The Journal of steroid biochemistry and molecular biology
-
The vitamin D status depends on the production of vitamin D3 in the skin under the influence of ultraviolet radiation and vitamin D intake through the diet or vitamin D supplements. The serum 25-hydroxyvitamin D (25(OH)D) concentration is the parameter of choice for the assessment of vitamin D status. Low serum levels of calcium and phosphate and an elevated level of alkaline phosphatase can also point to vitamin D deficiency. ⋯ This may be due to a lighter skin and sun seeking behaviour and a high consumption of cod liver oil in the Northern countries while in Southern Europe people stay out of the sunshine and have a somewhat darker skin. A very poor vitamin D status was observed in non-western immigrants, especially in pregnant women. In conclusion, vitamin D deficiency and insufficiency are globally still very common especially in risk groups such as young children, pregnant women, elderly and immigrants.
-
J. Steroid Biochem. Mol. Biol. · Jul 2010
Notch- and vitamin D signaling in 1,25(OH)2D3-resistant glioblastoma multiforme (GBM) cell lines.
Recently, an important role of Notch activation for Ras-induced transformation of glial cells and for glioma growth and survival has been demonstrated. It was concluded that activation of Notch-signaling may represent a new target for glioblastoma multiforme (GBM) therapy. We now analyzed five GBM cell lines (Tx3095, Tx3868, U87, U118, U373) for key components of Notch-signaling pathways (Notch-1, Notch-2, Notch-3, Notch-4, Delta-like 1, Delta-like 3, Delta-like 4, Jagged-1, Jagged-2) using conventional RT-PCR. ⋯ In conclusion, our findings point at a differential expression of key components of Notch-signaling in GBM cell lines that may be of importance for the growth characteristics of GBM. Our findings indicate that GBM cell lines are resistant against the antiproliferative effects of 1,25(OH)2D3, and that this resistance may not be overcome by modulation of epigenetic silencing. Our findings do not support the hypothesis that modulation of Notch-signaling pathways by 1,25(OH)2D3 may regulate growth of GBM cell lines.