Hsa_circ_0001839 is associated with poor prognosis and promotes tumor progression in gastric cancer.
BACKGROUND AND STUDY AIMS Circular RNAs (circRNAs) are characterized by their covalently closed-loop configuration. They are increasingly being recognized as key modulators of tumorigenesis and cancer progression. Studies have revealed aberrant hsa_circ_0001839 expression in various cancer types. However, its effect and underlying mechanisms in gastric cancer (GC) remain unknown. Therefore, we systematically investigated the clinical importance of hsa_circ_0001839 in gastric cancer and its molecular mechanisms in disease progression. PATIENTS AND METHODS Paired tumor specimens and histologically normal adjacent tissues were collected from 117 patients with GC who underwent curative surgery. RT-qPCR was performed to measure hsa_circ_0001839 expression in clinical samples and cell lines. Kaplan-Meier survival curves and Cox proportional hazards models were used to evaluate the prognostic relevance of this circRNA. Lastly, cell transfection, CCK-8, Transwell invasion, and dual-luciferase reporter assays were performed to validate the functional effects on GC cells and regulatory interactions with target genes. RESULTS Compared with matched non-tumor tissues, hsa_circ_0001839 expression was markedly increased in gastric cancer tissues. High hsa_circ_0001839 expression significantly correlated with larger tumor dimensions, deeper invasion depth, advanced TNM stage, and the presence of lymph node metastasis. Multivariate Cox analysis revealed that high hsa_circ_0001839 expression is an independent predictor of poor prognosis. Functionally, hsa_circ_0001839 knockdown effectively suppressed the malignant phenotypes of GC cells, significantly decreasing their proliferative, migratory, and invasive abilities. Mechanistically, hsa_circ_0001839 directly binds to the 3'-untranslated region of miR-634, thereby repressing its function. CONCLUSION As an oncogenic circRNA, hsa_circ_0001839 is critically implicated in gastric cancer progression and unfavorable patient outcomes, underscoring its dual application as a promising prognostic biomarker and a potential therapeutic intervention target.