[Effect of cytochalasin D on DNA synthesis in cultured cells]

The effect of cytochalasin D (CD), an agent specifically destroying actin cytoskeleton, on DNA replication of cultured mouse embryonic fibroblasts (MEF) and BALB/3T3 strain cells was studied. Incubation of normal cells with CD resulted in progressive inhibition of DNA synthesis: in the first 16-20 h the percentage of cells pulse-labelled with 3H-thymidine was similar to that in control cultures, on day 8 the percentage of labelled cells was 7-8 times lower than in the control. The transfer of cells into fresh medium upon 8-day incubation in the presence of CD resulted in the recovery of DNA synthesis. Similar curves of DNA synthesis inhibition in the presence of CD and of DNA synthesis recovery in fresh medium were observed both in mononuclear and binuclear cells. Thus, CD-induced reorganization of actin cytoskeleton can have an abrupt but reversible disturbing effect on normal cell cycle.