Influence of autophagy on epithelial-mesenchymal transition and invasion of glioma cells

Abstract

Objective To investigate the influence of autophagy on epithelial-mesenchymal transition (EMT) and invasion of glioma cells. Methods Autophagy of glioma cell line, SHG-44, was induced by starvation in Hank’s balanced salt solution (HBSS). The change in markers expression and invasion of SHG-44 cells was observed. The small interfering RNA (siRNA) of Atg3 was constructed and transfected into SHG-44 cells to inhibit autophagy under starvation. The change in the markers expression and invasion after transfection was compared to investigate the role of autophagy in EMT and invasion of SHG-44 cells. Results HBSS significantly induced autophagy of SHG-44 cells. The expression of epithelial marker, glia fibrillary acidic protein (GFAP) was downregulated whereas the expression of mesenchymal markers, Vimentin and matrix metalloproteinase (MMP)-2 was notably upregulated. The invasion number of cells was also significantly increased (18 100±1 500 vs. 68 750±3 350, t=864.345, P=0.001). After transfection of siRNA-Atg3, the starvation-induced autophagy of SHG-44 cells was obviously inhibited. In contrast to the control cells, there was no notable change in epithelial and mesenchymal markers expression, and the invasion number of SHG-44 cells was also significantly reduced (68 750±3 350 vs. 25 450±1 450, t=565.441, P=0.001). Conclusion Autophagy significantly induces EMT of glioma cells and promote their invasion. Key words: Glioma; Autophagy; Epithelial-mesenchymal transition; Invasion