Ultrastructural changes in HeLa cells following treatment with the antineoplastic agent cis-acid.

The ultrastructure of HeLa cells arrested in the G2 phase of the cell cycle by the antineoplastic agent cis-acid was studied and compared with that of normal G2-phase-synchronized cells. The results demonstrate that the chromatin of drug-treated cells was fragmented and clumped, the membranous structures had degenerated or were destroyed and the polyribosomes were decreased. The mitochondria were swollen and vacuolated, suggesting that energy production might have been impaired.