In vitro antitumor activity of carboplatin and analogues.

In order to obtain compounds with better biological activity and lower toxicity, numerous modifications have been made to the cisplatin and carboplatin molecules. The aim of the study was to examine the in vitro antiproliferative activity of two new carboplatin analogues and their effect on both the cell cycle and the induction of apoptosis. Carboplatin and analogues were tested on four human cell lines: myelogenous leukemia K562, colon adenocarcinoma HT-29, breast adenocarcinoma MCF-7 and lung fibroblasts MRC-5. Cell lines were exposed to commercial and synthesized carboplatin and two carboplatin analogues. Their growth inhibition was measured by the MTT test after 24 h incubation. The cell cycle modulation and induction of apoptosis were analyzed by flow cytometry on MCF-7 cell line. After 24 h exposure, both carboplatin analogs induced dose-dependent cytotoxicity in all tested cell lines. The most sensitive was MCF-7 cell line. Tested substances showed moderate cytotoxicity against healthy MRC-5 cells. Flow cytometry analysis showed that both analogues modulated the cell cycle, increasing cell population in sub-G1 phase. The same response in the form of the apoptosis induction was also obtained with the Annexin-V test. Apoptosis induction was confirmed with double-fluorescence staining method. Two new carboplatin analogues strongly inhibit the growth of MCF-7 breast cancer cells, inducing apoptosis and changes in cell cycle distribution. [ABSTRACT FROM AUTHOR]