[Role of SCUBE3 in promoting osteosarcoma cell growth and its association with prognosis]

To detect the expression of SCUBE3 in human osteosarcoma cell lines and surgical specimens of osteosarcomas and investigate its association with the patients' prognosis.

The expression of SCUBE3 protein was detected in 5 osteosarcoma cell lines using Western blotting. CCK8 assay was used to assess the effect of SCUBE3 suppression mediated by two specific small interfering RNAs (siRNAs) on the proliferation of U2OS osteosarcoma cells, and the cell cycle changes were detected using flow cytometry. Immunohistochemistry was performed to detect the expression of SCUBE3 in 60 osteosarcoma tissues, and Kaplan-Meier method was performed for survival analysis of the patients.

Compared with osteoblast hFOB1.19 cells, the osteosarcoma cell lines all showed significantly higher expressions of SCUBE3. In U2OS cells, suppression of SCUBE3 expression by siRNA significantly inhibited the cell proliferation (P<0.05). Kaplan-Meier survival analysis indicated that patients with high SCUBE3 expression had worse prognosis than those with low SCUBE3 expression (P=0.036).

SCUBE3 is up-regulated in the 5 osteosarcoma cell lines and in primary osteosarcoma tissues to promote the proliferation of osteosarcoma cells. A high SCUBE3 expression in osteosarcoma tissues is associated with a poor prognosis of the patients, suggesting that SCUBE3 can serve as a potential therapeutic target for osteosarcoma.