Expression of miR-1908-5p in breast cancer and its correlation with survival outcome and chemosensitivity

Abstract Objectives One dangerous tumor that can seriously harm a woman’s health is breast cancer, and adriamycin resistance is a critical factor contributing to poor prognosis. Because of their role in the mechanisms underlying tumor treatment resistance, miRNAs have attracted more attention in recent years. This work aims to investigate the role of miR-1908-5p in the DOX resistance mechanism of breast cancer cells. Methods Quantitative PCR was performed to detect miR-1908-5p expression levels in cancerous and paracancerous tissues. The association of miR-1908-5p expression with clinicopathological characteristics and patient outcomes was assessed using Cox regression models and Kaplan-Meier survival analysis. The possible targets of miR-1908-5p were identified using TargetScanHuman and further confirmed by dual-luciferase reporter assays. Cell growth, programmed cell death, movement, and infiltration were evaluated using the CCK-8 method, flow cytometry analysis, and Transwell experiments, respectively. Results The expression of miR-1908-5p was markedly elevated in tumor tissues and showed a close relationship with the TNM stage, lymph node metastasis, tumor size, and unfavorable survival outcomes, acting as an independent prognostic indicator. Inhibition of miR-1908-5p enhanced the suppressive effects of DOX on cancer cells, which were reversed upon ASCL3 reintroduction, thereby confirming ASCL3 as a downstream target. Conclusions miR-1908-5p regulates DOX sensitivity by targeting ASCL3, and its high expression correlates with adverse clinicopathological features and worse prognosis. The miR-1908-5p/ASCL3 axis highlights a promising target for precision therapy against breast cancer drug resistance.