[Study on the Characteristics of cell cycle and proliferation of CD34+ hematopoietic stem cells in myelodysplastic syndromes].
OBJECTIVE
To study the characteristics of cell cycle and proliferation of CD34+ hematopoietic stem cells in patients with myelodysplastic syndromes (MDS).


METHODS
Propidium iodide staining was used to examine cell cycle parameters (G(0)/G(1), S and G(2)/M) of bone marrow mononuclear cells (BMMNCs) while immunofluorescent double staining and FACS techniques were used to measure Ki67 expression in BM CD34+ cells from normal control, patients with MDS, acute myeloid leukemia preceded by MDS (MDS-AML) and primary AML.


RESULTS
There was a statistical up-tendency in G(0)/G(1) phase proportion of BMMNCs whereas a statistical down-tendency in S and G(2)/M phase proportions among normal control, MDS and primary AML. Compared to primary AML, MDS-AML had significantly higher ratios of S (P < 0.05), G(2)/M (P < 0.05) and S + G(2)/M (P < 0.05) phase cells while lower ratio of G(0)/G(1) phase cells (P < 0.05). The proportion of CD34+Ki67+ cells in MDS patients was significantly higher than that in normal control (P = 0.004). So were the percentages of CD34+Ki67+ cells in low-risk [(0.54 +/- 0.49)%, P < 0.05] and high-risk MDS patients [(1.69 +/- 1.66)%, P = 0.022]. Furthermore, there was statistical difference between low-risk and high-risk MDS (P < 0.05). Compared to normal control and primary AML, MDS-patients had the highest proportion of CD34+Ki67+ cells [(16.75 +/- 13.58)%, P < 0.05]. The proportion of CD34+Ki67+ cells in CD34+ cells in MDS patients [(48.50 +/- 20.49)%] was significantly higher than that in normal control [(27.71 +/- 16.04)%, P < 0.01]. So were the low-risk [(51.85 +/- 21.80)%, P = 0.002] and high-risk MDS [(43.93 +/- 18.57)%, P < 0.05]. The proportion of CD34+Ki67+ cells in CD34+ cells in MDS-AML patients [(60.92 +/- 30.12)%] was the highest, and was statistically higher than that in both normal control (P < 0.01) and primary AML patients [(17.01 +/- 15.93)%, P < 0.001]. The proportion of CD34+Ki67+ cells in Ki67+ cells in MDS patients [(4.91 +/- 4.68)%, P < 0.01] was significantly higher than that [(2.43 +/- 2.37)%] in normal controls. In the low-risk MDS group it was (4.11 +/- 3.94)%, (P > 0.05) and in high-risk MDS group it was (5.76 +/- 5.38)%, (P < 0.05).


CONCLUSIONS
High proportion of G(0)/G(1) cells and G(1) phase arrest occurred in MDS. High proliferation capacity of MDS clone, especially that derived from CD34+ cells, might play an important role in the clonal expansion, diseases deterioration and worse prognosis of MDS.
Shi
Jun
J
Institute of Hematology and Blood Diseases Hospital, CAMS and PUMC, Tianjin 300020, China.
Shao
Zong-hong
ZH
Liu
Hong
H
Jia
Hai-rong
HR
Sun
Juan
J
Bai
Jie
J
Wu
Yu-hong
YH
Jing
Li-ping
LP
He
Guang-sheng
GS
Cao
Yan-Ran
YR
Wang
Xiu-li
XL
Tu
Mei-feng
MF
Hao
Yu-shu
YS
Yang
Tian-ying
TY
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000097:blood; D001854:Bone Marrow Cells / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle; D049109:Cell Proliferation; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D019394:Ki-67 Antigen / Q000097:blood; D007951:Leukemia, Myeloid / Q000097:blood; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000097:blood*; D055815:Young Adult
D018952:Antigens, CD34; D019394:Ki-67 Antigen