[Effects of inhibition of PKC alpha on breast cancer cell phenotype and expressions of cyclin E and CDK2].

Human breast cancer cell line Bcap-37 was stably transfected with the plasmid expressing antisense PKC alpha RNA, and cells, in which PKC alpha was inhibited due to antisense PKC alpha RNA, were isolated. Changes in serum-dependent growth in cell culture, cell clonogenicity in soft agar and growth in nude mice were tested, and the expressions of cyclin E and CDK2 were analyzed. After PKC alpha was inhibited, the cells showed that serum-dependent growth and anchorage-dependent growth enhanced, tumorigenicity in nude mice decreased. The results suggest that less aggressive breast cancer phenotypes may be induced by inhibition of PKC alpha. Levels of cyclin E and CDK2 mRNA in cells with antisense PKC alpha RNA were lower than those in control cell. These indicate that signal transduction system with PKC alpha is closely related to cell cycle control system with cyclin/CDK in the functions.