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

PURPOSE: 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. METHODS: 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. RESULTS: Lobaplatin and heptaplatin had an inhibiting effect in all resistant cell lines, dicycloplatin demonstrate only weak antitumor activity in vitro. CONCLUSIONS: 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.