Apoptotic Effects of Melittin on 4T1 Breast Cancer Cell Line is associated with Up Regulation of Mfn1 and Drp1 mRNA Expression

Background and Purpose: Melittin, as the main ingredient of honeybee venom, that has shown anticancer properties. The present study aimed at investigating the cytotoxic impacts of melittin on 4T1 breast cancer cells. Methods: Hemolytic activity of different concentrations (0.125, 0.25, 0.5, 1, 2, 4, 8 mu g/ml) of melittin was assayed and then cytotoxicity of selected concentrations of melittin (2, 4, 8, 16, 32, and 64 mu g/ml), 2 and 4 mu g/ml of cisplatin and 0.513, 0.295 and 0.123 mu g/ml of doxorubicin was evaluated on 4T1 cells using MTT assay. We used Morphological evaluation and flow cytometric analysis was used. Real time PCR was also used to determine mRNA expression of Mfn1 and Drp1 genes. Results: All compounds showed anti-proliferative effects on the tumor cell line with different potencies. Melittin had higher cytotoxicity against 4T1 breast cancer cells (IC50- 32 mu g/ml-72h) and higher hemolytic activity (HD50 = 1 mu g/ml), as compared to cisplatin and doxorubicin. Mellitin at 16 and 32 mu g/ml showed apoptotic effects on 4T1 cells according to the flow cytometric analysis. The Real time PCR analysis of Drp1 and Mfn1 expression in cells treated with l6 mu g/ml of melittin revealed an up-regulation in Drp1 and Mfn1 genes mRNA expression in comparison with control group. Treatment with 32 mu g/ml of melittin was also associated with a rise in mRNA expression of Drp1 and Mfn1 as compared to the control group. Conclusion: The results of this study showed that melittin has anticancer effects on 4T1 cell lines in a dose and time dependent manner and can be a good candidate for further research on breast cancer treatment.