LAUSR

BACKGROUND Bladder cancer is the leading transitional cell carcinoma affecting men and women with high morbidity and mortality rates, justifying the need to develop new molecular target therapies using microRNAs. This study aimed to evaluate the behavior of the T24 cell line after transfection with miR-Let-7c precursor mimic through invasion, migration, apoptosis, and cell cycle assays. METHODS AND RESULTS: T24 cell was transfected with the Let-7c mimic and its respective control and evaluated after 24 h. The expression levels of miR-Let-7c were analyzed by qPCR. We performed wound healing, Matrigel and flow cytometry, apoptosis, and cell cycle assays to determine its effect on cellular processes. Cells transfected with miR-Let-7c showed increased apoptosis rates (p = 0.019), decreased migration 24 h (p = 0.031) and 48 h (p = 0.0006), invasion potential (p = 0.0007), and cell proliferation (p = 0.002). CONCLUSIONS Our results demonstrate that miR-Let-7c can act in different pathways of the carcinogenic cellular processes of muscle-invasive urothelial carcinoma cells, inhibiting cell proliferation and increasing apoptosis levels, consequently limiting their invasion potential. However, further studies should be carried out better to elucidate this microRNA's role in high-grade urothelial carcinomas and unveil which targets this microRNA may present, which are intrinsically related to the cancer survival pathways.