Quinacrine Enhances Cisplatin-Induced Cytotoxicity in Four Cancer Cell Lines

BACKGROUND: Quinacrine has potential as a chemosensitizer when combined with chemotherapy, but its anti-cancer mechanisms remain unclear. The purpose of this study was to explore the capability of quinacrine to enhance the cytotoxic effects of cisplatin and the underlying mechanism involved. METHODS: The potential role of quinacrine in enhancing the effects of cisplatin was investigated in Hela, SCC-VII, SACC-83 and C6 cancer cell lines with different pathologies. The inhibitory effects of quinacrine plus cisplatin on these cell lines were detected using a CCK-8 assay for viability and a TUNEL assay for apoptosis. The molecules involved in apoptotic signal translation, including cIAP-1, Bax, p53 and cleaved caspase-3, were detected by Western blot to investigate the underlying mechanism. RESULTS: The CCK8 assay showed that quinacrine markedly enhanced the cytotoxicity of cisplatin in a dose-dependant manner in the 4 cancer cell lines. The TUNEL assay showed that treating the 4 cell lines for 24 h with cisplatin plus quinacrine significantly increased the percentage of apoptotic cells compared to treatment with single-agent treatment or untreated controls. Western blot analysis showed that quinacrine plus cisplatin significantly down-regulated cIAP-1 and up-regulated Bax and cleaved caspase-3 expression in Hela and SCC-VII cells compared with single-agent treatment. CONCLUSIONS: Quinacrine has the potential to be used as a chemotherapy adjuvant when combined with cisplatin.