Apigenin increases radiosensitivity of glioma stem cells by attenuating HIF-1 α-mediated glycolysis

AbstractApigenin, a natural flavonoid compound present in a variety of edible plants and health foods, has an anti-tumor effect and inhibits hypoxia inducible factor-l α (HIF-1α) expression in hypertrophic cardiac tissues. However, whether or not apigenin has a radiosensitization effect on glioma stem cells (GSCs) is unknown. Our present study aimed to investigate the effect of apigenin and its possible mechanisms. The human GSCs SU3 and its radioresistance line SU3-5R were treated with apigenin, radiation, or their combination, and the cell proliferation, migration, colony formation, and intracellular lactic acid and glycolytic related protein expressions were determined. Additionally, a cell model with hypoxia-induced HIF-1α expression was used and trea ted with apigenin. The current results displayed that the combination of apigenin and radiation could synergically reduce the viability, colony formation, and migration of the both GSCs. Moreover, this combination could also decrease the radiation-induced increments of glycolytic production lactic a cid in the both GSCs and related protein expressions, including HIF-1α, glucose transporter (GLUT)-1/3, nuclear factor kappa B (NF-κB) p65, and pyruvate kinase isozyme type M2 (PKM2). Further study confirmed that after treatment of hypoxia-cultured SU3 or SU3-5R cells with apigenin, the expressio n levels of HIF-1α, GLUT-1/3, NF-κB p65, and PKM2 proteins were reduced. These results demonstrated that apigenin could increas...
Source: Medical Oncology - Category: Cancer & Oncology Source Type: research