WGCNA-identified COL13A1 drives osteosarcoma metastasis and progression via TGF-β signaling.

Osteosarcoma (OS) is a malignant bone tumor with high incidence of metastasis. However, the molecular landscape of osteosarcoma remains incompletely understood. Weighted gene co-expression network analysis (WGCNA), differential expressed genes (DEGs), Cox regression, gene set enrichment analysis (GSEA), receiver operating characteristic curve (ROC) and survival analysis were conducted to screen potential targets and molecular mechanism for OS. Seven modules were considered to be closely related to the prognosis of OS. Subsequent immunohistochemistry (IHC), survival and ROC analysis indicated that high expression of COL13A1 was seen in OS tissue and was significantly associated with poor clinical outcome. COL13A1 expression may correlate with inhibition of M1 polarization and could serve as a predictor for immunotherapy response. Further cellular experiments showed that the expression of COL13A1 promoted the proliferation, migration and invasion. Besides, high expression of COL13A1 enhanced TGF-β signaling through β1 integrin and upregulated MMP9 and cyclin D1 expression. Finally, the low expression of COL13A1 limited the weight and lung metastasis of tumor, and reduced bone destruction in the orthotopic tumor-bearing model. COL13A1 was identified as a novel regulator of OS progression via TGF-β signaling, suggesting its potential as a therapeutic target pending further validation.