
pmid: 27417236
Epigenetic regulation by histone methyltransferase G9a is known to control autophagic responses. As the link between autophagy and metabolic homeostasis is widely accepted, we investigated whether G9a affects metabolic circuitries to affect autophagic response in glioma cells. Both pharmacological inhibition and siRNA mediated knockdown of G9a increased autophagy marker LC3B in glioma cells. G9a inhibitor BIX-01294 (BIX) induced Akt-dependent increase in HIF-1α expression and activity. Inhibition of Akt-HIF-1α axis reversed BIX-mediated (i) increase in LC3B expression and (ii) decrease in Yes-associated protein 1 (YAP1) phosphorylation. YAP1 over-expression abrogated BIX induced increase in LC3B expression. Interestingly, BIX induced increase in metabolic modelers TIGAR (TP53-induced glycolysis and apoptosis regulator) and PKM2 (Pyruvate kinase M2) were crucial for BIX-mediated changes, as transfection with TIGAR mutant or PKM2 siRNA reversed BIX-mediated alterations in pYAP1 and LC3B expression. Coherent with the in vitro observation, BIX had no significant effect on the tumor burden in heterotypic xenograft glioma mouse model. Elevated LC3B and PKM2 in BIX-treated xenograft tissue was accompanied by decreased YAP1 levels. Taken together, our findings suggest that Akt-HIF-1α axis driven PKM2-YAP1 cross talk activates autophagic responses in glioma cells upon G9a inhibition.
Thyroid Hormones, Membrane Proteins, Azepines, Histone-Lysine N-Methyltransferase, Hypoxia-Inducible Factor 1, alpha Subunit, Phosphoproteins, Epigenesis, Genetic, Gene Expression Regulation, Neoplastic, Cell Transformation, Neoplastic, Cell Line, Tumor, Histocompatibility Antigens, Autophagy, Quinazolines, Humans, Enzyme Inhibitors, Carrier Proteins, Microtubule-Associated Proteins, Adaptor Proteins, Signal Transducing, Cell Proliferation, Transcription Factors
Thyroid Hormones, Membrane Proteins, Azepines, Histone-Lysine N-Methyltransferase, Hypoxia-Inducible Factor 1, alpha Subunit, Phosphoproteins, Epigenesis, Genetic, Gene Expression Regulation, Neoplastic, Cell Transformation, Neoplastic, Cell Line, Tumor, Histocompatibility Antigens, Autophagy, Quinazolines, Humans, Enzyme Inhibitors, Carrier Proteins, Microtubule-Associated Proteins, Adaptor Proteins, Signal Transducing, Cell Proliferation, Transcription Factors
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 30 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
