DNA Damage and Repair in Ovarian Cancer: Focus on MicroRNAs.

Ovarian cancer (OvCa) is one of the most life-threatening female malignancies that affects 300,000 women annually worldwide. Impaired mechanisms of DNA repair are the leading cause of mutations underlying the OvCa development. microRNAs are short non-coding RNAs that regulate the expression of genes by binding to their transcripts and inducing mRNA degradation or inhibition of translation. Here, we review the miRNA-mediated dysregulation of genes involved in DNA damage response (DDR) and DNA repair pathways in OvCa. Apparently, miRNAs are capable of targeting the crucial mediators of DDR (e.g., miR-203a-3p targeting ATM (Ataxia Telangiectasia Mutated)), homologous repair (such as BRCA1 targeted by miR-9, miR-1255b, miR-193b, and miR-148b), non-homologous end joining (with RNF8 being regulated by miR-214), nucleotide excision repair (involving DDB2 targeted by miR-328-3p), or translesion DNA synthesis (involving RAD18, participating also in homologous repair and targeted by miR-379-5p). We also discuss miRNAs (such as miR-519a-3p, let-7e, miR-216b), which affect responses to OvCa therapy by targeting PARP1 (Poly(ADP-Ribose) Polymerase-1). Finally, we also discuss why, despite the identification of multiple miRNAs capable of regulating DNA repair genes, as well as those involved in the response to therapy, no miRNA-based drugs have been approved for OvCa treatment in clinics.