Abstract
1,25-Dihydroxyvitamin D 3 (1,25-(OH) 2D 3) receptor concentration, cell proliferation, and the steady-state level of c- myc mRNA were examined in the C3H/10T1/2 mouse embryo fibroblasts, before and after exposing the cells to 1,25-(OH) 2D 3. The non-transformed, logarithmically growing C3H/10T1/2 Cl 8 cells contained a high concentration of 1,25-(OH) 2D 3 receptor (164 fmol/mg of protein). An up-regulation of the 1,25-(OH) 2D 3 receptor and a potent inhibition of cell growth were observed by exposing the cells to 10 nM 1,25-(OH) 2D 3. The concentration of 1,25-(OH) 2D 3 receptor in the two chemically transformed, tumorigenic cell lines, C3H/10T1/2 Cl 16 and C3H/10T1/2 TPA 482, was 218 and 63 fmol/mg of protein, respectively. In the two transformed cell lines, 10 nM 1,25-(OH) 2D 3 had only negligible effect on cell growth. In the Cl 16 cells, an up-regulation of the 1,25-(OH) 2D 3 receptor was demonstrated, but only a weak up-regulation was found in the TPA 482 cells by the 1,25-(OH) 2D 3 treatment. No major changes were found in c- myc mRNA levels by the 1,25-(OH) 2D 3 treatment. Despite inhibition of cell growth, the steady-state level of c- myc mRNA was slightly induced (35%, mean) in the Cl 8 cells compared to control cells. In the transformed cells, no consistent change of the c- myc level was found. In contrast to earlier reports, we did not find any correlation between the 1,25-(OH) 2D 3 receptor and c- myc level, nor did we find any decrease of c- myc mRNA by 1,25-(OH) 2D 3 treatment in the C3H/10T1/2 fibroblasts.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call