The synergistic effects of betanin and radiotherapy in a prostate cancer cell line: an in vitro study.

Abstract

Prostate cancer is among the most common cancers in men with an increasing incidence rate. Radiation therapy (RT) is a therapeutic strategy for the management of prostate cancer after surgery; nonetheless, it has different side effects on neighboring healthy cells/tissues. Moreover, radioresistance has been an increasing phenomenon in the recent years. Therefore, there is an urgent need for the introduction of a safe and effective radiosensitizing agent. Accordingly, the recent trend in the development of novel drugs is accompanied by a push toward natural compounds. Our study evaluated the effects of betanin combined with RT as a potential radiosensitizing agent in the PC-3 cell line. MTT assay was utilized to determine the growth inhibitory impact of betanin. The possible synergistic effect was evaluated with CompuSyn software upon Trypan blue exclusion test. Apoptosis-related gene expression was evaluated via Real-time PCR and the protein expression of P21 was determined using western blotting. A synergistic anticancer effect with an optimal combination index of 0.61 was achieved by treating PC-3 cells with betanin and RT. The results pointed out that betanin synergistically triggered RT-mediated apoptosis and cell cycle arrest through modulating gene and protein expression in comparison with each of the monotherapies. These findings shed light on the synergistic antitumor effect of betanin and RT in prostate cancer, indicating the potential use of betanin as a radiosensitizer agent.