miR‐506: a regulator of chemo‐sensitivity through suppression of the RAD51‐homologous recombination axis

Guoyan Liu, Fengxia Xue, Wei Zhang

Ovarian carcinoma is the most lethal gynecologic malignancy. Resistance to platinum is considered the major problem affecting prognosis. Our recent study established that microRNA-506 (miR-506) expression was closely associated with progression-free survival and overall survival in two independent patient cohorts totaling 598 epithelial ovarian cancer cases. Further functional study demonstrated that miR-506 could augment the response to cisplatin and olaparib through targeting RAD51 and suppressing homologous recombination in a panel of ovarian cancer cell lines. Systemic delivery of miR-506 in an orthotopic ovarian cancer mouse model significantly augmented the cisplatin response, thus recapitulating the clinical observation. Therefore, miR-506 plays a functionally important role in homologous recombination and has important therapeutic value for sensitizing cancer cells to chemotherapy, especially in chemo-resistant patients with attenuated expression of miR-506.