title: An essential role of CBL and CBL-B ubiquitin ligases in mammary stem cell maintenance.
abstract: The ubiquitin ligases CBL and CBL-B are negative regulators of tyrosine kinase signaling with established roles in the immune system. However, their physiological roles in epithelial tissues are unknown. Here, we used MMTV-Cre-mediatedCblgene deletion on aCbl-bnull background, as well as a tamoxifen-inducible mammary stem cell (MaSC)-specificCblandCbl-bdouble knockout (Cbl/Cbl-bDKO) using Lgr5-EGFP-IRES-CreERT2, to demonstrate a mammary epithelial cell-autonomous requirement of CBL and CBL-B in the maintenance of MaSCs. Using a newly engineered tamoxifen-inducibleCblandCbl-bdeletion model with a dual fluorescent reporter (Cblflox/flox; Cbl-bflox/flox; Rosa26-CreERT; mT/mG), we show thatCbl/Cbl-bDKO in mammary organoids leads to hyperactivation of AKT-mTOR signaling with depletion of MaSCs. Chemical inhibition of AKT or mTOR rescued MaSCs fromCbl/Cbl-bDKO-induced depletion. Our studies reveal a novel, cell-autonomous requirement of CBL and CBL-B in epithelial stem cell maintenance during organ development and remodeling through modulation of mTOR signaling.
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Bhopal
authors.initials: B
authors.lastname: Mohapatra
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Pathology & Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Neha
authors.initials: N
authors.lastname: Zutshi
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Genetics, Cell Biology & Anatomy, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: An
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Goetz
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Genetics, Cell Biology & Anatomy, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Arya
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Bielecki
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Pathology & Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Insha
authors.initials: I
authors.lastname: Mushtaq
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Storck
authors.affiliation: Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Jane L
authors.initials: JL
authors.lastname: Meza
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Genetics, Cell Biology & Anatomy, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Fred & Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Vimla
authors.initials: V
authors.lastname: Band
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA hband@unmc.edu.|Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Pathology & Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Department of Genetics, Cell Biology & Anatomy, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.|Fred & Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Hamid
authors.identifier: 0000-0002-4996-9002
authors.initials: H
authors.lastname: Band
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D000066673:Cell Self Renewal / Q000187:drug effects; D002469:Cell Separation; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D019426:Integrases / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000254:growth & development; D008324:Mammary Tumor Virus, Mouse / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009940:Organoids / Q000166:cytology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D050721:Proto-Oncogene Proteins c-cbl / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D013629:Tamoxifen / Q000494:pharmacology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C118387:Cblb protein, mouse; C493597:Lgr5 protein, mouse; D043562:Receptors, G-Protein-Coupled; D013629:Tamoxifen; D050721:Proto-Oncogene Proteins c-cbl; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; C045073:Cre recombinase; D019426:Integrases
keywords: Basal cells; CBLB; Casitas B-lineage lymphoma; Lgr5; Luminal cells; Mammary gland development; Mammary stem cells; Mouse; mTOR signaling