/106), 100% of HGD (11/11), 72% of LGD (13/18), 66% of BE (23/35), 84% of CM (52/62), and 36% of SE (30/83). The patients with high expression of TGR5 exhibited significantly worse overall survival compared to the patients with nonhigh expression. TGR5 high expression was significantly increased in the males compared to the females in all cases with an odds ratio of 1.9 times. The vitamin D receptor (VDR) was significantly correlated with TGR5 expression. Our findings indicated that TGR5 may play an important role in the development and prognosis of EAC through a bile acid ligand. Gender differences in TGR5 and VDR expression may explain why males have a higher incidence of EAC compared to females.

Characteristic patterns of cancer incidence: Epidemiological data, biological theories, and multistage models

We investigate and classify several patterns in cancer incidence and relative risk data which persist across different countries and multiple published studies. We then explore biological hypotheses as well as many mathematical models in the literature that attempt to explain these patterns. A general modeling framework is presented which is general enough to model most of observed behaviors. It is our belief that this model has sufficient flexibility to be adapted to new information as it is discovered. As one application of this framework, we give a model for the effect of aging on the process of carcinogenesis.

Biological underpinnings of breastfeeding challenges: the role of genetics, diet, and environment on lactation physiology

Lactation is a dynamic process that has evolved to produce a complex biological fluid that provides nutritive and nonnutritive factors to the nursing offspring. It has long been assumed that once lactation is successfully initiated, the primary factor regulating milk production is infant demand. Thus, most interventions have focused on improving breastfeeding education and early lactation support. However, in addition to infant demand, increasing evidence from studies conducted in experimental animal models, production animals, and breastfeeding women suggests that a diverse array of maternal factors may also affect milk production and composition. In this review, we provide an overview of our current understanding of the role of maternal genetics and modifiable factors, such as diet and environmental exposures, on reproductive endocrinology, lactation physiology, and the ability to successfully produce milk. To identify factors that may affect lactation in women, we highlight some information gleaned from studies in experimental animal models and production animals. Finally, we highlight the gaps in current knowledge and provide commentary on future research opportunities aimed at improving lactation outcomes in breastfeeding women to improve the health of mothers and their infants.

Molecular assessment of vitamin D receptor polymorphism as a valid predictor to the response of interferon/ribavirin-based therapy in Egyptian patients with chronic hepatitis C

OBJECTIVE

The aim of this study was to find an association between serum concentration of vitamin D and vitamin D receptor (VDR) polymorphisms to achieve a sustained virological response (SVR).

METHODS

We conducted a case-control study in which 250 participants were recruited and divided into three groups (100 chronic hepatitis C [CHC] patients who achieved SVR, 100 CHC patients who did not achieve SVR and 50 apparently healthy individuals as controls). Blood samples were collected to measure serum vitamin D concentration, and four VDR polymorphisms (FokI, ApaI, TaqI, and BsmI) were detected using polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Non-responders were found to have significantly low vitamin D concentration compared with responders and control groups. Concerning VDR polymorphisms, both FokI and TaqI polymorphisms were associated with successful treatment.

CONCLUSION

Vitamin D concentration, FokI, and TaqI may be considered as the predictors for the response of CHC patients to a combination therapy of pegylated interferon and ribavirin.

The vitamin D receptor gene ApaI polymorphism is associated with increased risk of renal cell carcinoma in Chinese population

Molecular epidemiologic studies previously reported that 1,25-dihydroxy vitamin D₃ (1,25(OH)₂ D₃) appears to influence cancer risk. It exerts its activity through the intracellular vitamin D receptor (VDR), which regulates the transcription of genes. This study aimed to investigate the genetic association of VDR polymorphisms with renal cell carcinoma (RCC) risk in the Chinese population. The genotypes of five VDR polymorphisms (TaqI, BsmI, Cdx-2, ApaI, and FokI) were studied using polymerase chain reaction in 302 RCC patients and 302 healthy controls. ApaI variant AA and AC genotypes were found to be associated with a significantly increased risk of RCC compared with the CC genotype (OR = 2.60, 95% CI = 1.39–4.85 for AA vs. CC, and OR = 1.52, 95% CI = 1.08–2.13 for AC vs. CC). The AA genotype was also associated with a higher Fuhrman grade (OR = 2.87, 95% CI = 1.15–7.16 for AA vs. CC). No significant difference was found between the other four VDR polymorphisms and RCC risk. Our study suggests that VDR ApaI genotypes may be involved in the increased risk and progression of RCC in the Chinese Han population.

Vitamin D Receptor Polymorphism and Breast Cancer Risk: A Meta-Analysis

The objective was to perform a meta-analysis to summarize the available evidence from prospective nested case-control studies on the association of vitamin D receptor (VDR) polymorphism and the risk of breast cancer.We searched PubMed, ISI web of science, EMBASE, and reference lists for included articles. Study specific odds ratios (ORs) and 95% confidence intervals (CIs) were pooled by using fixed-effect or random-effects models.Eight studies were included in the meta-analysis. There were no association between Fok1 gene allele contrast f versus F (OR: 0.859; 95%CI: 0.685-1.079), ff versus FF (OR: 0.893; 95%CI: 0.763-1.045), recessive models ff versus FF+Ff (OR: 0.932; 95%CI: 0.796-1.092), and dominant models ff+Ff versus FF (OR: 0.899; 95%CI: 0.780-1.037). The estimated VDR polymorphism showed no significant association between Bsm1, Taq1, Apa1 polymorphism, and breast cancer risk. In the Caucasian ethnic subgroup, no association was found between allele contrast, recessive models, and dominant models on Fok1, Bsm1 polymorphism, and breast cancer risk.VDR polymorphism (Fok1, Bsm1, Taq1, and Apa1) were not associated with the risk of breast cancer in the general population as well as Caucasian population.

Influence of Serum Levels of Vitamins A, D, and E as well as Vitamin D Receptor Polymorphisms on Micronucleus Frequencies and Other Biomarkers of Genotoxicity in Workers Exposed to Formaldehyde

BACKGROUND/AIM

Formaldehyde is classified as carcinogenic to humans, making it a major concern, particularly in occupational settings. Fat-soluble vitamins, such as vitamins A, D, and E, are documented as antigenotoxic and antimutagenic and also correlate with the cell antioxidant potential. This study investigates the influence of these vitamins on genotoxicity biomarkers of formaldehyde-exposed hospital workers.

METHODS

The target population were hospital workers exposed to formaldehyde (n = 55). Controls were nonexposed individuals (n = 80). The most used genotoxicity biomarkers were the cytokinesis-block micronucleus assay for lymphocytes and the micronucleus test for exfoliated buccal cells. Vitamins A and E were determined by high-performance liquid chromatography with a diode array detector (HPLC-DAD) and vitamin D receptor (VDR) polymorphisms by real-time PCR.

RESULTS

Significant correlations were found between genotoxicity biomarkers and between vitamins A and E in controls. Multiple regression showed that vitamin A was significantly associated with a higher mean of nucleoplasmic bridges (p < 0.001), and vitamin E was significantly associated with a decreased frequency of nuclear buds (p = 0.045) in the exposed group. No effect of vitamin D was observed. The VDRBsmI TT genotype carriers presented higher means of all the genotoxicity biomarkers; however, we found no significant associations.

CONCLUSIONS

The study suggests that vitamin levels may modulate direct signs of genotoxicity.

FokI Polymorphism of the Vitamin D Receptor Gene Is Associated with Susceptibility to Gastric Cancer: A Case-Control Study

Vitamin D is a potential protective agent against cancer, and its activity is mediated mainly by vitamin D receptor (VDR). The FokI polymorphism (rs10735810) represents a T-to-C transition (ATG to ACG) in exon 2 of the VDR gene, and this ATG represents the translation-initiation codon, encoded by the f allele. The FokI polymorphism results in the generation of a protein shortened by three amino acids, translated from the downstream ATG codon (the F allele). We investigated the relationship between the FokI polymorphism and gastric cancer in a Chinese Han population. A total of 187 patients and 212 healthy controls were enrolled. The FokI polymorphism was detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. The f allele frequency was higher in patients than that in controls (51.6% and 43.6%, P < 0.05). Multivariate logistics regression analysis revealed patients with the f allele (Ff + ff) showed a higher risk of gastric cancer [odds ratio (95% confidence interval) 2.73 (1.13~4.32)]. Patients with the f allele (Ff + ff) also presented a poorly differentiated type of gastric cancer (P < 0.05) and higher levels of C-reactive protein on admission than the FF group (5.5 ± 2.4 mg/L vs. 3.4 ± 1.3 mg/L, P < 0.05). Here, we show an association between the VDR FokI polymorphism and the susceptibility to gastric cancer, which may be helpful for early detection of high-risk individuals with the f allele for gastric cancer. Conversely, the F allele may be a protective factor against gastric cancer.

Sun exposure and melanoma prognostic factors

Previous studies have reported an association between sun exposure and the increased survival of patients with cutaneous melanoma (CM). The present study analyzed the association between ultraviolet (UV) light exposure and various prognostic factors in the Italian Clinical National Melanoma Registry. Clinical and sociodemographic features were collected, as well as information concerning sunbed exposure and holidays with sun exposure. Analyses were performed to investigate the association between exposure to UV and melanoma prognostic factors. Between December 2010 and December 2013, information was obtained on 2,738 melanoma patients from 38 geographically representative Italian sites. A total of 49% of the patients were >55 years old, 51% were men, 50% lived in the north of Italy and 57% possessed a high level of education (at least high school). A total of 8 patients had a family history of melanoma and 56% had a fair phenotype (Fitzpatrick skin type I or II). Of the total patients, 29% had been diagnosed with melanoma by a dermatologist; 29% of patients presented with a very thick melanoma (Breslow thickness, >2 mm) and 25% with an ulcerated melanoma. In total, 1% of patients had distant metastases and 13% exhibited lymph node involvement. Holidays with sun exposure 5 years prior to CM diagnosis were significantly associated with positive prognostic factors, including lower Breslow thickness (P<0.001) and absence of ulceration (P=0.009), following multiple adjustments for factors such as sociodemographic status, speciality of doctor performing the diagnosis and season of diagnosis. Sunbed exposure and sun exposure during peak hours of sunlight were not significantly associated with Breslow thickness and ulceration. Holidays with sun exposure were associated with favorable CM prognostic factors, whereas no association was identified between sunbed use and sun exposure during peak hours of sunlight with favorable CM prognostic factors. However, the results of the present study do not prove a direct causal effect of sun exposure on melanoma prognosis, as additional confounding factors, including vitamin D serum levels, may have a role.

Calcitriol in Combination Therapy for Prostate Cancer: Pharmacokinetic and Pharmacodynamic Interactions

Epidemiological studies indicate that vitamin D insufficiency could have an etiological role in prostate cancer. In addition, calcitriol, used in combination with currently available drugs, has the potential to potentiate their anticancer effects or act synergistically by inhibiting distinct mechanisms involved in prostate cancer growth. Clinical data have not yet provided sufficient evidence to demonstrate benefit of vitamin D due to the limited and underpowered studies that have been published to date. Here, we review the preclinical and clinical studies that describe the activity of calcitriol, applied either alone or in combination and assessed the mechanistic basis of pharmacodynamic and pharmacokinetic interactions with calcitriol. Important considerations for calcitriol use in combination therapy with respect to safety and clinical outcomes have been discussed. Many of these combinations have therapeutic potential for the treatment of several cancer types and it is anticipated that future clinical research will put emphasis on well‑designed clinical trials to establish efficacy.

Genetic variations in vitamin D-related pathways and breast cancer risk in African American women in the AMBER consortium

Studies of genetic variations in vitamin D-related pathways and breast cancer risk have been conducted mostly in populations of European ancestry, and only sparsely in African Americans (AA), who are known for a high prevalence of vitamin D deficiency. We analyzed 24,445 germline variants in 63 genes from vitamin D-related pathways in the African American Breast Cancer Epidemiology and Risk (AMBER) consortium, including 3,663 breast cancer cases and 4,687 controls. Odds ratios (OR) were derived from logistic regression models for overall breast cancer, by estrogen receptor (ER) status (1,983 ER positive and 1,098 ER negative), and for case-only analyses of ER status. None of the three vitamin D-related pathways were associated with breast cancer risk overall or by ER status. Gene-level analyses identified associations with risk for several genes at a nominal p ≤ 0.05, particularly for ER- breast cancer, including rs4647707 in DDB2. In case-only analyses, vitamin D metabolism and signaling pathways were associated with ER- cancer (pathway-level p = 0.02), driven by a single gene CASR (gene-level p = 0.001). The top SNP in CASR was rs112594756 (p = 7 × 10(-5), gene-wide corrected p = 0.01), followed by a second signal from a nearby SNP rs6799828 (p = 1 × 10(-4), corrected p = 0.03). In summary, several variants in vitamin D pathways were associated with breast cancer risk in AA women. In addition, CASR may be related to tumor ER status, supporting a role of vitamin D or calcium in modifying breast cancer phenotypes.

Association of vitamin D receptor gene polymorphisms with response to peginterferon plus ribavirin in Asian patients with chronic hepatitis C

BACKGROUND/PURPOSE

Recent studies have shown that serum vitamin D deficiency is a negative predictor of response to peginterferon plus ribavirin therapy for Caucasian patients with chronic hepatitis C (CHC). Whether vitamin D receptor (VDR) gene polymorphisms associate with antiviral response in Asian CHC patients remains unclear.

METHODS

We recruited 139 Asian patients with CHC genotype-1 who achieved 80/80/80 adherence of response-guided peginterferon plus ribavirin therapy. BsmI rs1544410, ApaI rs7975232, and TaqI rs731236 were genotyped and related to clinical and virological features and to treatment outcome.

RESULTS

Patients carrying bAt [CCA] haplotype (p=0.033), ApaI CC genotype (p = 0.033), and TaqI AA genotype (p = 0.037) had a higher HCV load as compared to those with other haplotypes, ApaI CA/AA genotype and TaqI AG genotype, respectively. A sustained virological response (SVR) was achieved in 74 (53%) of the patients. Polymorphisms in VDR gene did not correlate with rapid virological response and SVR achievement. Stepwise logistic regression analysis showed that rs12979860 CC type [odds ratio (OR): 5.56, p=0.007], platelet counts ≥ 15 × 10(10)/L (OR: 4.80, p=0.001), and rapid virological response achievement (OR: 8.36, p<0.001) were independent factors of SVR.

CONCLUSION

Despite their associations with high hepatitis C virus load, VDR gene polymorphisms are not related to the response to peginterferon plus ribavirin therapy in Asian CHC patients.