title: mTORC1 signaling governs hematopoietic stem cell quiescence.
abstract: The stringent regulation of hematopoietic stem cell (HSC) quiescence versus cell cycle progression is essential for the preservation of a pool of long-term self-renewing cells and vital for sustaining an adequate supply of all blood lineages throughout life. Cell growth, the process that is mass increase, serves as a trigger for cell cycle progression and is regulated predominantly by mammalian target of rapamycin complex 1 (mTORC1) signaling. Emerging data from various mice models show deletion of several mTORC1 negative regulators, including PTEN, TSC1, PML and Fbxw7 result in similar HSC phenotypes characterized as HSC hyper-proliferation and subsequent exhaustion, and defective repopulating potential. Further pharmacological approaches show that PTEN, TSC1 and PML regulate HSC maintenance through mTORC1. mTORC1-mediated cell growth regulatory circuits thus play a critical role in the regulation of HSC quiescence.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine and Genetics, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Boyi
authors.initials: B
authors.lastname: Gan
authors.forename: Ronald A
authors.initials: RA
authors.lastname: DePinho
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D044783:F-Box Proteins / Q000378:metabolism*; D000073979:F-Box-WD Repeat-Containing Protein 7; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D000071156:Promyelocytic Leukemia Protein; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D000077004:Tuberous Sclerosis Complex 1 Protein; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
chemical_list: C519509:Crtc1 protein, mouse; D044783:F-Box Proteins; D000073979:F-Box-WD Repeat-Containing Protein 7; C513272:Fbxw7 protein, mouse; D009687:Nuclear Proteins; C513293:Pml protein, mouse; D000071156:Promyelocytic Leukemia Protein; D014157:Transcription Factors; C000624651:Tsc1 protein, mouse; D000077004:Tuberous Sclerosis Complex 1 Protein; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D051059:PTEN Phosphohydrolase; C487757:Pten protein, mouse