circular rna circ_0000517 facilitates the growth andmetastasis of non-small cell lung cancer by sponging mir-326/mir-330-5p

Objective: there is growing evidence showing that circular rnas (circrnas) are crucial regulators in modulating the biological behavior of tumors. this work is aimed to probe the role of circ_0000517 in non-small cell lung cancer (nsclc) and to elucidate its mechanism of action. materials and methods: in this experimental study, the differentially expressed circrnas in nsclc were screened using the geo database (gse158695). circ_0000517, mir-326, mir-330-5p, and mmp2 expression levels were determined by quantitative real-time polymerase chain reaction (qrt-pcr) analysis and western blot. the proliferation, apoptosis, migration, and invasion of nsclc cells were detected by cck-8, flow cytometry, and transwell assays. rna immunoprecipitation (rip), rna pull-down, and dual-luciferase reporter gene assays were performed to clarify the association between the circ_0000517 and mir-326/mir-330-5p. results: circ_0000517 was shown to be up-regulated in nsclc tissues and cell lines. the up-regulation of circ_0000517 is closely associated with advanced clinical stage of cancer, lymph node metastasis, and poor prognosis in nsclc patients. circ_0000517 knockdown impeded the proliferation, migration, and invasion of nsclc cells and enhanced their apoptosis. mechanistically, circ_0000517 was demonstrated to up-regulate mmp2 expression via decoying mir-326 and mir-330-5p to facilitate the malignant biological behaviors of nsclc cells. conclusion: this work reveals that circ_0000517 is implicated in nsclc cell growth and metastasis through the modulation of mir-326/mir-330-5p/mmp2, providing novel insights into the role of circrnas in nsclc progression.