Abstract
Lung cancer cells tend to develop resistance to cisplatin (DDP) during continuous chemotherapy, making it crucial to improve DDP sensitivity to enhance therapeutic outcomes. The levels of miR-149-3p in lung tissues and cells, as well as the biological behaviors of lung cancer cells, were analyzed. H446/DDP and A549/DDP cell lines were established to investigate how miR-149-3p affects lung cancer cells' sensitivity to DDP. Bioinformatics analysis predicted transmembrane serine protease 4 (TMPRSS4) as a downstream target of miR-149-3p, which was subsequently confirmed. Western blot analysis was used to examine proteins related to migration, invasion, apoptosis, and TMPRSS4 expression. Additionally, a subcutaneous graft tumor model in nude mice was created to assess the impact of miR-149-3p on tumor growth. In lung cancer tissues and cells, miR-149-3p expression was reduced, while TMPRSS4 expression was elevated. Overexpression of miR-149-3p inhibited cancer progression, promoted apoptosis, and enhanced the chemosensitivity of lung cancer cells to DDP. Moreover, miR-149-3p negatively regulated TMPRSS4, reducing malignancy-associated characteristics of lung cancer cells and further improving their DDP sensitivity. In vivo, high miR-149-3p expression increased the chemosensitivity of cancer cells. In conclusion, miR-149-3p suppresses the aggressive progression of lung cancer by directly downregulating TMPRSS4 and enhances the responsiveness of lung cancer cells to DDP.