Abstract 3285: Synergistic anticancer effects of resveratrol and clofarabine in malignant mesothelioma cells.

Abstract Malignant mesothelioma is highly resistant to apoptosis. Hence, new strategies to enhance the apoptotic signal and overcome resistance to therapeutic drugs are necessary to improve the therapeutic efficacy of malignant mesothelioma. Here, we investigated the effects of the combined treatment of various phytochemicals as a chemo-potentiator in combination with the chemotherapeutic agent clofarabine in malignant mesothelioma MSTO-211H cells and normal mesothelial Met-5A cells. Treatment with resveratrol in combination with clofarabine at a subtoxic concentration produced a synergistic antiproliferative effect and induced apoptotic cell death, as evidenced by increased subG1 peak on flow cytometric analysis, chromatin condensation and nuclear fragmentation on DAPI staining, and DNA laddering on agarose gel electrophoresis, in MSTO-211H cells, but not in Met-5A cells. In MSTO-211H cells, endogenous expression of the transcription factors Nrf2 and Sp1 proteins, several Nrf2 and Sp1-regulated gene products (HO-1, c-Met, and cyclin D1), and Akt phosphorylation, were effectively suppressed by the combined treatment of clofarabine and resveratrol. Furthermore, the nuclear accumulations of Nrf2 and Sp1 were inhibited by the combination treatment. In combination with clofarabine, the ability of resveratrol to increase the contents of the phosphorylated p53 and the apoptotic molecules, PARP and cleaved caspase 3, was also evident in a time- and dose-dependent experiment. Taken together, the data provide evidence that the synergistic antiproliferative effect of resveratrol and clofarabine is linked to simultaneous suppression of multi-target molecules, such as Nrf2, Sp1, and Akt activities, and suggest that this combination may have therapeutic value in treatment of malignant mesothelioma. Citation Format: David M. Lee, Yoon-Jin Lee, Jae-Hyuk Im, Seong-Youn Won, Hae-Seon Nam, Sang-Han Lee. Synergistic anticancer effects of resveratrol and clofarabine in malignant mesothelioma cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3285. doi:10.1158/1538-7445.AM2013-3285