MFAP2 induces epithelial-mesenchymal transformation of osteosarcoma cells by activating the Notch1 pathway.

BACKGROUND

Osteosarcoma (OS) is a malignancy originating from mesenchymal tissue. Microfibril-associated protein 2 () plays a crucial role in cancer, notably promoting epithelial-mesenchymal transition (EMT). However, its involvement in OS remains unexplored.

METHODS

was silenced in U2OS cells using shRNA targeting (sh-MFAP2) and validated by quantitative real-time polymerase chain reaction (qRT-PCR). We extracted gene chip data of from multiple databases (GSE28424, GSE42572, and GSE126209). Correlation analyses between and the Notch1 pathway identified through the gene set variation analysis (GSVA) enrichment analysis were conducted using the Pearson correlation method. Cellular behaviors (viability, migration, and invasion) were assessed via the Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays. EMT markers (N-cadherin, vimentin, and β-catenin) and Notch1 levels were examined by western blotting and qRT-PCR. Cell morphology was observed microscopically to evaluate EMT. Finally, the role of in OS was validated through a xenograft tumor model.

RESULTS

OS cell lines exhibited higher mRNA expression than normal osteoblasts. knockdown in U2OS cells significantly reduced viability, migration, and invasion, along with downregulation of N-cadherin and vimentin, as well as upregulation of β-catenin. significantly correlated with the Notch1 pathway in OS and its knockdown inhibited Notch1 protein expression. Furthermore, Notch1 activation reversed the inhibitory effects of knockdown on the malignant characteristic of U2OS cells. Additionally, knockdown inhibited tumor growth, expression levels of EMT markers, and Notch1 expression in OS tumor tissues.

CONCLUSIONS

Our study revealed that was an upstream regulator of the Notch1 signaling pathway to promote EMT in OS. These findings suggested as a potential OS therapy target.