[Etoposide effect on cell cycle kinetics of a human lung cancer cell line]

The lethal and kinetic effects of Etoposide on a cell line of human small cell carcinoma of the lung (PC-6) were analyzed in vitro using flow cytometric measurement of DNA content. The drug effect is dependent on concentration and exposure time. When PC-6 cells were exposed to Etoposide for 1 hour then washed, a increase of cells in G2 phase was observed followed by prompt recovery. Continuous treatment with Etoposide for 24 hours caused a retardation of S phase transit, and high concentrations (greater than 10 micrograms/ml) resulted in stoppage of the whole cell cycle. This drug may be useful in combination chemotherapy regimens.