Vitamin D and tumours - sun and tumours - vitamin D and sun. Triangle of conflict or synergy?
|Fakulta / Pracoviště MU|
|Popis||Vitamin D shows the ability to inhibit mitogen-activated protein kinase (MAPK) and thus negative growth regulation of mammary carcinoma cells both in vivo and in vitro. The mechanism of action is interpreted in two ways: it regulates gene transcription of the gene through the specific intracellular vitamin D receptor (VDR) and, by means of activation of transmembrane transfer, it induces a fast non-transcriptional response of the character of modification of growth factors and peptide hormones. Based on these activities there occurs an antiproliferative, proapoptotic influence on many cell lines.. In discussions on the mutual relationship between vitamin D and tumorous growth there frequently appears the theme of exposure to solar radiation as a significant source of vitamin D for man in contrast to the rising occurrence of malignant melanoma, in whose pathogenesis exposure to solar radiation plays indeed an important role. In discussions regarding the mutual relationship between the vitamin D level and potential antiproliferative action and solar radiation as the principal presumed pathogenetic factor of the development of malignant melanoma, but also as a source of vitamin D, there arises the question of quantity, i.e., what the optimal serum level of vitamin D should be. Many authors denote values between 70 and 100 nmol/l as optimal, both for patients with malignant melanoma and for the healthy population. The relationship evaluation between sun exposition and the harm of the skin must reflect different types of skin, their sun burn time (SBT), different types of outdoor activities and recommended dose of sun exposition as a vitamin D source.|