title: Electronic volume, aldehyde dehydrogenase, and stem cell marker expression in cells from human peripheral blood apheresis samples.
abstract: BACKGROUND
  Over-expression of aldehyde dehydrogenase and other stem cell markers is characteristic of cells with tumorigenic potential in NOD/SCID mice. Most of these studies have focused on metastatic cells in bone marrow and on solid tumors. There are no studies on correlation of marker expression with ALDH1 expression in cells from human peripheral blood apheresis (HPC-A) samples.
  
  
  METHODS
  HPC-A samples from 44 patients were incubated with Aldefluor with or without the presence of aldehyde dehydrogenase inhibitor DEAB. Cells with high aldehyde dehydrogenase expression (ALDH1(bright)) were analyzed for stem/progenitor markers CD34, CD90, CD117, and CD133. Electronic volume measured by Coulter principal in a Quanta flow analyzer was correlated with ALDH1 and marker expression.
  
  
  RESULTS
  In ALDH1(bright)/SSC(low) cells, 0.13% of the cells had CD34(+) expression and three distinct populations were seen. Expression of CD90 was dim and the frequency of ALDH1(bright)/SSC(low)/CD90(dim) cells amongst the nonlineage depleted samples was 0.04%. CD117(dim-bright) expression was seen in 0.17% of the samples. Three distinct populations of cells with CD133 expression were seen in ALDH1(bright)/SSC(low) nonlineage depleted cells with a frequency of 0.28%. The ALDH1(bright)/CD90(dim) cells had the smallest mean electronic volume of 264.9 microm(3) when compared with cells with CD34(bright) expression (270.2 microm(3)) and ALDH1(dim)/CD90(dim) cells (223 microm(3)).
  
  
  CONCLUSIONS
  ALDH1(bright)/SSC(low) cells show heterogeneity in expression of the four stem cell markers studied. The CD90 cells in both the ALDH1(bright) and ALDH1(dim) populations had the smallest mean electronic volume when compared with similar cells with CD117 expression.
authors.affiliation: Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Sharma
authors.forename: Sherry
authors.initials: S
authors.lastname: Shariatmadar
authors.forename: Awtar
authors.initials: A
authors.lastname: Krishan
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000276:immunology; D015703:Antigens, CD / Q000096:biosynthesis* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D001781:Blood Component Removal; D005434:Flow Cytometry / Q000379:methods*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D012680:Sensitivity and Specificity; D010128:p-Aminoazobenzene / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; C007368:C.I. Solvent Yellow 56; D010128:p-Aminoazobenzene; D000444:Aldehyde Dehydrogenase