Exosomal miR-93-5p as an important driver of bladder cancer progression

BACKGROUND: Tumor-derived exosomes are involved in the process of tumor metastasis and angiogenesis. MicroRNAs (miRNAs) are the most widely investigated factors in exosomes. Therefore, we hope to find a new therapeutic target in bladder cancer (BLCA), which has high incidence rate and mortality. METHODS: Exosomal microRNA(miR)-93-5p expression level, downstream target molecules, and biological functions were examined with bioinformatics technology. Exosomes were extracted by sequential differential centrifugation and verified by transmission electron microscopy. The exosomal miR-93-5p on cell proliferation, invasion, and angiogenesis abilities in 5637 and T24 cells was determined by Cell Counting Kit 8 (CCK-8), colony-forming assay, Transwell assay, and vascular ring formation assay. A mouse xenograft model with intratumor injection was adopted to evaluate the correlation between BLCA-derived exosomes and tumor growth in vivo. RESULTS: The results revealed that exosomes play an important role in the biological progression of BLCA, with miR-93-5p being a particularly important molecule. Compared to normal cells, more malignant cells release more exosomal miR-93-5p, and tumor-derived exosomal miR-93-5p could significantly promote cell proliferation, invasion, and angiogenesis in vitro and in vivo. We identified phosphatase and tensin homolog (PTEN) as the most significant target of miR-93-5p in BLCA and human umbilical vein endothelial cells. CONCLUSIONS: Our study successfully revealed the biological role and mechanism of BLCA-derived exosomes in tumor progression. Target at tumor exosomes and exosomal miR-93-5p may be an effective treatment in BLCA.