ABSTRACT
Phytochemicals are among the natural chemopreventive agents with most potential for delaying, blocking or reversing the initiation and promotional events of carcinogenesis. They therefore offer cancer treatment strategies to reduce cancer related death. One such promising chemopreventive agent which has attracted considerable attention is sulforaphane (SFN), which exhibits anti-cancer, anti-diabetic, and anti-microbial properties. The present study was undertaken to assess effect of SFN alone and in combination with a chemotherapeutic agent, gemcitabine, on the proliferative potential of MCF-7 cells by cell viability assay and authenticated the results by nuclear morphological examination. Further we analyzed the modulation of expression of Bcl-2 and COX-2 on treatment of these cells with SFN by RT-PCR. SFN showed cytotoxic effects on MCF-7 cells in a dose- and time-dependent manner via an apoptotic mode of cell death. In addition, a combinational treatment of SFN and gemcitabine on MCF-7 cells resulted in growth inhibition in a synergistic manner with a combination index (CI) <1. Notably, SFN was found to significantly downregulate the expression of Bcl-2, an anti-apoptotic gene, and COX-2, a gene involved in inflammation, in a time-dependent manner. These results indicate that SFN induces apoptosis and anti-inflammatory effects on MCF-7 cells via downregulation of Bcl-2 and COX-2 respectively. The combination of SFN and gemcitabine may potentiate the efficacy of gemcitabine and minimize the toxicity to normal cells. Taken together, SFN may be a potent anti-cancer agent for breast cancer treatment.
Subject(s)
Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Cell Proliferation/drug effects , Deoxycytidine/analogs & derivatives , Isothiocyanates/pharmacology , Anti-Inflammatory Agents/pharmacology , Apoptosis/drug effects , Breast Neoplasms/metabolism , Cell Death/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Cyclooxygenase 2/metabolism , Deoxycytidine/pharmacology , Down-Regulation/drug effects , Drug Synergism , Female , Humans , MCF-7 Cells , Proto-Oncogene Proteins c-bcl-2/metabolism , Sulfoxides , GemcitabineABSTRACT
BACKGROUND: One of the most challenging stumbling blocks for the treatment of cancer is the ability of cancer cells to break the natural barriers and spread from its site of origin to non-adjacent regional and distant sites, accounting for high cancer mortality rates. Gamut experimental and epidemiological data advocate the use of pharmacological or nutritional interventions to inhibit or delay various stage(s) of cancer such as invasion and metastasis. Genistein, a promising chemopreventive agent, has gained considerable attention for its powerful anti-carcinogenic, anti-angiogenic and chemosensitizing activities. METHODS: In this study, the cytotoxic potential of genistein on HeLa cells by cell viability assay and the mode of cell death induced by genistein were determined by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Moreover, to establish its inhibitory effect on migration of HeLa cells, scratch wound assay was performed and these results were correlated with the expression of genes involved in invasion and migration (MMP-9 and TIMP-1) by RT-PCR. RESULTS: The exposure of HeLa cells to genistein resulted in significant dose- and time-dependent growth inhibition, which was found to be mediated by apoptosis and cell cycle arrest at G(2)/M phase. In addition, it induced migration-inhibition in a time-dependent manner by modulating the expression of MMP-9 and TIMP-1. CONCLUSION: Our results signify that genistein may be an effective anti-neoplastic agent to prevent cancer cell growth and invasion and metastasis. Therefore therapeutic strategies utilizing genistein could be developed to substantially reduce cancer morbidity and mortality.
