HYPERPLOIDIZATION OF V79 CELLS BY K-252A IN COMPARISON WITH DEMECOLCINE

The cellular responses of the V79 cell cycle to K-252a, a protein kina se inhibitor, were examined by flow cytometry (FCM) and by time-lapse videomicrography. At a concentration of 0.5 mu M of K-252a for 72 h, V 79 cells became hyperploid, having above 32c DNA content. The cycle ti mes in the hyperploidizing process were 11.2 (4c-8c), 16.3 (8c-16c) an d 19.3 (16c-32c) hours, values which were less than twice that of the control (10.5 h). After the washout of K-252a, the DNA content was wid ely distributed in the V79 cell population and hyperploid V79 cells re duced DNA content through a variety of cell division modes. These cell ular responses to hyperploidization of V79 cells by K-252a were in rea sonable agreement with those by demecolcine.