Association of vitamin D and polymorphisms of its receptor with antiviral therapy in pregnant women with hepatitis B

BACKGROUND The interruption of mother-to-child transmission(MTCT)is considered important to decrease the individual and population morbidity of hepatitis B virus(HBV)infection as well as the global burden of hepatitis B.Serum vitamin D(VD)is associated with hepatitis B.AIM To assess whether baseline VD levels and single nucleotide polymorphisms of the VD receptor gene(VDR SNPs)are associated with the efficacy of tenofovir disoproxil fumarate(TDF)in the prevention of MTCT in pregnant women with high HBV viral loads.METHODS Thirty-eight pregnant women who were at high risk for MTCT of HBV(those with an HBV DNA level≥2×10^(5)IU/mL during 12-24 wk of gestation)receiving antiviral therapy of TDF between June 1,2019 and June 30,2021 in Mianyang were included in this retrospective study.The women received 300 mg TDF once daily from gestational weeks 24-28 until 3 mo after delivery.To further characterize the clinical relevance of maternal serum HBV DNA levels,we stratified patients according to HBV DNA level as follows:Those with levels<2×10_(5)(full responder group)vs those levels≥2×10^(5)IU/mL(partial responder group)at delivery.Serum levels of 25-hydroxyvitamin D[25(OH)D],liver function markers,virological parameters,VDR SNPs and other clinical parameters were collected to analyze their association with the efficacy of TDF.The Mann-Whitney U test or t test was used to analyze the serum levels of 25(OH)D in different groups.Multiple linear regressions were utilized to analyze the determinants of the maternal HBV DNA level at delivery.Univariate and multivariate logistic regression analyses were employed to explore the association of targeted antiviral effects with various characteristics at baseline and delivery.RESULTS A total of 38 pregnant women in Mianyang City at high risk for MTCT of HBV were enrolled in the study.The MTCT rate was 0%.No mother achieved hepatitis B e antigen or hepatitis B surface antigen(HBsAg)clearance at delivery.Twenty-three(60.5%)participants were full responders,and 15(39.5%)participants were partial responders according to antiviral efficacy.The present study showed that a high percentage(76.3%)of pregnant women with high HBV viral loads had deficient(<20 ng/mL)or insufficient(≥20 but<31 ng/mL)VD levels.Serum 25(OH)D levels in partial responders appeared to be significantly lower than those in full responders both at baseline(25.44±9.42 vs 17.66±5.34 ng/mL,P=0.006)and delivery(26.76±8.59 vs 21.24±6.88 ng/mL,P=0.044).Serum 25(OH)D levels were negatively correlated with maternal HBV DNA levels[log(10)IU/mL]at delivery after TDF therapy(r=-0.345,P=0.034).In a multiple linear regression analysis,maternal HBV DNA levels were associated with baseline maternal serum 25(OH)D levels(P<0.0001,β=-0.446),BMI(P=0.03,β=-0.245),baseline maternal log10 HBsAg levels(P=0.05,β=0.285)and cholesterol levels at delivery(P=0.015,β=0.341).Multivariate logistic regression analysis showed that baseline serum 25(OH)D levels(OR=1.23,95%CI:1.04-1.44),maternal VDR Cdx2 TT(OR=0.09,95%CI:0.01-0.88)and cholesterol levels at delivery(OR=0.39,95%CI:0.17-0.87)were associated with targeted antiviral effects(maternal HBV DNA levels<2×10^(5) at delivery).CONCLUSION Maternal VD levels and VDR SNPs may be associated with the efficacy of antiviral therapy in pregnant women with high HBV viral loads.Future studies to evaluate the therapeutic value of VD and its analogs in reducing the MTCT of HBV may be justified.

Loss of the vitamin D receptor in human breast and prostate cancers strongly induces cell apoptosis through downregulation of Wnt/β-catenin signaling

Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.

Associations between Vitamin D and Type 2 Diabetes Mellitus: The Role of Vitamin D Receptor and Binding Protein

Background: Type 2 diabetes mellitus (T2DM) is a chronic disease that is characterized by β-cell dysfunction and resistance for insulin. Vitamin D is necessary for insulin secretion so it is a crucial factor in the development of T2DM. This study was done to investigate the association between serum 25-hydroxy Vitamin D [25(OH)3D], VDR (Vitamin D receptor) and VDBP (Vitamin D binding protein) with type 2 diabetic patients compared to control subjects. Subjects and Methods: This study carried out 110 female patients who were previously diagnosed with type 2 diabetes and 110 age, sex and weight matched as controls. All participants were subjected to full history taking, clinical examination and assessment of fasting blood glucose, HbA1c , lipid profile, 25-hydroxy Vitamin D [25(OH)3D], VDR and VDBP. Results: Results showed that the level of 25(OH)3D was significantly lower in diabetic group compared to controls and was significantly negatively correlated with glycated hemoglobin, serum total cholesterol and low density lipoprotein cholesterol in type 2 DM. Decreasing Vitamin D level was significantly associated with decreasing VDR. No significant association was found between Vit D and VDBP levels. Conclusions: Vitamin D deficiency is frequent in diabetic patients and associated with poor control and outcome. This suggests a role of Vitamin D in the pathogenesis and control of T2DM. Serum VDBP in diabetes may be independent to the level of 25(OH)3D and needs further studies.

Serum vitamin D and colonic vitamin D receptor in inflammatory bowel disease

AIM: To determine serum vitamin D levels and colonic vitamin D receptor(VDR) expression in inflammatory bowel disease(IBD) and non-IBD patients and correlate these with histopathology.METHODS: Puerto Rican IBD(n = 10) and non-IBD(n = 10) patients ≥ 21 years old scheduled for colonoscopy were recruited. Each patient completed a questionnaire and provided a serum sample and a colonic biopsy of normal-appearing mucosa. For IBD patients, an additional biopsy was collected from visually diseased mucosa. Serum vitamin D levels were measured by ultra-performance liquid chromatography and mass spectrometry. Hematoxylin and eosin stained tissue sections from colonic biopsies were classified histologically as normal or colitis(active/inactive), and scored for the degree of inflammation present(0-3, inactive/absent to severe). Tissue sections from colonic biopsies were also stained by immunohistochemistry for VDR, for which representative diagnostic areas were photographed and scored for staining intensity using a 4-point scale.RESULTS: The IBD cohort was significantly younger(40.40 ± 5.27, P < 0.05) than the non-IBD cohort(56.70 ± 1.64) with a higher prevalence of vitamin D deficiency(40% vs 20%, respectively) and insufficiency(70% vs 50%, respectively). Histologic inflammation was significantly higher in visually diseased mucosa from IBD patients(1.95 ± 0.25) than in normalappearing mucosa from control patients(0.25 ± 0.08, P < 0.01) and from IBD patients(0.65 ± 0.36, P < 0.05) and correlated inversely with VDR expression in visually diseased colonic tissue from IBD patients(r =-0.44, P < 0.05) and from IBD patients with Crohn's disease(r =-0.69, P < 0.05), but not in normal-appearing colonic tissue from control patients or IBD patients. Control and IBD patient serum vitamin D levels correlated positively with VDR expression in normal colon from control and IBD patients(r = 0.38, P < 0.05) and with patient age(r = 0.54, P < 0.01). CONCLUSION: Levels of serum vitamin D correlate positively with colonic VDR expression in visually normal mucosa whereas inflammation correlates negatively with colonic VDR expression in visually diseased mucosa in Puerto Rican patients.

Bsm I(rs1544410) and Fok I(rs2228570) vitamin D receptor polymorphisms, smoking, and body mass index as risk factors of cutaneous malignant melanoma in northeast Italy

Objective:To investigate whether vitamin D receptor gene(VDR)Bsm I-rs1544410 and Fok I-rs2228570 polymorphisms,smoking duration,and body mass index(BMI)are risk factors for cutaneous melanoma,especially metastatic melanoma.Methods:We studied 120 cutaneous melanoma cases[68 stage I and II non-metastatic melanoma(NMet M)patients,plus 52Stage III and IV metastatic melanoma(Met M)patients],and 120 matching healthy controls from northeast Italy.VDR polymorphisms were measured by restriction fragment length polymorphism analysis.Absence or presence of Bsm I and Fok I restriction sites was denoted by"B"and"F"or by"b"and"f,"respectively.Results:VDR-Bsm I bb genotype was more frequent among Met M(32.7%)than among NMet M cases(13.2%),with odds ratio(OR)=3.18.Comparison of all melanoma patients vs healthy controls showed that the following biomarkers were at risk:≥20 years of smoking(OR=2.43);≥20 years of smoking combined with bb(OR=4.78),Bb+bb(OR=2.30),Ff(OR=3.04),and Ff+ff(OR=3.08);obesity(BMI>30Conclusions:Risk factors for cutaneous Met M include two VDR polymorphisms combined with smoking duration and obesity.Results suggest gene-environment implications in melanoma susceptibility and severity.Future studies in larger cohorts and in subjects with different genetic background are warranted to extend our findings.

Overview of studies of the vitamin D/vitamin D receptor system in the development of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver disease in the world.NAFLD is known to be associated with obesity,type 2 diabetes,metabolic syndrome and increased cardiovascular events:for these reasons,it is becoming a global public health problem and represents an important challenge in terms of prevention and treatment.The mechanisms behind the pathogenesis of NAFLD are multiple and have not yet been completely unraveled;consequently,at moment there are not effective treatments.In the past few years a large body of evidence has been assembled that attributes an important role in hepatic aberrant fat accumulation,inflammation and fibrosis,to the vitamin D/vitamin D receptor(VD/VDR)axis,showing a strong association between hypovitaminosis D and the diagnosis of NAFLD.However,the data currently available,including clinical trials with VD supplementation,still provides a contrasting picture.The purpose of this editorial is to provide an overview of recent advances in the pathogenesis of NAFLD in relation to VD/VDR.Based on recent data from literature,we focused in particular on the hypothesis that VDR itself,independently from its traditional ligand VD,may have a crucial function in promoting hepatic fat accumulation.This might also offer new possibilities for future innovative therapeutic approaches in the management of NAFLD.

Is vitamin D receptor a druggable target for non-alcoholic steatohepatitis?

Nonalcoholic steatohepatitis(NASH)is a progressed stage of non-alcoholic fatty liver disease,and available therapeutic strategies for NASH are limited.Vitamin D receptor(VDR)is proposed as a druggable target for NASH due to the discovery of vitamin D deficiency in NASH patients.To date,vitamin D supplementation has not consistently conferred expected therapeutic benefits,raising the question of whether VDR can serve as a proper drug target for NASH.It is known that VDR can interact with other ligands such as bile acids in addition to vitamin D,and its expression can be induced by fatty acids,and insulin.It has also been shown that while activation of VDR in hepatic macrophages and hepatic stellate cells resulted in attenuation of hepatic inflammation and fibrosis,activation of VDR in hepatocytes could accelerate lipid accumulation.Thus,the multiplicity of VDR ligands,together with the cell type-specificity of VDR activation,must be taken into consideration in assessing the validity of VDR being a potential druggable target for NASH treatment.To this end,we have evaluated the relationship between VDR activation and various contributing factors,such as gut microbiota,bile acid,fatty acids,and insulin,in addition to vitamin D,with an expectation that a potential drug might be identified that can elicit VDR activation in a tissue-and/or cell type-specific manner and therefore achieving therapeutic benefits in NASH.

Expression of vitamin D receptor and cathelicidin in human corneal epithelium cells during fusarium solani infection

AIMTo observe the expression of vitamin D receptor (VDR) in human specimen and immortalized human corneal epithelium cells (HCEC) when challenged with fusarium solani. Moreover, we decided to discover the pathway of VDR expression. Also, we would like to detect the expression of cathelicidin antimicrobial peptide (CAMP) in the downstream pathway of VDR.METHODSImmunohistochemistry was used to examine the VDR expression in HCEC from healthy and fungal keratitis patients. Real time quantitative polymerase chain reaction (qPCR) was performed to observe the messenger ribonucleic acid (mRNA) change of VDR when immortalized HCEC were challenged with fusarium solani for different hours. CAMP was detected at both mRNA and protein levels.RESULTSWe found out that the VDR expression in fusarium solani keratitis patients' specimen was much more than that in healthy people. The mRNA and protein expression of VDR increased when we stimulated HCEC with fusarium solani antigen (P&#x0003c;0.01) and it could be inhibited by toll like receptor 2 (TLR2) monoclonal antibody. The CAMP expression was decreased because of fusarium solani antigen stimulation (P&#x0003c;0.01).CONCLUSIONThe VDR expression can be increased via TLR2/1-VDR pathway while the CAMP expression is decreased by the stimulation of fusarium solani antigen.

Plasma Vitamin D Levels And Vitamin D Receptor Polymorphisms Are Associated with Survival of Non-small Cell Lung Cancer

Objective：Vitamin D and its receptor（VDR） involve in multiple cellular processes and play an important role in the initiation and progression of malignancy.Thus we hypothesized that plasma vitamin D levels and single nucleotide polymorphisms（SNPs） in VDR may be of prognostic significance in non-small cell lung cancer（NSCLC）.Methods：We examined plasma 25-hydroxyvitamin D [25（OH）D] levels in 87 patients diagnosed with NSCLC using enzyme-linked immunosorbent assay（ELISA） and genotyped seven potentially functional SNPs in VDR in 568 NSCLC patients on Illumina Golden Gate platform.Results：Patients with higher plasma 25（OH）D levels had worse survival than patients with lower ones（P for trend = 0.048）.The SNPs of rs1544410 and rs739837 were independently associated with NSCLC survival（adjusted HR = 1.61,95% CIs = 1.06-2.45 for rs739837 AA vs AC/CC and adjusted HR = 1.51,95% CIs = 1.06-2.16 for rs1544410 AG/AA vs GG）.A joint effect was observed between rs1544410 and rs739837 and the risk of death elevated as the number of unfavourable genotypes patients carried increased（P for trend = 0.003）.There were no significant associations between VDR polymorphisms and plasma 25（OH）D levels.Conclusion：Our findings indicate that plasma 25（OH）D levels and genetic variants of VDR may serve as prognostic markers for NSCLC in this Chinese population.

Polymorphisms of the Vitamin D Receptor Gene and SexDifferential Associations with Lipid Profiles in Chinese Han Adults

Objective To explore the association of single nucleotide polymorphisms(SNPs)of the vitamin D receptor gene(VDR)with circulating lipids considering gender differences.Methods Of the Han Chinese adults recruited from a health examination center for inclusion in the study,the circulating lipids,25-hydroxyvitamin D(25OHD),and other parameters were measured.The VDR SNPs of Cdx2(rs11568820),Fok1(rs2228570),Apa1(rs7975232),and Taq1(rs731236)were genotyped with a qPCR test using blood DNA samples,and their associations with lipids were analyzed using logistic regression.Results In the female participants(n=236 with dyslipidemia and 888 without dyslipidemia),multiple genotype models of Fok1 indicated a positive correlation of B(not A)alleles with LDLC level(P<0.05).In the male participants(n=299 with dyslipidemia and 564 without dyslipidemia),the recessive model of Cdx2 and the additive and recessive models of Fok1 differed(P<0.05)between the HDLC-classified subgroups,respectively,and Fok1 BB and Cdx2 TT presented interactions with 25OHD in the negative associations with HDLC(P<0.05).Conclusion In the Chinese Han adults included in the study,the Fok1 B-allele of VDR was associated with higher LDLC in females,and the Fok1 B-allele and the Cdx2 T-allele of VDR were associated with lower HDLC in males.The interaction of VD and Fok1 BB or Cdx2 TT in males synergistically decreased HDLC levels.

Association of Vitamin D Receptor Gene Polymorphisms with Metabolic Syndrome in Rural Areas of China

Metabolic Syndrome (MS) is a combination of multiple complex diseases, whose etiology is complicated and has many influencing factors Randomized controlled trials have shown that vitamin D supplementation could delay the ameliorate symptoms of multiple chronic disease Therefore, it is reasonable to postulate that the expression levels of vitamin D and its related gene variants might be correlated with MS.

Association of Vitamin D Receptor Gene Polymorphisms with Calcium Oxalate Calculus Disease

To study the relationship between polymorphism of vitamin D receptor (VDR) allele with formation of calcium oxalate calculus and find the predisposing genes of calcium oxalate calculus, we screened out 150 patients who suffered from calcium oxalate calculus. 36 of them had idiopathic hypercalciuria according to analysis of calculus component and assay of urine calcium. The polymorphisms of VDR gene Taq1, Apa1 and Fok1 were detected using PCR-RFLP technique and the correlation were analyzed between the polymorphism and urinary calculus or between the polymorphism and hypercalciuria. The difference in each genotypic frequency of the allele of promoter Fok1 between calculus group and healthy group or between idiopathic hypercalciuria calculus group and health group was significant. The content of 24-h urine calcium of those who had genotype ff was obviously higher than that of those who have other genotypes in the same group. There was no significant difference in the polymorphism of gene Apa1 and Taq1 between each two groups. It is concluded that hypercalciuria and calcium oxalate calculus were related to the polymorphism of VDR gene's promoter Fok1 allele, but it had nothing to do with the polymorphism of gene Apa1 and Taq1. The genotype ff was a candidate heredity marker of calcium calculus disease.

Bisphosphonates and adipogenesis: Evidence for alendronate inhibition of adipocyte differentiation in 3T3-L1 preadipocytes through a vitamin D receptor mediated effect

Background: Adipocyte and osteoblast derive from the same mesenchimal progenitor. Age-related decrease in bone mass is accompanied by an increase in marrow adipose tissue. Vitamin D3 (VD3) inhibits adipogenesis in 3T3-L1 preadipocytes. Recently it has been demonstrated that alendronate (ALN) inhibits adipogenesis while promoting osteoblast differentiation of mesenchimal stem cells. Aim of the Study: To evaluate the role of ALN on adipocyte differentiation in vitro and the potential synergic role of VD3 co-treatment. Procedures: Murine 3T3-L1 and 3T3-F442A preadipocytes were routinely differentiated in presence of ALN and VD3 10-9 - 10-7 M for 7 days and then stained with Oil Red O. The effect of these treatments on mRNA expression of the main molecular markers of adipocyte differentiation (PPARγ and C/EBPα) and VD Receptor (VDR) were analyzed through RT-PCR. Results: Both ALN and VD3 showed a marked anti-adipogenic effect on 3T3-L1 cells. Co-incubation of ALN 10-8 M and VD3 10-9 M displayed no synergic effect on inhibition of adipogenesis. PPARγ mRNA expression was significantly reduced by ALN and VD3. mRNA expression of C/EBPα was reduced only by VD3 treatment. An increase in VDR mRNA expression of 3T3-L1 cells was observed with both ALN and VD3. On the contrary, 3T3-F442A cells, which are in a more advanced adipogenic differentiation stage compared to 3T3-L1, did not express detectable levels of VDR. Interestingly, adipose differentiation of 3T3-F442A was not affected by ALN nor VD3. These results suggest that VDR may represent the molecular target of the anti-adipogenic effect of ALN. Conclusion: VDR plays a critical role in mediating the anti-adipogenic effect of ALN. Further studies to clarify this mechanism are warranted.

Study of Vitamin D Receptor (VDR) Gene Polymorphisms among Egyptian Cohort Patients with Different Stages of Colorectal Cancer

Colorectal cancer represents the third cancer worldwide. Studies showed thatinsufficient levels of vitamin D may result in colorectal cancer. Genetic variations in genes controlling vitamin D activity would play a role in determining susceptibility to colorectal cancer. Aim of the work: to study the different genotypes of VDR polymorphisms and detect the association between serum levels of 25(OH)VitD and 1,25(OH)2VitD among sample of Egyptian patients with different stages of colorectal cancer. Methods: Ninety patients (60 with different stages of colorectal cancer and 30 patients with benign pathology of the colon) together with 30 healthy controls were examined using PCR-RFLP analysis for FokI, ApaI and TaqI polymorphisms. Results: Genotype distribution for ApaI polymorphism showed no statistically significant difference between patients (colorectal cancer and benign) and controls with p = 0.1. There was no statistically significant difference in FokI polymorphism where p = 0.26 and genotype distribution for TaqI was also insignificant with p = 0.016. The median serum level of 25(OH)VitD was low in cancer cases compared to the control group and benign cases with (p 0.001). There was no statisticallysignificant difference of median serum level of 1,25(OH)2VitD between benign and cancer cases. There was statistically significant difference of median serum level of 25(OH)VitD and 1,25(OH)2VitD between stage I and stage II with (p = 0.004) and (p 0.001), and between stage I and stage III with (p = 0.001)and (p 0.001), but no statistically significant difference between stage II and III with (p = 0.514). Conclusions: There is ethnic variability in vitamin D receptor gene polymorphisms. The lack of significant association of the studied gene polymorphism in our population suggests that its association with other functionally known gene polymorphism might have a role in the pathogenesis of colorectal cancer.

Colonic vitamin D receptor expression is inversely associated with disease activity and jumonji domain-containing 3 in active ulcerative colitis

BACKGROUND The expression of jumonji domain-containing 3(Jmjd3)and trimethylated H3 lysine 27(H3K27me3)in active ulcerative colitis(UC)and the correlation between vitamin D receptor(VDR)and the Jmjd3 pathway are unknown.AIM To study the relationship between VDR,Jmjd3 and H3K27me3 in patients with active UC.METHODS One hundred patients with active UC and 56 healthy controls were enrolled in this study.The patients with active UC were divided into groups according to mild(n=29),moderate(n=32)and severe(n=29)disease activity based on the modified Mayo score.Vitamin D levels were measured by radioimmunoassay.Colonic mucosal tissues from UC patients and controls were collected by colonoscopy.The expression of VDR,Jmjd3 and H3K27me3 in the intestinal mucosa was determined by immunohistochemistry staining.RESULTS Patients with active UC had lower levels of serum vitamin D(13.7±2.8 ng/mL,P<0.001)than the controls(16.2±2.5 ng/mL).In the UC cohort,serum vitamin D level was negatively correlated with disease activity(r=-0.323,P=0.001).VDR expression in the mucosa of UC patients was reduced compared to that in normal tissues(P<0.001)and negatively correlated with disease activity(r=-0.868,P<0.001).Similar results for VDR expression were noted in the most serious lesion(defined as UC diseased)and 20 cm proximal to the anus(defined as UC normal)(P<0.05).Simultaneously,Jmjd3 expression significantly increased in UC patients(P<0.001),but no difference was found between the different sites in UC patients.H3K27me3 expression in UC patients was significantly down-regulated when compared with normal tissues(P<0.001),but up-regulated in the mild disease activity group in comparison with the moderate disease activity group of UC patients(P<0.05).Jmjd3 Level was negatively correlated with the level of VDR(r=-0.342,P=0.002)and H3K27me3(r=-0.341,P=0.002),while VDR level was positively correlated with H3K27me3(r=0.473,P<0.001).CONCLUSION Serum vitamin D and VDR were inversely correlated with disease activity in active UC.Jmjd3 expression increased in the colonic mucosa of active UC patients and was negatively associated with VDR and H3K27me3 level.

The effects of vitamin D and its receptor on tumor

Background:Vitamin D and vitamin D receptors are closely related to human bone,muscle,fat and other tissues.The traditional role of vitamin D is centered on regulating calcium and bone metabolism.In recent years,studies have shown that vitamin D and vitamin D receptors can affect specific cellular pathways in the process of malignant tumors,and affect tumor cell apoptosis,differentiation and metastasis.In addition,they can also enhance the effects of chemical drugs and alleviate the adverse reactions of cachexia.This article summarizes the anti-tumor mechanism of vitamin D and its receptors.

Association between vitamin D receptor gene polymorphism and prognosis in patients with end stage renal disease undergoing dialysis

Objective:To investigate the relationship between vitamin D receptor gene polymorphism and prognosis in patients with end stage renal disease(ESRD)undergoing dialysis.Methods:80 patients with ESRD who underwent regular hemodialysis in our hospital were admitted from January 2016 to June 2016,and 80 healthy volunteers from our hospital were collected as control group during the same period.The polymorphisms of rs1544410(BsmI)of vitamin D receptor gene were identified by peripheral blood DNA amplification and specific enzyme digestion,including wild type GG(bb)and mutant GA(Bb)and AA(BB).Then analyze and compare the distribution of BsmI in patients with ESRD and normal volunteers,further analyze the correlation between BsmI locus and clinical characteristics of patients with ESRD,and analyze the relationship between BsmI locus and prognosis of patients with ESRD according to the follow-up results of patients.Results:The incidence of wild type(bb)of vitamin D receptor BsmI locus in patients with ESRD was significantly lower than that in the control group,while the incidence of mutant type(Bb and BB)was higher than that in the control group,with an advantage ratio of 1.378(P=0.004).The allele frequency of BsmI locus showed that the incidence of A-base in patients with ESRD was higher than that in control group,with an advantage ratio of 1.368(P=0.010).Comparing the genotype and clinical characteristics of BsmI locus in patients with ESRD,it was found that there were no differences in age,sex ratio between men and women,BMI,hypertension,diabetes,LDL,HDL,TG,urea nitrogen,creatinine,calcium,phosphorus,albumin and vitamin D levels among different genotypes.One year after treatment,the survival rate of bb group was significantly higher than that of Bb group and BB group(P=0.006).K-M analysis showed that the median survival time of BB group was 20 months,that of BB group was 8 months,and that of BB group was 4 months(P=0.000).Conclusion:There is a high mutation rate of BsmI locus(GA,AA type)in patients with ESRD,that is,the mutation rate of G-base to A is higher,and the survival time of patients with mutation is significantly shortened.

EFFECTS OF VITAMIN D RECEPTOR GENE POLYMORPHISMS ON SUSCEPTIBILITY TO TYPE 1 DIABETES MELLITUS

Objective To investigate the influence of vitamin D receptor (VDR) gene polymorphisms on susceptibility to type 1 diabetes mellitus (T1DM) in the Chinese Han population. Method One hundred and thirty-six Chinese Han people, including 54 T1DM patients and 82 unrelated healthy subjects as control were genotyped by polymerase chain reaction-restriction fragment length polymorphism for three restriction sites in the VDR gene, which were ApaI, TaqI, and BamI. Results The frequency of B allele of BsmI site in VDR gene was significantly higher in T1DM patients than in healthy subjects (P = 0.033) while no difference was found between the two groups in the distribution of ApaI and TaqI polymorphisms. Conclusion The BsmI polymorphism of VDR gene may be associated with the susceptibility to T1DM in the Chinese Han population of Beijing.

Immunohistochemical evaluation of vitamin D receptor(VDR) expression in cutaneous melanoma tissues and four VDR gene polymorphisms

Objective:Vitamin D receptor(VDR)mediates vitamin D activity.We examined whether VDR expression in excised melanoma tissues is associated with VDR gene(VDR)polymorphisms.Methods:We evaluated VDR protein expression(by monoclonal antibody immunostaining),melanoma characteristics,and carriage of VDR-Fok I-rs2228570(C>T),VDR-Bsm I-rs1544410(G>A),VDR-ApaI-rs7975232(T>G),and VDR-TaqI-rs731236(T>C)polymorphisms(by restriction fragment length polymorphism).Absence or presence of restriction site was denoted by a capital or lower letter,respectively:"F"and"f"for Fok I,"B"and"b"for Bsm I,"A"and"a"for ApaI,and "T"and"t"for TaqI endonuclease.Seventy-four Italian cutaneous primary melanomas(52.1±12.7 years old)were studied;51.4% were stage Ⅰ,21.6% stage Ⅱ ,13.5% stage Ⅲ,and 13.5% stage Ⅳ melanomas.VDR expression was categorized as follows:100% positive vs.<100%;over the median 20%(high VDR expression)vs.≤20%(low VDR expression);absence vs.presence of VDR-expressing cells.Results:Stage I melanomas,Breslow thickness of<1.00 mm,level II Clark invasion,Aa heterozygous genotype,and AaTT combined genotype were more frequent in melanomas with high vs.low VDR expression.Combined genotypes BbAA,bbAa,AATt,BbAATt,and bbAaTT were more frequent in 100%vs.<100%VDR-expressing cells.Combined genotype AATT was more frequent in melanomas lacking VDR expression(odds ratio=14.5;P=0.025).VDR expression was not associated with metastasis,ulceration,mitosis>1,regression,tumor-infiltrating lymphocytes,tumoral infiltration of vascular tissues,additional skin and non-skin cancers,and melanoma familiarity.Conclusions:We highlighted that VDR polymorphisms can affect VDR expression in excised melanoma cells.Low VDR expression in AATT carriers is a new finding that merits further study.VDR expression possibly poses implications for vitamin D supplementation against melanoma.VDR expression and VDR genotype may become precise medicinal tools for melanoma in the future.