NR4A2 promotes DNA double-strand break repair upon exposure to UVR

Exposure of melanocytes to ultraviolet radiation (UVR) induces the formation of UV-lesions that can produce deleterious effects in genomic DNA. Encounters of replication forks with unrepaired UV-lesions can lead to several complex phenomena, such as the formation of DNA double strand breaks (DSBs). The NR4A family of nuclear receptors are transcription factors that have been associated with mediating DNA repair functions downstream of the MC1R signalling pathway in melanocytes. In particular, emerging evidence shows that upon DNA damage, the NR4A2 receptor can translocate to sites of UV-lesion by mechanisms requiring post-translational modifications within the N-terminal domain and at a serine residue in the DNA biding domain at position 337. Following this, NR4A2 aids in DNA repair by facilitating chromatin relaxation, allowing accessibility for DNA repair machinery. Using A2058 and HT144 melanoma cells engineered to stably express wild-type or mutant forms of the NR4A2 proteins, we reveal that the expression of functional NR4A2 is associated with elevated cytoprotection against UVR. Conversely, knock-down of NR4A2 expression by siRNA results in a significant loss of cell viability after UV insult. By analysing the kinetics of the ensuing 53BP1 and RAD51 foci following UV-irradiation, we also reveal that the expression of mutant NR4A2 isoforms, lacking the ability to translocate, trans-activate or undergo phosphorylation, display compromised repair capacity. Implications: These data expand the understanding of the mechanism by which the NR4A2 nuclear receptor can facilitate DNA DSB repair

mRNA vaccine quality analysis using RNA sequencing

Abstract The success of mRNA vaccines has been realised, in part, by advances in manufacturing that enabled billions of doses to be produced at sufficient quality and safety. However, mRNA vaccines must be rigorously analysed to measure their integrity and detect contaminants that reduce their effectiveness and induce side-effects. Currently, mRNA vaccines and therapies are analysed using a range of time-consuming and costly methods. Here we describe a streamlined method to analyse mRNA vaccines and therapies using long-read nanopore sequencing. Compared to other industry-standard techniques, VAX-seq can comprehensively measure key mRNA vaccine quality attributes, including sequence, length, integrity, and purity. We also show how direct RNA sequencing can analyse mRNA chemistry, including the detection of nucleoside modifications. To support this approach, we provide supporting software to automatically report on mRNA and plasmid template quality and integrity. Given these advantages, we anticipate that RNA sequencing methods, such as VAX-seq, will become central to the development and manufacture of mRNA drugs

Long noncoding RNAs CUPID1 and CUPID2 mediate breast cancer risk at 11q13 by modulating the response to DNA damage

Breast cancer risk is strongly associated with an intergenic region on 11q13. We have previously shown that the strongest risk-associated SNPs fall within a distal enhancer that regulates CCND1. Here, we report that, in addition to regulating CCND1, this enhancer regulates two estrogen-regulated long noncoding RNAs, CUPID1 and CUPID2. We provide evidence that the risk-associated SNPs are associated with reduced chromatin looping between the enhancer and the CUPID1 and CUPID2 bidirectional promoter. We further show that CUPID1 and CUPID2 are predominantly expressed in hormone-receptor-positive breast tumors and play a role in modulating pathway choice for the repair of double-strand breaks. These data reveal a mechanism for the involvement of this region in breast cancer