The Role And Mechanism Of Malic Enzyme2 In Proneural-mesenchymal Transition In Human Glioma

Objective: To investigate the role and mechanism of malic enzyme2(ME2)in proneural-mesenchymal transition(PMT)of human glioma cells,which might provide new strategy for clinical treatment.Methods:(1)The correlation between m RNA level of ME2 and glioblastomas,and patients' overall survival were analyzed in clinical databases;The protein expression pattern of ME2 in glioma was detected by immunohistochemistry and in Human Protein Atlas;(2)Expression level of ME2 was determined by q RT-PCR and Western blotting in glioma cells,and the levels of mesenchymal markers(Met,YKL-40)and proneural marker(OLIG2)were determined by Western blotting;(3)CCK-8 and Colony formation assay were used to evaluate the cell growth ability;(4)Transwell migration and wound healing assay were conducted to evaluate the migratory abilities,and transwell invasion assay was used to assess the invasive abilities of glioma cells;(5)Western blotting,immunofluorescence and chemiluminescence were used to analyze the effect of ME2 on PMT and lipid metabolism.Resu Lts:(1)The m RNA expression level of ME2 in the clinical specimen was higher than that in normal brain,and was negatively related to the patients' total survival;The protein level of ME2 in glioblastomas was higher than that in normal brain and low grade gliomas;(2)The expression of ME2 and mesenchymal markers in LN229 and U87 MG was higher than that in SW1783 and U251 MG,and proneural marker was lower than that in SW1783 and U251MG;(3)ME2 overexpression enhanced the proliferative,colony formative,migratory and invasive abilities in SW1783 and U251 MG,and ME2 knockdown reduced the proliferative,colony formative,migratory and invasive abilities in LN229 and U87MG;(4)The expression of mesenchymal markers(N-ca?Met?YKL-40)was increased and that of proneural(OLIG2)and epithelial(E-ca)marker was decresed by ME2 overexpression;ME2 overexpression promoted the lipogenesis to shift from ACLY to ACSS2 pathway in SW1783 and U251MG;The expression of mesenchymal markers was decreased and that of proneural and epithelial marker was increased by ME2 knockdown;ME2 knockdown promoted the lipogenesis to shift from ACSS2 to ACLY pathway in LN229 and U87 MG.Conclusions:(1)ME2 expression positively correlates with mesenchymal phenotype,and negatively correlates with the patients' overall survival;(2)ME2 promotes the proliferation,migration,invasion and proneural-mesenchymal transition of glioma cells;(3)ME2 induces the metabolic reprogramming of lipid in glioma cells,which might provide a new approach for glioma treatments.