miR-944 inhibits malignant progression of bladder cancer through ATIC/AKT/FOXO3 A axis mediated by SHMT1

To investigate the role of miR-944 in the progression of bladder cancer (BC) and explore its potential as a therapeutic target. In this study, we collected 12 pairs of BC tissues and paracancerous tissues and subcutaneously injected T24 cells into BALB/c nude mice at 1 × 10⁶/mouse to establish the BC animal model for experimental investigation. RT-qPCR and western blot were used to detect the expression of related genes and proteins, and the malignant progression of T24 cells and BC was detected by CCK-8, Transwell, scratch wound, and immunohistochemistry. This study found that miR-944 expression was low in BC clinical samples and cell lines. Overexpression of miR-944 inhibited the proliferation, migration, and invasion of BC cells and inhibited BC tumor growth in vivo. Mechanistically, overexpression of miR-944 downregulated ATIC by inhibiting SHMT1, thereby activating the AKT/FOXO3A signaling pathway and promoting the expression of autophagy-related proteins LC3II/I and Beclin1. At the same time, it can inhibit the expression of epithelial-mesenchymal transition (EMT)-related proteins vimentin, fibronectin, and N-cadherin, ultimately inhibiting the proliferation, migration, and invasion of BC cells, and increasing the apoptosis level of BC cells to improve the development of BC. Our study confirmed that the upregulation of miR-944 may become a new target for the treatment of BC.