The medicinal fungus Antrodia cinnamomea regulates DNA repair and enhances the radiosensitivity of human esophageal cancer cells

Abstract

This study investigated the adjunctive effects of Antrodia cinnamomea mycelial fermentation broth (AC-MFB), a Taiwanese medicinal fungus, in enhancing the radiosensitivity of esophageal cancer cells. Human CE81T/VGH squamous and BE3 adenocarcinoma esophageal cancer cells were used in this study. A colony formation assay showed that pretreatment with AC-MFB decreased the survival of irradiated esophageal cancer cells, with a maximum sensitizer enhancement ratio of 1.91% and 37% survival. A DNA histogram study showed that AC-MFB pretreatment enhanced cell cycle arrest at the G2/M phase, the most radiosensitive phase. An immunofluorescence assay and a Western blotting assay showed that AC-MFB delayed the abrogation of γ-H2AX, upregulated p21 expression, and attenuated the radiation-induced phosphorylation of ataxia telangiectasia-mutated kinase and checkpoint kinase 2. An in vivo validation study showed that AC-MFB treatment tended to have a synergistic effect with radiation on the tumor growth delay of CE81T/VGH cells in BALB/c mice. These data suggest that this edible fungus product could enhance the effect of radiotherapy against esophageal cancer.