Exosomal miR-664a-5p as a therapeutic target biomarker for PARP inhibitor response in prostate cancer.

This study investigated the role of urinary exosomal miR-664a-5p as a potential therapeutic target in prostate cancer (PCa). Small RNA sequencing of urinary exosomes from PCa patients with different responses to PARP inhibitors revealed that miR-664a-5p was significantly upregulated in responsive patients. Overexpression of miR-664a-5p enhanced the sensitivity of PCa cells to PARP inhibitors by directly targeting FOXM1, a transcription factor involved in DNA damage repair, leading to the downregulation of DNA damage response genes. Combined treatment with miR-664a-5p and olaparib synergistically inhibited tumor growth in a PC-3 xenograft mouse model. These findings suggest that urinary exosomal miR-664a-5p is a potential therapeutic biomarker for PARP inhibitor response in PCa patients, and targeting FOXM1 via miR-664a-5p represents a promising strategy for enhancing PARP inhibitor efficacy in PCa treatment.