RESUMO
OBJECTIVE: To explore the mechanism of circular RNA (circRNA)-AnnexinA7 (ANXA7) in non-small cell lung cancer (NSCLC) cisplatin (DDP) resistance through microRNA (miR)-545-3p to target Cyclin D1 (CCND1). METHODS: DDP-resistant and non-resistant NSCLC tissues and normal tissues were collected. DDP-resistant cells (A549/DDP and H460/DDP) were constructed. circ-ANXA7, miR-545-3p, CCND1, P-Glycoprotein, and glutathione S-transferase-π in tissues and cells were measured. Analysis of circ-ANXA7 ring structure was performed, as well as detection of circ-ANXA7 distribution in cells. Cell proliferation was detected by MTT and colony formation assay, apoptosis rate was detected by flow cytometry, and cell migration and invasion were evaluated by Transwell assay. The targeting relationship between circ-ANXA7, miR-545-3p and CCND1 was verified. Measurement of tumor volume and quality in mice was performed. RESULTS: Circ-ANXA7 and CCND1 were elevated, while miR-545-3p was suppressed in DDP-resistant NSCLC tissues and cells. Circ-ANXA7 combined with miR-545-3p, which targeted CCND1 to expedite A549/DDP cell proliferation, migration, invasion, DDP resistance, but inhibited cell apoptosis. CONCLUSION: Circ-ANXA7 enhances DDP resistance in NSCLC via absorbing miR-545-3p to target CCND1 and might be a latent therapeutic target for NSCLC.