CircDLG1 promotes malignant development of non-small cell lung cancer through regulation of the miR-630/CENPF axis

Circular RNAs (circRNAs) have been reported to be crucial modulatory molecules in the etiology of non-small cell lung cancer (NSCLC). This study aimed to probe the precise role and mechanism of circRNA discs large MAGUK scaffold protein 1 (circDLG1) in the malignant progression of NSCLC.

The abundances of circDLG1, miR-630, and centromere protein F (CENPF) mRNAs were gauged by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was tested in 3‑(4, 5‑dimethylthiazol-2-yl)-2, 5‑diphenyltetrazolium bromide (MTT) assay and 5‑ethynyl-2′-deoxyuridine (EdU)-incorporation assay. Cell apoptosis was analyzed by flow cytometry. Cell migration and invasion were assessed by transwell assay. Western blot was exploited to examine the levels of all proteins. The interaction between miR-630 and circDLG1 or CENPF was verified by dual-luciferase reporter, RNA pull-down, and/or RNA immunoprecipitation assays. Tumor xenograft assay and immunohistochemistry (IHC) were executed for the role of circDLG1 in tumor growth in vivo.

CircDLG1 and CENPF were highly expressed in NSCLC, while miR-630 was downregulated. CircDLG1 silencing repressed proliferation, migration, and invasion, and expedited apoptosis of NSCLC cells in vitro. Mechanistically, circDLG1 deficiency modulated NSCLC cell malignant development through interacting with miR-630. Furthermore, CENPF was targeted by miR-630, and circDLG1 could positively control CENPF expression through acting as an miR-630 sponge. Furthermore, CENPF overexpression reversed the repressive impacts of circDLG1 inhibition in the malignant behaviors of NSCLC cells. Besides, circDLG1 interference hindered tumor growth in vivo.