miR-34a sensitizes lung cancer cells to cisplatin via p53/miR-34a/MYCN axis.

Cisplatin is the most potent and widespread used chemotherapy drug for lung cancer treatment. However, a large proportion of NSCLC patients were insensitive to chemotherapy. This study explored the role of miR-34a in regulating sensitivity of NSCLC cells to cisplatin and its downstream targets. The quantitative PCR result showed that miR-34a expression was upregulated in cisplatin sensitive NSCLC patients compared cisplatin insensitive NSCLC controls. By applying loss-and-gain function analysis, we demonstrated that miR-34a directly targeted to MYCN to sensitize NSCLC cells to cisplatin. In addition, p53 was found to monitor the expression of miR-34a in NSCLC cells after cisplatin treatment. Therefore, the sensitivity of cisplatin in NSCLC cells was modulated via p53/miR-34a/MYCN axis.