Midazolam increases cisplatin-sensitivity in non-small cell lung cancer (NSCLC) via the miR-194-5p/HOOK3 axis

BackgroundsAs previously reported, midazolam anesthesia exerts tumor-suppressing effects in non-small cell lung cancer (NSCLC), but the regulating effects of this drug on cisplatin-resistance in NSCLC have not been studied. Thus, we designed this study to investigate this issue and preliminarily delineate the potential molecular mechanisms.MethodsWe performed MTT assay and trypan blue staining assay to measure cell proliferation and viability. Cell apoptosis was examined by FCM. qRT-PCR and immunoblotting were performed to determine the expression levels of genes. The targeting sites between genes were predicted by bioinformatics analysis and were validated by dual-luciferase reporter gene system assay. Mice tumor-bearing models were established and the tumorigenesis was evaluated by measuring tumor weight and volume. Immunohistochemistry (IHC) was used to examine the pro-proliferative Ki67 protein expressions in mice tumor tissues.ResultsThe cisplatin-resistant NSCLC (CR-NSCLC) cells were treated with high-dose cisplatin (50 mu g/ml) and low-dose midazolam (10 mu g/ml), and the results showed that midazolam suppressed cell proliferation and viability, and promoted cell apoptosis in cisplatin-treated CR-NSCLC cells. In addition, midazolam enhanced cisplatin-sensitivity in CR-NSCLC cell via modulating the miR-194-5p/hook microtubule-tethering protein 3 (HOOK3) axis. Specifically, midazolam upregulated miR-194-5p, but downregulated HOOK3 in the CR-NSCLC cells, and further results validated that miR-194-5p bound to the 3' untranslated region (3'UTR) of HOOK3 mRNA for its inhibition. Also, midazolam downregulated HOOK3 in CR-NSCLC cells by upregulating miR-194-5p. Functional experiments validated that both miR-194-5p downregulation and HOOK3 upregulation abrogated the promoting effects of midazolam on cisplatin-sensitivity in CR-NSCLC cells.ConclusionsTaken together, this study found that midazolam anesthesia reduced cisplatin-resistance in CR-NSCLC cells by regulating the miR-194-5p/HOOK3 axis, implying that midazolam could be used as adjuvant drug for NSCLC treatment in clinical practices.