Role of apoptosis and autophagy in folic acid‐induced cytotoxicity of human breast cancer cells in vitro

Obstacles to the successful treatment of breast cancer patients with chemotherapeutic agents can be overcome with effective new strategies. It is still unclear how folic acid affects the onset and spread of breast cancer. The purpose of this study was to determine how folic acid affected the apoptotic and autophagic pathways of the breast cancer cell lines MCF‐7 and MDA‐MB‐231. In the present study, folic acid was applied to MCF‐7 and MDA‐MB‐231 breast cancer cell lines at different concentrations and for different durations. MTT analysis was used to investigate cytotoxic activity. All groups underwent the Tunel staining procedure to identify apoptosis and the immunofluorescence staining approach to identify the autophagic pathway. 24‐hour folic acid values were accepted as the most appropriate cytotoxic dose. In MCF‐7, cell cycle arrest was observed in the S phase and MDA‐MB‐231 G1/G0 phases. When apoptotic TUNEL staining was evaluated in both cell lines, folic acid significantly increased apoptosis. While a significant difference was observed between the groups in terms of Beclin 1 immunoreactivity in the MDA‐MB‐231 cell line, there was no significant difference in the MCF‐7 cell line. In addition, statistical significance was not observed LC3 immunoreactivity in both cell lines. In the study, it was observed that folic acid induced autophagy at the initial stage in the MDA‐MB‐231 cell line but had no inductive effect in the MCF‐7 cell line. In conclusion, our findings showed that folic acid has a potential cytotoxic and therapeutic effect on MCF‐7 and MDA‐MB‐231 breast cancer cell lines.