title: TERT promotes epithelial proliferation through transcriptional control of a Myc- and Wnt-related developmental program.
abstract: Telomerase serves a critical role in stem cell function and tissue homeostasis. This role depends on its ability to synthesize telomere repeats in a manner dependent on the reverse transcriptase (RT) function of its protein component telomerase RT (TERT), as well as on a novel pathway whose mechanism is poorly understood. Here, we use a TERT mutant lacking RT function (TERT(ci)) to study the mechanism of TERT action in mammalian skin, an ideal tissue for studying progenitor cell biology. We show that TERT(ci) retains the full activities of wild-type TERT in enhancing keratinocyte proliferation in skin and in activating resting hair follicle stem cells, which triggers initiation of a new hair follicle growth phase and promotes hair synthesis. To understand the nature of this RT-independent function for TERT, we studied the genome-wide transcriptional response to acute changes in TERT levels in mouse skin. We find that TERT facilitates activation of progenitor cells in the skin and hair follicle by triggering a rapid change in gene expression that significantly overlaps the program controlling natural hair follicle cycling in wild-type mice. Statistical comparisons to other microarray gene sets using pattern-matching algorithms revealed that the TERT transcriptional response strongly resembles those mediated by Myc and Wnt, two proteins intimately associated with stem cell function and cancer. These data show that TERT controls tissue progenitor cells via transcriptional regulation of a developmental program converging on the Myc and Wnt pathways.
authors.affiliation: Department of Medicine, Stanford School of Medicine, Stanford, California, United States of America.
authors.forename: Jinkuk
authors.initials: J
authors.lastname: Choi
authors.forename: Lucinda K
authors.initials: LK
authors.lastname: Southworth
authors.forename: Kavita Y
authors.initials: KY
authors.lastname: Sarin
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Venteicher
authors.forename: Wenxiu
authors.initials: W
authors.lastname: Ma
authors.forename: Woody
authors.initials: W
authors.lastname: Chang
authors.forename: Peggie
authors.initials: P
authors.lastname: Cheung
authors.forename: Sohee
authors.initials: S
authors.lastname: Jun
authors.forename: Maja K
authors.initials: MK
authors.lastname: Artandi
authors.forename: Naman
authors.initials: N
authors.lastname: Shah
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Kim
authors.forename: Steven E
authors.initials: SE
authors.lastname: Artandi
mesh_terms: D000465:Algorithms; D000818:Animals; D001706:Biopsy; D049109:Cell Proliferation; D062109:Dermatologic Surgical Procedures; D004847:Epithelial Cells / Q000502:physiology*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006197:Hair / Q000378:metabolism; D018859:Hair Follicle / Q000166:cytology / Q000378:metabolism; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D009154:Mutation; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D012867:Skin / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D051153:Wnt Proteins / Q000235:genetics*
chemical_list: D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D051153:Wnt Proteins; D019098:Telomerase; C509187:Tert protein, mouse