miR-29b-3p targetedly regulates VEGF to inhibit tumor progression and cisplatin resistance through Nrf2/HO-1 signaling pathway in non-small cell lung cancer.

ABSTRACT

BACKGROUNDS Non-small cell lung carcinoma (NSCLC) is a common type of lung cancer. Prior investigations have elucidated the pivotal role of miR-29b-3p in restraining tumor growth and metastasis. Nonetheless, it remains to be determined whether miR-29b-3p can effectively suppress NSCLC progression and enhance the sensitivity of NSCLC cells to cisplatin. This investigation sought to determine the mechanism by which miR-29b-3p inhibited the advancement of NSCLC and mitigated resistance to cisplatin. METHODS: We initially assessed miR-29b-3p and VEGF levels in NSCLC tissues and cell lines. Next, miR-29b-3p expression was elevated in NSCLC cell lines H1975 and A549 by overexpression plasmid transfection. Following this, a sequence of molecular biology experiments was conducted to evaluate the impact of miR-29b-3p on the biological behaviors of NSCLC cells and their resistance to cisplatin. Additionally, we predicted VEGF was a target gene of miR-29b-3p by bioinformatics analysis. We next employed western blot to evaluate the protein expression of Nrf2 and HO-1 in NSCLC cells. Finally, we elucidated the effects of VEGF and Nrf2/HO-1pathway on NSCLC progression and cisplatin resistance by in vitro assays. RESULTS: In comparison to paracancerous tissues and human normal lung epithelial cells, the expression of miR-29b-3p was notably reduced and VEGF expression was clearly elevated in NSCLC tissues and cells. Moreover, miR-29b-3p upregulated obviously suppressed the biological activities of NSCLC cells and increased their sensitivity to cisplatin. Furthermore, in NSCLC cells, miR-29b-3p bound to VEGF and negatively regulate its transcription. Additionally, miR-29b-3p overexpression also inhibited the Nrf2/HO-1 signaling pathway. Finally, the overexpression of VEGF and the activation of the Nrf2/HO-1 pathway reversed miR-29b-3p-mediated inhibitory effect on biological behaviors of NSCLC cells and increased the cisplatin resistance. CONCLUSION: Our findings indicate that miR-29b-3p impedes NSCLC cells' biological behaviors and augments their sensitivity to cisplatin by targeting VEGF to modulate the Nfr2/HO-1 signaling pathway.