Cisplatin inhibits pinocytosis in Dictyostelium discoideum.

The effects of cis-diamminedichloroplatinum(II) [cisplatin], a potential anticancer drug, were studied on pinocytotic functions in the cellular slime mould Dictyostelium discoideum by administering FITC-dextran as a fluid phase marker. Cisplatin treatment at a concentration of 100 and 200 micrograms/ml for 1 h causes inhibition in pinocytotic uptake in growing Dictyostelium cells in a dose-dependent manner. Cisplatin treatment induced the association of more actin with the cell cortex, thereby presumably restricting the flexibility of the cell membrane and inhibiting the formation of pinosomes. Ultrastructural analysis of cisplatin-treated cells showed a lower number of pinosomes. These results have been discussed in the light of cisplatin's known actions that affect various cellular functions.