Role of protein kinase cα in the induction of carcinoembryonic antigen by transforming growth factor β

✍ Scribed by Subhas Chakrabarty; Shuang Huang

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 640 KB
• Volume: 164
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041640119

✦ Synopsis

Previous studies showed that transforming growth factor Pl (TGFP1) regulates the expression of carcinoembryonic antigen (CEA) and CEA-cross-reactive glycoproteins (CEA-GLYs) in human colon carcinoma cells through a signal-transducing pathway associated with protein kinase C (PKC) (Chakrabarty, J. Cell. Physiol., 1992, 152:494499). In this study we determined the role of the PKCu isoform in the regulation of CEA and CEA-GLYs expression by TCFPl . Expression of PKCa antisense RNA, through transfection experiments with an antisense PKCa expression vector, resulted in down-modulation of PKCa RNA and protein expression. TGFpl was unable to stimulate the expression and secretion of CEA in cells in which the expression of PKCa protein was substantially reduced. The ability of TCFPl to stimulate the expression of the 95and 55-KDa CEA-GLYs, however, was not affected. We therefore conclude that TGFPl regulates the secretion and expression of CEA through a signal-transducing pathway associated with PKCa. TGFPl may also regulate the expression of CEA-GLYs through signal-transducing pathways associated with other PKC isoforms.