Is miR-10a a tumor suppressor that modulates proliferation and invasion in high-grade bladder cancer?

OBJECTIVES: Bladder Cancer (BC) is one of the most commonly diagnosed malignancies worldwide, with high rates of mortality and morbidity. It can be classified as non-muscle invasive bladder cancer (NMIBC) or muscle-invasive bladder cancer (MIBC), with radical cystectomy being the treatment for MIBC, which significantly reduces quality of life. MicroRNAs (miRs) act as critical genetic regulators, with both oncogenic and tumor-suppressive roles. MiR-10a is described as a tumor suppressor in various neoplasms, but its role in BC is controversial. This study aims to assess the activity of miR-10a in cellular invasion and proliferation in two distinct BC cell lines. METHODS: The study used high-grade T24 and low-grade RT4 bladder cell lines. Cells were transfected with miR-10a mimic or a non-targeting control. Transfection efficiency was validated by qPCR. Cell proliferation was cultured for 10-14 days. Cell migration and invasion were evaluated using Matrigel. All assays were conducted in triplicate. RESULTS: The T24 cells transfected with miR-10a presented decreased cellular proliferation and invasion compared to the Scramble (p = 0.0481 and p < 0.0001, respectively). In the RT4 cell line, there was only a significant reduction in cellular proliferation after miR-10a transfection (p = 0.0029). Conclusions: Our findings suggest that miR-10a has a tumoral suppressor role in BC, demonstrating higher efficacy in high-grade cells.