Resveratrol Chemosensitizes Breast Cancer Cells to Melphalan by Cell Cycle Arrest Fabiana Casanova, 1 Julia Quarti, 2 Danielly Cristiny Ferraz da Costa, 1 Caroline Arau ´ jo Ramos, 2 Jerson Lima da Silva, 1 and Eliane Fialho 2 * 1 Universidade Federal do Rio de Janeiro, Instituto de Bioquı ´mica Me ´dica, Rio de Janeiro, RJ 21941-590, Brazil 2 Universidade Federal do Rio de Janeiro, Instituto de Nutric ¸a ˜o Josue ´ de Castro, Departamento de Nutric ¸a ˜o Ba ´sica e Experimental, Rio de Janeiro, RJ 21941-590, Brazil ABSTRACT Melphalan (MEL) is a chemotherapeutic agent used in breast cancer therapy; however, MEL’s side effects limit its clinical applications. In the last 20 years, resveratrol (RSV), a polyphenol found in grape skins, has been proposed to reduce the risk of cancer development. The aim of this study was to investigate whether RSV would be able to enhance the antitumor effects of MEL in MCF-7 and MDA-MB-231 cells. RSV potentiated the cytotoxic effects of MEL in human breast cancer cells. This finding was related to the ability of RSV to sensitize MCF-7 cells to MEL-induced apoptosis. The sensitization by RSV involved the enhancement of p53 levels, the decrease of procaspase 8 and the activation of caspases 7 and 9. Another proposed mechanism for the chemosensitization effect of MCF-7 cells to MEL by RSV was the cell cycle arrest in the S phase. The treatment with RSV or MEL increased the levels of p-Chk2. The increase became pronounced in the combined treatments of the compounds. The expression of cyclin A was decreased by treatment with RSV and by the combination of RSV with MEL. While the levels of cyclin dependent kinase 2 (CDK2) remained unchanged by treatments, its active form (Thr 160 -phosphorylated CDK2) was decreased by treatment with RSV and by the combination of RSV with MEL. The activity of CDK7, kinase that phosphorylates CDK2 at Thr 160 , was inhibited by RSV and by the combination of RSV with MEL. These results indicate that RSV could be used as an adjuvant agent during breast cancer therapy with MEL. J. Cell. Biochem. 113: 2586–2596, 2012. ß 2012 Wiley Periodicals, Inc. KEY WORDS: APOPTOSIS; CANCER; CELL CYCLE; MELPHALAN; RESVERATROL C ancer is a growing health problem around the world particularly with the steady rise in life expectancy, increasing urbanization, and the subsequent changes in environmental conditions including lifestyle. According to a recent report [Jemal et al., 2011], cancer accounted for 7.6 million deaths (around 13% of all deaths) in 2008, and deaths from cancer worldwide are projected to continue to rise to over 11 million in 2030. The therapies available to date for cancer treatment are surgery, radiotherapy, and chemotherapy. Chemotherapy is often used as the main regimen in the treatment of most cancers. However, the development of tumor resistance to chemotherapy (chemoresis- tance) presents a major hurdle in cancer therapy [Higgins, 2007]. The use of cancer chemopreventive phytochemicals in combination with chemotherapeutic agents has been shown to be a pragmatic approach to overcome chemoresistance and sensitize cancer cells to apoptosis or growth arrest, while minimizing the side effects arising from the conventional therapy [Garg et al., 2005]. Among the potential chemosensitizers are bioactive compounds such as resveratrol (RSV). RSV is a natural phytoalexin that is present in especially high concentrations in grape skins and, as a consequence, in red wine [Gusman et al., 2001]. Its beneficial health effects include its anti- infective, antioxidant, and cardioprotective functions in addition to its anticancer potential [Baur and Sinclair, 2006; Marques et al., 2009]. Research from in vitro and in vivo studies indicate that RSV can sensitize tumor cells to chemotherapeutic agents by modulating Journal of Cellular Biochemistry ARTICLE Journal of Cellular Biochemistry 113:2586–2596 (2012) 2586 Grant sponsor: Fundac ¸a ˜o de Amparo a ` Pesquisa Carlos Chagas Filho do Estado do Rio de Janeiro (FAPERJ); Grant number: E-26/103.110/2008; Grant sponsor: Cancer Foundation/2009; Grant sponsor: Conselho Nacional de Desenvolvimento Cientı ´fico e Tecnolo ´ gico; Grant sponsor: Coordenac ¸a ˜o de Aperfeic ¸oamento de Pessoal de Nı ´vel Superior. *Correspondence to: Eliane Fialho, PhD, Departamento de Nutric ¸a ˜o Ba ´sica e Experimental, Instituto de Nutric ¸a ˜o Josue ´ de Castro, Centro de Cie ˆncias da Sau ´ de, Universidade Federal do Rio de Janeiro, UFRJ, Caixa Postal 68041, Cidade Universita ´ria, Ilha do Funda ˜o, Rio de Janeiro, CEP 21941-590, Brazil. E-mail: fialho@nutricao.ufrj.br Manuscript Received: 21 August 2011; Manuscript Accepted: 7 March 2012 Accepted manuscript online in Wiley Online Library (wileyonlinelibrary.com): 13 March 2012 DOI 10.1002/jcb.24134  ß 2012 Wiley Periodicals, Inc.