BAIAP2L2 promotes the proliferation, migration and invasion of osteosarcoma associated with the Wnt/β-catenin pathway

Abstract

Background: Osteosarcoma is the most common bone cancer that significantly affects the quality of life of patients. Studies have shown that overexpression of BAIAP2L2 elevates the proliferation and growth of some types of cancer cells. However, the role of BAIAP2L2 in osteosarcoma is unclear. This study aimed to investigate the functions of BAIAP2L2 in the development of osteosarcoma.

Methods: We used immunohistochemical and Western blot analysis to determine the expression levels of endogenic BAIAP2L2 in osteosarcoma cells. Cell counting kit-8 assay and colony formation assay were performed to investigate cell proliferation of tumor cells. Transwell assay was performed to detect cell migration. Flow cytometry assay was used to analyze cell apoptosis. The role of BAIAP2L2 in tumor growth was further explored in vivo.

Results: We found that BAIAP2L2 was significantly upregulated in human osteosarcoma, and inhibition of BAIAP2L2 suppressed the proliferation of osteosarcoma cells. In addition, down-regulation of BAIAP2L2 could lead to osteosarcoma cancer cell apoptosis, inhibit cell migration and invasion, and induce the inactivation of the Wnt/β-catenin pathway. In addition, down-regulation of BAIAP2L2 inhibited tumor growth in vivo.

Conclusion: In conclusion, down-regulation of BAIAP2L2 inhibited the proliferation, migration, and invasion of osteosarcoma associated with the Wnt/β-catenin pathway.

Keywords: BAIAP2L2; Combinational role; Osteosarcoma; Wnt/β-catenin pathway.

Fig. 1

BAIAP2L2 was upregulated in human osteosarcoma tissues and cells. A. Immunohistochemistry and B. Western blot analysis for the expression of BAIAP2L2 in tumor and para-sarcoma tissues. C. and D. Western blot analysis results for the expression of BAIAP2L2 in human osteosarcoma cell lines of MG-663, U2OS, SOSP-9607, SAOS-2 and HOS and human osteoblasts cell line of hFOB. T-test was used to perform statistic to compare each group, *p < 0.05.

Fig. 2

Inhibition of BAIAP2L2 suppressed the proliferation of osteosarcoma cells (MG-63 and HOS). A. The mRNA expression of BAIAP2L2 via qRT-PCR. B. Western blot analysis for the measurement of the expression of BAIAP2L2 protein transfected with siRNA. C. CCK-8 assay for cell viability. OD value was used to indirectly indicate the cell numbers. D. Colony formation ability of MG-63 and HOS cells. *p < 0.05.

Fig. 3

Knockdown of BAIAP2L2 induced apoptosis of MG-63 and HOS cells via the Bcl2/Bax axis. A. and B. Flow cytometry results for cell apoptosis in MG-63, and HOS, respectively. C. The protein expression of apoptosis signaling pathway by western blot. *p < 0.05.

Fig. 4

Down-regulation of BAIAP2L2 inhibited cell migration/invasion and induced inactivation of the Wnt/β-catenin pathway. A. Scratch assay showed that down-regulation of BAIAP2L2 transfection suppressed cell migration in MG-63 and HOS cells. B. Transwell assay indicated that transfection of siRNA inhibited cell invasion in MG-63 and HOS. C. Western blot analysis for the measurement of the expression of the Wnt/β-catenin pathway. D. Western blot analysis for the measurement of the hub protein expression of AKT/mTOR pathway and Wnt/β-catenin pathway *p < 0.05.

Fig. 5

Down-regulation of BAIAP2L2 inhibited tumor growth in vivo. A. Tumor comparison pictures. B. Tumor growth curve. The red line indicates the sh-BAIAP2L2 transfected cells, and the black line indicates the sh-NC transfected cells. The average tumor weights in the silencing of BAIAP2L2 and control group. C. The expression of BAIAP2L2 and Ki67 in xenograft tumors. Scale bar = 100 ųm. D. Western blot analysis for the measurement of the expression of BAIAP2L2 protein in tumors transfected with shRNA. *p < 0.05. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)