Migration-inducing gene-7 promotes glioma cell proliferation and invasiveness via activating the MAPK signaling pathway.

ABSTRACT

Glioma is a highly aggressive primary malignant tumor. Migration-inducing gene-7 (Mig-7) is closely related to tumor invasion and metastasis. However, the detailed molecular mechanism of Mig-7-mediated promotion of glioma cell invasion requires further investigation. Therefore, this study aimed to investigate the molecular mechanism by which Mig-7 promotes invasion and growth of glioma tumor cells. After collecting 65 glioma tissues and 16 non-tumor tissues, the expression difference of Mig-7 between tumor tissues and non-tumor tissues was analyzed. The molecular mechanism of Mig-7 in tumor cells was investigated by knockdown or overexpression of Mig-7 in U87MG cells. Specifically, the expression levels of mitogen-activated protein kinase (MAPK) signaling pathway-related molecules were detected in cells that knocked down Mig-7. MTT, Transwell, and three-dimensional cell culture assays were used to detect the survival, migration, invasion, and tube formation of U87MG cells that overexpressed Mig-7 were treated with the MAPK signaling pathway inhibitors (SP600125, SCH772984, and SB202190). The effect of Mig-7 on the tumorigenic ability of U87MG cells was investigated by subcutaneous tumorigenic experiment in nude mice. The corresponding results indicated that Mig-7 expression was significantly higher in glioma tissues and cell lines compared to that in non-neoplastic brain tissues and normal glial cell lines. In U87MG cells, downregulation or overexpression of Mig-7 inhibited or promoted the expression of MMP-2, MMP-9, LAMC2, EphA2, and VE-cadherin, and phosphorylation levels of ERK1/2, JNK, and p38. Mig-7 overexpression promoted migration, invasion, cell viability, and tube formation, which were reversed by the MAPK signaling pathway inhibitors. Mig-7 overexpression promoted subcutaneous tumor growth in mice and upregulated the phosphorylation levels of ERK1/2, JNK, and p38 and the expression of Ki-67. These effects of Mig-7 overexpression were reversed by MAPK pathway inhibitors. Overall, these results suggest that Mig-7 may be a novel biomarker and potential therapeutic target for glioma, with the MAPK pathway playing a key role in the corresponding Mig-7 mechanism of action.