GSE107438 25D3 and 1,25D3 target gene profiles in LNCaP

In this study, we investigated whole genome target gene profiles and intracellular behaviors of VDR after administration of 25D3 or 1,25D3 in prostate cancer LNCaP cells to elucidate the hormonal activity of 25D3. First, we confirmed that LNCaP cells possessed functional 25D3-VDR as well as 1,25D3-VDR signaling systems by qRT-PCR. By immunofluorescent examination of nuclear translocation, western blotting and most importantly, knockdown o f CYP27B1 and/or VDR after the introduction of the respective siRNA into these cells, we found that, just like 1,25D3, 10-7 M of 25D3, which is within its uppermost physiological concentrations in the bloodstream, induced VDR nuclear import and robustly activated its target gene such as CYP24A1 in t he virtual absence of CYP27B1 expression in LNCaP cells. These results indicate that the unconverted 25D3 alone behaved similarly to 1,25D3 in activating CYP24A1 mRNA expression. Our comprehensive microarray analyses verified the bioactivity of 25D3 and we found that 25D3 target gene profiles largel y matched those of 1,25D3, while the presence a small subset of 25D3-, or 1,25D3-specific target genes were not excluded. The concentration of 1,25D3 in the culture media after 25D3 treatment with or without siRNA for CYP27B1 mRNA was below the lower limit of the sensitivity measured by ultrasensiti ve LC/MS/MS method. These results indicated that 25D3 shares bioactivity with 1,25D3 without conversion to the latter at least in some prostate cancer cel...
Source: GEO: Gene Expression Omnibus - Category: Genetics & Stem Cells Tags: Expression profiling by array Homo sapiens Source Type: research