EFFECT OF ACUTE GLUCOSE DEPRIVATION ON THE EXPRESSION OF TUMOR PROTEIN P53-RELATED GENES INERN1 KNOCKDOWN U87 GLIOMA CELLS

Ischemia and well as endoplasmic reticulum stress are important factors of cancer growth. We have investigated the effect of glucose deprivation condition on the tumor protein TP53-related gene expressions. Among them TP53BP1(TP53binding protein 1), TP53BP2, TOPORS (topoisomerase I binding, arginine/serine-rich, E3 ubiquitin protein ligase), SESN1 (p53 regulated PA26 nuclear protein), RYBP (RING1 and YY1-binding protein), ZMAT3 (zinc finger, Matrin-type 3), and NME6 (NME/NM23 nucleoside diphosphate kinase 6) in glioma cells with ERN1 knockdown. The exposure of U87 glioma cells to the glucose deprivation condition leads to up-regulation of TP53BP1, TP53BP2, ZMAT3, and RYBP gene expressions as well as down-regulation of TOPORS and NME6 gene expressions. However, inhibition of ERN1 signaling enzyme function significantly changes the expression of TP53BP1, RYBP, TOPORS, and NME6 genes in U87 glioma cells upon glucose deprivation growth condition. At the same time, the ERN1 knockdown induces down-regulation on the SESN1 gene expression. Results of this investigation clearly demonstrate that the expression of most of the genes encoding TP53-related factors depends upon acute glucose deprivation condition as well as upon the activity of ERN1, the major signaling enzyme of the endoplasmic reticulum stress.