Checkpoint kinase 1 is essential for fetal and adult hematopoiesis. (17th June 2019)

• Record Type: Journal Article
• Authors: Schuler, Fabian; Afreen, Sehar; Manzl, Claudia; Häcker, Georg; Erlacher, Miriam; Villunger, Andreas
• Is Part Of: EMBO reports. Volume 20:Number 8(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-17
• Subjects: apoptosis -- BCL2 -- CHK1 -- DNA damage -- hematopoietic stem cells; Molecular biology -- Periodicals; Molecular Biology -- Periodicals; Molecular biology; Periodicals; 572.8
• DOI: 10.15252/embr.201847026
• Languages: English
• ISSNs: 1469-221X

Abstract

Abstract: Checkpoint kinase 1 (CHK1) is critical for S‐phase fidelity and preventing premature mitotic entry in the presence of DNA damage. Tumor cells have developed a strong dependence on CHK1 for survival, and hence, this kinase has developed into a promising drug target. Chk1 deficiency in mice results in blastocyst death due to G2/M checkpoint failure showing that it is an essential gene and may be difficult to target therapeutically. Here, we show that chemical inhibition of CHK1 kills murine and human hematopoietic stem and progenitor cells (HSPCs) by the induction of BCL2‐regulated apoptosis. Cell death in HSPCs is independent of p53 but requires the BH3‐only proteins BIM, PUMA, and NOXA. Moreover, Chk1 is essential for definitive hematopoiesis in the embryo. Noteworthy, cell death inhibition in HSPCs cannot restore blood cell formation as HSPCs lacking CHK1 accumulate DNA damage and stop dividing. Moreover, conditional deletion of Chk1 in hematopoietic cells of adult mice selects for blood cells retaining CHK1, suggesting an essential role in maintaining functional hematopoiesis. Our findings establish a previously unrecognized role for CHK1 in establishing and maintaining hematopoiesis. Synopsis: Checkpoint kinase 1 is needed for hematopoietic stem cell expansion and survival in the fetal liver. Conditional deletion of Chk1 in hematopoietic cells of adult mice selects cells retaining CHK1, suggesting an essential role in functional hematopoiesis. Hematopoietic stem and progenitor cells undergo BCL2‐regulated apoptosis in response to CHK1‐inhibition. Hematopoietic stem cell expansion in the fetal liver requires CHK1. Hematopoietic cells need to retain CHK1 expression for survival. Abstract : Checkpoint kinase 1 is needed for hematopoietic stem cell expansion and survival in the fetal liver. Conditional deletion of Chk1 in hematopoietic cells of adult mice selects cells retaining CHK1, suggesting an essential role in functional hematopoiesis.