Collagen type VIII alpha 2 chain (COL8A2), an important component of the basement membrane of the corneal endothelium, facilitates the malignant development of glioblastoma cells via inducing EMT.

Glioblastoma (GBM) is one of the most lethal tumor of all human cancers. Due to its poor response to chemotherapy and radiotherapy as well as its high rate of recurrence after treatment, the treatment is still undesired. The identification of potential related genes and bio-markers in the development of GBM could provide some new targets for the treatment of GBM. Our purpose in this study was to evaluate the mission of COL8A2 in GBM. Combined with TCGA, Oncomine databases, CGGA, GEPIA website and qRT-PCR analyses, we found that COL8A2 was up-regulated both in GBM tissues and cells compared to the controls. Moreover, the high COL8A2 expression was associated with the shorter overall survival of patients with GBM. The expression of COL8A2 was also positively correlated with metastasis-associated genes including vimentin, snail, slug, MMP2 and MMP7 according to GEPIA website. Knockdown of COL8A2 could suppress the cell proliferation, cell migration and invasion, whereas the overexpression of COL8A2 significantly expedited these processes. What's more, the outcome of western blot analysis manifested that COL8A2 could induced the expression of vimentin, snail, slug, MMP2 and MMP7. Taken together, COL8A2 activated cell proliferation, cell migration and invasion via raising the relative expression of EMT-related proteins in GBM. Therefore, our investigation suggests the oncogenic role of COL8A2 in GBM and provides a potential application of COL8A2 for GBM therapy.

Growth of G422 glioma implanted in the mouse brain was affected by the immune ability of the host.

BACKGROUND: It is generally accepted that gliomas are the most common primary brain tumors with poor prognosis. We aimed to explore the relationship of the immunity of the central nervous system and the genesis and development of glioma. METHODS: G422 glioma was implanted in the brain of BALB/c mice (immuno-competent mice), nude mice (T cell related immuno-deficient) and complement C3 knock-out mice (complement C3 related immunodeficient). The survival time of the host, growth and histopathology of the tumor, and concentrations of tumor necrosis factor-α (TNF-α) and interferon-γ (INF-γ) in tumor tissues were assessed. RESULTS: Tumor spheres were formed in all mice after injection, and glial fibrillary acidic protein (GFAP) positive staining of the cells declared their glioma origin. The longest median survival time of (44.3 ± 6.0) days was found in BALB/c mice, followed by (24.8 ± 5.2) days in nude mice and the shortest (18.6 ± 5.8) days in complement C3 knock-out mice. Accordingly, the growth of the tumor was fastest in complement C3 knock-out mice, followed by the nude mice and slowest in the BALB/c mice. Although the proportions of infiltrating CD68(+) lymphocytes in tumor tissues showed no significant difference (P > 0.05), TNF-α level in the nude and C3 knock-out mice, (28.11 ± 4.86) µmol/L and (22.87 ± 6.36) µmol/L respectively, were significantly lower (P < 0.01) than that in the BALB/c mice, which was (230.21 ± 39.17) µmol/L. The INF-γ level was highest in the BALB/c mice ((180.76 ± 29.19) µmol/L), followed by the nude mice ((113.46 ± 23.76) µmol/L) and then the C3 knock-out mice ((16.84 ± 4.45) µmol/L). CONCLUSIONS: The G422 glioma implanted in the brains of mice with different immune ability would be a useful model for studying the relationship of the immune system and tumor in the central nervous system. Furthermore, the T cells and complement C3 compartments of the immune response may affect the growth of implanted tumors and inflammatory factors such as TNF-α and INF-γ.