PMID- 10222652
OWN - NLM
STAT- MEDLINE
DCOM- 19990517
LR  - 20071114
IS  - 0925-5710 (Print)
IS  - 0925-5710 (Linking)
VI  - 69
IP  - 3
DP  - 1999 Apr
TI  - The relative extent and propensity of CD34+ vs. CD34- cells to undergo apoptosis 
      in myelodysplastic marrows.
PG  - 152-9
AB  - The paradox of peripheral cytopenias despite cellular bone marrow (BM) observed 
      in myelodysplastic syndromes (MDS) has been associated with excessive 
      intramedullary apoptosis of hematopoietic cells. Since MDS is regarded as a stem 
      cell disorder, the present studies were undertaken to examine the relative 
      susceptibility and propensity of early progenitor CD34+ cells to undergo 
      apoptosis as compared to more maturing/matured CD34- cells. Five serial studies 
      were performed on 4 independent groups of 36 newly diagnosed MDS patients. First, 
      in 2 separate groups of 16 and 8 patients each, measurement of the extent of 
      apoptosis in CD34+ and CD34- fractions of the BM aspirate mononuclear cells was 
      carried out using independent biparametric flow cytometry methods, CD34 
      labeling/terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling 
      (TUNEL) (n = 16), and CD34 labeling/reduced uptake of nucleic acid staining dye 
      LDS751 (n = 8). The difference in the median degrees of apoptosis in CD34+ vs. 
      CD34- cells was not statistically significant by either technique (P = 0.583 and 
      P = 0.674 for TUNEL and LDS751, respectively). In the next group of 4 MDS 
      patients, a double-labeling was performed on plastic embedded marrow biopsy 
      sections, to detect CD34 antigen with specific monoclonal antibody and apoptosis 
      by in situ end labeling (ISEL) of fragmented DNA. Despite high overall apoptosis 
      (56.2% +/- 18.4%), only an occasional CD34+ cell was found to be simultaneously 
      labeled with ISEL. Finally, in the last group of 8 MDS patients, CD34+ cells were 
      separated from CD34- cells on affinity column and cultured in serum containing 
      medium for 4 hours. At 0- and 4-hour time points, ISEL was carried out to label 
      apoptotic cells. In addition, a fluorometric assay was employed to estimate the 
      activity of a proapoptotic enzyme, Caspase 3. Both the net increase in % ISEL 
      labeled cells (apoptotic index or AI) and Caspase-3 activity were significantly 
      lower in CD34+ cells as compared to CD34- cells (AI, 0.87% +/- 0.5% vs. 3.97% +/- 
      1.4%, n = 6, P = 0.028 and Caspase-3 Units/mg protein, 46.9 +/- 25.0 vs. 71.7 +/- 
      23.03, n = 5, P = 0.042, respectively). We conclude that when estimated in a 
      total population of mononuclear cells, CD34+ cells and CD34- cells show 
      comparable degrees of apoptosis. However, once separated the CD34+ fraction 
      demonstrates lower propensity to undergo apoptosis, thereby suggesting the CD34- 
      fraction as being a possible source for proapoptotic signaling.
FAU - Mundle, S
AU  - Mundle S
AD  - Rush Cancer Institute, Rush Presbyterian-St. Luke's Medical Center, Chicago, 
      Illinois 60612, USA. smundle@rpslmc.edu
FAU - Venugopal, P
AU  - Venugopal P
FAU - Shetty, V
AU  - Shetty V
FAU - Ali, A
AU  - Ali A
FAU - Chopra, H
AU  - Chopra H
FAU - Handa, H
AU  - Handa H
FAU - Rose, S
AU  - Rose S
FAU - Mativi, B Y
AU  - Mativi BY
FAU - Gregory, S A
AU  - Gregory SA
FAU - Preisler, H D
AU  - Preisler HD
FAU - Raza, A
AU  - Raza A
LA  - eng
GR  - CA60085/CA/NCI NIH HHS/United States
GR  - CA60086/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - Japan
TA  - Int J Hematol
JT  - International journal of hematology
JID - 9111627
RN  - 0 (Antigens, CD34)
RN  - EC 3.4.22.- (CASP3 protein, human)
RN  - EC 3.4.22.- (Caspase 3)
RN  - EC 3.4.22.- (Caspases)
SB  - IM
MH  - Aged
MH  - Antigens, CD34/*immunology
MH  - Apoptosis/*physiology
MH  - Bone Marrow Cells/immunology
MH  - Caspase 3
MH  - Caspases/metabolism
MH  - Female
MH  - Flow Cytometry
MH  - Hematopoietic Stem Cells/immunology/*physiology
MH  - Humans
MH  - In Situ Nick-End Labeling
MH  - Male
MH  - Middle Aged
MH  - Myelodysplastic Syndromes/*physiopathology
MH  - Signal Transduction
EDAT- 1999/05/01 00:00
MHDA- 1999/05/01 00:01
CRDT- 1999/05/01 00:00
PHST- 1999/05/01 00:00 [pubmed]
PHST- 1999/05/01 00:01 [medline]
PHST- 1999/05/01 00:00 [entrez]
PST - ppublish
SO  - Int J Hematol. 1999 Apr;69(3):152-9.