Genetic Variants of the Vitamin D Receptor Gene Alter Risk of Cutaneous Melanoma

Malignant Melanoma: An Overview, New Perspectives, and Vitamin D Signaling

Melanoma, originating through malignant transformation of melanin-producing melanocytes, is a formidable malignancy, characterized by local invasiveness, recurrence, early metastasis, resistance to therapy, and a high mortality rate. This review discusses etiologic and risk factors for melanoma, diagnostic and prognostic tools, including recent advances in molecular biology, omics, and bioinformatics, and provides an overview of its therapy. Since the incidence of melanoma is rising and mortality remains unacceptably high, we discuss its inherent properties, including melanogenesis, that make this disease resilient to treatment and propose to use AI to solve the above complex and multidimensional problems. We provide an overview on vitamin D and its anticancerogenic properties, and report recent advances in this field that can provide solutions for the prevention and/or therapy of melanoma. Experimental papers and clinicopathological studies on the role of vitamin D status and signaling pathways initiated by its active metabolites in melanoma prognosis and therapy are reviewed. We conclude that vitamin D signaling, defined by specific nuclear receptors and selective activation by specific vitamin D hydroxyderivatives, can provide a benefit for new or existing therapeutic approaches. We propose to target vitamin D signaling with the use of computational biology and AI tools to provide a solution to the melanoma problem.

Vitamin D and Cutaneous Melanoma Risk: An Umbrella Review of Systematic Reviews and Meta-Analyses

Background: Vitamin D (VitD) properties can impact cancer cells. Despite the documented link between VitD levels and prevalence of several cancer types, conflicting findings have been reported for cutaneous melanoma (CM). Objective: This overview aims to compile the evidence from existing systematic reviews and meta-analyses, emphasizing the relationships between VitD serum levels, intake, receptor (VDR) gene polymorphisms, and CM risk. Methods: A literature search in electronic databases was conducted, based on certain inclusion criteria. Results: Twenty-one studies were included. Conflicting evidence between high VitD serum levels, dietary/supplementary intake, and CM risk is highlighted. VDR polymorphisms may play a role in the intricate CM pathogenesis. Also, high serum levels of VitD are associated with improved CM prognosis. Conclusions: This overview showed that the impact of VitD on CM is not clear, and thus further research is suggested to explore its true effect size on CM risk.

Updated Meta-Analysis of VDR FokI and TaqI Variants and Their Association with Melanoma Risk

BACKGROUND

Research suggests that melanoma patients with low vitamin D levels exhibit a higher risk of tumor ulceration and increased tumor mitotic rates. This has led to investigations into the vitamin D receptor (VDR) gene concerning its potential link to melanoma susceptibility. This meta-analysis aims to explore the association between VDR FokI and TaqI polymorphisms and melanoma risk, with an emphasis on the need for research in diverse populations to enhance our conclusions regarding interactions between skin phenotypes and VDR variations.

METHODS

A comprehensive literature search was conducted in databases, including PubMed, Scopus, and Web of Science, for studies linking VDR polymorphisms to melanoma risk, up to February 1, 2024. Keywords used included "Melanoma", "VDR", and various genetic terms. Quantitative synthesis was performed with Comprehensive Meta-Analysis (Version 4.0) and a significance threshold set at p < 0.05.

RESULTS

A total of twenty-one case-control studies involving 8,813 melanoma cases and 7,973 controls were included. Twelve studies on FokI had 4,642 cases and 4,534 controls, while nine TaqI studies included 4,171 cases and 3,439 controls. The results show a significant association between the VDR FokI polymorphism and increased melanoma risk across four genetic models (allele model: OR = 1.128, 95% CI 1.026-1.241; P = 0.013; homozygote model: OR = 1.166, 95% CI 1.020-1.332; P = 0.025; heterozygote model: OR = 1.255, 95% CI 1.046-1.507; P = 0.015; dominant model: OR = 1.243, 95% CI 1.052-1.470; P = 0.011). In contrast, the TaqI polymorphism showed no significant association with melanoma risk in the general population.

CONCLUSIONS

This meta-analysis suggests that the VDR FokI polymorphism is linked to an increased susceptibility to melanoma, while the TaqI variant does not show a significant association. Future research should explore the interactions between VDR polymorphisms, skin phenotypes, and melanoma risk in diverse populations, with larger and more varied studies needed to confirm these findings and enhance our understanding of genetic factors affecting melanoma susceptibility.

Significant Association of Poly-A and Fok1 Polymorphic Alleles of the Vitamin D Receptor with Vitamin D Serum Levels and Incidence of Squamous Cutaneous Neoplasia

Vitamin D3, a prohormone, is converted to circulating calcidiol and then to calcitriol, the hormone that binds to the vitamin D receptor (VDR) (a nuclear transcription factor). Polymorphic genetic sequence variants of the VDR are associated with an increased risk of breast cancer and melanoma. However, the relationship between VDR allelic variants and the risk of squamous cell carcinoma and actinic keratosis remains unclear. We examined the associations between two VDR polymorphic sites, Fok1 and Poly-A, and serum calcidiol levels, actinic keratosis lesion incidence, and the history of cutaneous squamous cell carcinoma in 137 serially enrolled patients. By evaluating the Fok1 (F) and (f) alleles and the Poly-A long (L) and short (S) alleles together, a strong association between genotypes FFSS or FfSS and high calcidiol serum levels (50.0 ng/ml) was found; conversely, ffLL patients showed very low calcidiol levels (29.1 ng/ml). Interestingly, the FFSS and FfSS genotypes were also associated with reduced actinic keratosis incidence. For Poly-A, additive modeling showed that Poly-A (L) is a risk allele for squamous cell carcinoma, with an OR of 1.55 per copy of the L allele. We conclude that actinic keratosis and squamous cell carcinoma should be added to the list of squamous neoplasias that are differentially regulated by the VDR Poly-A allele.

25-Hydroxyvitamin D serum levels and melanoma risk: a case-control study and evidence synthesis of clinical epidemiological studies

There is accumulating evidence that the vitamin D pathway may play a role in melanoma. The aim of this study was to investigate the association between 25-hydroxyvitamin D [25(OH)D] serum levels and the risk of cutaneous melanoma. A case-control study with 137 incident cases of melanoma (serum samples collected at the time of diagnosis) and 99 healthy controls (serum samples collected between October and April) was carried out and evaluated in the framework of an evidence synthesis of clinical epidemiological studies on the topic to facilitate comparisons and summarize the scientific evidence produced so far. There was a statistically significant difference in the median levels of serum vitamin D between melanoma patients and healthy controls (18.0 vs. 27.8 ng/ml, P<0.001). Among melanoma patients, 66.2%, compared with 15.2% of healthy controls, had vitamin D deficiency (≤20 ng/ml), whereas vitamin D sufficiency (≥30 ng/ml) was observed in only 7.4% of melanoma patients and in 37.4% of the healthy controls (P<0.001). A multivariate model including age, sex, and BMI showed a statistically significant inverse association between melanoma and vitamin D sufficiency versus deficiency (odds ratio=0.04; 95% confidence interval: 0.02-0.10, P<0.001). Also, vitamin D insufficiency versus deficiency was significantly inversely associated with melanoma (odds ratio=0.13; 95% confidence interval: 0.06-0.27, P<0.001). These results suggest that both deficient and insufficient serum levels of vitamin D are associated with melanoma and that a trend seems to be present with a reduced risk of melanoma when vitamin D approaches normal values.

Vitamin D receptor polymorphisms and melanoma

Melanoma represents the most aggressive skin cancer, with an unpredictable and often treatment resistant behavior. The etiology of melanoma is multifactorial and includes both environmental and genetic factors. Recent evidence indicates that vitamin D has a role in the development and progression of melanoma. The biologically active form of vitamin D/1,25-dihydroxyvitamin D3 acts by binding to a intranuclear receptor; vitamin D receptor (VDR). Single nucleotide polymorphisms (SNPs) in the vitamin D receptor gene may alter the expression or the function of the VDR protein leading to various diseases, including melanoma. More than 600 SNPs have been identified in the VDR gene, but only a few have been analyzed in relation to melanoma risk: FokI, TaqI, BsmI, ApaI, Cdx2, EcoRV, and BglI. Individual studies carried on small cohorts of patients reported controversial results. In an attempt to clarify the available data in the literature on this subject, we elaborated a systematic review in which we analyzed the relationship between VDR gene polymorphisms and melanoma risk and progression. We concluded that vitamin D pathway is important for the pathogenesis and the progression of cutaneous melanoma, illustrating the gene-environment interactions, but well-designed prospective studies that include data on both genotypes and phenotypes of vitamin D metabolism are essential in order to understand the mechanisms underlying the association between vitamin D and melanoma.

On the role of classical and novel forms of vitamin D in melanoma progression and management

Melanoma represents a significant clinical problem affecting a large segment of the population with a relatively high incidence and mortality rate. Ultraviolet radiation (UVR) is an important etiological factor in malignant transformation of melanocytes and melanoma development. UVB, while being a full carcinogen in melanomagenesis, is also necessary for the cutaneous production of vitamin D3 (D3). Calcitriol (1,25(OH)2D3) and novel CYP11A1-derived hydroxyderivatives of D3 show anti-melanoma activities and protective properties against damage induced by UVB. The former activities include inhibitory effects on proliferation, plating efficiency and anchorage-independent growth of cultured human and rodent melanomas in vitro, as well as the in vivo inhibition of tumor growth by 20(OH)D3 after injection of human melanoma cells into immunodeficient mice. The literature indicates that low levels of 25(OH)D3 are associated with more advanced melanomas and reduced patient survivals, while single nucleotide polymorphisms of the vitamin D receptor or the D3 binding protein gene affect development or progression of melanoma, or disease outcome. An inverse correlation of VDR and CYP27B1 expression with melanoma progression has been found, with low or undetectable levels of these proteins being associated with poor disease outcomes. Unexpectedly, increased expression of CYP24A1 was associated with better melanoma prognosis. In addition, decreased expression of retinoic acid orphan receptors α and γ, which can also bind vitamin D3 hydroxyderivatives, showed positive association with melanoma progression and shorter disease-free and overall survival. Thus, inadequate levels of biologically active forms of D3 and disturbances in expression of the target receptors, or D3 activating or inactivating enzymes, can affect melanomagenesis and disease progression. We therefore propose that inclusion of vitamin D into melanoma management should be beneficial for patients, at least as an adjuvant approach. The presence of multiple hydroxyderivatives of D3 in skin that show anti-melanoma activity in experimental models and which may act on alternative receptors, will be a future consideration when planning which forms of vitamin D to use for melanoma therapy.

Vitamin D signaling and melanoma: role of vitamin D and its receptors in melanoma progression and management

Ultraviolet B (UVB), in addition to having carcinogenic activity, is required for the production of vitamin D3 (D3) in the skin which supplies >90% of the body's requirement. Vitamin D is activated through hydroxylation by 25-hydroxylases (CYP2R1 or CYP27A1) and 1α-hydroxylase (CYP27B1) to produce 1,25(OH)₂D3, or through the action of CYP11A1 to produce mono-di- and trihydroxy-D3 products that can be further modified by CYP27B1, CYP27A1, and CYP24A1. The active forms of D3, in addition to regulating calcium metabolism, exert pleiotropic activities, which include anticarcinogenic and anti-melanoma effects in experimental models, with photoprotection against UVB-induced damage. These diverse effects are mediated through an interaction with the vitamin D receptor (VDR) and/or as most recently demonstrated through action on retinoic acid orphan receptors (ROR)α and RORγ. With respect to melanoma, low levels of 25(OH)D are associated with thicker tumors and reduced patient survival. Furthermore, single-nucleotide polymorphisms of VDR and the vitamin D-binding protein (VDP) genes affect melanomagenesis or disease outcome. Clinicopathological analyses have shown positive correlation between low or undetectable expression of VDR and/or CYP27B1 in melanoma with tumor progression and shorter overall (OS) and disease-free survival (DFS) times. Paradoxically, this correlation was reversed for CYP24A1 (inactivating 24-hydroxylase), indicating that this enzyme, while inactivating 1,25(OH)₂D3, can activate other forms of D3 that are products of the non-canonical pathway initiated by CYP11A1. An inverse correlation has been found between the levels of RORα and RORγ expression and melanoma progression and disease outcome. Therefore, we propose that defects in vitamin D signaling including D3 activation/inactivation, and the expression and activity of the corresponding receptors, affect melanoma progression and the outcome of the disease. The existence of multiple bioactive forms of D3 and alternative receptors affecting the behavior of melanoma should be taken into consideration when applying vitamin D management for melanoma therapy.

Identification of Genotypes and Allelic Frequencies of Vitamin D Receptor Gene Polymorphism (TaqI) in Egyptian Melasma Patients

Background:

Melasma is a characteristic pattern of facial hyperpigmentation, occurring primarily on the forehead, cheeks, and chin, in a mask-like distribution. The pathogenesis of melasma is not fully understood. Vitamin D plays a role in skin pigmentation. It exerts its effect through vitamin D receptor (VDR), which is expressed in variable cells including normal melanocytes.

Aim and Objective:

The aim of the current work was to investigate if VDR gene polymorphism (TaqI) confers susceptibility to melasma in Egyptian patients.

Materials and Methods:

A total of 45 female patients with melasma were recruited and 50 healthy subjects that were matched on age, sex, body mass index, and skin phototype, were included as a control group. TaqI polymorphism was investigated using restriction fragment length polymorphism polymerase chain reaction (RFLP PCR).

Results:

Presence of (t) allele and (tt) genotype was significantly associated with melasma cases compared with control group (P < 0.001 for both). No significant association was found between (tt) genotype or (t) allele and clinical data of the studied cases.

Conclusion:

TaqI polymorphism is associated with melasma. Further, large-scale studies are recommended to underscore and validate the current findings. It is also necessary for future studies to extend the research to other populations and ethnicities. Investigating other VDR gene polymorphisms in melasma is also warranted. Since melasma is a multifactorial disease, gene–gene and gene–environment interactions should be considered in future genetic-epidemiologic researches to apply more comprehensive insight into the role of VDR gene in its pathogenesis.

PTH and Vitamin D

PTH and Vitamin D are two major regulators of mineral metabolism. They play critical roles in the maintenance of calcium and phosphate homeostasis as well as the development and maintenance of bone health. PTH and Vitamin D form a tightly controlled feedback cycle, PTH being a major stimulator of vitamin D synthesis in the kidney while vitamin D exerts negative feedback on PTH secretion. The major function of PTH and major physiologic regulator is circulating ionized calcium. The effects of PTH on gut, kidney, and bone serve to maintain serum calcium within a tight range. PTH has a reciprocal effect on phosphate metabolism. In contrast, vitamin D has a stimulatory effect on both calcium and phosphate homeostasis, playing a key role in providing adequate mineral for normal bone formation. Both hormones act in concert with the more recently discovered FGF23 and klotho, hormones involved predominantly in phosphate metabolism, which also participate in this closely knit feedback circuit. Of great interest are recent studies demonstrating effects of both PTH and vitamin D on the cardiovascular system. Hyperparathyroidism and vitamin D deficiency have been implicated in a variety of cardiovascular disorders including hypertension, atherosclerosis, vascular calcification, and kidney failure. Both hormones have direct effects on the endothelium, heart, and other vascular structures. How these effects of PTH and vitamin D interface with the regulation of bone formation are the subject of intense investigation.

Cytochromes p450 and skin cancer: role of local endocrine pathways

Skin is the largest body organ forming a metabolically active barrier between external and internal environments. The metabolic barrier is composed of cytochromes P450 (CYPs) that regulate its homeostasis through activation or inactivation of biologically relevant molecules. In this review we focus our attention on local steroidogenic and secosteroidogenic systems in relation to skin cancer, e.g., prevention, attenuation of tumor progression and therapy. The local steroidogenic system is composed of locally expressed CYPs involved in local production of androgens, estrogens, gluco- and mineralo-corticosteroids from cholesterol (initiated by CYP11A1) or from steroid precursors delivered to the skin, and of their metabolism and/or inactivation. Cutaneous 7-hydroxylases (CYP7A1, CYP7B1 and CYP39) potentially can produce 7-hydroxy/oxy-steroids/sterols with modifying effects on local tumorigenesis. CYP11A1 also transforms 7-dehydrocholesterol (7DHC)→22(OH)7DHC→20,22(OH)2-7DHC→7-dehydropregnenolone, which can be further metabolized to other 5,7- steroidal dienes. These 5,7-dienal intermediates are converted by ultraviolet radiation B (UVB) into secosteroids which show pro-differentiation and anti-cancer properties. Finally, the skin is the site of activation of vitamin D3 through two alternative pathways. The classical one involves sequential hydroxylation at positions 25 and 1 to produce active 1,25(OH)2D3, which is further inactivated through hydroxylation at C24. The novel pathway is initiated by CYP11A1 with predominant production of 20(OH)D3 which is further metabolized to biologically active but non-calcemic D3-hydroxyderivatives. Classical and non-classical (novel) vitamin D analogs show pro-differentiation, anti-proliferative and anticancer properties. In addition, melatonin is metabolized by local CYPs. In conclusion cutaneously expressed CYPs have significant effects on skin physiology and pathology trough regulation of its chemical milieu.

Association of vitamin D receptor FokI and ApaI polymorphisms with lung cancer risk in Tunisian population

Many studies reported that Vitamin D Receptor (VDR) gene polymorphisms might influence the cancer risk due to their antiproliferative, antiangiogenic, and apoptotic effects. The aim of this study was to explore the genetic association of VDR polymorphisms with lung cancer risk in Tunisian population. The genotype and haplotype frequencies of four VDR polymorphisms, FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) were studied using polymerase chain reaction and restriction fragment length polymorphism analysis in 240 patients with lung cancer and 280 healthy controls. The distribution of genotype frequencies differed significantly between lung cancer subjects and controls (FokI P adj = 0.002; ApaI P adj = 0.013). Haplotype analyses revealed a significant association between G-A-C and A-C-T haplotypes and lung cancer risk (P corr = 0.0128, P corr = 0.008). When patients were stratified according to gender, age, and smoking, significant associations were detected with FokI and TaqI polymorphisms. We found a lack of association between BsmI, TaqI polymorphisms and lung cancer risk (P > 0.05). Only, the attributable proportion due to interaction and the synergic index for interaction between ApaI polymorphism and smoking were statistically significant (P adj = 0.74, 95 % CI = 0.38-1.20) and (P adj = 0.63, 95 % CI = 0.05-1.21), respectively. Both the additive interaction measures suggested the existence of a biological interaction between SNP ApaI, but not FokI, and smoking. The multiplicative interaction measure was not statistically significant (P > 0.05). This is the first study in Tunisia, which suggested that VDR FokI and ApaI polymorphisms might be risk factors for lung cancer development.

Vitamin D and melanoma

Recreational sun exposure and sunburn are causal for melanoma but the risk is strongly genetically determined. Health promotion advice about sun protection should be aimed at susceptible individuals (pale skin, freckles, large numbers of melanocytic nevi and a family history). We discuss here the evidence that sun-sensitive people have lower vitamin D levels and that, in practice, it is very difficult for such individuals to achieve sufficient levels without supplementation in the UK at least. We conclude that melanoma susceptible sun-avoidant individuals should be advised to avoid insufficiency by supplementation.

Vitamin D is anti-proliferative in vitro for some melanoma cell lines. In a large melanoma cohort we have observed that lower serum 25-hydroxyvitamin D₂/D₃ levels at diagnosis were associated with thicker tumors and poorer prognosis (study as yet not validated). In the UK, melanoma patients commonly have sub-optimal 25-hydroxyvitamin D₂/D₃ levels at and post diagnosis; we discuss approaches to management of such patients based on some new data from our group.

Vitamin D receptor TaqI and ApaI polymorphisms: a comparative study in patients with Behçet's disease and Rheumatoid arthritis in Tunisian population

Recent genetic surveys have identified vitamin D receptor (VDR) as a susceptibility gene for several autoimmune diseases. This study was designed to investigate the association of VDR gene polymorphisms with Behçet's disease (BD) and Rheumatoid arthritis (RA). A case-control study including 151 BD, 106 RA patients and an appropriate number of healthy control subjects were performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. Association between TaqI polymorphism and BD was marginal under codominant and recessive models (P=0.078 and P=0.058, respectively). After stratification, we found evidence for a significant association between TaqI polymorphism and BD in the elderly subjects (P=0.037). The minor ApaI a allele tended to confer an increased risk for BD susceptibility (P=0.087). BD patients with VDR homozygous AA or aa genotypes were at increased risk for development of erythema nodosum (EN) skin manifestation (P=0.038). No significant association was observed for VDR ApaI and TaqI polymorphisms with RA risk (P>0.05). TaqI and ApaI polymorphisms might be modestly implicated in BD pathogenesis. They could be considered as potential biomarkers in BD rather than susceptibility genes. However, TaqI and ApaI seemed not to be implicated in RA pathogenesis.

Vitamin D and melanoma incidence and mortality

The role of vitamin D (25-OH-D, or 25-hydroxyvitamin D) and its potential confounders in relationship to melanoma risk and mortality is discussed. The paradox that ultraviolet radiation (UVR) exposure is the major environmental risk factor for melanoma etiology as well as a major source of vitamin D might be explained by viewing vitamin D levels as the result of a healthy lifestyle rather than a cause of health.

New vitamin D analogs as potential therapeutics in melanoma

Extensive evidence shows that the active form of vitamin D3--1α,25-dihydroxyvitamin D3--plays an important role in cancer prevention, has tumorostatic activity and may potentially be used in therapy for melanoma. Vitamin D3 and its analogs (secosteroids) exert multiple effects on cancer cells, including inhibition of cell growth and induction of differentiation. Activity of secosteroids depends on multiple cellular factors, including expression of the vitamin D receptor. Despite its endogenous origin, the key drawback for the use of pharmacologically effective doses of 1α,25-dihydroxyvitamin D3 is its hypercalcemic effect leading to profound toxicity. The solution may lie in properties of vitamin D3 analogs with modified side chains, which demonstrate low calcemic activity but conserve the anti-tumor properties. Noncalcemic vitamin D compounds were found to be potent in multiple studies that mandate further clinical testing. Finally, recent studies revealed alternative metabolic pathways for secosteroids and new targets in the cells, which opens up new therapeutic possibilities.

No association of vitamin D metabolism-related polymorphisms and melanoma risk as well as melanoma prognosis: a case-control study

Melanoma is one of the most aggressive human cancers. The vitamin D system contributes to the pathogenesis and prognosis of malignancies including cutaneous melanoma. An expression of the vitamin D receptor (VDR) and an anti-proliferative effect of vitamin D in melanocytes and melanoma cells have been shown in vitro. Studies examining associations of polymorphisms in genes coding for vitamin D metabolism-related proteins (1α-hydroxylase [CYP27B1], 1,25(OH)₂D-24hydroxylase [CYP24A1], vitamin D-binding protein [VDBP]) and cancer risk are scarce, especially with respect to melanoma. Mainly VDR polymorphisms regarding melanoma risk and prognosis were examined although other vitamin D metabolism-related genes may also be crucial. In our hospital-based case–control study including 305 melanoma patients and 370 healthy controls single nucleotide polymorphisms in the genes CYP27B1 (rs4646536), CYP24A1 (rs927650), VDBP (rs1155563, rs7041), and VDR (rs757343, rs731236, rs2107301, rs7975232) were analyzed for their association with melanoma risk and prognosis. Except VDR rs731236 and VDR rs2107301, the other six polymorphisms have not been analyzed regarding melanoma before. To further improve the prevention as well as the treatment of melanoma, it is important to identify further genetic markers for melanoma risk as well as prognosis in addition to the crude phenotypic, demographic, and environmental markers used in the clinic today. A panel of genetic risk markers could help to better identify individuals at risk for melanoma development or worse prognosis. We, however, found that none of the polymorphisms tested was associated with melanoma risk as well as prognosis in logistic and linear regression models in our study population.

Combined effect of 25-OH vitamin D plasma levels and genetic vitamin D receptor (NR 1I1) variants on fibrosis progression rate in HCV patients

BACKGROUND

Decreased vitamin D levels have been described in various forms of chronic liver disease and associated with advanced fibrosis. Whether this association is a cause or consequence of advanced fibrosis remains unclear to date.

AIMS

To analyse combined effects of 25-OH vitamin D plasma levels and vitamin D receptor gene (VDR; NR1I1) polymorphisms on fibrosis progression rate in HCV patients.

METHODS

251 HCV patients underwent VDR genotyping (bat-haplotype: BsmI rs1544410 C, ApaI rs7975232 A and TaqI rs731236 A). Plasma 25-OH vitamin D levels were quantified in a subgroup of 97 patients without advanced fibrosis. The VDR haplotype and genotypes as well as plasma 25-OH vitamin D levels were associated with fibrosis progression.

RESULTS

The bAt[CCA]-haplotype was significantly associated with fibrosis progression >0.101 U/year (P = 0.007; OR = 2.02) and with cirrhosis (P = 0.022; OR = 1.84). Forty-five percent of bAt[CCA]-haplotype patients were rapid fibrosers, 21.1% were cirrhotic. Likewise, ApaI rs7975232 CC genotype was significantly associated with fibrosis progression and cirrhosis. Lower plasma 25-OH vitamin D levels were significantly associated with fibrosis progression >0.101 U/year in F0-2 patients (P = 0.013). Combined analysis of both variables revealed a highly significant additive effect on fibrosis progression with 45.5% rapid fibrosers for bAt[CCA]-haplotype and 25-OH vitamin D < 20 μg/L compared with only 9.1% for the most favourable combination (P = 0.006). In multivariate analysis, the bAt-haplotype was an independent risk factor for fibrosis progression (P = 0.001; OR = 2.83).

CONCLUSION

Low 25-OH vitamin D plasma levels and the unfavourable VDR bAt[CCA]-haplotype are associated with rapid fibrosis progression in chronic HCV patients. In combination, both variables exert significant additive effects on fibrosis progression.

Vitamin D receptor polymorphisms in patients with cutaneous melanoma

The vitamin D receptor (VDR) gene has been associated with cancer risk, but only a few polymorphisms have been studied in relation to melanoma risk and the results have been inconsistent. We examined 38 VDR gene single nucleotide polymorphisms (SNPs) in a large international multicenter population-based case-control study of melanoma. Buccal DNAs were obtained from 1,207 people with incident multiple primary melanoma and 2,469 with incident single primary melanoma. SNPs with known or suspected impact on VDR activity, haplotype tagging SNPs with ≥ 10% minor allele frequency in Caucasians, and SNPs reported as significant in other association studies were examined. Logistic regression was used to calculate the relative risks conferred by the individual SNP. Eight of 38 SNPs in the promoter, coding, and 3' gene regions were individually significantly associated with multiple primary melanoma after adjusting for covariates. The estimated increase in risk for individuals who were homozygous for the minor allele ranged from 25 to 33% for six polymorphisms: rs10875712 (odds ratios [OR] 1.28; 95% confidence interval (CI), 1.01-1.62), rs4760674 (OR 1.33; 95% CI, 1.06-1.67), rs7139166 (OR 1.26; 95%CI, 1.02-1.56), rs4516035 (OR 1.25; 95%CI, 1.01-1.55), rs11168287 (OR 1.27; 95%CI, 1.03-1.57) and rs1544410 (OR 1.30; 95%CI, 1.04-1.63); for two polymorphisms, homozygous carriers had a decreased risk: rs7305032 (OR 0.81; 95%CI 0.65-1.02) and rs7965281 (OR, 0.78; 95%CI, 0.62-0.99). We recognize the potential false positive findings because of multiple comparisons; however, the eight significant SNPs in our study outnumbered the two significant tests expected to occur by chance. The VDR may play a role in melanomagenesis.

The vitamin D receptor gene bAt (CCA) haplotype impairs the response to pegylated-interferon/ribavirin-based therapy in chronic hepatitis C patients

BACKGROUND

Chronic hepatitis C infection is a major cause of end-stage liver disease. Therapy outcome is influenced by 25-OH vitamin D deficiency. To further address this observation, our study investigates the impact of the vitamin D receptor (NR1I1) haplotype and combined effects of plasma vitamin D levels in a well-described cohort of hepatitis C patients.

METHODS

A total of 155 chronic hepatitis C patients were recruited from the Swiss Hepatitis C Cohort Study for NR1I1 genotyping and plasma 25-OH vitamin D level measurement. NR1I1 genotype data and combined effects of plasma 25-OH vitamin D level were analysed regarding therapy response (sustained virological response).

RESULTS

A strong association was observed between therapy non-response and the NR1I1 CCA (bAt) haplotype consisting of rs1544410 (BsmI) C, rs7975232 (ApaI) C and rs731236 (TaqI) A alleles. Of the HCV patients carrying the CCA haplotype, 50.3% were non-responders (odds ratio [OR] 1.69, 95% CI 1.07, 2.67; P=0.028). A similar association was observed for the combinational CCCCAA genotype (OR 2.94, 95% CI 1.36, 6.37; P=0.007). The combinational CCCCAA genotype was confirmed as an independent risk factor for non-response in multivariate analysis (OR 2.50, 95% CI 1.07, 5.87; P=0.034). Analysing combined effects, a significant impact of low 25-OH vitamin D levels on sustained virological response were only seen in patients with the unfavourable NR1I1 CCA (bAt) haplotype (OR for non-SVR 3.55; 95% CI 1.005, 12.57; P=0.049).

CONCLUSIONS

NR1I1 vitamin D receptor polymorphisms influence response to pegylated-interferon/ribavirin-based therapy in chronic hepatitis C and exert an additive genetic predisposition to previously described low 25-OH vitamin D serum levels.

Sun exposure, vitamin D receptor polymorphisms FokI and BsmI and risk of multiple primary melanoma

BACKGROUND

Sunlight exposure increases risk of melanoma. Sunlight also potentiates cutaneous synthesis of vitamin D, which can inhibit melanoma cell growth and promote apoptosis. Vitamin D effects are mediated through the vitamin D receptor (VDR). We hypothesized that genetic variation in VDR affects the relationship of sun exposure to risk of a further melanoma in people who have already had one.

METHODS

We investigated the interaction between VDR polymorphisms and sun exposure in a population-based multinational study comparing 1138 patients with a multiple (second or subsequent) primary melanoma (cases) to 2151 patients with a first primary melanoma (controls); essentially a case-control study of melanoma in a population of melanoma survivors. Sun exposure was assessed using a questionnaire and interview, and was shown to be associated with multiple primary melanoma. VDR was genotyped at the FokI and BsmI loci and the main effects of variants at these loci and their interactions with sun exposure were analyzed.

RESULTS

Only the BsmI variant was associated with multiple primary melanoma (OR=1.27, 95% CI 0.99-1.62 for the homozygous variant genotype). Joint effects analyses showed highest ORs in the high exposure, homozygous variant BsmI genotype category for each sun exposure variable. Stratified analyses showed somewhat higher ORs for the homozygous BsmI variant genotype in people with high sun exposure than with low sun exposure. P values for interaction, however, were high.

CONCLUSION

These results suggest that risk of multiple primary melanoma is increased in people who have the BsmI variant of VDR.

Vitamin D receptor (VDR) polymorphisms and skin cancer: A systematic review

Skin cancer is the most common cancer in humans. There are several types of skin cancer that include basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). The associations of vDr polymorphisms with skin cancer risk are not well characterized so far. Only a few epidemiologic studies have directly addressed the relationship between VDR polymorphisms and the incidence and prognosis of MM. To make the most of the available information on VDR polymorphisms and skin cancer (MM, BCC and SCC), we undertook a systematic review of published studies. In conclusion, data summarized in this review support the concept that the vitamin D endocrine system (VDES) is of importance for pathogenesis and progression of MM and other types of skin cancer.

Vitamin D receptor (VDR) polymorphisms and skin cancer: A systematic review

Skin cancer is the most common cancer in humans. There are several types of skin cancer that include basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). The associations of vDr polymorphisms with skin cancer risk are not well characterized so far. Only a few epidemiologic studies have directly addressed the relationship between VDR polymorphisms and the incidence and prognosis of MM. To make the most of the available information on VDR polymorphisms and skin cancer (MM, BCC and SCC), we undertook a systematic review of published studies. In conclusion, data summarized in this review support the concept that the vitamin D endocrine system (VDES) is of importance for pathogenesis and progression of MM and other types of skin cancer.

Expression of vitamin D receptor decreases during progression of pigmented skin lesions

1,25-dihydroxyvitamin D3 affects proliferation, differentiation, and apoptosis and protects DNA against oxidative damage with a net tumorostatic and anticarcinogenic effect. It acts through a specific nuclear receptor that is widely distributed through the body. Although a beneficial role of vitamin D in melanoma patients has been suggested, there is lack of information on the changes in the expression pattern of vitamin D receptor during progression of pigmented lesions. Using immunohistochemistry, we analyzed the expression of vitamin D receptor in 140 samples obtained form 82 patients, including 25 benign nevi, 70 primary cutaneous melanomas, 35 metastases, 5 re-excisions, and 5 normal skin biopsies. The strongest expression was observed in normal skin that significantly decreased in melanocytic proliferations with the following order of expression: normal skin > melanocytic nevi > melanomas = metastases. The vitamin D receptor expression in skin surrounding nevi and melanoma was also significantly reduced as compared to normal skin. Tumor-infiltrating and lymph node lymphocytes retained high levels of vitamin D receptor. There was negative correlation between tumor progression and vitamin D receptor expression with a remarkable decrease of the immunoreactivity in nuclei of melanoma cells at vertical versus radial growth phases and with metastatic melanomas showing the lowest cytoplasmic receptor staining. Furthermore, lack of the receptor expression in primary melanomas and metastases was related to shorter overall patients' survival. In addition, the receptor expression decreased in melanized melanoma cells in comparison to amelanotic or poorly pigmented cells. Therefore, we propose that reduction or absence of vitamin D receptor is linked to progression of melanocytic lesions, that its lack affects survival of melanoma patients, and that melanogenesis can attenuate receptor expression. In conclusion, changes in vitamin D receptor expression pattern can serve as important variables for diagnosis, predicting clinical outcome of the disease, and/or as a guidance for novel therapy of melanomas based on use of vitamin D or its derivatives.

Promoter polymorphisms in matrix metallopeptidase 1 and risk of cutaneous melanoma

Matrix metallopeptidase 1 (MMP1) is one of the interstitial collagens in the extracellular matrix metalloproteinase family and involved in tumour behaviours. However, there is no report on the role of genetic variation in MMP1 in risk of cutaneous melanoma (CM). We investigated the association between genotypes and haplotypes of seven reported MMP1 promoter polymorphisms [-1607G ins/del (2G/1G), -839G>A, -755T>G, -519A>G, -422A>T, -340A>G and -320T>C, genotyped by the TaqMan assay] and CM risk in 872 patients and 873 cancer-free controls. These seven polymorphisms were not in linkage disequilibrium among each other (r(2)<0.63). Compared to their common homozygous genotypes, the variant -519GG was associated with significantly decreased CM risk [adjusted odds ratio (OR)=0.71, 95% confidence interval (CI)=0.52-0.99], whereas variants -422TT and -320CC were associated with significantly increased CM risk (OR=1.50, 95% CI=1.11-2.03 and OR=1.72, 95% CI=1.05-2.81, respectively) after adjustment for age, sex, family history and sun-exposure-related risk factors. The number of risk alleles of these three polymorphisms was associated with CM risk in a dose-response manner (P(trend)=0.0002). In the stratification analysis, we found that the associations of these polymorphisms with CM risk were modified by some of the risk factors. Furthermore, the haplotypes Gdel-A-G-A-T-G-T and G-G-G-A-T-A-T were associated with significantly increased CM risk (ORs=1.56 and 2.13, 95% CIs=1.02-2.38 and 1.22-3.70, respectively). These findings suggest that MMP1 promoter polymorphisms may individually or jointly play roles in the development of CM.

Dermatologic management, sun avoidance and vitamin D status in organ transplant recipients (OTR)

It is well known that skin cancer, especially cutaneous squamous cell carcinoma (SCC), in organ transplant recipients (OTRs) has higher incidence rates, behaves more aggressively and has higher rates of metastasis. OTRs who have been treated for many years with immunosuppressive medication are at the highest risk for developing malignant skin tumors. Protection against solar and artificial UV-radiation is crucial to prevent skin cancer in OTRs. However, investigations have revealed that solar UV-B-exposure and serum 25(OH)D levels positively correlate with decreased risk for various internal malignancies (e.g. breast, colon, prostate, and ovarian cancer) and other severe diseases. Therefore, it is important to detect and treat vitamin D deficiency in OTRs. This review discusses guidelines for the optimal management of these patients, that require communication between the transplant teams, the treating dermatologist and other clinicians.

Vitamin D receptor variants and the malignant melanoma risk: a population-based study

BACKGROUND

There is continuing interest in identifying low-penetrance genes which are associated with an increased susceptibility to common types of cancer, including malignant melanoma.

METHODS

We sought to examine the association between four VDR common variants (rs1544410, rs731236, rs10735810, rs4516035) and the risk of melanoma in the Polish population. We also determined the prevalence of compound carriers of VDR and known MM genetic risk factors MC1R and CDKN2A (A148T) variants. We examined 763 unselected melanoma cases, 763 healthy adults matched for sex and age with the melanoma cases and 777 newborns.

RESULTS

None of the VDR variants alone or as compound carriers of two or more of the VDR genotypes were associated with MM risk. There were no major differences between the prevalences of the examined variants among patients with MM on UV-exposed and UV-non exposed skin areas, as well as among early-onset and late-onset cases. We found no association between VDR and MC1R or between VDR and CDKN2A common variants. A statistically significant over-representation of one VDR haplotype: rs731236_A+rs1544410_T (OR=3.2, p=0.02) was detected. Linkage disequilibrium of rs1544410 and rs731236 was confirmed.

CONCLUSION

To answer the question, whether VDR can be regarded as melanoma susceptibility gene, additional, large multi-center association studies have to be performed.

Vitamin D receptor polymorphisms in differentiated thyroid carcinoma

BACKGROUND

Vitamin D receptor (VDR) expression has been shown to be upregulated in several tumors and is supposed to represent an important endogenous response to tumor progression. To investigate the role of the VDR gene and its influence on 25(OH)D(3) and 1,25(OH)(2)D(3) plasma levels in thyroid carcinoma, we analyzed four VDR polymorphisms in patients and healthy controls (HC).

METHODS

Patients with thyroid carcinoma (n = 172) (n = 132 for papillary and n = 40 for follicular) and HC (n = 321) were genotyped for the ApaI (rs7975232), TaqI (rs731236), BsmI (rs1544410), and FokI (rs10735810) polymorphisms within the VDR gene and correlated with 25(OH)D(3) and 1,25(OH)(2)D(3) plasma levels.

RESULTS

The genotypes AA of the ApaI (rs7975232) and FF of the FokI (rs10735810) polymorphisms were significantly less frequent (12.5% vs. 35.2% and 25% vs. 42.1%, respectively, both corrected p [p(c)] = 0.04) in patients with follicular thyroid cancer (FTC) than in HC. Additionally, the haplotypes, Ta (57.5% vs. 41.4%; p(c) = 0.0207), af (24.6% vs. 14.3%; p(c) = 0.0116), Tab (51.1% vs. 36.8%; p(c) = 0.0495), and Tabf (18.7% vs. 13.6%; p(c) = 0.0240) were more frequent, whereas the haplotypes AF (17.1% vs. 37.2%; p(c) = 0.0008), BF (11.4% vs. 31.9%; p(c) = 0.012), tF (7.9% vs. 25.5%; p(c) = 0.0016), and tABF (7.6% vs. 23%; p(c) = 0.0115) were less frequent in the FTC patients compared to HC. Neither genotype nor haplotype frequencies differed between patients with papillary thyroid cancer (PTC) and HC. Further, individuals with PTC and FTC had a significantly lower level of circulating 1,25(OH)(2)D(3) compared to controls. In contrast, no differences of the 25(OH)D(3) concentration between patients and HC were observed. VDR polymorphisms were not associated with 25(OH)D(3) and 1,25(OH)(2)D(3) plasma levels.

CONCLUSIONS

Lower circulating levels of 1,25(OH)(2)D(3) are observed in patients with differentiated thyroid carcinoma. Further, while the alleles AA and FF of the ApaI (rs7975232) and FokI (rs10735810) VDR polymorphisms and the haplotype tABF confer to protection from follicular carcinoma, the haplotype Tabf appeared to be associated with an increased FTC risk. Since this is the first report associating VDR polymorphisms with thyroid carcinoma, these findings need to be confirmed in studies with larger numbers of patients.

Management of familial melanoma and nonmelanoma skin cancer syndromes

The clinical manifestations of hereditary skin cancer syndromes depend upon the interplay between environmental and genetic factors. Familial melanoma occurs in the setting of hereditary susceptibility, with a complex phenotype of early age of onset, multiple atypical moles, multiple primary melanomas, multiple melanomas in the family, and in some instances pancreatic cancer. Identification of individuals who may have a hereditary susceptibility for the development of melanoma is essential to provide an opportunity for primary prevention, and to target high-risk groups for early diagnosis and treatment. Consequently, the surgeon as one of the primary caregivers should be familiar with hereditary skin cancer syndromes and their pathogenesis, diagnosis, management, and surveillance recommendations. This article discusses a practical approach for some of the issues likely encountered by the surgeon in the management of familial melanoma and non-melanoma skin cancer.

Vitamin D and skin cancer: a meta-analysis

A comprehensive bibliographic search of the literature was conducted to identify studies on Cutaneous Malignant Melanoma (CMM) and non-melanoma skin cancer (NMSC), Vitamin D receptor (VDR) polymorphisms, Vitamin D intake and 25(OH)D serum levels. Fully adjusted risk estimates were found and extracted for the two polymorphisms FokI and BsmI and Vitamin D intake. Ten studies were included in the meta-analysis, with a total of 6805 skin cancer cases. We found an association with CMM for both polymorphisms. The summary relative risks (SRR) for the studies on CMM were: 1.21 (1.03-1.42) and 1.21 (0.95-1.54) for the Ff and ff versus wild-type of FokI, respectively. The SRR for ff versus wild-type became significant with the inclusion of NMSC. The SRR for the studies on CMM were: 0.78 (0.65-0.92) and 0.75 (0.59-0.95) for the Bb and BB versus wild-type of BsmI, respectively. There is also a slight indication of a role of dietary Vitamin D in CMM development. In conclusion, this meta-analysis suggests a possible significant role of VDR FokI and BsmI polymorphism in CMM and NMSC risk. The association with Vitamin D intake is less clear and further studies could be useful to clarify the role of diet.

Haplotype and genotypes of the VDR gene and cutaneous melanoma risk in non-Hispanic whites in Texas: a case-control study

In a hospital-based case-control study of 805 non-Hispanic whites with cutaneous melanoma and 841 cancer-free age-, sex- and ethnicity-matched control subjects, 3 VDR polymorphisms (i.e., TaqI, BsmI and FokI) were genotyped using blood samples collected between 1994 and 2006. We tested the hypothesis that the haplotypes and combined genotypes of these polymorphisms were associated with melanoma risk by interacting with known risk factors. Haplotypes t-B-F (adjusted odds ratio [OR], 0.52; 95% confidence interval [CI], 0.34-0.80) and t-B-f (adjusted OR, 0.51; CI, 0.27-0.94) were associated with a reduced risk when compared to T-b-f. The combined genotypes Tt+tt/Bb+BB/Ff+ff (adjusted OR, 0.69; CI, 0.52, 0.90) and Tt+tt/Bb+BB/FF (adjusted OR, 0.58; CI, 0.43, 0.78) were also associated with reduced risk, whereas the combined genotype TT/Bb+BB/Ff+ff genotype (adjusted OR, 2.35; CI, 1.13, 4.98) was associated with increased risk when compared to TT/bb/Ff+ff genotypes. On multivariate analysis, only the TaqI polymorphism was an independent risk factor, while the FokI polymorphism interacted with skin color (p = 0.029), moles (p = 0.017) and first-degree relatives with any cancer (p = 0.013) in modifying risk. Together, these findings suggest that VDR polymorphisms may directly affect or modify the risk associated with known melanoma risk factors. Larger, population-based studies are needed to replicate our findings.

Vitamin d and its role in cancer and immunity: a prescription for sunlight

Vitamin D has been recognized for more than a century as essential for the normal development and mineralization of a healthy skeleton. More extensive roles for vitamin D were suggested by the discovery of the vitamin D receptor (VDR) in tissues that are not involved in calcium and phosphate metabolism. VDR has been discovered in most tissues and cells in the body and is able to elicit a wide variety of biologic responses. These observations have been the impetus for a reevaluation of the physiologic and pharmacologic actions of vitamin D. Here, we review the role of vitamin D in regulation of the immune system and its possible role in the prevention and treatment of cancer and immune-mediated diseases.

DNA repair gene polymorphisms and genetic predisposition to cutaneous melanoma

The incidence of cutaneous melanoma is rising rapidly in a number of countries. The key environmental risk factor is exposure to the ultraviolet (UV) component in sunlight. The nucleotide excision repair (NER) pathway deals with the main forms of UV-induced DNA damage. We have investigated the hypothesis that polymorphisms in NER genes constitute genetic susceptibility factors for melanoma. However, not all melanomas arise on sun-exposed sites and so we investigated the hypothesis that genes involved in other pathways for the repair of oxidative DNA damage may also be involved in susceptibility to melanoma. Scotland, with its high incidence of melanoma and stable homogeneous population, was ideal for this case-control study, involving 596 Scottish melanoma patients and 441 population-based controls. Significant associations were found for the NER genes ERCC1 and XPF, with the strongest associations for melanoma cases aged 50 and under [ERCC1 odds ratio (OR) 1.59, P = 0.008; XPF OR 1.69, P = 0.003]. Although an XPD haplotype was associated with melanoma, it did not contain the variant 751 Gln allele, which has been associated with melanoma in some previous studies. No associations were found for the base excision repair and DNA damage response genes investigated. An association was also found for a polymorphism in the promoter of the vitamin D receptor gene, VDR (OR 1.88, P = 0.005). The products of the two NER genes, ERCC1 and XPF, where associations with melanoma were found, act together in a rate-limiting step in the repair pathway.

Mechanism of UV-related carcinogenesis and its contribution to nevi/melanoma

Melanoma consists 4-5 % of all skin cancers, but it contributes to 71-80 % of skin cancers deaths. UV light affects cell and tissue homeostasis due to its damaging effects on DNA integrity and modification of expression of a plethora of genes. DNA repair systems protect cells from UV-induced lesions. Several animal models of melanoma have been developed (Xiphophorus, Opossum Monodelphis domestica, mouse models and human skin engrafts into other animals). This review discusses possible links between UV and genes significantly related to melanoma but does not discuss melanoma genetics. These include oncogenes, tumor suppressor genes, genes related to melanocyte-keratinocyte and melanocyte-matrix interaction, growth factors and their receptors, CRH, ACTH, α-MSH, glucocorticoids, ID1, NF-kappaB and vitamin D3.