VDR peptide

Background Vitamin D has anticarcinogenic properties and acts through vitamin D receptor (VDR) to carry out its functions. Aims This study explored the independent and combined effects of dietary vitamin D and calcium, andVDRgenetic polymorphisms on colorectal cancer risk in a Chinese population. Methods This ongoing case-control study recruited 488 cases with histologically confirmed colorectal cancer and 496 sex- and age-matched controls. Vitamin D and calcium intakes were assessed by a validated food frequency questionnaire, andVDRgenotype was conducted forFok I(rs2228570),Bsm I(rs1544410),Apa I(rs7975232), andTaq I(rs731236). Unconditional logistic regression was used to calculate odds ratio and 95% confidence interval after adjusting for various confounders. Results No significant association was found betweenFok I,Bsm I,Apa I,Taq I, and colorectal cancer risk. Higher intakes of dietary vitamin D and calcium were associated with 47% and 50% reduction in colorectal cancer risk. Significant interaction was observed between dietary vitamin D intake andApa Ipolymorphisms in relation to colorectal cancer risk (P-interaction = 0.006). Subjects with higher dietary vitamin D intake and mutantApa IA allele had a substantially decreased risk of colorectal cancer compared toApa Iaa carriers with lower vitamin D intake. Conclusions Our study supports thatApa Imay interact with dietary vitamin D intake on colorectal cancer risk. However, no interactions were found between dietary vitamin D or calcium intakes andFok I, Bsm I, andTaq Iin relation to colorectal cancer risk.

Deficiency in circulatory vitamin D level and vitamin D receptor DNA methylation could be associated with weakened innate immune response and increased susceptibility to tuberculosis (TB) disease in children. Therefore, we aimed to study the effect of vitamin D receptor (VDR) gene methylation on plasma vitamin D level and the expression of the VDR gene in children with active-TB disease. A cross-sectional comparative study was conducted in 43 children with active-TB and 33 healthy control children (HC). The vitamin D level was measured in plasma, while the levels of VDR gene promoter methylation and VDR gene expression were measured in peripheral blood. Children with active-TB showed a significantly lower median vitamin D level than HC [Cases 17.18 ng/mL (IQR, 8.3-18.6 ng/mL); HC 41.34 ng/mL (IQR, 40.2-43.49 ng/mL) (p<0.0001)] and decreased mRNA expression level of VDR gene [Cases 0.51 (IQR, 0.40-0.70); HC 1.06 (IQR, 0.8-1.2) (p<0.0001)] and increased VDR DNA methylation [Cases 75% (IQR, 50-75%); HC 10% (IQR, 10-25%) (p<0.0001)]. The VDR hypermethylation is significantly associated with reduced vitamin D level and decreased expression level of VDR gene. Therefore this inverse association could be involved in the impairment in the VDR mediated cytolytic and antimicrobial effector cell response in pediatric TB disease.