Abstract: Objective To screen for aberrantly expressed genes in osteosarcoma cells and investigate the role of RHPN2 in regulating the proliferation, apoptosis, migration and tumorigenic abilities of osteosarcoma cells. Methods We used GEO2R to analyze the differential gene expression profile between osteosarcoma cells and normal cells in the GSE70414 dataset. RT-qPCR and Western blotting were performed to detect RHPN2 expression in osteosarcoma cell lines MG-63, 143B and SAOS2. Two RHPN2-shRNA and a control NC-shRNA were designed to silence the expression of RHPN2 in 143B cells, and CCK8 assay, colony-forming assay, annexin V-FITC/PI staining and scratch assays were carried out to examine the changes in proliferation, apoptosis and migration of the cells. We also established nude mouse models bearing osteosarcoma xenografts derived 143B cells and RHPN2-shRNA-transfected 143B cells, and assessed the effect of RHPN2 silencing on osteosarcoma cell tumorigenesis using HE staining. Kaplan-Meier survival curves were used to analyze the correlation between RHPN2 expression and survival outcomes of patients with osteosarcoma. Results RHPN2 expression was significantly upregulated in osteosarcoma cell lines MG-63, 143B and SAOS2 (P<0.01). Silencing of RHPN2 significantly inhibited the proliferation and migration of 143B cells in vitro, promoted cell apoptosis (P<0.01), and suppressed tumorigenic capacity of the cells in nude mice. A high expression of RHPN2 was significantly correlated with a poor prognosis of patients with osteosarcoma (P<0.05). Conclusion RHPN2 is highly expressed in osteosarcoma cells to promote cell proliferation and migration and inhibits cell apoptosis. A high expression of RHPN2 is associated with a poorer prognosis of the patients with osteosarcoma.

Key words: osteosarcoma; bioinformatics analysis; RHPN2; proliferation; prognosis