Small GTPase RAB45-mediated p38 activation in apoptosis of chronic myeloid leukemia progenitor cells

The regulation of Ia (HLA-DR) antigen expression on myeloid progenitor cells may be closely related to the control of myelopoiesis in both normal individuals and chronic myeloid leukemia (CML) patients. In an effort to study directly the expression and behavior of Ia surface molecules on myeloid progenitor cells, we used an immunologic purification technique to enrich these cells approximately 100-fold from the peripheral blood of CML patients. The majority of cells in this blast population expressed HLA-DR antigens. Thirty percent to 40% of cells could form a granulocyte or monocyte colony in agar, and these cells tended to express the highest levels of HLA-DR. The number of HLA- DR molecules per cell increased about twofold as the cells tranversed the cell cycle from G0/G1 to G2/M. This was true for unstimulated cells or cells exposed to colony-stimulating factors. Some of this increase was related to a corresponding increase in cell size and is also seen with other cell surface antigens such as beta-2-microglobulin. Ia antigen expression was not modified by culture with colony-stimulating factors, fetal calf serum, or serum-free, prostaglandin-free medium for periods of up to 24 hours. These results demonstrate that Ia antigens are expressed on the myeloid progenitor cells of CML, are increased in the S and G2/M phases of the cell cycle, and are stable under most in vitro culture conditions for at least 24 hours of culture.

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Identification of BCR/ABL-negative primitive hematopoietic progenitor cells within chronic myeloid leukemia marrow

Blood ◽

10.1182/blood.v81.3.801.bloodjournal813801 ◽

1993 ◽

Vol 81 (3) ◽

pp. 801-807 ◽

Cited By ~ 1

Author(s):

T Leemhuis ◽

D Leibowitz ◽

G Cox ◽

R Silver ◽

EF Srour ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Chronic Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Chronic Phase ◽

Polymerase Chain Reaction Analysis ◽

Hematopoietic Progenitor Cells ◽

Hematopoietic Progenitor ◽

Hematopoietic Stem

Chronic myeloid leukemia (CML) is a malignant disorder of the hematopoietic stem cell. It has been shown that normal stem cells coexist with malignant stem cells in the bone marrow of patients with chronic-phase CML. To characterize the primitive hematopoietic progenitor cells within CML marrow, CD34+DR- and CD34+DR+ cells were isolated using centrifugal elutriation, monoclonal antibody labeling, and flow cytometric cell sorting. Polymerase chain reaction analysis of RNA samples from these CD34+ subpopulations was used to detect the presence of the BCR/ABL translocation characteristic of CML. The CD34+DR+ subpopulation contained BCR/ABL(+) cells in 11 of 12 marrow samples studied, whereas the CD34+DR- subpopulation contained BCR/ABL(+) cells in 6 of 9 CML marrow specimens. These cell populations were assayed for hematopoietic progenitor cells, and individual hematopoietic colonies were analyzed by PCR for their BCR/ABL status. Results from six patients showed that nearly half of the myeloid colonies cloned from CD34+DR- cells were BCR/ABL(+), although the CD34+DR- subpopulation contained significantly fewer BCR/ABL(+) progenitor cells than either low-density bone marrow (LDBM) or the CD34+DR+ fraction. These CD34+ cells were also used to establish stromal cell-free long-term bone marrow cultures to assess the BCR/ABL status of hematopoietic stem cells within these CML marrow populations. After 28 days in culture, three of five cultures initiated with CD34+DR- cells produced BCR/ABL(-) cells. By contrast, only one of eight cultures initiated with CD34+DR+ cells were BCR/ABL(-) after 28 days. These results indicate that the CD34+DR- subpopulation of CML marrow still contains leukemic progenitor cells, although to a lesser extent than either LDBM or CD34+DR+ cells.

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Molecular persistence of chronic myeloid leukemia caused by donor T cells specific for lineage-restricted maturation antigens not recognizing immature progenitor-cells

Leukemia ◽

10.1038/sj.leu.2404169 ◽

2006 ◽

Vol 20 (6) ◽

pp. 1040-1046 ◽

Cited By ~ 12

Author(s):

P A von dem Borne ◽

S A P van Luxemburg-Heijs ◽

M H M Heemskerk ◽

I Jedema ◽

A Mulder ◽

...

Keyword(s):

T Cells ◽

Chronic Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Donor T Cells

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Simultaneous Inhibition of BCR-ABL1 Tyrosine Kinase and PAK1/2 Serine/Threonine Kinase Exerts Synergistic Effect against Chronic Myeloid Leukemia Cells

Cancers ◽

10.3390/cancers11101544 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1544 ◽

Cited By ~ 4

Author(s):

Sylwia Flis ◽

Ewelina Bratek ◽

Tomasz Chojnacki ◽

Marlena Piskorek ◽

Tomasz Skorski

Keyword(s):

Chronic Myeloid Leukemia ◽

Synergistic Effect ◽

Tyrosine Kinase ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Kinase Inhibitor ◽

Leukemia Cells ◽

Serine Threonine Kinase ◽

Threonine Kinase ◽

Simultaneous Inhibition

Tyrosine kinase inhibitors (TKIs) revolutionized the treatment of chronic myeloid leukemia in the chronic phase (CML-CP). However, it is unlikely that they can completely “cure” the disease. This might be because some subpopulations of CML-CP cells such as stem and progenitor cells are resistant to chemotherapy, even to the new generation of TKIs. Therefore, it is important to look for new methods of treatment to improve therapeutic outcomes. Previously, we have shown that class I p21-activated serine/threonine kinases (PAKs) remained active in TKI-naive and TKI-treated CML-CP leukemia stem and early progenitor cells. In this study, we aimed to determine if simultaneous inhibition of BCR-ABL1 oncogenic tyrosine kinase and PAK1/2 serine/threonine kinase exert better anti-CML effect than that of individual treatments. PAK1 was inhibited by small-molecule inhibitor IPA-3 (p21-activated kinase inhibitor III), PAK2 was downregulated by specific short hairpin RNA (shRNA), and BCR-ABL1 tyrosine kinase was inhibited by imatinib (IM). The studies were conducted by using (i) primary CML-CP stem/early progenitor cells and normal hematopoietic counterparts isolated from the bone marrow of newly diagnosed patients with CML-CP and from healthy donors, respectively, (ii) CML-blast phase cell lines (K562 and KCL-22), and (iii) from BCR-ABL1-transformed 32Dcl3 cell line. Herein, we show that inhibition of the activity of PAK1 and/or PAK2 enhanced the effect of IM against CML cells without affecting the normal cells. We observed that the combined use of IM with IPA-3 increased the inhibition of growth and apoptosis of leukemia cells. To evaluate the type of interaction between the two drugs, we performed median effect analysis. According to our results, the type and strength of drug interaction depend on the concentration of the drugs tested. Generally, combination of IM with IPA-3 at the 50% of the cell kill level (EC50) generated synergistic effect. Based on our results, we hypothesize that IM, a BCR-ABL1 tyrosine kinase inhibitor, combined with a PAK1/2 inhibitor facilitates eradication of CML-CP cells.

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Feeder-free and serum-free in vitro assay for measuring the effect of drugs on acute and chronic myeloid leukemia stem/progenitor cells

Experimental Hematology ◽

10.1016/j.exphem.2020.08.004 ◽

2020 ◽

Vol 90 ◽

pp. 52-64.e11 ◽

Cited By ~ 1

Author(s):

Hanyang Lin ◽

Jackie E. Damen ◽

Marta A. Walasek ◽

Stephen J. Szilvassy ◽

Ali G. Turhan ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

In Vitro Assay ◽

Vitro Assay ◽

Serum Free

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Identification of BCR/ABL-negative primitive hematopoietic progenitor cells within chronic myeloid leukemia marrow

Blood ◽

10.1182/blood.v81.3.801.801 ◽

1993 ◽

Vol 81 (3) ◽

pp. 801-807 ◽

Cited By ~ 49

Author(s):

T Leemhuis ◽

D Leibowitz ◽

G Cox ◽

R Silver ◽

EF Srour ◽

...

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Chronic Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Chronic Phase ◽

Polymerase Chain Reaction Analysis ◽

Hematopoietic Progenitor Cells ◽

Hematopoietic Progenitor ◽

Hematopoietic Stem

Abstract Chronic myeloid leukemia (CML) is a malignant disorder of the hematopoietic stem cell. It has been shown that normal stem cells coexist with malignant stem cells in the bone marrow of patients with chronic-phase CML. To characterize the primitive hematopoietic progenitor cells within CML marrow, CD34+DR- and CD34+DR+ cells were isolated using centrifugal elutriation, monoclonal antibody labeling, and flow cytometric cell sorting. Polymerase chain reaction analysis of RNA samples from these CD34+ subpopulations was used to detect the presence of the BCR/ABL translocation characteristic of CML. The CD34+DR+ subpopulation contained BCR/ABL(+) cells in 11 of 12 marrow samples studied, whereas the CD34+DR- subpopulation contained BCR/ABL(+) cells in 6 of 9 CML marrow specimens. These cell populations were assayed for hematopoietic progenitor cells, and individual hematopoietic colonies were analyzed by PCR for their BCR/ABL status. Results from six patients showed that nearly half of the myeloid colonies cloned from CD34+DR- cells were BCR/ABL(+), although the CD34+DR- subpopulation contained significantly fewer BCR/ABL(+) progenitor cells than either low-density bone marrow (LDBM) or the CD34+DR+ fraction. These CD34+ cells were also used to establish stromal cell-free long-term bone marrow cultures to assess the BCR/ABL status of hematopoietic stem cells within these CML marrow populations. After 28 days in culture, three of five cultures initiated with CD34+DR- cells produced BCR/ABL(-) cells. By contrast, only one of eight cultures initiated with CD34+DR+ cells were BCR/ABL(-) after 28 days. These results indicate that the CD34+DR- subpopulation of CML marrow still contains leukemic progenitor cells, although to a lesser extent than either LDBM or CD34+DR+ cells.

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Selective elimination of leukemic CD34+ progenitor cells by cytotoxic T lymphocytes specific for WT1

Blood ◽

10.1182/blood.v95.7.2198 ◽

2000 ◽

Vol 95 (7) ◽

pp. 2198-2203 ◽

Cited By ~ 311

Author(s):

Liquan Gao ◽

Ilaria Bellantuono ◽

Annika Elsässer ◽

Stephen B. Marley ◽

Myrtle Y. Gordon ◽

...

Keyword(s):

Transcription Factor ◽

Chronic Myeloid Leukemia ◽

T Lymphocytes ◽

Progenitor Cells ◽

Cytotoxic T Lymphocytes ◽

Colony Formation ◽

Myeloid Leukemia ◽

Leukemia Cell

Abstract Hematologic malignancies such as acute and chronic myeloid leukemia are characterized by the malignant transformation of immature CD34+ progenitor cells. Transformation is associated with elevated expression of the Wilm's tumor gene encoded transcription factor (WT1). Here we demonstrate that WT1 can serve as a target for cytotoxic T lymphocytes (CTL) with exquisite specificity for leukemic progenitor cells. HLA-A0201– restricted CTL specific for WT1 kill leukemia cell lines and inhibit colony formation by transformed CD34+ progenitor cells isolated from patients with chronic myeloid leukemia (CML), whereas colony formation by normal CD34+ progenitor cells is unaffected. Thus, the tissue-specific transcription factor WT1 is an ideal target for CTL-mediated purging of leukemic progenitor cells in vitro and for antigen-specific therapy of leukemia and other WT1-expressing malignancies in vivo.

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