The Bone Marrow Niche of Patients with Acute Lymphoblastic Leukemia Produces No Increased Asparagine Levels In Vivo That May Lead to Clinical Asparaginase Resistance

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1505-1505
Author(s):  
Wing H. Tong ◽  
Rob Pieters ◽  
Wim C.J. Hop ◽  
Claudia Lanvers-Kaminsky ◽  
Joachim Boos ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aspartic Acid ◽  
Peripheral Blood ◽  
Lymphoblastic Leukemia ◽  
Mesenchymal Cells ◽  
Leukemic Cells ◽  
Significant Difference ◽  
Trough Levels

Abstract Abstract 1505 Asparaginase is an essential component of combination chemotherapy of acute lymphoblastic leukemia (ALL). Asparaginase breaks down asparagine into aspartic acid and ammonia. Because asparagine is necessary for protein synthesis, its depletion leads to cell death. Recently, it has been suggested that mesenchymal cells in the bone marrow may produce asparagine and form ‘protective niches’ for leukemic cells. In vitro, this led to high levels of asparagine and asparaginase resistance of the ALL cells (Iwamoto et al. (J Clin Invest. 2007)). However, it is unknown if this holds true for the clinical in vivo situation. The aim of our study is to analyse whether mesenchymal cells or other cells in the bone marrow indeed produce significant amounts of asparagine in vivo that may lead to clinical asparaginase resistance. Ten de novo ALL patients were enrolled in this study. All children received induction chemotherapy according to protocol 1-A and 1-B of the Dutch Childhood Oncology Group (DCOG) ALL-10 protocol. Asparaginase levels and amino acid levels (asparagine, aspartic acid, glutamine and glutamic acid) were measured in bone marrow (BM) and peripheral blood at diagnosis (day 1), days 15, 33 and 79. On days that asparaginase was administered (days 15 and 33) it was ensured that study material was obtained before the E-coli L-asparaginase infusions. Changes over time of asparaginase trough levels in BM and peripheral blood were evaluated using Mixed models ANOVA. The amino acids levels in 0.5 ml BM, 3 ml BM and peripheral blood at days 15 and 33 were also compared using Mixed models ANOVA. All these analyses were done after log transformation of measured values to get approximate normal distributions. A two-sided p-value < 0.05 was considered statistically significant. The asparaginase levels were all below detection limit (< 5 IU/L) in BM and peripheral blood at days 1 and 79. In both compartments, the median asparaginase trough levels were not significantly different at days 15 and 33. At diagnosis, no significant difference in asparagine level between 3 ml BM and peripheral blood was found (median: 44.5 μM (range 20.6–59.6 μM) and 43.9 μM (range 18.4 –58.5 μM), respectively). However, the median level of aspartic acid at diagnosis in 3 ml BM (19.2 μM; range 6.2–52.6 μM) was significantly higher as compared to median level of peripheral blood (5.7 μM; range 2.4–10.1 μM) (p=0.002). The aspartic acid levels were also higher in BM compared to peripheral blood at days 15 and 33 (both p=0.001) and at day 79 (p=0.002). Aspartic acid levels were significantly higher in 0.5 ml versus 3 ml BM (p=0.001) and this difference was also found when comparing 0.5 ml BM versus peripheral blood (p<0.001) suggesting dilution with peripheral blood when taking higher volumes of ‘bone marrow’. Asparagine levels were all below the lower limit of quantification (LLQ < 0.2 μM) in both BM and blood during asparaginase treatment at days 15 and 33. At day 79, no significant difference in asparagine levels between BM (37.7 μM; range 33.4–50.3 μM) and peripheral blood (38.9 μM; range 25.7 –51.3 μM) was seen. During the time course of asparaginase infusions, the glutamine and glutamic acid levels did not change significantly. In conclusion, we demonstrate higher aspartic acid levels in bone marrow compared to peripheral blood. The higher aspartic acid levels are detected at diagnosis, during asparaginase therapy at days 15 and 33, and also at day 79 at complete remission, showing that these do not originate from leukemic cells nor from asparagine breakdown by asparaginase but from cells in the microenvironment of the bone marrow. However, there is no increased asparagine synthesis in vivo in the bone marrow of ALL patients. Therefore, increased asparagine synthesis by mesenchymal cells may be of relevance for resistance to asparaginase of leukemic cells in vitro but not in vivo. Disclosures: No relevant conflicts of interest to declare.

Identification of Non-Cardiotoxic hERG1 Blockers to Overcome Chemoresistance in Acute Lymphoblastic Leukemias

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1506-1506
Author(s):  
Marika Masselli ◽  
Serena Pillozzi ◽  
Massimo D'Amico ◽  
Luca Gasparoli ◽  
Olivia Crociani ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mouse Model ◽  
Map Kinases ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Significant Proportion ◽  
Leukemic Cells ◽  
K Channel

Abstract Abstract 1506 Although cure rates for children with acute lymphoblastic leukemia (ALL), the most common pediatric malignancy, have markedly improved over the last two decades, chemotherapy resistance remains a major obstacle to successful treatment in a significant proportion of patients (Pui CH et al. N Engl J Med., 360:2730–2741, 2009). Increasing evidence indicates that bone marrow mesenchymal cells (MSCs) contribute to generate drug resistance in leukemic cells (Konopleva M et al., Leukemia, 16:1713–1724, 2002). We contributed to this topic, describing a novel mechanism through which MSCs protect leukemic cells from chemotherapy (Pillozzi S. et al., Blood, 117:902–914, 2011.). This protection depends on the formation of a macromolecular membrane complex, on the plasma membrane of leukemic cells, the major players being i) the human ether-a-gò-gò-related gene 1 (hERG1) K+ channel, ii) the β1integrin subunit and iii) the SDF-1α receptor CXCR4. In leukemic blasts, the formation of this protein complex activates both the ERK 1/2 MAP kinases and the PI3K/Akt signalling pathways triggering antiapoptotic effects. hERG1 exerts a pivotal role in the complex, as clearly indicated by the effect of hERG1 inhibitors to abrogate MSCs protection against chemotherapeutic drugs. Indeed, E4031, a class III antiarrhythmic that specifically blocks hERG1, enhances the cytotoxicity of drugs commonly used to treat leukemia, both in vitro and in vivo. The latter was tested in a human ALL mouse model, consisting of NOD/SCID mice injected with REH cells, which are relatively resistant to corticosteroids. Mice were treated for 2 weeks with dexamethasone, E4031, or both. Treatment with dexamethasone and E4031 in combination nearly abolished bone marrow engraftment while producing marked apoptosis, and strongly reducing the proportion of leukemic cells in peripheral blood and leukemia infiltration of extramedullary sites. These effects were significantly superior to those obtained by treatment with either dexamethasone alone or E4031 alone. This model corroborated the idea that hERG1 blockers significantly increase the rate of leukemic cell apoptosis in bone marrow and reduced leukemic infiltration of peripheral organs. From a therapeutic viewpoint, to develop a pharmacological strategy based on hERG1 targeting we must consider to circumvent the side effects exerted by hERG1 blockers. Indeed, hERG1 blockers are known to retard the cardiac repolarization, thus lengthening the electrocardiographic QT interval, an effect that in some cases leads to life threatening ventricular arrhythmias (torsades de points). On the whole, it is mandatory to design and test non-cardiotoxic hERG1 blockers as a new strategy to overcome chemoresistance in ALL. On these bases, we tested compounds with potent anti-hERG1 effects, besides E4031, but devoid of cardiotoxicity (e.g. non-torsadogenic hERG1 blockers). Such compounds comprise erythromycin, sertindole and CD160130 (a newly developed drug by BlackSwanPharma GmbH, Leipzig, Germany). We found that such compounds exert a strong anti-leukemic activity both in vitro and in vivo, in the ALL mouse model described above. This is the first study describing the chemotherapeutic effects of non-torsadogenic hERG1 blockers in mouse models of human ALL. This work was supported by grants from the Associazione Genitori contro le Leucemie e Tumori Infantili Noi per Voi, Associazione Italiana per la Ricerca sul Cancro (AIRC) and Istituto Toscano Tumori. Disclosures: No relevant conflicts of interest to declare.

CXCR4 Antagonists Mobilize Acute Lymphoblastic Leukemia Cells into the Peripheral Blood and Inhibit Engraftment in Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4592-4592
Author(s):  
Julius Juarez ◽  
John Hewson ◽  
Adam Cisterne ◽  
Rana Baraz ◽  
Kenneth F. Bradstock ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Cell Count ◽  
Peripheral Blood ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Cxcr4 Antagonists

Abstract The role of CXCL12 in the growth of B cell progenitor acute lymphoblastic leukemia (ALL) and the homing of these cells to the bone marrow has been well established. However the effect of modulating CXCL12/CXCR4 interactions on the growth of ALL cells in vivo has not been examined. In this study we used specific peptide and small molecule antagonists of CXCR4 to examine the importance of CXCL12/CXCR4 interactions in the development of leukemia in an in-vivo murine model of ALL. CXCR4 antagonists induced mobilization of human and murine B cell progenitor ALL cells into the peripheral blood, with a 3.8±1.9 and 6.5±3.3 fold increase in leukemic cells/ml one hour after administration of the antagonist respectively, similar to that observed for normal progenitors. Daily administration of AMD3100 commencing the day following the injection of cells and continuing for 21 days resulted in a mean reduction in peripheral blood white cell count of 50±12% and the leukemic cell count of 63±4%. There was also a significant reduction in both the total cells in the spleen of 58±1% and the leukemic cell number in this organ of 75±11%. A significant reduction in leukemic cell numbers in the bone marrow was observed in one (44% reduction) case. There was reduced infiltration of other organs including kidney, liver and skeletal muscle. This study demonstrates that disrupting the CXCL12/CXCR4 axis in B cell progenitor ALL reduces the tumor burden. Whether this is due to direct inhibitory effects on proliferation and survival, or results from disruption of the leukemic cell interactions within the bone marrow remains to be determined.

Unrelated Allogeneic Stem Cell Transplantation with Myeloablative Conditioning in Adults with Acute Lymphoblastic Leukemia in Remission: Peripheral Blood or Bone Marrow?.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 174-174 ◽  
Author(s):  
Nadezda Basara ◽  
Myriam Labopin ◽  
Tapani Ruutu ◽  
Axel Zander ◽  
Oliver Ottmann ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Peripheral Blood ◽  
Lymphoblastic Leukemia ◽  
Chronic Gvhd ◽  
Peripheral Blood Stem Cells ◽  
Significant Difference ◽  
B Lineage ◽  
Group B

Abstract With the objective to compare outcomes of peripheral blood stem cells (PBSC) and bone marrow (BM) in patients with ALL in remission, we have studied 388 adults with ALL given an unrelated BMT and 337 PBSCT reported to EBMT from 1998 to 2004. The donors were HLA identical (HLA-A and -B low resolution and HLA-DRB1 allelic typing). Median age was 27 years for BM (range 16–63, male 60%) and 30 years for PBSC (range 16–63, male 62%), respectively. Fifty nine and 68% of patients were transplanted in first complete remission (CR1) in the BM and PBSC groups. Female donor to male recipient constellation was 18% in the BM and 15% in the PBSC group. Total Body Irradiation (TBI)-based preparative regimens were given in 85% and 88% of patients in the BM and PBSC group respectively. GvHD-prophylaxis consisted of cyclosporine A (CsA) (6% and 4%), CsA and methotrexate (77% and 58%) or in vivo T-cell depletion (17% and 38% in BM and PBSC group). With the median follow-up of 19 and 13 months, the incidence of GvHD grade II–IV was 37% in the BM group and 39% in the PBSC group (p=0.39). Probabilities of LFS, NRM and relapse were calculated using the Kaplan-Meier estimate. LFS was 45+/−3% vs 36+/−3% (p=0.03) nonrelapse related mortality (NRM) was 30+/−3% and 34+/−4 (p=0.39) while incidence of relapse (RI) was 24+/−4% and 30+/−5% (p=0.13), in the BM and PBSC groups respectively. Three years LFS for the patients transplanted in CR1 was 48% (BM) and 42% (PBSC, p=0.48). In a multivariate analysis adjusting for differences in patients with CR1 in both groups showed not statistically difference for RI, NRM and LFS. However, 3-years LFS for patients transplanted in CR2 was significantly higher in the BM (n=159) compared to the PBSC group (n=106) (40% and 27%, p&lt;0.04). The RI was significantly lower in BM compared to PBSC (33% vs 54%, p&lt;0.01) without there being a detectable difference in NRM at 3 years (40% vs 40%, p= 0.59). This finding led us to look in more details CR2 group of ALL patients. There was no statistically difference between patients receiving BM or PBSC regarding the incidence of Ph’+ or t(4;11) (20% vs 37% in BM and PBSC group), B-lineage (80% vs 76%, respectively) and T-lineage ALL (20% vs 24%, respectively), but patients were older in the PBSC group at the time of transplant (24y vs 27y, p= 0.02) and they received more in vivo T-cell depleted transplants by using antithymocyte globulin (p=0.02). The interval from diagnosis to transplant was longer in BM group (977d vs 687 d in BM and PBSC group, p=0.02). Three years LFS with an interval from diagnosis to Tx &gt; 30 months was not different in BM and PBSC group (48% vs 42%, p=0.65). However, there was a significant difference in LFS in BM group (32%) in comparison to PBSC group (17%) if an interval from diagnosis to Tx &lt;30 mo (p=0.001). The incidence of chronic GvHD in adult ALL in CR2 was 53% and 40% in PBSC and BM, respectively (p=0.09). After statistical adjustments for differences between the two groups, the interval from diagnosis to Tx &lt;30 mo was a risk factor for LFS. In addition, TBI-based conditioning and the interval from diagnosis to Tx &lt;30 mo were risk factors for RI. In conclusion, UD-SCT with either BM or PBSC as a graft source is an effective treatment for adult ALL patients in CR1 and CR2 when the interval between diagnosis and transplant is superior to 30 months. In patients transplanted in CR2 with an interval from diagnosis to Tx&lt;30 months outcomes are worse independent of the cell source used.

A Novel Inhibitor of Mutant IDH1 Induces Differentiation in Vivo and Prolongs Survival in a Mouse Model of Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3598-3598 ◽  
Author(s):  
Anuhar Chaturvedi ◽  
Michelle Maria Araujo Cruz ◽  
Ramya Goparaju ◽  
Nidhi Jyotsana ◽  
Heike Baehre ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mouse Model ◽  
Medical School ◽  
Peripheral Blood ◽  
Bone Marrow Cells ◽  
Leukemic Cells ◽  
Median Latency ◽  
Mutant Idh1

Abstract Mutations in the metabolic enzymes isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) are frequently found in patients with glioma, acute myeloid leukemia (AML), melanoma, thyroid cancer, cholangiocellular carcinoma and chondrosarcoma. Mutant IDH produces R-2-hydroxyglutarate (R2HG), which induces histone- and DNA-hypermethylation through inhibition of epigenetic regulators, thus linking metabolism to tumorigenesis. We recently established an in vivo mouse model and investigated the function of mutant IDH1. By computational drug screening, we identified an inhibitor of mutant IDH1 (HMS-101), which inhibits mutant IDH1 cell proliferation, decreases R2HG levels in vitro, and efficiently blocks colony formation of AML cells from IDH1 mutated patients but not of normal CD34+ bone marrow cells. In the present study we investigated the effect of the inhibitor in our IDH1/HoxA9-induced mouse model of leukemia in vivo. To identify the maximally tolerated dose of HMS-101, we treated normal C57BL/6 mice with variable doses of HMS-101 for 9 days and measured the serum concentration. Mice receiving 0.5 mg and 1mg intraperitoneally once a day tolerated the drug well with mean plasma concentrations of 0.1 to 0.3 µM. To evaluate the effect of HMS-101 in the IDH1 mouse model, we transduced IDH1 R132C in HoxA9-immortalized murine bone marrow cells. Sorted transgene positive cells were then transplanted into lethally irradiated mice. After 5 days of transplantation, mice were treated with HMS-101 intraperitoneally for 5 days/week. The R/S-2HG ratio in serum was reduced 3-fold in HMS-101 treated mice after 8 weeks of treatment compared to control treated mice. HMS-101 or PBS treated mice had similar levels of transduced leukemic cells in peripheral blood at 2 and 6 weeks after transplantation. However, from week 6 to week 15 leukemic cells in peripheral blood decreased from 76% to 58, 63% to 29%, 67% to 7%, and 74% to 38% in 4/6 mice treated with HMS-101. In one mouse the percentage of leukemic cells was constant, and in one mouse it increased from week 6 to week 15 after transplantation. Leukemic cells increased constantly in peripheral blood until death in control treated mice. While the control cohort developed severe leukocytosis, anemia and thrombocytopenia around 8 to 10 weeks post transplantation, mice treated with HMS-101 still had normal WBC, RBC and platelet counts at 15 weeks after transplantation. Moreover, the HMS-101 treated mice had significantly more differentiated Gr1+CD11b+ cells in peripheral blood than control mice at 6 weeks and 15 weeks after transplantation and at death (P=.01). Morphologic evaluation of blood cells at 15 weeks or death from HMS-101 treated mice revealed a high proportion of mature neutrophils that were GFP positive and thus derived from IDH1 transduced cells, whereas control treated mice had monocytic morphology with a high proportion of immature cells. Importantly, HMS-101 treated mice survived significantly longer with a median latency of 87 days (range 80-118), whereas PBS-treated mice died with a median latency of 66 days (range 64-69) after transplantation (P<.001). Of note, HMS-101 was found to be specific for mutant IDH1, as mutant IDH2 cells were not preferentially inhibited over IDH2 wildtype cells in vitro. This data demonstrates that HMS-101 specifically inhibits R2HG-production of mutant IDH1 in vivo, inhibits proliferation, induces differentiation in leukemic cells, and thus prolongs survival of IDH1mutant leukemic mice. Therefore, HMS-101 - a novel inhibitor of mutant IDH1 - shows promising activity in vivo and warrants further development towards clinical use in IDH1 mutated patients. Disclosures Chaturvedi: Hannover Medical School: Patents & Royalties. Preller:Hannover Medical School: Patents & Royalties. Heuser:Hannover Medical School: Patents & Royalties.

Characteristics of Cell Proliferation in Children's Lymphoblastic Leukemia

1968 ◽  
Vol 54 (2) ◽  
pp. 147-160 ◽  
Author(s):  
Alessandro Pileri ◽  
Renzo Pietro Tarocco ◽  
Felice Gavosto ◽  
Alberto Ponzone ◽  
Paolo Nicola
Keyword(s):  
Bone Marrow ◽  
Peripheral Blood ◽  
Proliferative Activity ◽  
Tritiated Thymidine ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cells ◽  
Cell Diameter ◽  
Acute Leukemias ◽  
Peripheral Cells

The proliferative activity of the bone marrow and peripheral cells of acute infant lymphoblastic leukemia was evaluated by « in vitro » incorporation of thymidine-H3. The proliferative activity of leukemic lymphoblasts proved roughly similar to that already observed in hemocito-myeloblastic acute leukemias of adults. Within the lymphoblastic population, incorporation of tritiated thymidine was distributed very heterogeneously and there was no labelling of the smaller blasts. In the larger blasts, the labelling index increased progressively with the increase in cell diameter. The acute leukemia population can thus be divided into two classes: proliferating and non-proliferating. A study of the proliferative activity of lymphoblasts, contemporaneously in bone marrow and peripheral cells, suggested a division of cases into two groups. In one proliferative activity in the marrow was greater than in the peripheral blood; in the other it was equal to or less than in the peripheral blood. The second group was made up of cases whose clinical features presented a much more marked hepato-splenomegaly and high peripheral leucocytosis. A more detailed study of proliferative activity considering various classes of blasts within the same population showed that, in the first group of patients, the highest percentage of large blast cells is found at bone marrow level, while in the second the percentage of large blasts in the marrow is equal to or less than that observed in the peripheral blood. It was also shown that total proliferative activity is correlated to the percentage of large blasts. On the basis of these findings, one may admit that in first group forms the leukemia cells are generated prevalently in the bone marrow, while in second group forms most leukemic cells are formed elsewhere.

scholarly journals Efficacy of Focal Adhesion Kinase Inhibition in Combination with Dasatinib in BCR-ABL1 Acute Lymphoblastic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3766-3766 ◽  
Author(s):  
Michelle L. Churchman ◽  
Luke Jones ◽  
Kathryn Evans ◽  
Jennifer Richmond ◽  
Irina M Shapiro ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Leukemic Cells ◽  
Employment Equity ◽  
Self Renewal ◽  
Equity Ownership

Abstract Introduction: BCR-ABL1+ B-progenitor acute lymphoblastic leukemia (Ph+ B-ALL) is a highly aggressive disease that is often refractory to currently available therapies. Our previous genomic profiling studies have identified loss-of-function or dominant negative mutations in IKZF1, encoding the lymphoid transcription factor Ikaros, in over 80% of Ph+ ALL. In addition, deletion of CDKN2A, which encodes the INK4A and ARF tumor suppressors, is observed in approximately half of all cases (Mullighan et al., 2008). Alterations of IKZF1 are associated with poor outcome despite the use of tyrosine kinase inhibitors (TKIs). Ikzf1 alterations, including Ikaros isoform 6 (IK6), result in the acquisition of stem cell-like features, enhanced self-renewal, expression of adhesion molecules, and transcriptional upregulation of focal adhesion kinase (FAK), resulting in increased adhesion in vitro and in vivo, and decreased sensitivity to TKIs (Churchman, Cancer Cell, in press). VS-4718 is a potent, selective, and orally bioavailable FAK inhibitor currently under evaluation in a phase 1 clinical trial in subjects with various solid tumors, however in vivo efficacy in hematological malignancies had not been evaluated. Targeting FAK with VS-4718 is an attractive approach to abrogate the adhesive phenotype of IKZF1-altered leukemic cells potentially enhancing the effects of dasatinib in the treatment of high-risk BCR-ABL1 B-ALL. Methods: We examined the efficacy and mechanisms of FAK inhibition using VS-4718 as a single agent and in combination with dasatinib in vitro and in vivo in a range of xenograft and genetically engineered mouse models of BCR-ABL1 ALL. Each model had concomitant deletion of Arf which is observed in approximately 50% of human cases. Results: A pre-clinical in vivo trial of dasatinib and VS-4718 combination therapy in a murine C57Bl/6 Arf-/- BCR-ABL1 pre-B cell model resulted in a marked increase in survival in both IK6-expressing and non-IK6 cohorts of mice, and one complete long-term remission in the IK6-expressing group. Further, we showed increased efficacy of VS-4718 and dasatinib, compared to either agent alone, against two highly aggressive human Ph+ IK6-expressing B-ALL xenografts in vivo, with decreased infiltration of leukemic cells in bone marrow and spleens demonstrating a synergistic effect of the VS-4718/dasatinib combination. In vitro cell viability was reduced with induction of apoptosis at increasing concentrations of VS-4718 as a single agent, and further potentiated the effects of dasatinib in cytotoxicity assays using human xenografted and murine leukemic cells. VS-4718 profoundly diminished the ability of BCR-ABL1-expressing cells to form cell-matrix adhesions in vitro, as evident by the reduced adherence to fibronectin monolayers and bone marrow stromal cells. VS-4718 almost completely abolished the colony-forming potential of BCR-ABL1-expressing murine pre-B cells with and without Ikzf1 alterations at drug concentrations that do not affect cell viability suggestive of a reduction in self-renewal. Calvarial imaging of mice transplanted with Ikzf1-altered BCR-ABL1 leukemic cells and treated with VS-4718 alone in vivo revealed a discernible reduction in adhesion in the intact bone marrow niche of Prrx1-Cre; LSL-tdTomato recipient mice. VS-4718 treated leukemic cells localized to Prrx1-expressing perivascular endothelial cells and exhibited round morphology in contrast to the typical spindle-like appearance of Ikzf1-altered pre-B cells adhering to the bone marrow stroma, suggesting that VS-4718 treatment abolished the aberrant leukemic cell-stromal adhesion induced by Ikaros alterations in vivo. Conclusions: Direct inhibition of FAK with VS-4718 attenuates the adhesive, stem-like properties of IKZF1-altered BCR-ABL1 leukemic cells that contribute to the poor prognosis of patients treated with currently available therapies. Targeted FAK inhibition is thus a promising avenue for improving the response of BCR-ABL1 ALL to dasatinib, particularly in refractory cases harboring IKZF1 alterations. These data support the clinical development of VS-4718 in combination with dasatinib in Ph+ B-ALL. Disclosures Shapiro: Verastem: Employment, Equity Ownership. Pachter:Verastem: Employment, Equity Ownership. Weaver:Verastem: Employment, Equity Ownership. Mullighan:Amgen: Honoraria, Speakers Bureau; Cancer Science Institute: Membership on an entity's Board of Directors or advisory committees; Loxo Oncology: Research Funding; Incyte: Consultancy, Honoraria. Off Label Use: The FAK inhibitor VS-4718 for the treatment of BCR-ABL1 acute lymphoblastic leukemia in preclinical models.

In vitro cytotoxicity of docetaxel in childhood acute leukemias.

1998 ◽  
Vol 16 (3) ◽  
pp. 907-913 ◽  
Author(s):  
R Consolini ◽  
C H Pui ◽  
F G Behm ◽  
S C Raimondi ◽  
D Campana
Keyword(s):  
Bone Marrow ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Leukemic Cells ◽  
Allogeneic Bone ◽  
Acute Leukemias ◽  
Growing Cell

PURPOSE In seeking to identify novel effective antileukemic agents, we assessed the in vitro activity of the taxoid docetaxel (Taxotere; Rhone-Poulenc Rorer, Antony, France) in primary leukemic cells supported in culture by bone marrow-derived stromal layers. MATERIALS AND METHODS Bone marrow samples from children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) were cultured on allogeneic bone marrow-derived stromal layers and exposed to various concentrations of docetaxel. After 7 days of culture, the number of viable leukemic cells were counted by flow cytometry and compared with that in parallel cultures without drugs. RESULTS In 20 samples tested (15 B-lineage ALL, one T-lineage ALL, and four AML), the median cytotoxicity was 78% after a 7-day culture in the presence of 100 ng/mL docetaxel (range, 54% to 95%). The effects were dose-dependent and extended to all five ALL samples with the t(9;22)(q34;q11) (Philadelphia chromosome) or 11q23 abnormalities, karyotypes associated with an unfavorable outcome. Studies with continuously growing cell lines demonstrated that docetaxel exerted its cytotoxic effect by inducing apoptosis, and was consistently more effective than paclitaxel (Taxol; Bristol-Myers Squibb, Wallingford, CT) (mean 50% cell kill [LC50], 6.93 v 12.86 ng/mL in six leukemic cell lines). The antileukemic activities of docetaxel and vincristine were synergistic. While the mean (+/- SD) cytotoxicity of vincristine (0.1 ng/mL) was 11.2% +/- 7.3% and that of docetaxel (10 ng/mL) was 19.3% +/- 17.5% in CEM-C7 cells after 24 hours, combining the two agents increased the cytotoxicity to 62.5% +/- 20.7% (P = .003). CONCLUSION Docetaxel, at concentrations achievable in vivo, is cytotoxic to ALL and AML cells. These results provide a rationale for clinical trials of docetaxel in patients with acute leukemia.

scholarly journals Colony formation in vitro by leukemic cells in acute lymphoblastic leukemia (ALL)

Blood ◽  
1978 ◽  
Vol 52 (4) ◽  
pp. 712-718 ◽  
Author(s):  
SD Smith ◽  
EM Uyeki ◽  
JT Lowman
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Bone Marrow Cells ◽  
Lymphoblastic Leukemia ◽  
Lymphoid Cells ◽  
Assay System ◽  
Leukemic Cells ◽  
Specific Cell ◽  
Specific Cell Surface

Abstract An assay system in vitro for the growth of malignant lymphoblastic colony-forming cells (CFC) was established. Growth of malignant myeloblastic CFC has been previously reported, but this is the first report of growth of malignant lymphoblastic CFC. Established assay systems in vitro have been very helpful in elucidating the control of growth and differentiation of both normal and malignant bone marrow cells. Lymphoblastic CFC were grown from the bone marrow aspirates of 20 children with acute lymphoblastic leukemia. Growth of these colonies was established on an agar assay system and maintained in the relative hypoxia (7% oxygen) of a Stulberg chamber. The criteria for malignancy of these colonies was based upon cellular cytochemical staining characteristics, the presence of specific cell surface markers, and the ability of these lymphoid cells to grow without the addition of a lymphoid mitogen. With this technique, specific nutritional requirements and drug sensitivities can be established in vitro, and these data may permit tailoring of individual antileukemic therapy.

scholarly journals Primitive Human Hematopoietic Cells Are Enriched in Cord Blood Compared With Adult Bone Marrow or Mobilized Peripheral Blood as Measured by the Quantitative In Vivo SCID-Repopulating Cell Assay

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 3919-3924 ◽  
Author(s):  
Jean C.Y. Wang ◽  
Monica Doedens ◽  
John E. Dick
Keyword(s):  
Bone Marrow ◽  
Cord Blood ◽  
Peripheral Blood ◽  
Hematopoietic Cells ◽  
Allogeneic Transplantation ◽  
Functional Assay ◽  
Hematopoietic Stem ◽  
Mobilized Peripheral Blood

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.

Overexpression of hTLX3 in Association with Mutant IL7Rα Is Sufficient to Generate T-ALL In Vivo and to Transform Thymocytes in Vitro

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 21-21
Author(s):  
Gisele Olinto Libanio Rodrigues ◽  
Julie Hixon ◽  
Hila Winer ◽  
Erica Matich ◽  
Caroline Andrews ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Lymphoblastic Leukemia ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Counts

Mutations of the IL-7Rα chain occur in approximately 10% of pediatric T-cell acute lymphoblastic leukemia cases. While we have shown that mutant IL7Ra is sufficient to transform an immortalized thymocyte cell line, mutation of IL7Ra alone was insufficient to cause transformation of primary T cells, suggesting that additional genetic lesions may be present contributing to initiate leukemia. Studies addressing the combinations of mutant IL7Ra plus TLX3 overexpression indicates in vitro growth advantage, suggesting this gene as potential collaborative candidate. Furthermore, patients with mutated IL7R were more likely to have TLX3 or HOXA subgroup leukemia. We sought to determine whether combination of mutant hIL7Ra plus TLX3 overexpression is sufficient to generate T-cell leukemia in vivo. Double negative thymocytes were isolated from C57BL/6J mice and transduced with retroviral vectors containing mutant hIL7R plus hTLX3, or the genes alone. The combination mutant hIL7R wild type and hTLX3 was also tested. Transduced thymocytes were cultured on the OP9-DL4 bone marrow stromal cell line for 5-13 days and accessed for expression of transduced constructs and then injected into sublethally irradiated Rag-/- mice. Mice were euthanized at onset of clinical signs, and cells were immunophenotyped by flow cytometry. Thymocytes transduced with muthIL-7R-hTLX3 transformed to cytokine-independent growth and expanded over 30 days in the absence of all cytokines. Mice injected with muthIL7R-hTLX3 cells, but not the controls (wthIL7R-hTLX3or mutIL7R alone) developed leukemia approximately 3 weeks post injection, characterized by GFP expressing T-cells in blood, spleen, liver, lymph nodes and bone marrow. Furthermore, leukemic mice had increased white blood cell counts and presented with splenomegaly. Phenotypic analysis revealed a higher CD4-CD8- T cell population in the blood, bone marrow, liver and spleen compared in the mutant hIL7R + hTLX3 mice compared with mice injected with mutant IL7R alone indicating that the resulting leukemia from the combination mutant hIL7R plus hTLX3 shows early arrest in T-cell development. Taken together, these data show that oncogenic IL7R activation is sufficient for cooperation with hTLX3 in ex vivo thymocyte cell transformation, and that cells expressing the combination muthIL7R-hTLX3 is sufficient to trigger T-cell leukemia in vivo. Figure Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document