Localization of CD44 and CD90 positive cells to the invasive front of breast tumors.
BACKGROUND
A variety of markers have been proposed to identify breast cancer stem cells. Here, we used immunohistostaining and flow cytometry to analyze their interrelationships and to sort cells for tumorigenicity studies.


METHODS
Cytokeratin, CD44, and CD90 were localized to primary breast cancer and normal breast (NB) tissue by immunohistostaining and related to CD117 and CD133 expression by flow cytometry. Immunodeficient NOD.CB17-Prkdc(scid) /J and NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl) /SzJ mice were used to test tumorigenicity of sorted CD90+ low-light scatter, CD90+ high-light scatter, and CD90(neg) tumor cells.


RESULTS
NB basal cells coexpressed CD44 and CD90. As cells transited luminally, CD44 was retained and downmodulated, and CD90 was lost and cytokeratin increased. In breast tumors, basal-like CD44+/CD90+ cells were localized to the tumor periphery, adjacent to CD90+ stroma. Like normal luminal cells, interior tumor cells were CD44+/CD90-. Immunophenotyping (CD44/CD90/CD117/CD133) of cytokeratin+ cells revealed no significant difference in expression between tumors and tumor-free breast. In both, CD133 was distributed approximately equally among CD44/CD90 subsets, whereas CD117 expression was highest in the basal-associated CD44+/CD90+ subset. Sorted CD90+ pleural effusion cells with lymphoid light scatter, 49% of which were CD44+, were uniquely tumorigenic in immunodeficient mice (100 cells/injection).


CONCLUSIONS
Our data demonstrate that all tumors contain a small population of CD44+/CD90+ cells, mimicking the phenotype of ductal-basal cells. These are localized to the tumor periphery, adjacent to CD90+ stroma. Among the nonhematopoietic, nonmesothelial cells found in metastatic pleural effusions, low-light scatter CD90+ cells are most potently tumorigenic, compared to high-scatter CD90+ cells and CD90- cells. © 2010 International Clinical Cytometry Society.
Donnenberg
Vera S
VS
University of Pittsburgh Cancer Center, Pittsburgh, Pennsylvania, USA. donnenbergvs@upmc.edu
Donnenberg
Albert D
AD
Zimmerlin
Ludovic
L
Landreneau
Rodney J
RJ
Bhargava
Rohit
R
Wetzel
Ryan A
RA
Basse
Per
P
Brufsky
Adam M
AM
D000071916:AC133 Antigen; D000230:Adenocarcinoma / Q000276:immunology* / Q000473:pathology; D000818:Animals; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis / Q000276:immunology; D001943:Breast Neoplasms / Q000276:immunology* / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006023:Glycoproteins / Q000032:analysis / Q000276:immunology; D006801:Humans; D018960:Hyaluronan Receptors / Q000276:immunology*; D007633:Keratins / Q000032:analysis; D051379:Mice; D016688:Mice, Inbred NOD; D009361:Neoplasm Invasiveness; D014411:Neoplastic Stem Cells / Q000276:immunology* / Q000473:pathology; D010455:Peptides / Q000032:analysis / Q000276:immunology; D016066:Pleural Effusion, Malignant / Q000276:immunology* / Q000473:pathology; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis / Q000276:immunology; D018800:Thy-1 Antigens / Q000276:immunology*; D023041:Xenograft Model Antitumor Assays
D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; C497483:CD44 protein, human; D006023:Glycoproteins; D018960:Hyaluronan Receptors; C000606023:PROM1 protein, human; D010455:Peptides; C000606024:Prom1 protein, mouse; D018800:Thy-1 Antigens; D007633:Keratins; D019009:Proto-Oncogene Proteins c-kit