1,25-Dihydroxyvitamin D3 selectively translocates PKCα to nuclei in ROS 17/2.8 cells

Activation of rapid signaling pathways does not contribute to 1α,25‐dihydroxyvitamin D3‐induced growth inhibition of mouse prostate epithelial progenitor cells

“…PKCα is another kinase that has been shown to be activated rapidly by 1,25(OH) 2 D treatment in a variety of cell types [Balogh et al, 2000; Capiati et al, 2000; Rivera-Bermudez et al, 2002; Boyan et al, 2003; Schwartz et al, 2003; Wali et al, 2003]. In contrast to these reports showing rapid activation of PKCα by 1,25(OH) 2 D, our study did not show this effect in prostate epithelial progenitor cells.…”

“…The nVDR plays a critical role in mediating ligand-induced transcriptional regulation of a variety of genes that are important for cell proliferation, differentiation, and apoptosis. In addition, several kinases have been shown to be rapidly regulated by 1,25(OH) 2 D, including extracellular-regulated kinase (ERK) 1/2 [Beno et al, 1995; Marcinkowska et al, 1997; Song et al, 1998; Chen et al, 1999; Morelli et al, 2001; Buitrago et al, 2001a,b; Galbiati et al, 2002; Schwartz et al, 2002; Johansen et al, 2003; Capiati et al, 2004; Pardo and de Boland, 2004] and protein kinase C α (PKCα) [Balogh et al, 2000; Capiati et al, 2000; Rivera-Bermudez et al, 2002; Boyan et al, 2003; Schwartz et al, 2003; Wali et al, 2003], which may contribute to the regulation of genes that are not direct targets of nVDR [Farach-Carson and Davis, 2003]. However, the mechanisms mediating growth inhibition by vitamin D that lead to prostate cancer prevention, as well as therapy by vitamin D analogues, are not known definitively.…”

“…Another rapid signal previously reported to be induced by 1,25(OH) 2 D is PKCα [Balogh et al, 2000; Capiati et al, 2000; Rivera-Bermudez et al, 2002; Boyan et al, 2003; Schwartz et al, 2003; Wali et al, 2003]. PKCα is classified as a classical PKCs (cPKC), and a downstream target of extracellular stimulated receptors, including G-protein coupled receptors (GPCRs) [Breitkreutz et al, 2007].…”

“…Activated PKCα phosphorylates proteins on serine/threonine residues and thereby regulating their activity [Breitkreutz et al, 2007]. Rapid PKC activation by 1,25(OH) 2 D has been shown in myoblasts and myotubes [Capiati et al, 2000], duodenal mucosae [Balogh et al, 2000], chondrocytes [Boyan et al, 2003; Schwartz et al, 2003], osteoblasts [Wali et al, 2003], osteosarcoma cell line [Rivera-Bermudez et al, 2002]. …”

1,25‐dihydroxyvitamin D3 stimulated protein kinase C phosphorylation of type VI adenylyl cyclase inhibits parathyroid hormone signal transduction in rat osteoblastic UMR 106‐01 cells

“…In addition to the nuclear receptors, many studies have demonstrated the effects of 1,25(OH) 2 D 3 on PKC isoforms in a number of different cell lines including rat osteoblasts [van Leeuwen et al, 1992;Boyan et al, 2002;Rivera-Bermudez et al, 2002]. It is not clear how 1,25(OH) 2 D 3 regulates PKC activity in these cells.…”