Abstract
BACKGROUND: Gastric cancer (GC) is a globally prevalent malignancy with high mortality. Long non-coding RNA CCDC18-AS1 is implicated in GC progression, yet its interaction with miR-214-3p and functional mechanisms remain unclear. METHODS: Using samples from 128 GC patients, CCDC18-AS1 and miR-214-3p levels were quantified via quantitative real-time polymerase chain reaction. Kaplan-Meier and Cox regression analyzed prognosis. Dual-luciferase reporter assay and RNA immunoprecipitation assays validated their binding. Functional impacts of CCDC18-AS1 knockdown on proliferation, migration, and invasion were evaluated using Cell Counting Kit-8 and Transwell assays. Western blotting analyzed apoptosis and cell cycle-related protein changes. RESULTS: CCDC18-AS1 was upregulated, while miR-214-3p was downregulated in GC. High CCDC18-AS1 correlated with poor survival and was an independent prognostic risk factor. CCDC18-AS1 was directly bound to miR-214-3p and inhibited miR-214-3p. Knockdown of CCDC18-AS1 increased miR-214-3p and suppressed proliferation, migration, and invasion. It also upregulated Bax and P21 while downregulating Bcl-2 and Cyclin B1, effects reversed by inhibiting miR-214-3p. CONCLUSION: CCDC18-AS1 is overexpressed in GC and independently predicts poor prognosis. It promotes GC progression by targeting miR-214-3p, thereby regulating key oncogenic processes.