Berberine can amplify cytotoxic effect of radiotherapy by targeting cancer stem cells

Aim: Our objective was to investigate the effect of ionizing radiation (IR) and berberine on the expression
of stem cell markers OCT4 and SOX2. Materials & methods: The study involved the following groups:
Group I: MCF-7 spheroids as untreated control; Group II: MCF-7 spheroids treated with IR; Group III: MCF-
7 spheroids treated with berberine; and Group IV: MCF-7 spheroids treated with berberine + IR. MCF-7
spheroids’ metabolic activity and viability was determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl
tetrazolium bromide assay. OCT4 and SOX2 genes expression were assayed by real time-plymerase chain
reaction (RT-PCR). Results: IR and berberine treatment decreased the viability of MCF-7 spheroids and
reduced OCT4 and SOX2 genes expression. Combining berberine with IR leads to a significant reduction
in cell viability and OCT4 and SOX2 genes expression when compared with radiation alone treated group.
Conclusion: Berberine showed to be a good candidate for further studies as a new anticancer drug in the
treatment of breast cancer. Berberine has a radiosensitizing effect through targeting cancer stem cells.