DNA double strand breaks (DSBs) are abrasions caused in both strands of the DNA duplex following exposure to both exogenous and endogenous conditions. Such abrasions have deleterious effect in cells leading to genome rearrangements and cell death. A number of repair systems including homologous recombination (HR) and non-homologous end-joining (NHEJ) have been evolved to minimize the fatal effects of these lesions in cell. The role of protein coding genes in regulation of these pathways has been assessed previously. However, a number of recent studies have focused on evaluation of non-coding RNAs participation in DNA repair. Researchers from Shahid Beheshti University of Medical Sciences review the existing data highlighting the role of long non-coding RNAs in DSB repair as well as dysregulation in their expression which would lead to pathological conditions such as cancer. The specific mechanism of their contribution in DNA repair pathways has been elucidated for a few of them. LncRNAs participate in several steps of DNA repair pathways and regulate the expression of key components of these pathways including p53 tumor suppressor gene.
Several lncRNAs are involved in different steps of DNA damage response
IR: ionizing radiation, BARD1 9’L: BRCA1-associated RING domain protein 1 9’L, PCAT1: prostate cancer associated transcript 1, MDC-AS1: mediator of DNA damage checkpoint 1- antisense RNA, TERRA: telomeric repeat-containing RNA, TODRA: transcribed in the opposite direction of RAD51, LncRNA-JA DE: LncRNA-Jade family plant homeo domain (PHD) finger, DDSR1: DNA damage-sensitive RNA 1, dsDNA: double stranded DNA, MDC: mediator of DNA damage checkpoint 1, RNF8: ring finger protein 8, UBC13: E2 ubiquitin-conjugating protein UBC13, RNF168: ring finger protein 168, BRCA1: breast cancer 1, DNA repair associated, BRCA2: breast cancer 2, DNA repair associated, MRN complex: Mre11, Rad50, Nbs1, ATM: ataxia telangiectasia mutated, Rap80: ubiquitin interaction motif containing 1(UIMC1), PALB2: partner and localizer of BRCA2, Rad51: RAD51 recombinase (RAS associated with diabetes protein 51).