DDEL-14THE RELATIONSHIP BETWEEN APOPTOSIS AND STMN1 REGULATING THE CHEMOSENSITIVITY OF GLIOMA CELLS TO TMZ

OBJECTIVE: To investigate the role of autophagy in the process of STMN1 regulating glioma chemosensitivity to TMZ. METHODS: Using TEM observe autophagy ultrastructure-autophagolysosome after TMZ induction in U251-MG (RNAi-STMN1). Western-blot was used to detect protein expression. To observe the TMZ-induced autophagic vacuoles in U251-MG through GFP-LC3B tracer method under laser scanning confocal microscope (RNAi-STMN1), as well as fluorescence intensity changes after the suppression of autophagy by 3-MA or bafilomycin A1. And qRT-PCR and western-blot are used to detect gene and protein expression levels. Finally, the sensitivity to TMZ of U251-MG (RNAi-STMN1) is assayed by CCK-8 kits after the inhibition of autophagy by 3-MA and/or bafilomycin A1 early and late. RESULTS: After TMZ induction, autophagic vacuoles emerge in cytoplasm of U251-MG. For U251-MG (Si-STMN1), The degree of cell damage is worse than U251-MG and U251-MG(Scramble), and autophagic vacuoles in the cytoplasm increase after TMZ induction. In U251-MG and A172 cell lines, LC3, Beclin1 and ATG5 mRNA and protein expression level significantly increase(P 0.05). CONCLUSION: TMZ can induce autophagy in U251-MG and U251-MG (Si-STMN1), autophagy-related genes / proteins significantly increase after TMZ induction.