Currently, the molecular mechanisms underlying bladder cancer progression remain unclear. Immune checkpoint inhibitors (ICIs) have been used to treat bladder cancer, but their efficacy is limited. Exosomes, which play a critical role in cell communication, can alter the tumor microenvironment. Therefore, it is essential to investigate the impact of bladder cancer exosomes on the tumor microenvironment. Our research demonstrates a significant up-regulation of miR-184 in exosomes derived from bladder cancer cells. miR-184 promotes bladder cancer cell proliferation in vitro and facilitates tumor growth in mice by targeting the 3' UTR of AKR1C3 mRNA. Additionally, miR-184 targets IRF2 mRNA, reducing its transcriptional inhibition on CXCL10. This process induces the expression of CXCL10, which promotes the infiltration of CD8+ T cells into the tumor. However, these infiltrating T cells become exhausted. In summary, our study reveals that bladder cancer-derived exosomes deliver miR-184, which targets AKR1C3, contributing to bladder carcinogenesis and development. We also investigate how the IRF2-CXCL10 pathway induces T cell exhaustion and leads to immune escape. This research provides new insights into the immunotherapy of bladder cancer, highlighting potential molecular targets for more effective treatment strategies.
Keywords: AKR1C3; Bladder cancer; CD8 + T cell; Extracellular vesicles; IRF2; T cell exhaustion.
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