Promotive effects of capillary morphogenetic protein 2 on glioma cell invasion and the molecular mechanism

We aimed to explore the role of capillary morphogenetic protein 2 (CMG2) in glioma cell invasion and the possible molecular mechanism. Glioma cells U87 and U251 stably overexpressing CMG2 were constructed by lentiviral transfection. The changes of cell invasion and migration were tested by Matrigel-transwell assay and scratch assay, respectively. A mouse model with orthotopically transplanted tumour was established to evaluate the effects of CMG2 overexpression on the in vivo invasion of glioma cells and survival time. The differences of filopodia and lamellar pseudopodia among glioma cells with different CMG2 expressions were observed by immunofluorescence assay. The expressions of YAP and p-YAP in glioma cells overexpressing CMG2 or not were compared by Western blot. Compared with the control group, overexpression of CMG2 enhanced the invasion and migration capacities of glioma cells (p < 0.05). The tumour tissues of mice transplanted with glioma cells overexpressing CMG2 were obviously invaded, and their survival time was significantly shortened (p < 0.05). Immunofluorescence staining showed that glioma cells overexpressing CMG2 formed more lamellipodia and filopodia than those of the control group. As glioma cells overexpressing CMG2 formed more pseudopodia, the expression of YAP, a key effector protein of the Hippo pathway, was up-regulated. CMG2 promoted the invasion of glioma cells, and may induce pseudopodium formation by up-regulating YAP expression.