Transcription Restores DNA Repair to Heterochromatin, Determining Regional Mutation Rates in Cancer Genomes

Autor: Christina L. Zheng, Nicholas J. Wang, Jongsuk Chung, Homayoun Moslehi, J. Zachary Sanborn, Joseph S. Hur, Eric A. Collisson, Swapna S. Vemula, Agne Naujokas, Kami E. Chiotti, Jeffrey B. Cheng, Hiva Fassihi, Andrew J. Blumberg, Celeste V. Bailey, Gary M. Fudem, Frederick G. Mihm, Bari B. Cunningham, Isaac M. Neuhaus, Wilson Liao, Dennis H. Oh, James E. Cleaver, Philip E. LeBoit, Joseph F. Costello, Alan R. Lehmann, Joe W. Gray, Paul T. Spellman, Sarah T. Arron, Nam Huh, Elizabeth Purdom, Raymond J. Cho
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Cell Reports, Vol 9, Iss 4, Pp 1228-1234 (2014)
Druh dokumentu: article
ISSN: 2211-1247
44774613
DOI: 10.1016/j.celrep.2014.10.031
Popis: Somatic mutations in cancer are more frequent in heterochromatic and late-replicating regions of the genome. We report that regional disparities in mutation density are virtually abolished within transcriptionally silent genomic regions of cutaneous squamous cell carcinomas (cSCCs) arising in an XPC−/− background. XPC−/− cells lack global genome nucleotide excision repair (GG-NER), thus establishing differential access of DNA repair machinery within chromatin-rich regions of the genome as the primary cause for the regional disparity. Strikingly, we find that increasing levels of transcription reduce mutation prevalence on both strands of gene bodies embedded within H3K9me3-dense regions, and only to those levels observed in H3K9me3-sparse regions, also in an XPC-dependent manner. Therefore, transcription appears to reduce mutation prevalence specifically by relieving the constraints imposed by chromatin structure on DNA repair. We model this relationship among transcription, chromatin state, and DNA repair, revealing a new, personalized determinant of cancer risk.
Databáze: Directory of Open Access Journals