Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ultraviolet radiation (UVR) may protect against prostate cancer via a mechanism involving vitamin D. Thus, the vitamin D receptor (VDR) gene is a susceptibility candidate, though published data are discrepant. We studied the association of prostate cancer risk with five VDR single nucleotide polymorphisms (SNPs): G/A(1229) (SNP 1), A/G(3944) (SNP 2), T/C(30875) (SNP 3), C/T(48200) (SNP 4) and C/T(65013) (SNP 5), in 430 cancer and 310 benign prostatic hypertrophy (BPH) patients. The SNP 2 GG genotype frequency was lower in cancer than BPH patients (odds ratio = 0.63, 95% CI = 0.41-0.98, p = 0.039). SNPs 1 and 2, and SNPs 4 and 5, were in linkage disequilibrium. Two copies of haplotypes comprising SNPs 1-2, G-G (odds ratio = 0.63, p = 0.039), SNPs 2-3 G-C (odds ratio = 0.45, p = 0.008) and SNPs 1-2-3 G-G-C (odds ratio = 0.44, p = 0.006), but not SNPs 1-3, G-C (odds ratio = 0.81, p = 0.34), were associated with reduced risk (reference, no copies of the haplotypes). These associations were observed after stratification of subjects by extent of UVR exposure. These data show that SNP 2 GG genotype mediates prostate cancer risk, complementing studies reporting this allele is protective in malignant melanoma pathogenesis. They further suggest that published associations of risk with SNP 1 may result from linkage disequilibrium with SNP 2.
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PMID:Associations between G/A1229, A/G3944, T/C30875, C/T48200 and C/T65013 genotypes and haplotypes in the vitamin D receptor gene, ultraviolet radiation and susceptibility to prostate cancer. 1662 32

Adaptive physiologic buffers enable organisms to respond to environmental variation with appropriate plasticity. Modern humans have substantially remodeled their environment such that many interactions with the environment have become relatively discontinuous functions compared to the past. Examples include sunlight, temperature, and altitude. We propose that environmental discontinuity represents a Darwinian maladaptation and may promote disease by inducing buffer dysfunctions. Skin pigmentation is an adaptive, dynamic buffer that normalizes sunlight exposure to balance the potential harm of damaging rays with the importance of sunlight in driving systemic biologic functions such as melatonin and vitamin D. Due to lifestyle characteristics such as indoor-outdoor living, well-intended sun-avoidance campaigns, and inhomogeneous use of apparel and sunblock techniques, modern humans increasingly experience sunlight variation as a discontinuous function. The resulting skin pigmentation buffer dysfunction may promote diseases associated with over- or under-exposure to sunlight, the most striking example being melanoma. In addition to promoting discontinuity of sunlight exposure, sun-avoidance campaigns may undermine sun-dependent biologic pathways such as melatonin and vitamin D that appear to protect against cancer. These issues may partly explain the rise in melanoma rates despite the implementation of sun-avoidance campaigns. Also discussed is the potential role that discontinuous temperature variation associated with modern lifestyles plays in diseases such as viral infection, heart failure, and acute coronary syndromes. Acute discontinuous changes in pressure and oxygen levels related to air travel may contribute to autonomic dysfunction, venous thromboembolism, and viral infections. Therapeutic implications are discussed.
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PMID:Environmental discontinuity hypothesis: Buffer dysfunctions as a source of human disease. 1675 13

While 1,25 dihydroxycholecalciferol (calcitriol) is best recognized for its effects on bone and mineral metabolism, epidemiological data indicate that low vitamin D levels may play a role in the genesis and progression of breast, lung, colorectal and prostate cancer, as well as malignant lymphoma and melanoma. Calcitriol has strong antiproliferative effects in prostate, breast, colorectal, head/neck and lung cancer, as well as lymphoma, leukemia and myeloma model systems. Antiproliferative effects are seen in vitro and in vivo. The mechanisms of these effects are associated with G0/G1 arrest, induction of apoptosis, differentiation and modulation of growth factor-mediated signaling in tumor cells. In addition to the direct effects on tumor cells, recent data strongly support the hypothesis that the stromal effects of vitamin D analogs (e.g., direct effects on tumor vasculature) are also important in the antiproliferative effects. Antitumor effects are seen in a wide variety of tumor types and there are few data to suggest that vitamin D-based approaches are more effective in any one tumor type. Glucocorticoids potentiate the antitumor effect of calcitriol and decrease calcitriol-induced hypercalcemia. In addition, calcitriol potentiates the antitumor effects of many cytotoxic agents. Preclinical data indicate that maximal antitumor effects are seen with pharmacological doses of calcitriol and that such exposure can be safely achieved in animals using a high dose, intermittent schedule of administration. AUC and C(max) calcitriol concentrations of 32 ng.h/ml and 9.2 ng/ml are associated with striking antitumor effects in a murine squamous cell carcinoma model and there is increasing evidence from clinical trials that such exposures can be safely attained in patients. Another approach to maximizing intra-tumoral exposure to vitamin D analogs is to inhibit their catabolism. The data clearly indicate that agents which inhibit the major vitamin D catabolizing enzyme, CYP24 (24 hydroxylase), potentiate calcitriol killing of prostate tumor cells in vitro and in vivo. Phase I and II trials of calcitriol, either alone or in combination with carboplatin, taxanes or dexamethasone, as well as the non-specific CYP24 inhibitor, ketoconazole, have been initiated in patients with androgen-dependent and -independent prostate cancer and other advanced cancers. The data indicate that high-dose calcitriol is feasible on an intermittent schedule, no dose-limiting toxicity has been encountered, but the optimal dose and schedule remain to be delineated. Clinical responses have been seen with the combination of high-dose calcitriol + dexamethasone in androgen-independent prostate cancer (AIPC) and, in a large randomized trial in men with AIPC, potentiation of the antitumor effects of docetaxel were seen.
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PMID:Vitamin D compounds: clinical development as cancer therapy and prevention agents. 1688 63

Calcitriol is a potent antiproliferative agent against various tumour cells in vitro. Here, the results of a study on vitamin D compounds (calcitriol's analogues PRI-1906 and PRI-2191) as potential agents in combined antitumour therapy in vitro are presented. Applying antiproliferative SRB and MTT assays, the growth inhibitory effects of the vitamin D compounds, applied alone or in combination with either cisplatin or doxorubicin, were measured. The following cancer cell lines were employed: A549 (human non-small cell lung carcinoma), B16 (murine melanoma), CCRF, HL-60 (human leukaemia), SW707 (human colon cancer), MCF-7, T47D (human breast cancer), WEHI-3 (mouse leukaemia) and normal cells: BALB 3T3 (normal murine fibroblast cell line). It was shown that the treatment of tumour cells, which are sensitive to vitamin D compounds, with the combination of vitamin D compounds and cytostatics decreased the inhibitory concentration 50% (IC50) values compared with the effects of the cytostatics applied alone.
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PMID:Antiproliferative activity of vitamin D compounds in combination with cytostatics. 1688 80

Folate and vitamin D have been shown to be influenced by ultraviolet (UV) radiation. UVA radiation can break down plasma folate, whereas vitamin D can be synthesized in UVB-exposed skin. Folate metabolism is involved in DNA synthesis and repair, and vitamin D processes anti-proliferative effects. The functions of both nutrients are implicated in skin carcinogenesis. We evaluated genetic polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene (C677T and A1298C) and the vitamin D receptor (VDR) gene (Fok1, Bsm1 and Cdx2) with skin cancer risk in a nested case-control study within the Nurses' Health Study [219 melanoma, 286 squamous cell carcinoma (SCC), 300 basal cell carcinoma (BCC) and 873 controls]. No significant associations were observed for the two MTHFR polymorphisms on skin cancer risk. We observed an interaction between the C677T polymorphism and total folate intake on SCC risk (P, interaction=0.04); the highest risk was observed among women with TT genotype and low folate intake (OR=2.14; 95% CI=1.01-4.50). The VDR Bsm1 BB genotype was significantly associated with an increased SCC risk (OR=1.51; 95% CI=1.00-2.28). An interaction between the Bsm1 polymorphism and total vitamin D intake on SCC was observed, with the highest risk seen in women with the BB genotype and high vitamin D intake (OR=2.38; 95% CI=1.22-4.62) (P, interaction=0.08). This study suggests a possible role of the polymorphisms in MTHFR and VDR interacting with dietary intakes of folate and vitamin D in skin cancer development, especially for SCC. Due to a large number of comparisons and tests, the possible associations should be interpreted with caution and confirmed by other studies.
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PMID:Polymorphisms in the MTHFR and VDR genes and skin cancer risk. 1695 Aug

There is increasing evidence that vitamin D reduces the risk of many types of cancer. Geographic variations in cancer mortality rates in Spain are apparently linked to variations in solar ultraviolet (UV) irradiances and other factors. Cancer mortality rates for 48 continental Spanish provinces for 1978-1992 were used in linear regression analyses with respect to mortality rates for latitude (an index of solar UVB levels), skin cancer (an index of high cumulative UVB irradiance), melanoma (an index related to solar UV irradiance and several other factors) and lung cancer (an index of cumulative effects of smoking). The 9 cancers with mortality rates significantly correlated with latitude for 1 or both sexes were brain, gastric, melanoma, nonmelanoma skin cancer (NMSC), non-Hodgkin's lymphoma (NHL), pancreatic, pleural, rectal and thyroid cancer. Inverse correlations with latitude were found for laryngeal, lung and uterine corpus cancer. The 17 cancers inversely correlated with NMSC are bladder, brain, breast, colon, esophageal, gallbladder, Hodgkin's lymphoma, lung, melanoma, multiple myeloma, NHL, ovarian, pancreatic, pleural, rectal, thyroid and uterine corpus cancer. The 16 correlated with melanoma are bladder, brain, breast, colon, gallbladder, leukemia, lung, multiple myeloma, NHL, ovarian, pancreatic, pleural, prostate, rectal, renal and uterine corpus cancer. The results for lung cancer were in accordance with the literature. These results provide more support for the UVB/vitamin D/cancer hypothesis and indicate a new way to investigate the role of solar UV irradiance on cancer risk. They also provide more evidence that melanoma and NMSC have different etiologies.
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PMID:An ecologic study of cancer mortality rates in Spain with respect to indices of solar UVB irradiance and smoking. 1714 99

We studied effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], its analog seocalcitol (EB 1089), and 25-hydroxyvitamin D3 [25(OH)D3], on the growth of seven melanoma cell lines. While three cell lines (MeWo, SK-Mel-28, SM) responded to antiproliferative effects of active vitamin D analogs, the others (SK-Mel-5, SK-Mel-25, IGR, MeUuso) were resistant. A strong induction (7000-fold) of 1,25-dihydroxyvitamin D-24-hydroxylase (24OHase, CYP24) mRNA was detected in responsive cell lines along with 1,25(OH)2D3-treatment, indicating functional integrity of vitamin D receptor (VDR)-mediated transcription. In contrast, induction of 24OHase was much lower in resistant melanoma cells (70-fold). VDR mRNA was induced up to 3-fold both in responsive and resistant cell lines along with 1,25(OH)2D3-treatment. RNA for vitamin D-activating enzymes vitamin D-25-hydroxylase (25OHase, CYP27A1) and 25-hydroxyvitamin D-lalpha-hydroxylase (lalphaOHase, CYP27B1) was detected in all melanoma cell lines analyzed, additionally we show splicing variants of lalphaOHase in SK-Mel-28 cells. Expression of 250Hase and laOHase was marginally modulated along with treatment. Proliferation of melanoma cells was not inhibited by treatment with 25(OH)D3, indicating no significant stimulation of endogeneous production of antiproliferative acting 1,25(OH)2D3. In conclusion, we characterize the vitamin D endocrine system in melanoma cells and demonstrate that the majority of melanoma cell lines analyzed is resistant to antiproliferative effects of 1,25(OH)2D3. It can be speculated that these alterations are of importance for pathogenesis and growth of metastasizing malignant melanoma. Additionally, our findings indicate that only a minority of cases with metastasizing melanoma may represent a promising target for palliative treatment with new vitamin D analogs that exert little calcemic side effects or for pharmacological modulation of 1,25(OH)2D3-synthesis/metabolism.
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PMID:In vitro comparison of the vitamin D endocrine system in 1,25(OH)2D3-responsive and -resistant melanoma cells. 1717 23

It was initially hypothesized that sun exposure might cause non-Hodgkin lymphoma (NHL) on the following grounds: its incidence was increasing in parallel with that of cutaneous melanoma; its risk was increased in those with a history of melanoma or other skin cancer; sun exposure causes immune suppression; and immunosuppression for other reasons is associated with an increased risk of NHL. The association of NHL with prior skin cancer has been found consistently in subsequent studies, but results of ecological analyses have only partially supported this hypothesis. Contrary to it, three recent studies of NHL in individuals found that risk decreased, generally by 25% to 40%, across categories of increasing total or recreational, but not occupational, sun exposure. One study, thus far reported only in abstract, showed the opposite. Production of vitamin D from sun exposure offers a plausible mechanism for protection against NHL by sun exposure. A recent study has found a reduced risk of NHL in people with a high dietary intake of vitamin D. Results of additional studies in individuals and a planned original-data meta-analysis of case-control studies should help to resolve the present conflicting results on sun exposure and NHL.
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PMID:Sun exposure and non-Hodgkin lymphoma. 1733 44

Ozone depletion leads to an increase in the ultraviolet-B (UV-B) component (280-315 nm) of solar ultraviolet radiation (UVR) reaching the surface of the Earth with important consequences for human health. Solar UVR has many harmful and some beneficial effects on individuals and, in this review, information mainly published since the previous report in 2003 (F. R. de Gruijl, J. Longstreth, M. Norval, A. P. Cullen, H. Slaper, M. L. Kripke, Y. Takizawa and J. C. van der Leun, Photochem. Photobiol. Sci., 2003, 2, pp. 16-28) is discussed. The eye is exposed directly to sunlight and this can result in acute or long-term damage. Studying how UV-B interacts with the surface and internal structures of the eye has led to a further understanding of the location and pathogenesis of a number of ocular diseases, including pterygium and cataract. The skin is also exposed directly to solar UVR, and the development of skin cancer is the main adverse health outcome of excessive UVR exposure. Skin cancer is the most common form of malignancy amongst fair-skinned people, and its incidence has increased markedly in recent decades. Projections consistently indicate a further doubling in the next ten years. It is recognised that genetic factors in addition to those controlling pigment variation can modulate the response of an individual to UVR. Several of the genetic factors affecting susceptibility to the development of squamous cell carcinoma, basal cell carcinoma and melanoma have been identified. Exposure to solar UVR down-regulates immune responses, in the skin and systemically, by a combination of mechanisms including the generation of particularly potent subsets of T regulatory cells. Such immunosuppression is known to be a crucial factor in the generation of skin cancers. Apart from a detrimental effect on infections caused by some members of the herpesvirus and papillomavirus families, the impact of UV-induced immunosuppression on other microbial diseases and vaccination efficacy is not clear. One important beneficial effect of solar UV-B is its contribution to the cutaneous synthesis of vitamin D, recognised to be a crucial hormone for bone health and for other aspects of general health. There is accumulating evidence that UVR exposure, either directly or via stimulation of vitamin D production, has protective effects on the development of some autoimmune diseases, including multiple sclerosis and type 1 diabetes. Adequate vitamin D may also be protective for the development of several internal cancers and infections. Difficulties associated with balancing the positive effects of vitamin D with the negative effects of too much exposure to solar UV-B are considered. Various strategies that can be adopted by the individual to protect against excessive exposure of the eye or the skin to sunlight are suggested. Finally, possible interactions between ozone depletion and climate warming are outlined briefly, as well as how these might influence human behaviour with regard to sun exposure.
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PMID:The effects on human health from stratospheric ozone depletion and its interactions with climate change. 1766 23

The active form of vitamin D, 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], is an endocrine hormone whose classic role is the maintenance of calcium homeostasis. It is well documented that 1,25(OH)(2)D(3) also has anti-tumor effects on a number of cancers and cancer cell lines including breast, colorectal, gastric, liver, ovarian, prostate, and non-melanoma skin cancers. Included in the anti-tumor activities of 1,25(OH)(2)D(3) are its ability to cause antiproliferation, prodifferentation and decrease angiogenesis. Furthermore, through regulation of the plaminogen activator (PA) system and a class of proteolytic enzymes called matrix metalloproteinases (MMPs), 1,25(OH)(2)D(3) reduces the invasive spread of tumor cells. Because of the calcemic limitations of using 1,25(OH)(2)D(3) as a therapy, we have tested the effects of a novel Gemini vitamin D analogue, Deuterated Gemini (DG), on mouse colorectal cancer. We demonstrated that DG is more potent in reducing tumor volume and mass, compared to control and 1,25(OH)(2)D(3). DG significantly prevented (100% reduction, p<0.05) the invasive spread of colorectal tumor cells into the surrounding muscle, and had no effect on serum calcium levels. Thus, DG acts as a selective vitamin D receptor modulator (SVDRM) by enhancing select anti-tumor characteristic 1,25(OH)(2)D(3) activities, without inducing hypercalcemia. Thus, DG shows promise in the development of colorectal cancer therapies.
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PMID:Selective vitamin D receptor modulators and their effects on colorectal tumor growth. 1736 90


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