Hamid Cheshomi - Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
Hamid Cheshomi - Cellular and Molecular Research Center, Faculty of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
Mohammad Hosseinzadeh Hesari - Paramedicine College, Sabzevar University of Medical Sciences, Sabzevar, Iran
Gholam Hossein Ghasemzadeh - Faculty of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran

Introduction & Aim: The natural phenolic compounds including caffeic acid (CA) have been considered as inhibitors of several cancers such as breast cancer. In the present study, caffeic acid (3,4-dihydroxycinnamic acid) was appraised for its possible cytotoxic activity via investigation of its effect on expression changes of the most important apoptotic genes, P21, in breast cancer cell line (MCF-7). Methods: MCF-7 cells were cultured for 48h in DMEM media and caffeic acid was appraised for their possible cytotoxic effects this cell line. To determine half maximal inhibitory concentration, we treated MCF-7 cells different concentrations of this compound by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Furthermore, morphological changes in MCF-7 cells were examined and the expression level of P21 was measured using real-time reverse-transcription polymerase chain reaction (RT-PCR). Results: The decreased cell proliferation was coincident with a significant increase in the expression of P21. These results demonstrate that CA inhibits MCF-7 cell proliferation by inducing an arrest of cell cycle dependent on an increased expression of P21. Too, this alteration in gene expression probably occurs along the intrinsic apoptotic signaling pathway. Conclusion: Caffeic acid showed toxic and morphological effects on breast cancer cells, and induced its effects via apoptosis induction, suggesting possible future application as antitumor agents.