期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：52
页码：26644-26652
DOI：10.1073/pnas.1909720116
出版社：The National Academy of Sciences of the United States of America
摘要：Loss of function of CDKN2A / B , also known as INK4 / ARF [encoding p16 INK4A , p15 INK4B , and p14 ARF (mouse p19 Arf )], confers susceptibility to cancers, whereas its up-regulation during organismal aging provokes cellular senescence and tissue degenerative disorders. To better understand the transcriptional regulation of p16 INK4A , a CRISPR screen targeting open, noncoding chromatin regions adjacent to p16 INK4A was performed in a human p16 INK4A-P2A-mCherry reporter cell line. We identified a repressive element located in the 3′ region adjacent to the ARF promoter that controls p16 INK4A expression via long-distance chromatin interactions. Coinfection of lentiviral dCas9-KRAB with selected single-guide RNAs against the repressive element abrogated the ARF / p16 INK4A chromatin contacts, thus reactivating p16 INK4A expression. Genetic CRISPR screening identified candidate transcription factors inhibiting p16 INK4A regulation, including ZNF217, which was confirmed to bind the ARF / p16 INK4A interaction loop. In summary, direct physical interactions between p16 INK4A and ARF genes provide mechanistic insights into their cross-regulation.
