title: Characterization of mammary cancer stem cells in the MMTV-PyMT mouse model.
abstract: Breast cancer stem cells, the root of tumor growth, present challenges to investigate: Primary human breast cancer cells are difficult to establish in culture and inconsistently yield tumors after transplantation into immune-deficient recipient mice. Furthermore, there is limited characterization of mammary cancer stem cells in mice, the ideal model for the study of breast cancer. We herein describe a pre-clinical breast cancer stem cell model, based on the properties of cancer stem cells, derived from transgenic MMTV-PyMT mice. Using a defined set of cell surface markers to identify cancer stem cells by flow cytometry, at least four cell populations were recovered from primary mammary cancers. Only two of the four populations, one epithelial and one mesenchymal, were able to survive and proliferate in vitro. The epithelial population exhibited tumor initiation potential with as few as 10 cells injected into syngeneic immune-competent recipients. Tumors initiated from injected cell lines recapitulated the morphological and physiological components of the primary tumor. To highlight the stemness potential of the putative cancer stem cells, B lymphoma Mo-MLV insertion region 1 homolog (Bmi-1) expression was knocked down via shRNA targeting Bmi-1. Without Bmi-1 expression, putative cancer stem cells could no longer initiate tumors, but tumor initiation was rescued with the introduction of a Bmi-1 overexpression vector in the Bmi-1 knockdown cells. In conclusion, our data show that primary mammary cancers from MMTV-PyMT mice contain putative cancer stem cells that survive in culture and can be used to create a model for study of mammary cancer stem cells.
authors.affiliation: Translational and Functional Genomics Laboratory, Ordway Research Institute, Albany, NY 12208, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.forename: Denise Grant
authors.initials: DG
authors.lastname: Lanza
authors.forename: Ian
authors.initials: I
authors.lastname: Guest
authors.forename: Chang
authors.initials: C
authors.lastname: Uk-Lim
authors.forename: Anna
authors.initials: A
authors.lastname: Glinskii
authors.forename: Gennadi
authors.initials: G
authors.lastname: Glinsky
authors.forename: Stewart
authors.initials: S
authors.lastname: Sell
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000235:genetics / Q000473:pathology* / Q000821:virology; D008324:Mammary Tumor Virus, Mouse / Q000472:pathogenicity; D051379:Mice; D008822:Mice, Transgenic; D014411:Neoplastic Stem Cells / Q000473:pathology* / Q000821:virology; D063150:Polycomb Repressive Complex 1 / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012192:Retroviridae Infections / Q000235:genetics / Q000473:pathology / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014412:Tumor Virus Infections / Q000235:genetics / Q000473:pathology / Q000821:virology
chemical_list: C489421:Bmi1 protein, mouse; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D063150:Polycomb Repressive Complex 1