title: Profiling of normal and malignant breast tissue show CD44high/CD24low phenotype as a predominant stem/progenitor marker when used in combination with Ep-CAM/CD49f markers.
abstract: BACKGROUND
  Accumulating evidence supports cancer to initiate and develop from a small population of stem-like cells termed as cancer stem cells (CSC). The exact phenotype of CSC and their counterparts in normal mammary gland is not well characterized. In this study our aim was to evaluate the phenotype and function of stem/progenitor cells in normal mammary epithelial cell populations and their malignant counterparts.
  
  
  METHODS
  Freshly isolated cells from both normal and malignant human breasts were sorted using 13 widely used stem/progenitor cell markers individually or in combination by multi-parametric (up to 9 colors) cell sorting. The sorted populations were functionally evaluated by their ability to form colonies and mammospheres, in vitro.
  
  
  RESULTS
  We have compared, for the first time, the stem/progenitor markers of normal and malignant breasts side-by-side. Amongst all markers tested, we found CD44high/CD24low cell surface marker combination to be the most efficient at selecting normal epithelial progenitors. Further fractionation of CD44high/CD24low positive cells showed that this phenotype selects for luminal progenitors within Ep-CAMhigh/CD49f + cells, and enriches for basal progenitors within Ep-CAM-/low/CD49f + cells. On the other hand, primary breast cancer samples, which were mainly luminal Ep-CAMhigh, had CD44high/CD24low cells among both CD49fneg and CD49f + cancer cell fractions. However, functionally, CSC were predominantly CD49f + proposing the use of CD44high/CD24low in combination with Ep-CAM/CD49f cell surface markers to further enrich for CSC.
  
  
  CONCLUSIONS
  Our study clearly demonstrates that both normal and malignant breast cells with the CD44high/CD24low phenotype have the highest stem/progenitor cell ability when used in combination with Ep-CAM/CD49f reference markers. We believe that this extensive characterization study will help in understanding breast cancer carcinogenesis, heterogeneity and drug resistance.
authors.affiliation: Stem Cell & Tissue Re-engineering Program, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.
authors.forename: Hazem
authors.initials: H
authors.lastname: Ghebeh
authors.forename: Ghida Majed
authors.initials: GM
authors.lastname: Sleiman
authors.forename: Pulicat S
authors.initials: PS
authors.lastname: Manogaran
authors.forename: Amer
authors.initials: A
authors.lastname: Al-Mazrou
authors.forename: Eman
authors.initials: E
authors.lastname: Barhoush
authors.forename: Falah H
authors.initials: FH
authors.lastname: Al-Mohanna
authors.forename: Asma
authors.initials: A
authors.lastname: Tulbah
authors.forename: Khalid
authors.initials: K
authors.lastname: Al-Faqeeh
authors.forename: Chaker N
authors.initials: CN
authors.lastname: Adra
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis / Q000096:biosynthesis; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D051927:CD24 Antigen / Q000032:analysis / Q000096:biosynthesis; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000096:biosynthesis; D000071858:Epithelial Cell Adhesion Molecule; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis / Q000096:biosynthesis; D007150:Immunohistochemistry; D039503:Integrin alpha6 / Q000032:analysis / Q000096:biosynthesis; D051379:Mice; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D010641:Phenotype; D059467:Transcriptome; D014183:Transplantation, Heterologous
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D051927:CD24 Antigen; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule; D018960:Hyaluronan Receptors; D039503:Integrin alpha6