ERN1 knockdown modifies the hypoxic regulation of homeobox gene expression in U87MG glioblastoma cells
Author:
Krasnytska Daria A.1, Khita Olena O.1, Viletska Yuliia M.1, Minchenko Dmytro O.12, Halkin Oleh V.1, Rudnytska Olha V.1, Hoian Sofiia L.1, Minchenko Oleksandr H.1
Affiliation:
1. Department of Molecular Biology, Palladin Institute of Biochemistry , National Academy of Sciences of Ukraine , Kyiv , Ukraine 2. Department of Pediatrics , National Bohomolets Medical University , Kyiv , Ukraine
Abstract
Abstract
Objective.
Homeobox genes play an important role in health and disease including oncogenesis. The present investigation aimed to study ERN1-dependent hypoxic regulation of the expression of genes encoding homeobox proteins MEIS (zinc finger E-box binding homeobox 2) and LIM homeobox 1 family, SPAG4 (sperm associated antigen 4) and NKX3-1 (NK3 homeobox 1) in U87MG glioblastoma cells in response to inhibition of ERN1 (endoplasmic reticulum to nucleus signaling 1) for evaluation of their possible significance in the control of glioblastoma growth.
Methods.
The expression level of homeobox genes was studied in control (transfected by vector) and ERN1 knockdown U87MG glioblastoma cells under hypoxia induced by dimethyloxalylglycine (0.5 mM for 4 h) by quantitative polymerase chain reaction and normalized to ACTB.
Results.
It was found that hypoxia down-regulated the expression level of LHX2, LHX6, MEIS2, and NKX3-1 genes but up-regulated the expression level of MEIS1, LHX1, MEIS3, and SPAG4 genes in control glioblastoma cells. At the same time, ERN1 knockdown of glioblastoma cells significantly modified the sensitivity of all studied genes to a hypoxic condition. Thus, ERN1 knockdown of glioblastoma cells removed the effect of hypoxia on the expression of MEIS1 and LHX1 genes, but increased the sensitivity of MEIS2, LHX2, and LHX6 genes to hypoxia. However, the expression of MEIS3, NKX3-1, and SPAG4 genes had decreased sensitivity to hypoxia in ERN1 knockdown glioblastoma cells. Moreover, more pronounced changes under the conditions of ERN1 inhibition were detected for the pro-oncogenic gene SPAG4.
Conclusion.
The results of the present study demonstrate that hypoxia affected the expression of homeobox genes MEIS1, MEIS2, MEIS3, LHX1, LHX2, LHX6, SPAG4, and NKX3-1 in U87MG glioblastoma cells in gene-specific manner and that the sensitivity of all studied genes to hypoxia condition is mediated by ERN1, the major pathway of the endoplasmic reticulum stress signaling, and possibly contributed to the control of glioblastoma growth. A fundamentally new results of this work is the establishment of the fact regarding the dependence of hypoxic regulation of SPAG4 gene expression on ER stress, in particular ERN1, which is associated with suppression of cell proliferation and tumor growth.
Publisher
Walter de Gruyter GmbH
Reference48 articles.
1. Almanza A, Carlesso A, Chintha C, Creedican S, Doultsinos D, Leuzzi B, Luis A, McCarthy N, Montibeller L, More S, Papaioannou A, Puschel F, Sassano ML, Skoko J, Agostinis P, de Belleroche J, Eriksson LA, Fulda S, Gorman AM, Healy S, Kozlov A, Munoz-Pinedo C, Rehm M, Chevet E, Samali A. Endoplasmic reticulum stress signalling - from basic mechanisms to clinical applications. FEBS J 286, 241–278, 2019. 2. Auf G, Jabouille A, Guerit S, Pineau R, Delugin M, Bouchecareilh M, Favereaux A, Maitre M, Gaiser T, von Deimling A, Czabanka M, Vajkoczy P, Chevet E, Bikfalvi A, Moenner M. A shift from an angiogenic to invasive phenotype induced in malignant glioma by inhibition of the unfolded protein response sensor IRE1. Proc Natl Acad Sci USA 107, 15553–15558, 2010. 3. Auf G, Jabouille A, Delugin M, Guerit S, Pineau R, North S, Platonova N, Maitre M, Favereaux A, Vajkoczy P, Seno M, Bikfalvi A, Minchenko D, Minchenko O, Moenner M. High epiregulin expression in human U87 glioma cells relies on IRE1alpha and promotes autocrine growth through EGF receptor. BMC Cancer 13, 597, 2013. 4. Bi M, Naczki C, Koritzinsky M, Fels D, Blais J, Hu N, Harding H, Novoa I, Varia M, Raleigh J, Scheuner D, Kaufman RJ, Bell J, Ron D, Wouters BG, Koumenis C. ER stress-regulated translation increases tolerance to extreme hypoxia and promotes tumor growth. EMBO J 24, 3470–3481, 2005. 5. Bravo R, Parra V, Gatica D, Rodriguez AE, Torrealba N, Paredes F, Wang ZV, Zorzano A, Hill JA, Jaimovich E, Quest AF, Lavandero S. Endoplasmic reticulum and the unfolded protein response: dynamics and metabolic integration. Int Rev Cell Mol Biol 301, 215–290, 2013.
|
|