1,25(OH)2D3 Initially Reduces TGF? Activity in PC-3 Prostate Cancer Cells
The vitamin D metabolite 1,25(OH)2D3 has long been known to inhibit growth of prostate cancer cells and this mainly through a VDR-mediated pathway controlling target gene expression, resulting in cell cycle arrest, apoptosis and differentiation. Another major way in which 1,25(OH)2D3 inhibits cell growth in prostate cancer is via membrane-initiated steroid signalling, which triggers activation of signal cascades upon steroid binding to a receptor complex, leading to induction of genes regulating cell growth, proliferation and apoptosis. The main prostate cancer inhibiting membrane-initiated route is the TGF? signalling pathway, elicited by the protein TGF?. In this experiment the activating effects of 1,25(OH)2D3 on TGF? in prostate cancer cells, as well as two other important proteins downstream in this cascade, Smad2 and 3, were investigated. PC-3 cells were incubated for 3, 5, 10, 30 and 60 minutes as well as 38 hours both together with 1,25(OH)2D3 of the concentrations 10-10 and 10-7 M and without. As the downstream cascade protein JNK is a known activator of Smad2/3, this procedure was also repeated with a JNK inhibitor. An ELISA assay scanning for activated TGF? was then performed on supernatants from the cells treated without JNK inhibitor. In addition, a Western Blot scanning for activated Smad2 and 3 was performed on supernatants from all groups of treatment. The analysis of the result values showed that 10-10 M 1,25(OH)2D3 significantly lowered the content of active TGF? in PC-3 cells within 3 and 5 minutes. Unfortunately the Western Blot was unsuccessful and needs therefore be repeated.
School:Högskolan i Skövde
Source Type:Master's Thesis
Keywords:prostate cancer pc 3 proliferation growth inhibition vitamin d 1 25 oh 2d3 tgf? smad2 smad3
Date of Publication:08/14/2008