■同源异型盒基因在健康和疾病包括肿瘤发生中起重要作用。本研究旨在研究ERN1依赖的低氧调节编码同源盒蛋白MEIS(锌指E盒结合同源盒2)和LIM同源盒1家族的基因的表达,SPAG4(精子相关抗原4)和NKX3-1(NK3同源盒1)在U87MG胶质母细胞瘤细胞中响应于ERN1(内质网到核信号1)的抑制,以评估它们在控制胶质母细胞瘤生长中的可能意义。
■通过定量聚合酶链反应研究了对照(通过载体转染)和ERN1在二甲氧合甘氨酸(0.5mM,4小时)诱导的缺氧下敲除U87MG胶质母细胞瘤细胞中同源异型盒基因的表达水平。
■发现低氧下调LHX2,LHX6,MEIS2和NKX3-1基因的表达水平,但上调MEIS1,LHX1,MEIS3和SPAG4基因在对照胶质母细胞瘤细胞中的表达水平。同时,胶质母细胞瘤细胞的ERN1敲除显着改变了所有研究基因对缺氧条件的敏感性。因此,ERN1敲低的胶质母细胞瘤细胞清除缺氧对MEIS1和LHX1基因表达的影响,但增加了MEIS2,LHX2和LHX6基因对缺氧的敏感性。然而,MEIS3,NKX3-1和SPAG4基因的表达降低了ERN1敲低的胶质母细胞瘤细胞对缺氧的敏感性。此外,在ERN1抑制条件下检测到原癌基因SPAG4的更明显变化.
■本研究的结果表明,低氧影响同源异型盒基因MEIS1,MEIS2,MEIS3,LHX1,LHX2,LHX6,SPAG4和NKX3-1的表达并可能有助于控制胶质母细胞瘤的生长。这项工作的一个根本性的新结果是建立了关于SPAG4基因表达的低氧调节对ER应激的依赖性的事实,尤其是ERN1,其与细胞增殖和肿瘤生长的抑制有关。
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.