The sensitivity of Bloom's syndrome (bl/bl) fibroblasts to ultraviolet light (254 nm) has been estimated by 4 criteria: sister-chromatid exchange (SCE) formation, micronucleus production, cell survival, and host-cell reactivation of UV-irradiated adenovirus 2. In general, bl/bl strains did not differ significantly from the normal (+/+) strains in their response to UV treatment by any of the 4 criteria. One bl/bl strain, GM1492, was exceptional: It was abnormally sensitive to UV light in the SCE, micronucleus, and host-cell reactivation assays, but was not sensitive to UV as estimated by colony-forming ability. Thus, although one of the bl/bl strains studied in the experiments was sensitive to UV light as judged by some criteria, UV sensitivity is not a universal characteristic of Bloom's syndrome cells. It is unclear whether the UV sensitivity of the GM1492 strain reflects genetic diversity within the syndrome or some unrelated property of this strain.
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http://dx.doi.org/10.1016/0027-5107(80)90100-1 | DOI Listing |
Expert Rev Vaccines
January 2025
Hospital Universitario La Paz-IdiPAZ, Madrid, Spain.
Introduction: Vaccines to prevent important infections involving, e.g. influenza viruses, severe acute respiratory syndrome-causing coronaviruses (e.
View Article and Find Full Text PDFEMBO Rep
January 2025
Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.
Homologous recombination is a largely error-free DNA repair mechanism conserved across all domains of life and is essential for the maintenance of genome integrity. Not only are the mutations in homologous recombination repair genes probable cancer drivers, some also cause genetic disorders. In particular, mutations in the Bloom (BLM) helicase cause Bloom Syndrome, a rare autosomal recessive disorder characterized by increased sister chromatid exchanges and predisposition to a variety of cancers.
View Article and Find Full Text PDFNat Chem Biol
January 2025
Department of Gynecology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
The regressed arms of reversed replication forks exhibit structural similarities to one-ended double-stranded breaks and need to be protected against uncontrolled nucleolytic degradation. Here, we identify MSANTD4 (Myb/SANT-like DNA-binding domain-containing protein 4), a functionally uncharacterized protein that uniquely counters the replication protein A (RPA)-Bloom (BLM)/Werner syndrome helicase (WRN)-DNA replication helicase/nuclease 2 (DNA2) complex to safeguard reversed replication forks from detrimental degradation, independently of the breast cancer susceptibility proteins (BRCA1/2)-DNA repair protein RAD51 pathway. MSANTD4 specifically interacts with the junctions between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) in DNA substrates harboring a 3' overhang, which resemble the structural features of regressed arms processed by WRN-DNA2.
View Article and Find Full Text PDFGenetics
January 2025
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Bloom Syndrome helicase (Blm) is a RecQ family helicase involved in DNA repair, cell-cycle progression, and development. Pathogenic variants in human BLM cause the autosomal recessive disorder Bloom Syndrome, characterized by predisposition to numerous types of cancer. Prior studies of Drosophila Blm mutants lacking helicase activity or protein have shown sensitivity to DNA damaging agents, defects in repairing DNA double-strand breaks (DSBs), female sterility, and improper segregation of chromosomes in meiosis.
View Article and Find Full Text PDFPediatr Pulmonol
January 2025
Department of Pediatrics & Kawasaki Disease Research Center, University of California San Diego (UCSD) & Rady Children's Hospital, San Diego, California, USA.
Importance: There is growing understanding that Social Determinants of Health (SDH) impact on the outcomes of different pediatric conditions. We aimed to determine whether SDH affect the severity of MIS-C.
Design: Retrospective cohort study, 2021-2023.
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