Ribosomal Protein S27-Like is overexpressed in glioma cells and inhibition of RPS27L expression suspends the tumorigenesis
Abstract Background: Ribosomal Protein S27-Like is an evolutionarily conserved ribosomal protein and the role of RPS27L influencing the malignance of several cancers has been reported. However, its effects on glioma were still unknown. This investigation aims to characterize the clinical significance and the biological functions of RPS27L in gliomas.Methods: TCGA databases were explored to analyze the correlation between RPS27L expression and the clinical characteristics of glioma patients. Immunohistochemical staining was performed on glioma cases and normal brain tissues. The function of RPS27L in glioma was further explored using U87MG and A172 cell lines and a orthotopic xenograft model of nude mice.Results: Data obtained from TCGA database showed higher expression of RPS27L in glioma than normal, and the overall survival was lower in the high expression group. Immunohistochemistry showed the expression levels of RPS27L were increased with the tumor grade rising in gliomas. Functional assays showed knockdown of RPS27L inhibited proliferation, cell cycle transition, migration and invasion, while promoted apoptosis. Data of western blot indicated that knockdown of RPS27L increased the level of p21,Bax and Cleaved Caspase-3 while decreased the level of CDK4, cyclinD1, cyclinE1, Bcl-2 and MMP2, MMP9 in glioma cells. In vivo, the growth of orthotopic glioma xenografts was suppressed by expression of RPS27L shRNA, and the tumors with RPS27L shRNA showed less aggressiveness and reduced expression of Ki67, Bcl-2 and MMP2. Conclusions: RPS27L is overexpressed in glioma cells. Knockdown of RPS27L could inhibit the proliferation, migration and invasion while promote apoptosis of glioma cells in vitro and in vivo. RPS27L might be a potential prognostic biomarker and possible target for future therapy in glioma.