Tag Archives: glucose and glutamine deprivation

ERN1 dependent regulation of TMED10, MYL9, SPOCK1, CUL4A and CUL4B genes expression at glucose and glutamine deprivations in U87 glioma cells

O. H. Minchenko*, O. S. Hnatiuk, D. O. Tsymbal, Y. M. Viletska,
S. V. Danilovskyi, O. V. Halkin, I. V. Kryvdiuk, O. V. Rudnytska

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
*e-mail: ominchenko@yahoo.com

Received: 05 April 2020; Accepted: 25 June 2020

It was shown previously that inhibition of ERN1 (endoplasmic reticulum to nucleus signaling 1) pathway, a central mediator of the unfolded protein response, leads to suppression of tumor growth through down-regulation of key pro-proliferative and up-regulation of tumor suppressor factors and modifies the sensitivity of these genes to glucose and glutamine deprivation. However, the executive mechanisms of ERN1 mediated control of glioma cell proliferation are not yet known. The goal of this study was to estimate the effect of glucose and glutamine deprivations on expression of cancer related genes in glioma U87 cells at ERN1 signaling inhibition for evaluation of their possible significance in ERN1 mediated control of glioma cell proliferation.  We have studied the effect of glucose and glutamine deprivations on the expression level of cancer related genes encoding TMED10 (transmembrane p24 trafficking protein 10), MYL9 (myosin, light chain 9, regulatory), SPOCK1 (sparc/osteonectin, cwcv and kazal-like domains proteoglycan 1), CUL4A (cullin 4A), and CUL4B in U87 glioma control cells and cells with ERN1 knockdown. It was shown that at glucose deprivation the expression level of MYL9, SPOCK1 and CUL4B genes was significantly up-regulated in control glioma cells. ERN1 knockdown modified the sensitivity to glucose deprivation of all studied genes except TMED10 gene. At glutamine deprivation the expression of MYL9, CUL4A and CUL4B genes was shown to be up-regulated in control glioma cells. The sensitivity of MYL9, TMED10 and CUL4B gene expression to glutamine deprivation in glioma cells with ERN1 knockdown was significantly modified, while CUL4A and SPOCK1 gene expression did not respond to ERN1 inhibition. The present study demonstrates that glucose and glutamine deprivation affected the expression of the most studied genes in a specific manner and that inhibition of ERN1 signaling preferentially modified their expression at glucose and glutamine deprivation.

Effect of glutamine or glucose deprivation on the expression of cyclin and cyclin-dependent kinase genes in glioma cell line U87 and its subline with suppressed activity of signaling enzyme of endoplasmic reticulum–nuclei-1

D. O. Minchenko1,2,3, O. V. Hubenya1, B. M. Terletsky1,
M. Moenner3, O. H. Minchenko1,3

1Palladin Institute of Biochemistry, National Academy of Science of Ukraine, Kyiv;
e-mail: ominchenko@yahoo.com;
2National O. O. Bohomoletz Medical University, Kyiv, Ukraine;
3INSERM U920 Molecular Mechanisms of Angiogenesis Laboratory,
University Bordeaux 1, Talence, France

Ischemia has been shown to induce a set of complex intracellular signaling events known as the unfolded protein response, which is mediated by endoplasmic reticulum–nuclei-1 sensing enzyme. We have studied the expression of several cyclin and cyclin-dependent kinase genes which participate in the control of cell cycle and proliferation under ischemic conditions (glucose or glutamine deprivation) in endoplasmic reticulum–nuc­lei 1-deficient glioma cells. It was shown that blockade of endoplasmic reticulum–nuclei signaling enzyme-1, the key endoplasmic reticulum stress sensor, leads to an increase of the expression levels of cyclin-dependent kinase-2 and cyclin A2, D3, E2 and G2 genes but suppresses cyclin D1. Moreover, the expression level of cyclin-dependent kinase-2 as well as cyclin A2, D3 and E2 mRNAs is significantly decreased under glucose or glutamine deprivation conditions both in control and endoplasmic reticulum–nuclei-1-deficient glioma cells. However, cyclin-dependent kinase-4 and -5 mRNA expressions is increased, but in glucose deprivation conditions only.  Results of this study have shown that the expression of most tested genes of encoded cyclins and cyclin-dependent kinases is dependent on endoplasmic reticulum–nuclei-1 signaling enzyme function both in normal and glutamine and glucose deprivation conditions and possibly participates in cell adaptive response to endoplasmic reticulum stress associated with ischemia.