Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Spotlight on IMATINIB as a Model for Signal Transduction Inhibitors

Effects of imatinib on bone marrow engraftment in syngeneic mice

Abstract

Chronic myeloid leukemia (CML) and a subset of acute lymphoblastic leukemias arise from the genetic reciprocal translocation t(9;22), forming the BCR-ABL fusion gene. These lead to the expression of the constitutively active tyrosine kinase BCR-ABL, which is the causative oncogene for these leukemias. Allogeneic bone marrow transplantation (BMT) or stem cell transplantation (SCT) is currently considered the only curative treatment for chronic myeloid leukemia (CML). Recently, the selective tyrosine kinase inhibitor imatinib mesylate (Glivec, formerly STI-571) has been shown to induce durable hematologic and major cytogenetic responses in a high percentage of patients with chronic phase CML. In patients with advanced disease remissions are transient and most patients relapse despite continued imatinib treatment. Some of these patients go on to receive allogeneic BMT or SCT, during which administration of imatinib is usually discontinued as it is believed to interfere with bone marrow engraftment. In this study, we examined the effect of imatinib on hematopoietic engraftment in a syngeneic mouse model. We found that imatinib has no significant influence on hematopoietic recovery in lethally irradiated mice in vivo. Thus, our results suggest that continued administration of imatinib in the course of BMT or SCT may be a feasible therapeutic regimen.

Introduction

Imatinib is a competitive inhibitor at the ATP binding site of BCR-ABL, which plays a central role in the pathophysiology of Ph+ malignancies.1 Durable hematologic (98%) and major cytogenetic responses (31%) were observed in first clinical trials in a high percentage of patients in chronic phase CML treated with imatinib.2,3 In contrast, imatinib-induced hematologic responses in advanced phase CML and Ph+ ALL were not durable in most cases.4,5 While imatinib is still at an early stage of clinical development and standard protocols for the most beneficial treatment have yet to be determined, allogeneic SCT remains the only proven curative therapy for CML.6 Following the promising advances and the growing experience with imatinib, the results of allogeneic SCT for patients with CML or Ph+ ALL might be improved by the use of imatinib. A combination regimen could possibly help to reduce relapse rates ranging between 5 and 35% among allografted recipients,6 as well as to improve the outcome in autologous SCT.7 The use of imatinib with high-dose chemotherapy and stem cell support might also prevent resistance against imatinib itself, which frequently develops in advanced Ph+ leukemias.8,9,10,11,12

Indeed, recently published data indicate that imatinib is able to improve the outcome in patients relapsing after autologous or allogeneic SCT.13,14,15 Here, imatinib treatment was initiated after SCT and only mild to moderate adverse events were reported. So far, there have been no reports about the concomitant use of imatinib in the transplantation setting.

The major critical point in combining imatinib with BMT or SCT is the possible influence of imatinib on bone marrow engraftment. Imatinib is presumed to interfere with normal cellular function, since in addition to the inhibition of BCR-ABL, imatinib shows activity against other tyrosine kinases such as platelet-derived growth factor receptor and c-kit (CD117).16,17 In particular, c-kit has been shown to play a crucial role in the regulation of early hematopoiesis.18,19,20 Thus, imatinib administration during BMT/SCT is discontinued in the few clinical studies published to date, as administration of the tyrosine kinase inhibitor is believed to delay hematopoetic reconstitution.21,22

Using a syngeneic mouse transplantation model we addressed the question whether imatinib has a negative effect on bone marrow engraftment causing delayed hematopoietic reconstitution after BMT in mice.

Materials and methods

Bone marrow harvest

Male donor Balb/C-mice were primed with 3 mg 5-fluorouracil (5-FU) 5 days prior to bone marrow harvest. Bone marrow cells flushed from the tibia and femur were counted, suspended in Hanks’ balanced salt solution (HBSS) and used directly to either reconstitute lethally irradiated syngeneic female recipients or for in vitro assays.

Sorting of HSCs and clonal colony assay

Flow cytometric cell sorting (MoFlo cytometer, Cytomation, CO, USA) was performed after immunostaining of approximately 1 × 106 mononuclear bone marrow cells (BMC) using FITC-conjugated Sca1 (Ly-6A/E) antibody and PE-labeled antibody against c-kit (CD117) (BD-Pharmingen, Heidelberg, Germany). Sorting gates were set to obtain Sca1+ and Sca1 cells within the c-kit+ population.

Freshly separated Sca1+/c-kit+ and Sca1/c-kit+ HSCs were added to 1.2 ml methylcellulose medium (Methocult GF M3434; Stem Cell Technologies, Vancouver, Canada) and plated at a density of 400 cells per plate into 35 mm2 tissue culture dishes in duplicate and incubated at 37°C, 5% CO2. After 9 days of culture, colonies consisting of more than eight cells were scored by standard morphological criteria using an inverted microscope.

Imatinib

Imatinib (Imatinib mesylate, formerly STI-571) was provided by Novartis Pharma, Basel, Switzerland. For in vitro experiments, stock solutions were prepared at 10 mM in distilled water. Preparations for administration to animals were made twice a day at the concentration of 5 mg/ml.

Bone marrow transplantation

All animals were kept in a special caging system (Thoren, PA, USA) providing a specific pathogen-free environment and received acidified water and food ad libitum. All experiments using animals were reviewed and approved by the university supervisory animal care committee.

After lethal irradiation (800 rad total dose) recipient female Balb/C-mice 16 to 20 weeks of age (Harlan, Indianapolis, IN, USA) were transplanted with native mononuclear bone marrow cells (BMC) via tail vein injection. Seven days prior to BMT mice were started on imatinib or placebo, respectively, in order to ensure adequate therapeutic levels of imatinib during BMT. Oral administration of imatinib (at 25 mg/kg twice daily) was performed in a volume of 100 μl sterile water by gavage. After BMT mice were monitored for reconstitution by obtaining blood counts at least every 2 days (Vet abc blood counter; Scil, Viernheim, Germany). After complete hematopoietic reconstitution, engraftment was assessed by secondary transplantation and by flow cytometry analyzing the Sca1 (Ly-6A/E), c-kit (CD117) and Thy1.2 (CD90) surface marker expression of freshly harvested bone marrow cells. Furthermore, we confirmed successful long-term engraftment by secondary transplantation of 1 x 106 BMCs.

Results

Inhibitory effect of imatinib on c-kit+ colony-forming cells in vitro

Previously published results showed an inhibitory effect of imatinib on normal hematopoiesis in vitro.17,23Imatinib is known to possess activity against the platelet-derived growth factor receptor and c-kit (CD117), which is critical in the survival and development of progenitor cells. Therefore, we tried to delineate the influence of imatinib on progenitor cells and long-term reconstitution in vivo.

First, we determined the inhibitory effect of imatinib on hematopoietic progenitor cell growth in vitro using clonal colony assays. We analyzed two separate murine populations with in vivo repopulation capacity both expressing the surface marker c-kit.24,25 Bone marrow cells were fractionated by flow cytometric cell sorting into more primitive Sca1+/c-kit+ stem cells and Sca1/c-kit+ progenitor cells. As shown in Figure 1, both of these populations were sensitive to growth inhibition by imatinib in vitro. Analysis of CFU-growth 9 days after incubation using an inverted microscope showed that already at the concentration of 0.5 μM a reduction in colony formation became evident. Exposure of cells to increasing doses of imatinib (2.0 and 5.0 μM) revealed effective inhibition of CFU growth. Overall, proliferation of the more committed Sca1/c-kit+ cells was less susceptible to inhibition by imatinib as compared to Sca1+/c-kit+ cells (28.1% Sca1/c-kit+ colonies and 9.5% Sca1+/c-kit+ colonies at 5.0 μM imatinib compared to no treatment). The reduction in size (data not shown) as well as colony number underscores the antiproliferative effect of imatinib on hematopoietic progenitor cells in vitro in accordance with earlier studies.

Figure 1
figure1

Methylcellulose assay illustrating the influence of imatinib upon murine hematopoietic stem/progenitor cells in vitro. After flow cytometric sorting of freshly harvested murine BMCs using c-kit-PE and Scal-FITC antibodies, 800 progenitor cells each were cultured in methylcellulose medium (Methocult GF M3434). Different concentrations of imatinib (0.0 μM, 0.5 μM, 2.0 μM or 5.0 μM) were added to evaluate imatinib dependent CFU-growth. Total number of CFUs was determined 9 days after incubation.

Imatinib does not delay engraftment after syngeneic BMT in mice

Next we sought to determine whether the inhibitory effects of imatinib on hematopoietic cells in vitro were also relevant in an in vivo setting. Sixteen lethally irradiated (800 rad total dose) recipient mice of identical age were transplanted with either 1 × 105 or 2.5 × 105 mononuclear bone marrow cells (BMCs) from 5-FU-treated male donor mice. Administration of imatinib or placebo was begun 7 days prior to transplantation in order to ensure adequate in vivo blood levels of imatinib in the recipient mice. Our imatinib treatment regimen, in comparison to doses of 300–1000 mg/day (3–15 mg/kg/day) given to patients in clinical trials, consisted of 25 mg/kg every 12 h applied via gavage. The dose of imatinib was chosen according to previous papers and our experience in investigating molecular mechanisms of imatinib resistance using a murine retroviral CML transduction and transplantation model.17,26,27 Twice daily administration of imatinib in this animal model is necessary since the half-life of imatinib in mice is shorter than in humans.26 CML mice with elevated blood counts responded to this dose of imatinib after 3–5 days and rapidly normalized white blood cell counts (data not shown).

Interestingly, within both groups no significantly delayed hematopoietic short-term reconstitution was observed when comparing eight mice receiving 1.0 mg imatinib (50 mg/kg/day) with eight control mice (Figure 2). All animals regained normal peripheral blood cell counts after 14 to 16 days (platelets, erythrocytes) and 16 to 18 days (leukocytes). Recovery kinetics showed that the time of reconstitution depended mainly on the number of transplanted cells, which is in line with previous studies from other groups28 (Figure 2, compare upper and lower graphs). On average, transplantation of 1 × 105 compared to 2.5 × 105 mononuclear BMCs led to a 2 day delayed reconstitution.

Figure 2
figure2

Influence of imatinib treatment on hematopoietic recovery in 16 Balb/C-mice syngeneically transplanted with two different doses of native mononuclear BMCs (MNCs). Donor mice were given 3 mg 5-FU 5 days before bone marrow harvest and transplantation. After lethal irradiation (800 rad) recipient mice were injected with either 100 000 cells and treated with imatinib () or given H2O () (upper panel) or were injected with 250 000 cells and treated with imatinib (▪) or given H2O (□) (lower panel). Administration of imatinib (H2O respectively) was started 7 days prior to transplantation.

Long-term engraftment is not affected by administration of imatinib

Analysis of blood counts up to 43 days post transplant showed normal cell numbers in all transplanted mice, indicating that sufficient long-term engraftment had been achieved. We next performed secondary transplantation of mononuclear BMCs from primary imatinib treated or control mice to confirm successful long-term engraftment and to investigate potential cumulative effects of imatinib treatment on stem cell survival (Figure 3). For the reconstitution of four female lethally irradiated syngeneic Balb/C-mice approximately 1 × 106 mononuclear BMCs from non-5-FU-treated primary animals were used. Again, the secondary transplanted Balb/C-mice showed nearly identical hematopoietic recovery independent of prior imatinib administration. In addition, we did not observe any difference in the proportion of HSC populations of four primary recipients as assessed by flow cytometry analyzing the Sca1 (Ly-6A/E), c-kit (CD117) and Thy1.2 (CD90) surface marker expression of freshly harvested BMCs (data not shown). Thus, neither short-term nor long-term hematopoietic reconstitution after syngeneic BMT was significantly influenced by the concomitant administration of imatinib.

Figure 3
figure3

Hematopoietic recovery of secondary transplanted Balb/C-mice. After lethal irradiation mice were transplanted with 1 × 106 mononuclear BMCs from either one primary imatinib treated mouse (squares) or one H2O-control mouse (triangles). Four recipient mice were again treated with imatinib (solid symbols) or given H2O (open symbols) starting 7 days prior to transplantation. Illustrated blood curves demonstate successful long-term engraftment independent from imatinib or H2O administration.

Discussion

Although allogeneic SCT is considered the only curative approach for Ph+ leukemias, a significant fraction of these patients encounters relapse. In this situation treatment with imatinib has been shown to reinduce hematologic remissions in few published cases until now.13,14,15 New treatment approaches using imatinib concomitant with autologous or allogeneic transplantation may lead to improved outcome.

We conducted this study to determine whether hematopoietic engraftment is impaired by continued administration of imatinib during BMT. First, we chose a methylcellulose-based clonal colony assay to investigate possible inhibitory effects of imatinib on hematopoietic stem/progenitor cells as described earlier.17 Our results clearly showed that sorted c-kit+ hematopoietic progenitor cells are growth inhibited by imatinib in vitro. The rate of colony formation compared to control incubated cells dramatically decreased to 9.5% and 28.1%, respectively, at 5.0 μM imatinib. One explanation is that inhibition of the c-kit and platelet-derived growth factor receptor, two molecules also known to be effectively targeted by imatinib, may play an important role in the reduction of proliferation and differentiation in this assay. This assumption is supported by the fact that growth inhibition by imatinib in c-kit sorted cells as used in this paper was more prominent by far than in the report by Druker and colleagues17 in which unsorted BMCs were used. Although this in vitro assay does not adequately reproduce conditions in vivo, these observations seemed to argue for a possible imatinib-dependent delay of hematopoietic reconstitution. Thus, we examined the influence of imatinib on bone marrow engraftment in a murine transplantation model. Interestingly, no significant difference in complete hematopoietic reconstitution and engraftment was detectable when comparing eight control mice with eight mice treated with imatinib starting at day −7. In line with previously published data, regeneration of normal blood counts mainly depended on the number of transplanted BMCs,28 and the administration of 25 mg/kg imatinib every 12 h had no significant effect.

Both short- and long-term engraftment were demonstrated by repeated blood counts at least every other day over a period of at least 42 days and by flow cytometric analysis of the hematopoietic cell population after successful engraftment. In addition, secondary transplantations were performed from four primary transplanted Balb/C-mice pretreated with imatinib. Again, blood cell counts and flow cytometric analysis indicated normal hematopoietic reconstitution and successful engraftment. The serially transplanted mice regained normal blood cell counts after the same period of time. Together these data indicate that in transplanted mice engraftment and proliferation of hematopoietic stem cells was not compromised by imatinib.

Several mechanisms may be responsible for the divergent effects induced by imatinib in vitro and in vivo. The colony assays were performed using a methylcellulose culture medium containing a limited number of growth factors and cytokines and do not adequately mimick conditions in vivo. Furthermore, colony assays rather assess the proliferative potential of more committed progenitor cells and do not reflect stem cell function. It has recently been described that imatinib seems to inhibit committed Ph+ progenitors from CML patients, but also from normal BM, more strongly than primitive progenitor cells.29 Thus, the synergistic effects of hematopoietic growth factors, cytokines and the bone marrow microenvironment as well as a reduced susceptibility of early hematopoetic progenitor cells may explain the differences between the in vitro and in vivo data.

In summary, although conditions in murine BMT differ from human transplantation, our results may indicate that imatinib also does not have a negative effect on stem cell engraftment in humans. Thus, the application of imatinib in the course of allogeneic BMT or SCT could be a therapeutic regimen without suppressive influence on engraftment and hematopoietic regeneration. Further studies will be neccessary to establish whether these results can be confirmed in patients.

References

  1. 1

    Faderl S, Talpaz M, Estrov Z, O'Brien S, Kurzrock R, Kantarjian HM . The biology of chronic myeloid leukemia N Engl J Med 1999 341: 164–172

    CAS  Article  Google Scholar 

  2. 2

    Druker BJ, Talpaz M, Resta DJ, Peng B, Buchdunger E, Ford JM, Lydon NB, Kantarjian H, Capdeville R, Ohno-Jones S, Sawyers CL . Efficacy and safety of a specific inhibitor of the BCR-ABL tyrosine kinase in chronic myeloid leukemia N Engl J Med 2001 344: 1031–1037

    CAS  Article  Google Scholar 

  3. 3

    Kantarjian H, Sawyers C, Hochhaus A, Guilhot F, Schiffer C, Gambacorti-Passerini C, Niederwieser D, Resta D, Capdeville R, Zoellner U, Talpaz M, Druker B . Hematologic and cytogenetic responses to imatinib mesylate in chronic myelogenous leukemia N Engl J Med 2002 346: 645–652

    CAS  Article  Google Scholar 

  4. 4

    Druker BJ, Sawyers CL, Kantarjian H, Resta DJ, Reese SF, Ford JM, Capdeville R, Talpaz M . Activity of a specific inhibitor of the BCR-ABL tyrosine kinase in the blast crisis of chronic myeloid leukemia and acute lymphoblastic leukemia with the Philadelphia chromosome N Engl J Med 2001 344: 1038–1042

    CAS  Article  Google Scholar 

  5. 5

    Talpaz M, Silver RT, Druker BJ, Goldman JM, Gambacorti-Passerini C, Guilhot F, Schiffer CA, Fischer T, Deininger MW, Lennard AL, Hochhaus A, Ottmann OG, Gratwohl A, Baccarani M, Stone R, Tura S, Mahon FX, Fernandes-Reese S, Gathmann I, Capdeville R, Kantarjian HM, Sawyers CL . Imatinib induces durable hematologic and cytogenetic responses in patients with accelerated phase chronic myeloid leukemia: results of a phase 2 study Blood 2002 99: 1928–1937

    CAS  Article  Google Scholar 

  6. 6

    Goldman J . Implications of imatinib mesylate for hematopoietic stem cell transplantation Semin Hematol 2001 38: 28–34

    CAS  Article  Google Scholar 

  7. 7

    Carella AM, Lerma E, Corsetti MT, Dejana A, Basta P, Vassallo F, Abate M, Soracco M, Benvenuto F, Figari O, Podesta M, Piaggio G, Ferrara R, Sessarego M, Parodi C, Pizzuti M, Rubagotti A, Occhini D, Frassoni F . Autografting with Philadelphia chromosome-negative mobilized hematopoietic progenitor cells in chronic myelogenous leukemia Blood 1999 93: 1534–1539

    CAS  PubMed  PubMed Central  Google Scholar 

  8. 8

    von Bubnoff N, Schneller F, Peschel C, Duyster J . BCR-ABL gene mutations in relation to clinical resistance of Philadelphia-chromosome-positive leukaemia to STI571: a prospective study Lancet 2002 359: 487–491

    CAS  Article  Google Scholar 

  9. 9

    Gorre ME, Mohammed M, Ellwood K, Hsu N, Paquette R, Rao PN, Sawyers CL . Clinical resistance to STI-571 cancer therapy caused by BCR-ABL gene mutation or amplification Science 2001 293: 876–880

    CAS  Article  Google Scholar 

  10. 10

    Hochhaus A, Kreil S, Corbin A, La Rosee P, Lahaye T, Berger U, Cross NC, Linkesch W, Druker BJ, Hehlmann R, Gambacorti-Passerini C, Corneo G, D'Incalci M . Roots of clinical resistance to STI-571 cancer therapy Science 2001 293: 2163a

    Article  Google Scholar 

  11. 11

    Branford S, Rudzki Z, Walsh S, Grigg A, Arthur C, Taylor K, Herrmann R, Lynch KP, Hughes TP . High frequency of point mutations clustered within the adenosine triphosphate-binding region of BCR/ABL in patients with chronic myeloid leukemia or Ph-positive acute lymphoblastic leukemia who develop imatinib (STI571) resistance Blood 2002 99: 3472–3475

    CAS  Article  Google Scholar 

  12. 12

    Hofmann WK, Jones LC, Lemp NA, de Vos S, Gschaidmeier H, Hoelzer D, Ottmann OG, Koeffler HP . Ph(+) acute lymphoblastic leukemia resistant to the tyrosine kinase inhibitor STI571 has a unique BCR-ABL gene mutation Blood 2002 99: 1860–1862

    Article  Google Scholar 

  13. 13

    Fischer T . Results up to now of administration of STI-571 (Glivec) in recurrence after allogenic and autologous stem cell transplantation in chronic myeloid leukemia Med Klin 2002 97 (Suppl. 1): 22–27

    Google Scholar 

  14. 14

    Wassmann B, Klein SA, Scheuring U, Pfeifer H, Martin H, Gschaidmeier H, Hoelzer D, Ottmann OG . Hematologic and cytogenetic remission by STI571 (Glivec) in a patient relapsing with accelerated phase CML after second allogeneic stem cell transplantation Bone Marrow Transplant 2001 28: 721–724

    CAS  Article  Google Scholar 

  15. 15

    Olavarria E, Craddock C, Dazzi F, Marin D, Marktel S, Apperley JF, Goldman JM . Imatinib mesylate (STI571) in the treatment of relapse of chronic myeloid leukemia after allogeneic stem cell transplantation Blood 2002 99: 3861–3862

    CAS  Article  Google Scholar 

  16. 16

    Buchdunger E, Zimmermann J, Mett H, Meyer T, Muller M, Druker BJ, Lydon NB . Inhibition of the Abl protein-tyrosine kinase in vitro and in vivo by a 2-phenylaminopyrimidine derivative Cancer Res 1996 56: 100–104

    CAS  Google Scholar 

  17. 17

    Druker BJ, Tamura S, Buchdunger E, Ohno S, Segal GM, Fanning S, Zimmermann J, Lydon NB . Effects of a selective inhibitor of the Abl tyrosine kinase on the growth of Bcr-Abl positive cells Nat Med 1996 2: 561–566

    CAS  Article  Google Scholar 

  18. 18

    Anderson DM, Lyman SD, Baird A, Wignall JM, Eisenman J, Rauch C, March CJ, Boswell HS, Gimpel SD, Cosman D, Williams DE . Molecular cloning of mast cell growth factor, a hematopoietin that is active in both membrane bound and soluble forms Cell 1990 63: 235–243

    CAS  Article  Google Scholar 

  19. 19

    Nocka K, Majumder S, Chabot B, Ray P, Cervone M, Bernstein A, Besmer P . Expression of c-kit gene products in known cellular targets of W mutations in normal and W mutant mice – evidence for an impaired c-kit kinase in mutant mice Genes Dev 1989 3: 816–826

    CAS  Article  Google Scholar 

  20. 20

    Nocka K, Tan JC, Chiu E, Chu TY, Ray P, Traktman P, Besmer P . Molecular bases of dominant negative and loss of function mutations at the murine c-kit/white spotting locus: W37, Wv, W41 and W EMBO J 1990 9: 1805–1813

    CAS  Article  Google Scholar 

  21. 21

    Deininger MWN, Schleuning M, Olavarria E, Fischer T, Nagler A, Sayer H, Boque C, Volin L, Piotelli G, Russel N, Wandt H, Schanz U, Greinix H, Sponk L, Verdonck L, Lennard A, Wimmer M, Hegenbart U, Lange T, Niederwieser D . Safety and efficacy of glivec prior to allografting for CML and Ph-positive ALL: European experience Bone Marrow Transplant 2002 29 (Suppl. 2): Abstr. 183

  22. 22

    Wassmann B, Pfeifer H, Scheuring U, Atta J, Martin H, Brck P, Gschaidmeier H, Hoelzer D, Ottmann OG . Salvage therapy with STI571 (glivec) prior to allogeneic stem cell transplantation (Allo Sct) in relapsed or refractory Philadelphia-chromosome positive acute lymphoblastic leukemia (Ph+All) Bone Marrow Transplant 2002 29 (Suppl. 2): Abstr. P405

  23. 23

    Holtz MS, Slovak ML, Zhang F, Sawyers CL, Forman SJ, Bhatia R . Imatinib mesylate (STI571) inhibits growth of primitive malignant progenitors in chronic myelogenous leukemia through reversal of abnormally increased proliferation Blood 2002 99: 3792–3800

    CAS  Article  Google Scholar 

  24. 24

    Spangrude GJ, Heimfeld S, Weissman IL . Purification and characterization of mouse hematopoietic stem cells Science 1988 241: 58–62

    CAS  Article  Google Scholar 

  25. 25

    Li CL, Johnson GR . Murine hematopoietic stem and progenitor cells: I. Enrichment and biologic characterization Blood 1995 85: 1472–1479

    CAS  Google Scholar 

  26. 26

    Gambacorti-Passerini C, Barni R, le Coutre P, Zucchetti M, Cabrita G, Cleris L, Rossi F, Gianazza E, Brueggen J, Cozens R, Pioltelli P, Pogliani E, Corneo G, Formelli F, D'Incalci M . Role of alpha1 acid glycoprotein in the in vivo resistance of human BCR- ABL(+) leukemic cells to the abl inhibitor STI571 J Natl Cancer Inst 2000 92: 1641–1650

    CAS  Article  Google Scholar 

  27. 27

    Wolff NC, Ilaria RL Jr . Establishment of a murine model for therapy-treated chronic myelogenous leukemia using the tyrosine kinase inhibitor STI571 Blood 2001 98: 2808–2816

    CAS  Article  Google Scholar 

  28. 28

    Weissman IL . Translating stem and progenitor cell biology to the clinic: barriers and opportunities Science 2000 287: 1442–1446

    CAS  Article  Google Scholar 

  29. 29

    Graham SM, Jorgensen HG, Allan E, Pearson C, Alcorn MJ, Richmond L, Holyoake TL . Primitive, quiescent, Philadelphia-positive stem cells from patients with chronic myeloid leukemia are insensitive to STI571 in vitro Blood 2002 99: 319–325

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was supported by a grant to JD and CP from the BMBF, German national genome project No 01-GS-0105 and 01-GS-015, by SFB grant No 456 to JD, KG and CP and by a grant from the Mildred-Scheel Stiftung to JD. CM is supported by a fellowship from the Deutsche Jose Carreras Leukämie Stiftung (DJCLS 2001/NAT-2). We thank H Gschaidmeier (Novartis Pharma, Nürnberg, Germany) and E Buchdunger (Novartis Pharma, Basel, Switzerland) for the generous gift of imatinib.

Author information

Affiliations

Authors

Corresponding author

Correspondence to J Duyster.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hoepfl, J., Miething, C., Grundler, R. et al. Effects of imatinib on bone marrow engraftment in syngeneic mice. Leukemia 16, 1584–1588 (2002). https://doi.org/10.1038/sj.leu.2402679

Download citation

Keywords

  • imatinib
  • Glivec
  • Gleevec
  • STI-571
  • CML
  • bone marrow transplantation
  • stem cell transplantation

Further reading

Search

Quick links