Two Flow Cytometric Approaches of NKG2D Ligand Surface Detection to Distinguish Stem Cells from Bulk Subpopulations in Acute Myeloid Leukemia

Abstract Background Leukemia stem cells (LSCs) are responsible for the initiation, progression, and relapse of acute myeloid leukemia (AML). Therefore, a therapeutic strategy targeting LSCs is a potential approach to eradicate AML. In this study, we aimed to identify LSC-specific surface markers and uncover the underlying mechanism of AML LSCs. Methods Microarray gene expression data were used to investigate candidate AML-LSC-specific markers. CD9 expression in AML cell lines, patients with AML, and normal donors was evaluated by flow cytometry (FC). The biological characteristics of CD9-positive (CD9+) cells were analyzed by in vitro proliferation, chemotherapeutic drug resistance, migration, and in vivo xenotransplantation assays. The molecular mechanism involved in CD9+ cell function was investigated by gene expression profiling. The effects of alpha-2-macroglobulin (A2M) on CD9+ cells were analyzed with regard to proliferation, drug resistance, and migration. Results CD9, a cell surface protein, was specifically expressed on AML LSCs but barely detected on normal hematopoietic stem cells (HSCs). CD9+ cells exhibit more resistance to chemotherapy drugs and higher migration potential than do CD9-negative (CD9−) cells. More importantly, CD9+ cells possess the ability to reconstitute human AML in immunocompromised mice and promote leukemia growth, suggesting that CD9+ cells define the LSC population. Furthermore, we identified that A2M plays a crucial role in maintaining CD9+ LSC stemness. Knockdown of A2M impairs drug resistance and migration of CD9+ cells. Conclusion Our findings suggest that CD9 is a new biomarker of AML LSCs and is a promising therapeutic target.

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Bone marrow niche-mediated survival of leukemia stem cells in acute myeloid leukemia: Yin and Yang

Cancer Biology and Medicine ◽

10.20892/j.issn.2095-3941.2016.0023 ◽

2016 ◽

Vol 13 (2) ◽

pp. 248-259 ◽

Cited By ~ 44

Author(s):

Hong-Sheng Zhou ◽

Bing Z. Carter ◽

Michael Andreeff ◽

Bing Z. Carter ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Leukemia Stem Cells ◽

Bone Marrow Niche ◽

Yin And Yang ◽

Acute Myeloid

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Evidence for malignant transformation in acute myeloid leukemia at the level of early hematopoietic stem cells by cytogenetic analysis of CD34+ subpopulations

Blood ◽

10.1182/blood.v86.8.2906.bloodjournal8682906 ◽

1995 ◽

Vol 86 (8) ◽

pp. 2906-2912 ◽

Cited By ~ 2

Author(s):

D Haase ◽

M Feuring-Buske ◽

S Konemann ◽

C Fonatsch ◽

C Troff ◽

...

Keyword(s):

Stem Cells ◽

Acute Myeloid Leukemia ◽

Hematopoietic Stem Cells ◽

Malignant Transformation ◽

Cell Sorting ◽

Myeloid Leukemia ◽

De Novo ◽

Leukemic Cells ◽

Hematopoietic Stem ◽

Acute Myeloid

Acute myeloid leukemia (AML) is a heterogenous disease according to morphology, immunophenotype, and genetics. The retained capacity of differentiation is the basis for the phenotypic classification of the bulk population of leukemic blasts and the identification of distinct subpopulations. Within the hierarchy of hematopoietic development and differentiation it is still unknown at which stage the malignant transformation occurs. It was our aim to analyze the potential involvement of cells with the immunophenotype of pluripotent stem cells in the leukemic process by the use of cytogenetic and cell sorting techniques. Cytogenetic analyses of bone marrow aspirates were performed in 13 patients with AML (11 de novo and 2 secondary) and showed karyotype abnormalities in 10 cases [2q+, +4, 6p, t(6:9), 7, +8 in 1 patient each and inv(16) in 4 patients each]. Aliquots of the samples were fractionated by fluorescence-activated cell sorting of CD34+ cells. Two subpopulations, CD34+/CD38-(early hematopoietic stem cells) and CD34+/CD38+ (more mature progenitor cells), were screened for karyotype aberations as a marker for leukemic cells. Clonal abnormalities and evaluable metaphases were found in 8 highly purified CD34+/CD38-populations and in 9 of the CD34+/CD38-specimens, respectively. In the majority of cases (CD34+/CD38-, 6 of 8 informative samples; CD34+/CD38+, 5 of 9 informative samples), the highly purified CD34+ specimens also contained cytogenetically normal cells. Secondary, progression-associated chromosomal changes (+8, 12) were identified in the CD34+/CD38-cells of 2 patients. We conclude that clonal karyotypic abnormalities are frequently found in the stem cell-like (CD34+/CD38-) and more mature (CD34+/CD38+) populations of patients with AML, irrespective of the phenotype of the bulk population of leukemic blasts and of the primary or secondary character of the leukemia. Our data suggest that, in AML, malignant transformation as well as disease progression may occur at the level of CD34+/CD38-cells with multilineage potential.

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