Chemosensitivity of resistant colon cancer cell lines to lobaplatin, heptaplatin, and dicycloplatin.

Lobaplatin, heptaplatin, and dicycloplatin are three new platinum drugs. The aim of this study is to investigate the chemosensitivity of resistant colon cancer cell lines to these three drugs. Eight resistant colon cancer cell lines (four oxaliplatin-resistant colon cancer cell lines and four irinotecan-resistant colon cancer cell lines) were cultured in 96-well plates. Lobaplatin, heptaplatin, and dicycloplatin were added in various concentrations. IC50 was determined by MTT assay and the results were confirmed by CCK-8 assay. A cell death detection ELISA assay was performed to quantitate the apoptotic index by detecting the histone-associated DNA fragments generated by the apoptotic cells. Lobaplatin and heptaplatin had an inhibiting effect in all resistant cell lines, dicycloplatin demonstrate only weak antitumor activity in vitro. We confirmed the efficacy of two platinum drugs to oxaliplatin/ irinotecan-resistant colon cancer cell lines, suggesting these two drugs could be considered for improving the control of recurrent colon cancer following initial therapy with oxaliplatin and irinotecan.