ASPP2 inhibits osteosarcoma cell metastasis by stabilizing the β-catenin/E-cadherin complex

Abstract

Objective To explore the effect and mechanism of apoptosis stimulating protein 2 of p53 (ASPP2) in osteosarcoma metastasis. Methods Quantitative polymerase chain reaction was performed to determine ASPP2 mRNA expression levels in eight samples of human osteosarcoma tissue and four osteosarcoma cell lines. ASPP2 protein levels were detected with western blot. Metastatic ability of SAOS2 cells was assessed using a transwell invasion assay. The β-catenin/E-cadherin interaction was analyzed by co-immunoprecipitation. Immunofluorescence was used to detect nuclear expression of ASPP2 protein in osteosarcoma cells. Results ASPP2 mRNA expression was significantly decreased in eight osteosarcoma tissue samples compared to normal bone tissue collected from the same patients. The levels of ASPP2 mRNA and protein were also significantly decreased in normal human osteoblast cells compared to OS187, SAOS2, HOS, and MG63 osteosarcoma cell lines. Upon ASPP2 overexpression in SAOS2 cells, metastatic ability of cells was reduced, the β-catenin/E-cadherin interaction was enhanced, and nuclear translocation of β-catenin was inhibited. Conclusion ASPP2 reduces the metastatic characteristics of SAOS2 osteosarcoma cells by stabilizing the β-catenin/E-cadherin complex to inhibit β-catenin nuclear translocation.