THBS2 promotes gastric cancer progression and stemness via the Notch signaling pathway.

Thrombospondin-2 (THBS2), a secreted extracellular matrix protein, plays a crucial role in various biological processes including angiogenesis, tissue remodeling, and inflammation. Our study focuses on its function in human gastric cancer (GC). Through bioinformatics and tumor tissue analysis, we compared THBS2 expression in GC tissues and adjacent tissues, and predicted regulatory upstream and downstream molecules. The direct regulatory effect of miR-29b-3p on THBS2 was evaluated through dual-luciferase reporter assays, showing that miR-29b-3p targets the 3'-UTR of THBS2 mRNA, reducing its expression in GC cells. The influence of THBS2 on tumorigenesis and stemness was examined on protein expression levels via Western blot. In vivo, THBS2's role was investigated through xenograft and metastasis assays in nude mice, demonstrating that downregulation of THBS2 impairs GC tumorigenesis and liver metastasis. Our study identified THBS2 as a highly expressed prognostic factor in GC patients. Functionally, THBS2 promotes GC progression through the Notch signaling pathway by regulating Notch3, NEY1, and HES1 proteins, and sustains cancer stem cell-like characteristics by Notch3, including the expression of CD44, Nanog, OCT4, and SOX2. In sum, our study reveals that THBS2 promotes GC progression and stemness, modulated negatively by miR-29b-3p. This suggests potential therapeutic targets within the THBS2/Notch signaling axis for combating gastric cancer.