Targeted regulation of microRNA?423 on BAP1 expression and its effect on proliferation and apoptosis of lung squamous cell carcinoma cells

ZHOU Xiaomin; ZHAO Zhanqing; LIN Qidong; YU Bingchang; HUANG Guoding

doi:10.3969/j.issn.1009-0460.2019.08.002

Abstract：Objective To investigate the effect of microRNA-423 (miR-423) on the expression of BRCA1-associated protein 1 (BAP1) as well as the proliferation and apoptosis of lung squamous cell carcinoma NCI-H2170 cells. Methods The expression of miR-423 in lung adenocarcinoma and squamous cell carcinoma, its regulation signaling pathway and relationship with prognosis were analyzed by using miR-Pathway and Kaplan-Meier Plotter online.NCI-H2170 cells were transfected with miR-423 mimics (Overexpres-sion group) and inhibitors (Inhibition group) by liposome method, and the untransfected cells were used as Control group. Real-time quantitative PCR (QPCR) was used to detect the miR-423 level in NCI-H2170 cells. CCK-8 kit was used to detect the proliferation of NCI-H2170 cells and AnnexinⅤ-FITC／PI double-staining flow cytometry was used to detect apoptosis. Double luciferase reporter gene experiment was used to verify the targeting relationship between miR-423 and BAP1, and Western blotting was used to detect the level of BAP1. Results Online analysis indicated that miR-423 regulated 8 signaling pathways in lung adenocarcinoma and 35 signaling pathways in squamous cell carcinoma. Compared with normal tissues, miR-423 decreased in lung adenocarcinoma tissues but increased in lung squamous cell carcinoma tissues; miR-423 was only related to the prognosis of squamous cell carcinoma (HR＝0. 63, 95%CI:0. 46-0. 87, P＝0. 004). Compared with the Control group (1. 024±0. 206), the miR-423 level in the Overexpression group increased to 3. 162±0. 856, while that in the Inhibition group decreased to 0. 215±0. 043 with a significant difference (P＜0. 05). Compared with the Control group, the cell proliferation level increased in the Overexpression group at 48 and 72 h, while decreased in the Inhibition group (P＜0. 05). The results of flow cytometry showed that compared with the Control group (7. 352±1. 434)%, the apoptotic rate of the Overexpression group decreased to (2. 851±0. 723)%, while that of the Inhibition group increased to (16. 028±4. 206)% with a significant difference (P＜0. 05). MiR-423 mimics inhibited the relative luciferase activity of wild-type 3′untranslated region of BAP1 in NCI-H2170 cells, but had no effect on mutant BAP1.Compared with the Control group (0. 611±0. 016), the BAP1 level in Overex-pression group decreased to 0. 214±0. 054, while that in Inhibition group increased to 0. 851±0. 074 with a significant difference (P＜0. 05). Conclusion MiR-423 plays an oncogene role in the development of lung squamous cell carcinoma. It can regulate the prolifer-ation and inhibit apoptosis of cancer cells by targeting BAP1. It is expected to become a target for diagnosis and new biological therapy of lung squamous cell carcinoma.