Ultrasound-microbubbles-mediated microRNA-449a inhibits lung cancer cell growth via the regulation of Notch1

BACKGROUND: The application of gene-loaded microbubbles (MBs) combined with ultrasound that results in increased delivery efficiency may be an excellent method of gene delivery. This study aimed to discuss the effects of ultrasound-MB-mediated microRNA (miR)-449a on lung cancer (LC) development by targeting Notch1. METHODS: Initially, miR-449a expression in LC tissues, paracancerous tissues, LC cell lines, and lung epithelial cells was detected and its association with LC patients’ clinical characteristics was analyzed. The gain-of-function studies were performed to probe the roles of miR-449a and ultrasound-MB-mediated miR-449a in LC progression. Then, RT-qPCR combined with Western blot analysis was applied to verify the levels of miR-449a, Notch1, proliferation- and apoptosis-related proteins. Moreover, xenograft tumors in nude mice were also applied for in vivo experiments. RESULTS: Poorly expressed miR-449a was observed in LC, and its expression was associated with clinical staging, differentiation and lymph node metastasis of LC patients. Overexpression of miR-449a suppressed LC cell proliferation and promoted G2/M arrest and apoptosis. Ultrasound-MB-mediated miR-449a strengthened inhibitory effects of miR-449a on cell growth and resistance to apoptosis. miR-449a inhibited H1299 cell activity by targeting Notch1. CONCLUSION: Our data supported that miR-449a overexpression inhibited LC cell growth, and ultrasound-MB-mediated miR-449a reinforced the repressive effects of miR-449a on LC progression. This investigation may offer new insight for LC treatment.