Baicalin reverses radioresistance in nasopharyngeal carcinoma by downregulating autophagy

BACKGROUND: Radiation resistance is the main cause of recurrence after radiotherapy, and increased autophagy after radiotherapy is related to radiotherapy resistance. This study aims to investigate the reversal effect of baicalin on radioresistance and its related mechanism. METHODS: CCK-8 and flow cytometry were used to detect the effect of proliferation and apoptosis by baicalin. Clone formation test was used to verify the effect of baicalin radiosensitization. Western blot analysis and electron microscopy were employed to observe the effect of baicalin on autophagy. RESULTS: Compared with the radiation therapy (RT) group, the RT combined baicalin (RT + BA) group showed a significantly low 2 Gy survival fraction of radiation therapy (P < 0.05). LC3-II protein expression in the RT group was significantly higher than which in the RT + BA group (P < 0.05). Electron microscopy showed that more autophagic vacuoles were observed in the RT group than those in the RT + BA group. CONCLUSIONS: Overall, baicalin can reverse the radioresistance of human nasopharyngeal carcinoma CNE-2R cells by downregulating RT-enhanced autophagy.