Abstract
Background: The progression and metastasis of breast cancer patients are regulated by genetics and epigenetics. Circular RNA (circRNA) plays a pivotal role in modulating the advancement of tumors. The study aimed to explore the clinical performance and regulatory role of hsa-circVIM in breast cancer and its modulatory effect on tamoxifen resistance in hormone receptor (HR) positive breast cancer cells. Methods: RT-qPCR was performed to detect hsa-circVIM expression in breast cancer tissues and cells.CCK-8 assay, Transwell assay, and flow cytometric analyses were performed to evaluate the effects of hsa-circVIM on cellular activities in breast cancer cells and TAM sensitivity in MCF7/TR cells. Bioinformatic analyses were conducted to make function and pathway enrichment analyses. Results: hsa-circVIM expression was raised in breast cancer and predicted unsatisfactory overall survival outcomes. Silencing of hsa-circVIM suppressed cell viability, and migration capacities, while simultaneously enhancing TAM sensitivity and inducing apoptosis of HR-positive breast cancer cells by targeting miR-1294. Conclusion: Elevated hsa-circVIM expression in breast cancer suggested its potential as a prognostic biomarker. hsa-circVIM functions as both a cancer-promoting molecule and a regulator of TAM responsiveness in HR-positive breast cancer cells by regulating miR-1294 expression. Therefore, hsa-circVIM serves as a potent biomarker for prognosis, plays a promoting role in breast cancer progression, and may offer a therapeutic avenue to overcome TAM resistance.