Vitamin K3 Selectively Induces Apoptosis in Acute Lymphoblastic Leukemia Cells with Constitutive Activation of IKKα/NF-kB Activation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 859-859
Author(s):  
Ningxi Zhu ◽  
Lubing Gu ◽  
Harry W. Findley ◽  
Kuang-Yueh Chiang ◽  
Muxiang Zhou
Keyword(s):  
Cell Death ◽  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Cytotoxic Effect ◽  
Human Cancer ◽  
Lymphoblastic Leukemia ◽  
Vitamin K3 ◽  
Neoplastic Cells

Abstract Although the cytotoxic effect of vitamin K3 (VK3) on human cancer cells has been repeatedly reported, no clear conclusions from either in vitro or in vivo tests have so far been made for VK3 as an anticancer agent due to marked inter-tumor variability of efficacy in response to VK3 treatment. Here, we report that sensitivity of neoplastic cells to VK3-induced killing depends on IKKα expression/NF-kB activation in the cells. We tested the sensitivity to VK3 of 14 leukemic cell lines established from children with acute lymphoblastic leukemia (ALL). The 14 lines were classified into three groups: IKKα +/NF-kB+, IKKα +/NF-kB−, IKKα−/NF-kB−. IKKα +/NFkB+ cell lines that are generally resistant to doxorubicin are more sensitive to VK3 induced cell death than are the IKKα +/NFkB− lines that are usually sensitive to doxorubicin. The median of IC 50 values of VK3 and doxorubicin as tested by WST analysis for IKKα +/NFkB+ cells were 3.92 mM and 1.58 mM, respectively, compared to IKKα +/NFkB− cells (7.3 mM of VK3 and 0.71 mM of doxorubicin, p<0.01, t-test). Assays by testing activation of caspase and cleavage of death substrate PARP as well as flow cytometry showed that apoptosis was induced in a line with high levels of IKKα/NF-kB activation at 2 h after VK3 treatment. In contrast, apoptosis was not induced by VK3 even at 48 h post-treatment in two lines that lack IKKa expression and NF-kB activation. To test if IKKα/NF-kB is a molecular target of VK3 inducing apoptosis in ALL, we examined the expression and activation of IKKα/NF-kB in VK3-treated cells. VK3 specifically reduced IKKα expression and inhibited NF-kB activation, resulting in downregulation of NF-kB-mediated gene expression and apoptosis. These results suggest that inhibition of IKKα/NF-kB signaling pathway is essential for VK3 to induce cell death, and that VK3, a dietary factor with no cytotoxic effect on normal cells, would be a useful adjuvant in the treatment of ALL and other cancer patients whose neoplastic cells express constitutive NF-kB and are resistant to chemotherapy.

Effective Induction of Apoptosis by Mistletoe Plant Extracts in an Acute Lymphoblastic Leukemia Model.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1880-1880
Author(s):  
Georg Seifert ◽  
Patrick Jesse ◽  
Aram Prokop ◽  
Tobias Reindl ◽  
Stephan Lobitz ◽  
...  
Keyword(s):  
Cell Death ◽  
Body Weight ◽  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
The Body ◽  
Induction Of Apoptosis ◽  
First Time ◽  
Over Time

Abstract Mistletoe (Viscum album) is one of the most used alternative cancer therapies applied as monotherapy or in combination with conventional therapies. Anti-tumor effects of mistletoe (MT) extracts were related to cytostatic and immunomodulatory effects observed in vitro. Aqueous MT extracts contain the three mistletoe lectins I, II and III as one predominant group of biologically active agents. The MT lectins inhibit protein biosynthesis by inactivating the 60S ribosomal subunit. Mistletoe lectin-I (ML-I) is one important apoptosis inducing compound. It is a heterodimer that consists of a cytotoxic A-chain (ribosome inactivating protein, RIP type 1) linked by a carbohydrate binding B-chain for cellular lectin uptake. However, although MT is widely used, there is a lack of scientific preclinical and clinical data. Here, we describe for the first time efficacy and mechanism of MT extracts against lymphoblastic leukemia in vitro and in vivo. For this purpose, we first investigated both the cytotoxic effect and mechanism of action of two standardized aqueous MT extracts (MT obtained from fir trees (MT-A); MT obtained from pine trees (MT-P)) and isolated ML-I, in three human acute lymphoblastic leukemia (ALL) cell lines (NALM-6, sup-B-15 and REH). MT-A, MT-P and ML-I clearly inhibited cell proliferation as determined by LDH reslease assays at very low concentrations (ML-I LD50 from 0,05 ng/ml to 10 ng/ml depending on the host tree) with MT-P being the most cytotoxic extract. The mechanism of cell death was determined by DNA-fragmentation assays. These indicated dose dependent induction of apoptosis as the main mechanism of cell death. Finally, we evaluated the efficacy of MT-A and MT-P in an in vivo SCID-model of pre-B ALL (NALM-6). For this purpose, mice (n=8/group) were injected i.v. with 1 × 106NALM6 cells and treated by intraperitoneal injections four times per week for 3 weeks (day 1–4; 7–11; 14–18) at varying doses (1, 5 and 50 mg/Kg (plant weight/body weight)). Mice (n=8) treated with PBS and cyclophosphamide (100 mg/kg, once on day 1) were used as negative and positive controls, respectively. Toxicity, peripheral blood counts, bodyweight and survival was determined over time. Interestingly, both MT extracts in all tested concentrations significantly improved survival (up to 55,4 days) in contrast to controls (34,6 days). Furthermore, no hematologic side effects were observed from this treatment as indicated by completely stable blood counts. Also the body weight of treated animals remained stable over time indicating a complete absence of systemic toxicity in the selected dose range. In summary, we demonstrate for the first time efficacy and mechanism of MT extracts against ALL in vitro and in vivo and hereby provide an important base line for the design of clinical trials with these compounds.

Activity of vincristine, L-ASP, and dexamethasone against acute lymphoblastic leukemia is enhanced by the BH3-mimetic ABT-737 in vitro and in vivo

Blood ◽  
2007 ◽  
Vol 110 (6) ◽  
pp. 2057-2066 ◽  
Author(s):  
Min H. Kang ◽  
Yun Hee Kang ◽  
Barbara Szymanska ◽  
Urszula Wilczynska-Kalak ◽  
Michael A. Sheard ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Clinical Investigation ◽  
Lymphoblastic Leukemia ◽  
Annexin V ◽  
Cytochrome C Release ◽  
Synergistic Cytotoxicity ◽  
Bh3 Mimetic

Abstract Defects in apoptosis signaling contribute to poor outcome in pediatric acute lymphoblastic leukemia (ALL), and overexpression of antiapoptotic Bcl-2 (Bcl-2 and Bcl-XL) family proteins has been observed in ALL. ABT-737 is a small-molecule BH3-mimetic that inhibits the antiapoptotic Bcl-2 family proteins. We evaluated the cytotoxicity of ABT-737 in combination with vincristine, dexamethasone, and L-asparaginase (VXL) in 7 ALL cell lines. Multilog synergistic cytotoxicity was observed in all 7 cell lines with ABT-737 plus L-asparaginase or vincristine, and in 5 of 7 cell lines with ABT-737 plus dexamethasone or VXL. In leukemia cells, but not in normal lymphocytes, ABT-737 plus L-asparaginase induced greater mitochondrial depolarization (JC-1 staining); mitochondrial cytochrome c release; activation of Bax, Bid, and caspases (immunoblotting); and eventually apoptosis (annexin V staining) than did either drug alone. In mouse xenografts derived from patients with ALL at diagnosis (ALL-7) or at relapse (ALL-19), event-free survival (EFS) was significantly enhanced with ABT-737 plus VXL relative to VXL or ABT-737 alone (P ≤ .02). Thus, ABT-737 synergistically enhanced VXL cytotoxicity in ALL cell lines via a mitochondrial death pathway and enhanced EFS in VXL-treated mice bearing ALL xenografts. Combining VXL with a BH3-mimetic warrants clinical investigation in ALL at relapse and potentially in chemotherapy-resistant ALL subgroups.

Obinutuzumab (GA101) Significantly Enhances Cell Death and ADCC Compared to Rituximab Against CD20+ sensitive and Rituximab Resistant B-Cell Non-Hodgkin Lymphoma (NHL) and Lymphoblastic Leukemia (BLL)

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4865-4865 ◽  
Author(s):  
Aradhana Awasthi Tiwari ◽  
Janet Ayello ◽  
Carmella van de Ven ◽  
Danielle Glassman ◽  
Anthony Sabulski ◽  
...  
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Nk Cells ◽  
Cell Lines ◽  
Caspase 3 ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Dismal Prognosis

Abstract Abstract 4865 Background: Patients who relapse with CD20+ B-NHL and B cell lymphoblastic leukemia (B-LL) have a dismal prognosis, often associated with chemotherapy resistance (Cairo et al. JCO, 2012,Mils/Cairo et al. BJH,2012) and often require alternative therapeutic strategies. Rituximab (RTX) in combination with FAB 96 chemotherapy is a safe, well-tolerated treatment that is associated with > 90% EFS in children with newly diagnosed and advanced mature B-Cell NHL (Cairo M.S. et al. ASCO, 2010). Resistance to RTX, however, may predispose patients with CD20+ NHL to an increase risk of relapse and or disease progression (Barth/Cairo et al. BJH, 2012; Tsai et al. Cl. Can. Res, 2012). Obinutuzumab (GA101), a novel type II glycoengineered CD20 antibody of the IgG1 isotype, mediates enhanced cell death vs RTX and has a glycoengineered Fc region that induces significantly enhanced ADCC (Mössner et al. Bld, 2010; Niederfellner G. et al. Bld, 2011; Bologna L et al. JI, 2012). Objective: To evaluate the in-vitro efficacy of GA101 compared to RTX against RTX sensitive and resistant CD20+ B-NHL and B-LL cell lines. Methods: Raji (CD20+,ATCC, Manhass, VA), U698-M (CD20+, DSMZ, Germany), Loucy cells (CD20−) (T-ALL) (ATCC, Manhass, VA) and Raji-2R and Raji-4RH (generously supplied by M. Barth, Roswell Park Cancer Institute) were cultured in RPMI with 10% FBS and incubated with GA101 and/or RTX at 100 μg/ml for 24 hrs (n=6), 48 and 72 hrs (n=5). Cell death was evaluated by staining with AnnexinV/7AAD and flow-cytometry. Loucy cells (CD20−) were used as the negative control. The caspase 3/7 activity was measured by FAM caspase 3/7 assay kit by FLICA™ methodology. RSCL, RRCL, U698-M and Loucy were incubated with GA101 and RTX treatment for 24, 48 and 72 hrs, and caspase3/7 activity was detected by FACS using 488 nm excitation and emission filter (n=3). ADCC were performed with K562-IL-15–41BBL expanded NK cells (Ayello/Cairo et al. ASH, 2010) as well as IL-2 expanded NK cells, at 20:1 effector: target ratio (E: T, n=3) using europium release assay (Perkin-Elmer). Results: GA101 induced significantly more cell death compared to RTX in B-NHL and BLL cell lines. (Table-1) GA101 vs RTX shows a significantly increase in caspase 3/7 activity in Raji 16.92±0.84% vs 11.76±0.08% compared to Raji2R 6.7±0.62% vs 2.8±0.7%, Raji4RH 5.8±0.35% vs 2.0±0.3% and U698-M 12.54±0.44% vs 9.6±0.95% compared to Loucy 3.22±0.45% vs 2.59±0.05%, respectively, at 24 hrs of treatment (p<0.0001). GA101 vs RTX also elicited a significant increase a ADCC with K562-IL15–41BBL expanded NK cells, in Raji 73.8±8.1% vs 56.81±4.6% compared to Raji-2R 38.0±2.0% vs 21.6±1.2%, Raji-4RH 40.0±1.6% vs 0.5±1.1% and U698-M 70.0±1.6% vs 45.56±0.1%, compared to Loucy 21.67±0.48% vs 15.92±0.52%, respectively (p<0.001) at day 7.The IL-2 alone expanded Hu-NK cells demonstrated a reduction of 10–20% cytotoxicity compared to K562-IL15–41BBL Hu-NK cells at day 7 against BLL, RSCL and RRCL, in-vitro. Conclusion: Obinutuzumab compared to RTX significantly enhanced cell death, caspase3/7 activity and NK mediated ADCC in sensitive and RTX resistant B-NHL and B-LL. Obinutuzumab represents a promising candidate for treating RTX sensitive and resistant CD20+ B-Cell Lymphomas and lymphoblastic leukemia. Further studies will investigate the combination of activated NK cells or chemotherapy that may enhance or synergize with the efficacy of GA101 (Obinutuzumab) both in -vitro and in-vivo in xenografted NOD/SCID mice. Disclosures: No relevant conflicts of interest to declare.

Role of the Histone Deacetylase Inhibitor Givinostat (ITF2357) in Treatment of CRLF2 Rearranged Acute Lymphoblastic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2534-2534 ◽  
Author(s):  
Angela Maria Savino ◽  
Jolanda Sarno ◽  
Luca Trentin ◽  
Margherita Vieri ◽  
Grazia Fazio ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Combined Treatment ◽  
Cytokine Receptor ◽  
Human Leukemia ◽  
Xenograft Models ◽  
Stat Pathway

Abstract B Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) represents 35% of all cancers in pediatric age group. The cure rate for this disease approaches 90% with current treatment regimens, however only a third of patients with relapse are cured. Therefore, there is an urgent need to focus on subgroups of patients with hallmarks of bad prognosis that could benefit from novel therapeutic approaches. Alterations of Cytokine Receptor-like Factor 2 (CRLF2), a negative prognostic factor in pediatric BCP-ALL, have been identified in up to 10% of patients. However these patients represent half of the high risk Ph-like ALL and of Down Syndrome-associated BCP-ALL. Rearrangements of CRLF2 result in the overexpression of this component of the heterodimeric cytokine receptor for thymic stromal lymphopoietin (TSLP) and is associated with activating mutations of the JAK-STAT pathway. Together these cause hyperactivation of JAK/STAT and PI3K/mTOR signaling. Inhibition of CRLF2/JAK2 signaling has the potential to become a therapeutic targeted intervention for this subgroup of poor prognostic patients. Previous studies have shown that the HDAC inhibitor Givinostat/ITF2357 has potent anti-tumor activity against hematological malignancies, particularly JAK2V617F mutated myeloproliferative neoplasms (MPN) such as polycythemia vera, for which it has already a clinic application and established safety profile. We therefore studied the in vitro and in vivo efficacy of Givinostat in cases with CRLF2 rearrangements. Here we demonstrated that Givinostat inhibited proliferation and induced apoptosis of BCP-ALL CRLF2-rearranged MHH-CALL4 and MUTZ5 cell lines positive for exon 16 JAK2 mutations. Of note, the observed IC50 values for MHH-CALL4 were lower than those for the SET2 cell line positive control bearing JAK2V617F mutation, both for proliferation (IC50: 0.08±0.05µM vs. 0.14±0.03µM) and apoptosis (IC50: 0.17±0.03µM vs. 0.22±0.04µM). We next investigated the effect of Givinostat on blasts from CRLF2 rearranged BCP-ALL patient samples. For this purpose we developed xenograft models of human CRLF2 rearranged ALL to expand cells from patients and to recapitulate human leukemia in recipient mice. ALL blasts isolated from xenografts were co-cultured on OP9 stroma to perform ex vivo assays. Consistent with our findings in cell lines, Givinostat (0.2µM) reduced the % of live cells (Annexin V/Sytox negative) in all xenografts treated with the drug. In particular, after 72 hours, Givinostat was able to kill up to >90% of blast cells in all xenografts in contrast with the vehicle-treated samples which showed 25-60% of blasts still alive after treatment. The induction of cell death in Givinostat treated primografts was confirmed on primary samples from diagnosis using CyTOF which allowed us to observe that CD10+/CRLF2+ blasts were preferentially killed by the drug whereas CD45 high expressing cells (normal residue) remained unaffected by the treatment. Moreover, at low doses (0.2 µM), Givinostat downregulated genes of the JAK/STAT pathway (STAT5A, JAK2, IL7Rα, CRLF2, BCL2L1 and cMYC) and inhibited the basal and ligand induced signaling, reducing the phoshporylation of STAT5 in all tested primografts (mean fold decrease of pSTAT5: 2.4+0.6). Most importantly, to understand if the transcriptional downregulation of CRLF2 resulted in a functional effect, the downmodulation of CRLF2 protein was observed by flow cytometry (mean fold decrease 3.55+1.38). In vivo, Givinostat significantly reduced engraftment of human blasts in xenograft models of CRLF2 positive BCP-ALL (ranging from 1.9 to 34 fold decrease in bone marrow). Furthermore, Givinostat augmented the effect of chemotherapy in inhibiting proliferation and inducing apoptosis in CRLF2 rearranged cell lines and in primografts, in vitro. After 72 hours, the combined treatment reached 4.6-8.8 fold lower % of remaining viable blasts than chemotherapy alone (6.3-35.3% viable cells in chemotherapy-treated samples vs 1.4-4.3% of combination), 2.5-8.5 fold lower than Givinostat alone (4.3-36.4% vs 1.4-4.3%) and 2.4-13 fold lower than Methyl-prednisolone (5.2-39.1 vs 1-16.3%). In conclusion, Givinostat may represent a novel and effective tool, in combination with current chemotherapy, to treat this difficult to handle subset of ALL and these data strongly argue for the translation of Givinostat in combination with conventional therapy into human trials. Disclosures Davis: Fluidigm, Inc: Honoraria. Nolan:Fluidigm, Inc: Equity Ownership.

scholarly journals Preclinical Evaluation of Carfilzomib for Infant KMT2A-Rearranged Acute Lymphoblastic Leukemia

2021 ◽  
Vol 11 ◽  
Author(s):  
Laurence C. Cheung ◽  
Rebecca de Kraa ◽  
Joyce Oommen ◽  
Grace-Alyssa Chua ◽  
Sajla Singh ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Drug Testing ◽  
Hematological Malignancies ◽  
Lymphoblastic Leukemia ◽  
Proteasome Inhibition ◽  
Chemotherapeutic Agents ◽  
Combination Drug

BackgroundInfants with KMT2A-rearranged B-cell precursor acute lymphoblastic leukemia (ALL) have poor outcomes. There is an urgent need to identify novel agents to improve survival. Proteasome inhibition has emerged as a promising therapeutic strategy for several hematological malignancies. The aim of this study was to determine the preclinical efficacy of the selective proteasome inhibitor carfilzomib, for infants with KMT2A-rearranged ALL.MethodsEight infant ALL cell lines were extensively characterized for immunophenotypic and cytogenetic features. In vitro cytotoxicity to carfilzomib was assessed using a modified Alamar Blue assay with cells in logarithmic growth. The Bliss Independence model was applied to determine synergy between carfilzomib and the nine conventional chemotherapeutic agents used to treat infants with ALL. Established xenograft models were used to identify the maximal tolerated dose of carfilzomib and determine in vivo efficacy.ResultsCarfilzomib demonstrated low IC50 concentrations within the nanomolar range (6.0–15.8 nm) across the panel of cell lines. Combination drug testing indicated in vitro synergy between carfilzomib and several conventional chemotherapeutic agents including vincristine, daunorubicin, dexamethasone, L-asparaginase, and 4-hydroperoxycyclophosphamide. In vivo assessment did not lead to a survival advantage for either carfilzomib monotherapy, when used to treat both low or high disease burden, or for carfilzomib in combination with multi-agent induction chemotherapy comprising of vincristine, dexamethasone, and L-asparaginase.ConclusionsOur study highlights that in vitro efficacy does not necessarily translate to benefit in vivo and emphasizes the importance of in vivo validation prior to suggesting an agent for clinical use. Whilst proteasome inhibitors have an important role to play in several hematological malignancies, our findings guard against prioritization of carfilzomib for treatment of KMT2A-rearranged infant ALL in the clinical setting.

scholarly journals BCL-2, a Therapeutic Target for High Risk Hypodiploid B-Cell Acute Lymphoblastic Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 280-280 ◽  
Author(s):  
Ernesto Diaz-Flores ◽  
Evan Q. Comeaux ◽  
Kailyn Kim ◽  
Kyle Beckman ◽  
Kara L. Davis ◽  
...  
Keyword(s):  
Cell Death ◽  
Acute Lymphoblastic Leukemia ◽  
Board Of Directors ◽  
Cell Lines ◽  
Research Funding ◽  
Lymphoblastic Leukemia ◽  
Advisory Committees ◽  
Chromosomal Number ◽  
Patient Derived Xenograft

Abstract Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood. Specific genetic subsets, including hypodiploid ALL, are associated with particularly high rates of relapse. Despite the poor outcomes of hypodiploid B-ALL with traditional therapeutic approaches, there have been no known effective alternative therapies or novel candidates tested to improve outcome. We hypothesized that new therapeutic targets could by identified by integrated biochemical and genomic profiling, combined with functional drug assays in order to determine which pathways play an essential role in transformation. For biochemical profiling, we analyzed multiple pathways commonly deregulated in leukemias using phosphoflowcytometry (including receptor tyrosine kinases, JAK/STAT, MAPK, PI3K, PTEN, Bcl-2 survival and pro-apoptotic family members and p53). We subjected hypodiploid cell lines (NALM-16, MHH-CALL2) and patient derived xenograft samples in vitro to inhibitors against each of these pathways (PP2:Src family;Ruxolitinib: JAK/STAT; PD235901/CI1040: MAPK; GDC-0941, PI-90, PI-103, p110 (a, b, g, d): PI3K isoform specific; PP-242:mTOR; ABT-263/ABT-737: Bcl-2/Bcl-xl, and ABT-199: Bcl-2 specific). We found that the Bcl-2 inhibitors (ABT-263, ABT-737 and ABT-199) and to a lesser extent PI3K pathway inhibitors GDC-0941 and PP-242, but not the MAPK or RTK inhibitors, efficiently reduced proliferation of hypodiploid cells. However, only ABT-263/ABT-199 induced high levels of apoptosis at nanomolar concentrations. Based on the consistent efficacy observed with ABT-199 against hypodiploid patient-derived cells and cell lines in culture, we selected eight cryopreserved, previously xenografted (F3 generation) hypodiploid patient samples (4 low hypodiploid, chromosomal number between 32 and 39; and 4 Near Haploid, chromosomal number between 24 and 31) and three non-hypodiploid patient samples (Ph-positive,Ph-Like and Erg+) for a preclinical trial in immunodeficient mice. Each patient sample was engrafted into six mice, which were randomized to receive vehicle or ABT-199 daily over 60 days (Figure 1). Treatment started when the peripheral blood (PB) human CD45 count reached 15%. A rapid decrease in PB blasts was noted at 7 days (Figure 1). Eighty-five percent of the hypodiploid xenografts survived 60 days with either undetectable or low levels of leukemia in the PB. In contrastPh+ andPh-Like xenografts died within 10-20 days regardless of treatment. Importantly, hypodiploid leukemic blasts gradually emerged after discontinuing ABT-199 after 60 days. Additionally, despite low or undetectable levels of leukemic blasts in PB and reduced levels in bone marrow and spleen, all mice had high percentages of leukemic cells in the liver (Figure 2). In conclusion we have identified the survival protein Bcl-2 as a promising molecular target in hypodiploid B-ALL. ABT-199 for dramatically reduced leukemia cells in vitro and in vivo in patient-derived xenograft models of hypodiploid B-ALL. However, the liver represented a protective niche for these leukemias. In addition, our biochemical characterization of the organ infiltrating blasts collected from mice on trial indicate that the sensitivity of hypodiploid ALL to ABT-199 relies not only on high levels of Bcl-2 and deficiency for other survival proteins such as Bcl-xl but also on high levels of proapoptotic proteins, providing two different signatures that correlate with response to ABT-199. Using genome editing (CRISPR/Cas9) we interrogated the necessity for individual proapoptotic genes, including PUMA, NOXA, and BAD, for ABT-199-induced cell death. This study provides encouraging preclinical data that Bcl-2 may be a promising target for the treatment of hypodiploid B-ALL. Our studies identify signature biomarkers that correlate with drug response and identify essential proteins mediating ABT-199-induced cell death. Importantly, this report also identifies the limitations of using ABT-199 as single drug, and provides the rationale for using combinatorial therapies in order to improve the efficacy of the drug. Disclosures Mullighan: Loxo Oncology: Research Funding; Amgen: Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees. Loh:Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding.

scholarly journals Therapeutic potential of SGN-CD19B, a PBD-based anti-CD19 drug conjugate, for treatment of B-cell malignancies

Blood ◽  
2017 ◽  
Vol 130 (18) ◽  
pp. 2018-2026 ◽  
Author(s):  
Maureen C. Ryan ◽  
Maria Corinna Palanca-Wessels ◽  
Brian Schimpf ◽  
Kristine A. Gordon ◽  
Heather Kostner ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Cell Lines ◽  
Therapeutic Potential ◽  
Lymphoblastic Leukemia ◽  
Preclinical Models ◽  
B Cell Malignancies ◽  
Key Points

Key Points SGN-CD19B is broadly active in vitro against malignant B-cell lines, including double-hit and triple-hit lymphoma cell lines. SGN-CD19B shows significant antitumor activity in vivo in preclinical models of B-NHL and B-cell–derived acute lymphoblastic leukemia.

Zebrafish Xenotransplantation and Focused Chemical Genomics: A Preclinical Therapeutic Model For T-Cell Acute Lymphoblastic Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2670-2670
Author(s):  
Victoria L Bentley ◽  
Chansey J Veinotte ◽  
Dale Corkery ◽  
Marissa A Leblanc ◽  
Karen Bedard ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Human Cancer ◽  
Lymphoblastic Leukemia ◽  
Zebrafish Embryos ◽  
Chemical Genomics ◽  
Cell Acute Lymphoblastic Leukemia

Abstract T-cell acute lymphoblastic leukemia (T-ALL) is a high-risk subset of ALL, for which there is a need for new therapeutic strategies and efficient preclinical screening methods. We have pioneered an innovative zebrafish human cancer xenotransplantation (XT) model to examine drug-tumor interactions in vivo. T-ALL cell lines and primary patient T-ALL samples were microinjected into 48-hour zebrafish embryos, a stage at which the adaptive immune system has not yet developed. Fluorescent labelling of tumor cells prior to injection and use of casper pigment mutant fish facilitates evaluation of drug response both by direct observation in transparent fish and enumeration of human cells following embryo dissociation. Proliferation rates are rapidly determined by directly counting fluorescent cells using in silico-based programs and/or utilizing immunohistochemical approaches to distinguish human cancer cells from host cell populations. T-ALL cell lines harboring defined mutations in the NOTCH1, phosphoinositide 3-kinase (PI3K)/AKT and mTOR pathways differentially responded to targeted inhibition using the γ-secretase inhibitor Compound E, triciribine, and rapamycin, when xenografted into embryos, consistent with responses in vitro. Primary patient-derived T-ALL bone marrow samples similarly engrafted and proliferated in zebrafish embryos. Using this in vivo chemical genomic approach, a targetable mutation sensitive to γ-secretase inhibition was identified from the diagnostic bone marrow sample of a child with T-ALL, which was confirmed by exome Sanger sequencing, and validated as a gain-of-function mutation in the NOTCH1 gene by luciferase assay and Western blot. Focused chemical genomics using the zebrafish T-ALL XT model provides a means of tailoring therapy using a real time in vivo assay that more accurately recapitulates the tumor microenvironment than in vitro methods and more rapidly than mouse xenografts. Moreover, the efficiency and cost-effectiveness of this innovative platform provides a novel intermediary for the prioritization of much-needed drug candidates in the preclinical pipeline. Disclosures: No relevant conflicts of interest to declare.

scholarly journals AT1412, a Patient-Derived Antibody in Development for the Treatment of CD9 Positive Precursor B-Acute Lymphoblastic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4461-4461
Author(s):  
Greta De Jong ◽  
Sophie E Levie ◽  
Remko Schotte ◽  
Wouter Pos ◽  
Daniel Go ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Death ◽  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Melanoma Cells ◽  
Employment Equity ◽  
Equity Ownership

Despite rapid advances in immunotherapeutic options for precursor B-acute lymphoblastic leukemia (ALL), outcomes remain poor especially for adult ALL and relapsed pediatric ALL. With conventional chemotherapy, remission percentages in adult ALL range from 75 to 90%, but relapse rates are high and long-term leukemia-free survival ranges between 35-70% depending on age and risk group. The introduction of CD19 targeting immunotherapy has significantly improved patient outcomes in (relapsed) B-ALL. However, tumor escape via downregulation of CD19 occurs in a significant number of patients. Therefore an ongoing urgency remains for the identification of additional or alternative immunotherapeutic targets for the treatment of ALL. AT1412 is an antibody that was identified from the peripheral blood memory B cell pool of a patient cured of metastatic melanoma after adoptive T-cell therapy, using a B cell immortalization technology (AIMSelect) with ectopic Bcl-6 and Bcl-xL expression as described previously [Kwakkenbos et al. Nat. Med. 2010]. The antibody was selected based on differential binding to melanoma cells as compared to healthy melanocytes and was shown to be successful in killing melanoma cells in vitro and in vivo [manuscript submitted]. In addition to melanoma, AT1412 binds other tumor types including B-ALL, gastric, colon- and pancreatic cancer. The target of AT1412 is the tetraspanin CD9, which is expressed by more than half of all B-ALL. Expression of CD9 has been correlated with adverse prognosis [Liang et al. Cancer Biomark. 2018]. We assessed binding of this human CD9 antibody to a panel of ALL cell lines using flow cytometry. Binding of AT1412 to the B-ALL cell lines SUP-B15, MHH-CALL-2 and CCRF-SB varied as expected based on the CD9 levels that we detected using a commercial CD9 antibody. AT1412 induced antibody dependent cellular cytotoxicity (ADCC) on these cells, in line with the level of AT1412 binding. No binding was seen to the T-ALL cell line Jurkat. Importantly, these findings were confirmed in primary ALL samples, obtained prospectively at diagnosis from a cohort of patients with T- or B-ALL (n=30). AT1412 showed binding to 61% of B-ALL samples but not to T-ALL samples. The potential of AT1412 to induce ADCC was tested on patient samples from the same panel. Remarkably, AT1412 induced ADCC of all B-ALL samples it bound to (8 out of 14) and of none of the T-ALL samples. Cytotoxicity significantly correlated with the level of AT1412 binding. These findings were supported by the observation that AT1412 induced B-ALL cell death when a freshly drawn whole bone marrow sample from a patient with newly diagnosed B-ALL was cocultured with AT1412. AT1412-induced cell death of B-ALL blasts occurred without affecting the monocytic, granulocytic and lymphocytic populations. This cell death was not observed when this patient's ALL blasts were incubated with AML-targeting antibodies. Remarkably, AT1412 induced cell death in the absence of added effector cells or other (chemo)therapeutic agents, while the bone marrow sample contained over 80% blasts and as little as 3% lymphocytes. We are currently investigating the in vivo efficacy of the antibody in a humanized immune system mouse model with human B-ALL. Taken together, the majority of precursor B-ALL blasts express CD9 and expression of CD9 is associated with a dismal outcome. Our data demonstrate that CD9 can be successfully targeted by the human CD9 antibody AT1412, suggesting that AT1412 has the potential to be developed as a therapeutic antibody for B-ALL. AT1412 is currently being advanced through preclinical development. Disclosures De Jong: AIMM Therapeutics: Employment. Levie:AIMM Therapeutics: Employment. Schotte:AIMM Therapeutics: Employment, Equity Ownership, Patents & Royalties: Patent WO2017119811A1. Pos:AIMM Therapeutics: Patents & Royalties: Patent WO2017119811A1. Go:AIMM Therapeutics: Employment, Patents & Royalties: Patent WO2017119811A1. Yasuda:AIMM Therapeutics: Employment, Equity Ownership. Cercel:AIMM Therapeutics: Employment. van Hal-van Veen:AIMM Therapeutics: Employment. Frankin:AIMM Therapeutics: Employment. Villaudy:AIMM Therapeutics: Employment, Equity Ownership, Patents & Royalties: Patent WO2017119811A1. van Helden:AIMM Therapeutics: Employment, Equity Ownership, Patents & Royalties: Patent WO2017119811A1. van Eenennaam:AIMM Therapeutics: Employment. Spits:AIMM Therapeutics: Employment, Equity Ownership, Patents & Royalties: Patent WO2017119811A1. Hazenberg:AIMM Therapeutics: Other: Employment/equity of partner/spouse.

scholarly journals Synergistic Activity of the MCL-1-Specific Inhibitor S63845 with Venetoclax in B-Cell Precursor Acute Lymphoblastic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1416-1416
Author(s):  
Felix Seyfried ◽  
Felix Stirnweiß ◽  
Stefan Köhrer ◽  
Klaus-Michael Debatin ◽  
Lüder Hinrich Meyer
Keyword(s):  
Cell Death ◽  
Acute Lymphoblastic Leukemia ◽  
High Risk ◽  
B Cell ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Specific Inhibitor ◽  
Synergistic Activity ◽  
Cell Precursor

Abstract Deregulated cell death and survival pathways contribute to leukemogenesis and treatment failure of B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients. The intrinsic apoptosis pathway is regulated at the mitochondrial level by different pro- and anti-apoptotic molecules. Members of the BCL-2 family are key regulators of mitochondrial apoptosis signaling. Pro-apoptotic BH3-only proteins like BIM and BID activate pro-death proteins such as BAX and BAK leading to cell death. Anti-apoptotic BCL-2 family members including BCL-2, BCL-XL and MCL-1 bind to and sequester pro-apoptotic molecules, prevent activation of pro-death proteins and counter-regulate apoptosis induction. Small molecule inhibitors have been developed that block binding to anti-apoptotic molecules like BCL-2, leading to release of pro-apoptotic proteins and cell death induction. In particular, the BCL-2-specific inhibitor venetoclax (VEN) has demonstrated substantial anti-cancer activity and became an approved drug for the treatment of CLL patients. Investigating different, individual BCP-ALL samples, we and others recently identified heterogeneous sensitivities for VEN, suggesting that BCP-ALL cells might also depend on other pro-survival BCL-2 family proteins including MCL-1, leading to VEN insensitivity and resistance. A novel BH3-mimetic, S63845, that selectively targets MCL-1 has been reported. Here, we assessed the activity of S63845 and addressed a potential synergism of simultaneous blockage of BCL-2 and MCL-1 by VEN and S63845 (S) in BCP-ALL. The activity of the MCL-1 inhibitor was analyzed in a panel of BCP-ALL cell lines (N=6) and a series of primary, patient-derived BCP-ALL primograft samples (N=27) determining half-maximal effective concentrations (EC50) upon exposure to increasing concentrations of S and analysis of cell death induction. We observed heterogeneous sensitivities to S with EC50 values ranging from 16 nM to almost 10 µM. Protein expression of MCL-1 and other BCL-2 family members BCL-2, BCL-XL and BCL-W was assessed by western blot analysis and quantified, however neither association of MCL-1 levels nor expression of the other regulators and S sensitivity was found in cell lines and primograft leukemias. Moreover, we also compared sensitivities for both inhibitors but found independent activities of S and VEN in individual ALL samples. Next, we addressed the role of MCL-1 for VEN sensitivity and generated two MCL-1 knock out BCP-ALL cell lines by CRISPR/Cas9 gene editing. In both lines, clearly increased VEN sensitivities were observed upon depletion of MCL-1, indicating that MCL-1 is contributing to activity of the BCL-2 inhibitor VEN. Based on these findings, we investigated the effects of pharmacological MCL-1 inhibition for VEN sensitivity and incubated all 6 cell lines with VEN and S at increasing concentrations and observed clear synergistic effects upon combined BCL-2 and MCL-1 inhibition indicated by combination indices (CI) below 0.1. Moreover, we investigated 7 primograft BCP-ALL samples and found that MCL-1 inhibition by S clearly synergized with VEN activity (CI < 0.3). To investigate the anti-leukemia activity of co-targeting BCL-2 and MCL-1 in vivo in a pre-clinical setting, a high-risk leukemia derived from an infant, MLL/ENL rearranged pro-B ALL case was transplanted onto NOD/SCID mice. Upon ALL manifestation (presence of >5% human blasts in blood), recipients were treated with either VEN, S, the combination of both, or vehicle for 10 days. After treatment, leukemia loads were analyzed showing significantly reduced loads in the co-treated group as compared to vehicle, VEN or S alone in spleen, bone marrow, and central nervous system (p-values < 0.05), indicating synergistic activity of co-inhibition of BCL-2 and MCL-1 in vivo. Taken together, our data show heterogeneous sensitivity of individual BCP-ALL samples to MCL-1 inhibition by S, which is not associated with MCL-1 protein expression levels or VEN sensitivity. Both, genetic depletion and inhibition of MCL-1 by S synergizes with VEN leading to increased anti-leukemia activity in vitro and ex vivo. Importantly, co-targeting BCL-2 and MCL-1 significantly reduced leukemia infiltration in spleen, BM and CNS in a pre-clinical model of high-risk BCP-ALL, warranting further evaluation and possible clinical application of targeting MCL-1 alone and in combination with BCL-2 inhibition. Disclosures No relevant conflicts of interest to declare.

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