Background: Breast cancer is one of the most common types of malignancies in the world. Cancer resistance is an unavoidable consequence of therapy with radiation or other modalities. Ongoing research aims to improve cancer response to therapy.
Aim: The aim of this study was to evaluate the possible sensitization effect of imperatorin (IMP) in combination with external radiotherapy (ERT) or HT.
Methods: After treatment of MCF-7 breast cancer cells with IMP, cells were exposed to 4 Gy X-rays or HT (42 °C for 1 hour). The viability of MCF-7 cells was measured using an MTT assay. Furthermore, the expression of pro-apoptotic genes, including Bax, Bcl-2, caspase-3, caspase-8, and caspase- 9, was investigated using real-time PCR. The sensitizing effect of IMP in combination with ERT or HT was calculated and compared to ERT or HT alone.
Results: Results showed an increase in the expression of pro-apoptotic genes and downregulation of anti-apoptotic Bcl-2 following ERT and HT. Furthermore, cell viability was reduced following these treatments. IMP was able to augment these effects of ERT and HT.
Conclusion: IMP could increase the efficiency of HT and ERT. This effect of IMP may suggest it as an adjuvant for increasing the therapeutic efficiency of ERT.
Keywords: Imperatorin, radiotherapy, hyperthermia, MCF-7, breast cancer, apoptosis.