Polo-Like Kinase-1 (Plk-1) Inhibitor BI 2536 Induces Mitotic Arrest and Apoptosis in Vivo: First Demonstration of Target Inhibition in the Bone Marrow of AML Patients

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2641-2641
Author(s):  
Kang-Hun Lee ◽  
Richard F. Schlenk ◽  
Gesine Bug ◽  
Carsten Müller-Tidow ◽  
Ralph M. Waesch ◽  
...  

Abstract Background: BI 2536 is a potent and selective inhibitor of Plk-1, which plays a crucial role in the regulation of mitosis. Inhibition of Plk-1 leads to mitotic arrest and apoptosis. Therefore, Plk-1 inhibitors are currently in clinical testing as anti-proliferative agents in cancer patients. BI 2536, the first specific Plk-1 inhibitor in clinical testing, demonstrated strong anti-proliferative effects on AML cell lines in vitro and in in vivo models. To investigate target inhibition in the malignant cell, bone marrow samples from patients who participated in a Phase I/II study of BI 2536 single-agent therapy in elderly patients with relapsed or refractory AML were analyzed. Methods: Pharmacodynamic analyses including immunocytochemistry (ICC) and flow cytometry (FACS) of bone marrow (BM) were performed to examine cell morphology, phosphorylation of histone H3 (phospho-H3), and induction of apoptosis. Samples were acquired before and 24 h after the first administration of BI 2536. FACS analysis included propidium iodide (PI)-FACS to determine the percentage of cells residing in various cell cycle stages (G0/1-, S- and G2/M-phases) and Annexin V-Cy5-staining for apoptosis. Immunocytochemistry included staining for phosphorylated histone H3 and TUNEL assay for apoptosis. Results: At the time of analysis, data from 28 patients treated at doses in the range of 50 to 400 mg BI 2536 were available. BM taken after BI 2536 administration showed an increase of phospho-H3 positive cells as compared to baseline prior to treatment. There was a trend toward a positive correlation between phospho-H3 increase and increase in dosage of BI 2536 (p=0.16) when treatment at low doses (50 to 60 mg) of BI 2536 were compared to treatment at higher doses (100 to 400 mg). Furthermore, trends were observed that an increase of phospho-H3 is positively correlated with both a higher percentage of cells in G2/M and an increase in apoptotic cells. The typical morphology of cells in mitotic arrest could be demonstrated by ICC. Interestingly, when patients with progressive disease after one cycle (PD) were compared to patients with disease stabilization or response (nonPD), a statistically significant positive correlation between PD and increase in phospho-H3 compared to baseline was found (p=0.03). Also, there was a clear trend for an increase in the percentage of cells in G2/M phase and apoptosis in patients with PD compared to patients with nonPD. Preliminary evaluation of other disease characteristics including karyotype (normal vs complex), secondary AML, complete response in previous treatments, baseline value for blasts in the bone marrow or in the peripheral blood, did not reveal any signs of correlation with the clinical response to BI 2536 treatment. Conclusion: BI 2536 treatment increases the number of cells in G2/M phase (as detected by FACS analysis and phospho-H3 staining) and the number of apoptotic cells within 24 h after administration. In line with the clinical observation of rapid blast reduction both in the BM and the peripheral blood, these findings indicate that BI 2536 induces mitotic arrest and apoptosis of the malignant target cells in AML patients. The biological meaning of the correlation between the BM findings and the clinical response to BI 2536 is unclear, but if substantiated by more data, these results may suggest a predictive value of BM examinations for the response to BI 2536.

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 3919-3924 ◽  
Author(s):  
Jean C.Y. Wang ◽  
Monica Doedens ◽  
John E. Dick

Abstract We have previously reported the development of in vivo functional assays for primitive human hematopoietic cells based on their ability to repopulate the bone marrow (BM) of severe combined immunodeficient (SCID) and nonobese diabetic/SCID (NOD/SCID) mice following intravenous transplantation. Accumulated data from gene marking and cell purification experiments indicate that the engrafting cells (defined as SCID-repopulating cells or SRC) are biologically distinct from and more primitive than most cells that can be assayed in vitro. Here we demonstrate through limiting dilution analysis that the NOD/SCID xenotransplant model provides a quantitative assay for SRC. Using this assay, the frequency of SRC in cord blood (CB) was found to be 1 in 9.3 × 105 cells. This was significantly higher than the frequency of 1 SRC in 3.0 × 106 adult BM cells or 1 in 6.0 × 106 mobilized peripheral blood (PB) cells from normal donors. Mice transplanted with limiting numbers of SRC were engrafted with both lymphoid and multilineage myeloid human cells. This functional assay is currently the only available method for quantitative analysis of human hematopoietic cells with repopulating capacity. Both CB and mobilized PB are increasingly being used as alternative sources of hematopoietic stem cells in allogeneic transplantation. Thus, the findings reported here will have important clinical as well as biologic implications.


Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2276-2285 ◽  
Author(s):  
Maria De La Luz Sierra ◽  
Paola Gasperini ◽  
Peter J. McCormick ◽  
Jinfang Zhu ◽  
Giovanna Tosato

The mechanisms underlying granulocyte-colony stimulating factor (G-CSF)–induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood remain elusive. We provide evidence that the transcriptional repressor growth factor independence-1 (Gfi-1) is involved in G-CSF–induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood. We show that in vitro and in vivo G-CSF promotes expression of Gfi-1 and down-regulates expression of CXCR4, a chemokine receptor essential for the retention of hematopoietic stem cells and granulocytic cells in the bone marrow. Gfi-1 binds to DNA sequences upstream of the CXCR4 gene and represses CXCR4 expression in myeloid lineage cells. As a consequence, myeloid cell responses to the CXCR4 unique ligand SDF-1 are reduced. Thus, Gfi-1 not only regulates hematopoietic stem cell function and myeloid cell development but also probably promotes the release of granulocytic lineage cells from the bone marrow to the peripheral blood by reducing CXCR4 expression and function.


Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 54-59 ◽  
Author(s):  
AM Farese ◽  
P Hunt ◽  
T Boone ◽  
TJ MacVittie

Megakaryocyte growth and development factor (MGDF) is a novel cytokine that binds to the c-mpl receptor and stimulates megakaryocyte development in vitro and in vivo. This report describes the ability of recombinant human (r-Hu) MGDF to affect megakaryocytopoiesis in normal nonhuman primates. r-HuMGDF was administered subcutaneously to normal, male rhesus monkeys once per day for 10 consecutive days at dosages of 2.5, 25, or 250 micrograms/kg of body weight. Bone marrow and peripheral blood were assayed for clonogenic activity and peripheral blood counts were monitored. Circulating platelet counts increased significantly (P < .05) for all doses within 6 days of r-HuMGDF administration and reached maximal levels between day 12 and day 14 postcytokine administration. The 2.5, 25.0, and 250.0 micrograms/kg/d doses elicited peak mean platelet counts that were 592%, 670%, and 449% of baseline, respectively. Bone marrow-derived clonogenic data showed significant increases in the concentration of megakaryocyte (MEG)- colony-forming unit (CFU) and granulocyte-erythroid-macrophage- megakaryocyte (GEMM)-CFU, whereas that of granulocyte-macrophage (GM)- CFU and burst-forming unit-erythroid (BFU-e) remained unchanged during the administration of r-HuMGDF. These data show that r-HuMGDF is a potent stimulator of thrombocytopoiesis in the normal nonhuman primate.


Blood ◽  
2000 ◽  
Vol 95 (3) ◽  
pp. 829-836 ◽  
Author(s):  
Timothy W. Austin ◽  
Suzan Salimi ◽  
Gabor Veres ◽  
Franck Morel ◽  
Heini Ilves ◽  
...  

Using a mouse bone marrow transplantation model, the authors evaluated a Moloney murine leukemia virus (MMLV)-based vector encoding 2 anti-human immunodeficiency virus genes for long-term expression in blood cells. The vector also encoded the human nerve growth factor receptor (NGFR) to serve as a cell-surface marker for in vivo tracking of transduced cells. NGFR+ cells were detected in blood leukocytes of all mice (n=16; range 16%-45%) 4 to 5 weeks after transplantation and were repeatedly detected in blood erythrocytes, platelets, monocytes, granulocytes, T cells, and B cells of all mice for up to 8 months. Transgene expression in individual mice was not blocked in the various cell lineages of the peripheral blood and spleen, in several stages of T-cell maturation in the thymus, or in the Lin−/loSca-1+ and c-kit+Sca-1+ subsets of bone marrow cells highly enriched for long-term multilineage-reconstituting activity. Serial transplantation of purified NGFR+c-kit+Sca-1+bone marrow cells resulted in the reconstitution of multilineage hematopoiesis by donor type NGFR+ cells in all engrafted mice. The authors concluded that MMLV-based vectors were capable of efficient and sustained transgene expression in multiple lineages of peripheral blood cells and hematopoietic organs and in hematopoietic stem cell (HSC) populations. Differentiation of engrafting HSC to peripheral blood cells is not necessarily associated with dramatic suppression of retroviral gene expression. In light of earlier studies showing that vector elements other than the long-terminal repeat enhancer, promoter, and primer binding site can have an impact on long-term transgene expression, these findings accentuate the importance of empirically testing retroviral vectors to determine lasting in vivo expression.


Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 80
Author(s):  
Nazia Nazam ◽  
Mohammad Iqbal Lone ◽  
Abid Hamid ◽  
Talal Qadah ◽  
Alaa Banjar ◽  
...  

Dimethoate (DM) is an organophosphorus (OP) pesticide with wide use in the pest control. Its persistence in crops and soils could possibly cause adverse health consequences in humans as well as other non-target species. Since molecular studies confirming potential genotoxicity of DM have not been previously reported, the acute in vivo toxicological impact was evaluated in Wistar rats. Significant micronuclei induction and metaphase chromosome abnormalities in bone marrow cells exposed to three different DM doses (20, 40 and 60 mg/kg-bw) at multiple treatment durations (24, 48 and 72 h) indicated positive dose response relationship, confirming its genotoxic and cytotoxic potential. Significant mitotic index decrease was seen in dosed animals compared to vehicle control. The study used peripheral blood comet assay, indicating DM-mediated damage to DNA at all exposure levels in a time responsive manner. These assays were found to be an effective, precise, and fast technique with applied value in biomonitoring studies. Cell cycle and apoptosis along with mitochondrial membrane potential (MMP) in flow cytometric analyses confirmed DM exposure decreased MMP, affected the cell cycle, and inflicted DNA damage, which led to cellular apoptosis of leukocytes culminating into immunotoxic effects. The in silico experiments consequently augmented that DM showed acceptable binding energy value for Cyclin A2, suggesting that it could inhibit the cell cycle progression by inhibiting cyclin A2.


Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2234-2243 ◽  
Author(s):  
D. Dunon ◽  
N. Allioli ◽  
O. Vainio ◽  
C. Ody ◽  
B.A. Imhof

Abstract An in vivo thymus reconstitution assay based on intrathymic injection of hematopoietic progenitors into irradiated chicks was used to determine the number of T-cell progenitors in peripheral blood, paraaortic foci, bone marrow (BM), and spleen during ontogeny. This study allowed us to analyze the regulation of thymus colonization occurring in three waves during embryogenesis. It confirmed that progenitors of the first wave of thymus colonization originate from the paraaortic foci, whereas progenitors of the second and the third waves originate from the BM. The analysis of the number of T-cell progenitors indicates that each wave of thymus colonization is correlated with a peak number of T-cell progenitors in peripheral blood, whereas they are almost absent during the periods defined as refractory for colonization. Moreover, injection of T-cell progenitors into the blood circulation showed that they homed into the thymus without delay during the refractory periods. Thus, thymus colonization kinetics depend mainly on the blood delivery of T-cell progenitors during embryogenesis.


Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1595-1603 ◽  
Author(s):  
K Welte ◽  
CA Keever ◽  
J Levick ◽  
MA Bonilla ◽  
VJ Merluzzi ◽  
...  

Abstract The ability of peripheral blood mononuclear cells (PBMC) to produce and respond to interleukin-2 (IL-2) was evaluated in 50 recipients of HLA- identical bone marrow (BM) depleted of mature T cells by soybean agglutination and E rosetting (SBA-E-BM). In contrast to our previous findings in recipients of unfractionated marrow, during weeks 3 to 7 post-SBA-E-BM transplantation (BMT), PBMC from the majority of patients spontaneously released IL-2 into the culture medium. This IL-2 was not produced by Leu-11+ natural killer cells, which were found to be predominant in the circulation at this time, but by T11+, T3+, Ia antigen-bearing T cells. The IL-2 production could be enhanced by coculture with host PBMC frozen before transplant but not by stimulation with mitogenic amounts of OKT3 antibody, thus suggesting an in vivo activation of donor T cells or their precursors by host tissue. Spontaneous IL-2 production was inversely proportional to the number of circulating peripheral blood lymphocytes and ceased after 7 to 8 weeks post-SBA-E-BMT in most of the patients. In patients whose cells had ceased to produce IL-2 spontaneously or never produced this cytokine, neither coculture with host cells nor stimulation with OKT3 antibody thereafter induced IL-2 release through the first year posttransplant. Proliferative responses to exogenous IL-2 after stimulation with OKT3 antibody remained abnormal for up to 6 months post-SBA-E-BMT, unlike the responses of PBMC from recipients of conventional BM, which responded normally by 1 month post-BMT. However, the upregulation of IL- 2 receptor expression by exogenous IL-2 was found to be comparable to normal controls when tested as early as 3 weeks post-SBA-E-BMT. Therefore, the immunologic recovery of proliferative responses to IL-2 and the appearance of cells regulating in vivo activation of T cells appear to be more delayed in patients receiving T cell-depleted BMT. Similar to patients receiving conventional BMT, however, the ability to produce IL-2 after mitogenic stimulation remains depressed for up to 1 year after transplantation.


Leukemia ◽  
2017 ◽  
Vol 31 (6) ◽  
pp. 1340-1347 ◽  
Author(s):  
T M Herndon ◽  
S-S Chen ◽  
N S Saba ◽  
J Valdez ◽  
C Emson ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2867-2867
Author(s):  
M. Fischer ◽  
M. Schmidt ◽  
S. Klingenberg ◽  
C. Eaves ◽  
C. von Kalle4 ◽  
...  

Abstract The multidrug resistance transporter, ABCG2, is expressed in primitive hematopoietic stem cells from a variety of sources. These cells are detected in dual wave-length fluorescent FACS profiles as a “side population” (SP cells) on the basis of their ability to efflux the fluorescent dye, Hoechst 33342. We have previously shown that 2 types of human short term repopulating cells (STRC) can be enumerated by limiting dilution analysis of their efficient ability to regenerate exclusively myeloid cells after 3 weeks (STRC-Ms), or both myeloid and lymphoid cells after 6–12 weeks (STRC-MLs) in NOD/SCID-b2microglobulin-/- (b2m-/-) mice. Previous findings also implicated these STRCs as determinants of the rapidity of early hematologic recovery in patients transplanted with cultured mobilized peripheral blood (mPB) cells. Here we asked whether any human STRCs have an SP phenotype and hence whether the isolation of SP cells would retain the rapid repopulating activity of a clinical transplant. CD3- SP and non-SP cells were isolated by FACS from low-density (LD) mPB cells after Hoechst staining and transplanted at limiting dilutions into 117 sublethally irradiated b2m-/- mice. The numbers and types of human hematopoietic cells present in the bone marrow of these mice were subsequently monitored by FACS analysis of bone marrow cells aspirated serially, 3, 8 and 12 wks post-transplant. A verapamil-sensitive SP population was reproducibly detected in all 5 patients’ samples studied (0.039 ± 0.012% of the CD3- LD cells). The in vivo assays failed to detect either STRC-Ms or STRC-MLs in the SP fraction and all these activities were obtained from the non-SP cells. If even a single recipient of the largest dose of SP cells transplanted had been positive, this would have detected 10% of the STRCs present. Thus, &gt;90% of all STRC-M and STRC-ML in mPB are non-SP cells. However, 4 of 40 mice transplanted with SP mPB cells produced some B-lymphoid cells only starting 12 wks post-transplant. However, this result is difficult to interpret since subjecting the STRC-Ms to the Hoechst 33342 staining and FACS isolation procedure alone eliminated their ability to generate megakaryocytic progeny in vivo, although this did not occur when these cells were just stained for CD34 and then isolated by FACS. In addition, the differentiation behaviour of STRC-MLs was not affected by the Hoechst staining and subsequent FACS isolation procedure. In summary, we demonstrate that purification of SP cells depletes human mPB transplants of STRCs, thereby raising serious concerns about the safety of any clinical use of SP cell-enriched transplants as stem cell support after myeloablation. Our results also suggest that the staining and enrichment procedure for isolating SP human cells may differentially affect the lineage potential of some types of STRCs, including those whose activity may be indispensable for rapid and multi-lineage hematologic recovery.


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