in vitro radiosensitization of t47d and mda-mb-231 breast cancer cells with the neoflavonoid dalbergin

Background: radiotherapy is a frequently used therapeutic modality for breast cancer. dalbergin, a natural antioxidant, inhibits carcinogens and tumor progression. in the present study, we investigated the effect of dalbergin on the response of t47d and mda-mb-231 breast cancer cell lines to ionizing radiation. method: in this experimental in vitro study, doubling time of t47d and mdamb- 231 were obtained from the growth curve. the cytotoxic effect of dalbergin on t47d and mda-mb-231 breast cancer cells were estimated via mtt assay. to determine the clonogenic ability, we treated t47d and mda-mb-231 with dalbergin for 48 h prior to irradiation, subsequent to which a colony assay was performed. realtime polymerase chain reaction was employed to determine the gene expression level. results: dalbergin inhibited proliferation of t47d and mda-mb-231 in a timeand concentration-dependent manner. additionally, the most appropriate time for the treatment of these types of cancer cells was found to be 48 h and the drug's concentration in both cell lines was different. the ic50 values of t47d and mda-mb-231 cells were 0.001 and 0.0001 μm, respectively. moreover, this drug radiaosensitizes both cell lines effectively compared with the radiation only. finally, the gene expression level of p53, bcl-2, and stat3 were investigated in cancer cells. conclusion: dalbergin showed apoptotic effects probably through the stat/p53 signaling pathway. therefore, dalbergin could be considered as a radiosensitizer and its effects may be owing to increased cell death.