Hyperploidization of V79 cells by K-252a in comparison with demecolcine

The cellular responses of the V79 cell cycle to K-252a, a protein kinase inhibitor, were examined by flow cytometry (FCM) and by time-lapse videomicrography. At a concentration of 0.5 microM of K-252a for 72 h, V79 cells became hyperploid, having above 32c DNA content. The cycle times in the hyperploidizing process were 11.2 (4c-8c), 16.3 (8c-16c) and 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 widely distributed in the V79 cell population and hyperploid V79 cells reduced DNA content through a variety of cell division modes. These cellular responses to hyperploidization of V79 cells by K-252a were in reasonable agreement with those by demecolcine.