SETD8, a frequently mutated gene in cervical cancer, enhances cisplatin sensitivity by impairing DNA repair

Abstract Background Cisplatin is commonly used to treat cervical cancer while drug resistance limits its effectiveness. There is an urgent need to identify strategies that increase cisplatin sensitivity and improve the outcomes of chemotherapy. Results We performed whole exome sequencing (WES) of 156 cervical cancer tissues to assess genomic features related to platinum-based chemoresistance. By using WES, we identified a frequently mutated locus SETD8 (7%), which was associated with drug sensitivity. Cell functional assays, in vivo xenografts tumor growth experiments, and survival analysis were used to investigate the functional significance and mechanism of chemosensitization after SETD8 downregulation. Knockdown of SETD8 increased the responsiveness of cervical cancer cells to cisplatin treatment. The mechanism is exerted by reduced binding of 53BP1 to DNA breaks and inhibition of the non-homologous end joining (NHEJ) repair pathway. In addition, SETD8 expression was positively correlated with resistance to cisplatin and negatively associated with the prognosis of cervical cancer patients. Further, UNC0379 as a small molecule inhibitor of SETD8 was found to enhance cisplatin sensitivity both in vitro and in vivo. Conclusions SETD8 was a promising therapeutic target to ameliorate cisplatin resistance and improve the efficacy of chemotherapy.