Marked synergism of cytotoxic agents with either a prenylation inhibitor or M-TOR inhibitor in acute leukemia cell lines: Potential clinical implications

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 13103-13103
Author(s):  
D. R. Budman ◽  
A. Calabro

13103 Background: The most combinations of anticancer drugs are based upon empiricism. The potential permutations of drugs overwhelm the clinical trials system. Acute leukemia is sensitive to a variety of agents but relapses are common. Targeted agents are attractive new venues of therapy both as single agents and in combination with older agents. Isobologram median effect analysis allows up to three agents to be studied together in vitro to identify interesting combinations. We evaluated a commercially available statin, fluvastatin, to block prenylation which affects a variety of pathways, rapamycin and its experimental analogue RAD001 as M-TOR inhibitors to block downstream of the AKT pathway, and cytotoxic agents. Methods: The human leukemia cell lines AML-193 and KG-1 were obtained from ATTC (Rockville, MD), fluvastatin and RAD001 from Novartis Pharma, and the other agents from Sigma-Aldrich (St. Louis, MO). The IC50 of the single agent was determined by a 72 hr incubation of log growth cells using a MTT assay and the EZ-ED50 program (Perrella Scientific, Conyers, CA). The dosages of all agents were at clinically achievable concentrations. All reported values were the means of at least 3 experiments with each study using 4 wells per point. For isobologram analysis, a minimum of 8 concentrations of drug mixtures were studied above and below the IC50. Median effect CI values less than 1 are synergistic. Results: Doublets of fluvastatin with Ara-C (0.7), daunomycin (0.4), idarubicin (0.7), RAD001 (0.5), or rapamycin (0.3) demonstrated synergy. Doublets of RAD001 with Ara-C (0.3), daunomycin (0.7), or idarubicin (0.5) demonstrated synergy. Triplets of RAD001/daunorubicin/Ara-C, RAD001/daunomycin/fluvastatin, and RAD001/Ara-C/idarubicin all demonstrated marked synergy in both cell lines. Conclusion: A new potential non classical combination for further investigation is RAD001 or rapamycin with an inhibitor of prenylation such as fluvastatin. Additional potential combinations include cytotoxics with either fluvastatin or RAD001, and triplet combinations. No significant financial relationships to disclose.

Radiology ◽  
1981 ◽  
Vol 139 (2) ◽  
pp. 485-487 ◽  
Author(s):  
R R Weichselbaum ◽  
J S Greenberger ◽  
A Schmidt ◽  
A Karpas ◽  
W C Moloney ◽  
...  

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4044-4044
Author(s):  
Blake S Moses ◽  
Jennifer Fox ◽  
Xiaochun Chen ◽  
Samantha McCullough ◽  
Sang Ngoc Tran ◽  
...  

Abstract Antimalarial artemisinins have broad antineoplastic activity in vitro, are well tolerated and inexpensive, and can be parenterally or orally administered in humans. Artemisinin-derived trioxane diphenylphosphate dimer 838 (ART838; a potent artemisinin-derivative) inhibited acute leukemia growth in vivo and in vitro, at doses where normal human CD34+ hematopoietic stem-progenitor cell clonogenicity was essentially unaffected (Fox et al, Oncotarget 2016, PMID: 26771236). In our focused drug combination screen for drugs that synergize with ART838, the only BCL2 inhibitors in the screen library of 111 emerging antineoplastic compounds, navitoclax (ABT737) and venetoclax (ABT199; FDA-approved), were identified as 2 of the top 3 candidates. Synergies between ART838 and BCL2 inhibitors were validated in multiple acute leukemia cell lines and primary cases. This ART838-BCL2 inhibitor synergy may be due to reduced levels of MCL1 protein that we and others have observed in multiple acute leukemia cell lines and primary cases treated with artemisinins (Budhraja et al, Clin Cancer Res 2017, PMID: 28974549). Treatment of acute leukemia xenografts with the ART838 plus ABT199 combination reduced leukemia growth rates and prolonged survivals, compared to vehicle or either ART838 or ABT199 alone. To add to the efficacy of this ART838 plus ABT199 treatment regimen, we sought to rationally add a third low-toxicity active antileukemic agent. Sorafenib (SOR; FDA-approved) inhibits multiple kinases which may mediate its antileukemic activity, with the importance of the targets varying from case to case; e.g. FLT3 is an important target in many AMLs. In addition, several reports have found that SOR reduces MCL1 protein stability and translation through inhibition of the ERK and PI3K pathways (Wang et al, Clin Cancer Res 2016, PMID: 26459180; Huber et al, Leukemia 2011, PMID: 21293487). In all acute leukemia cell lines tested, we observed large reductions in MCL1 protein levels with SOR treatment, which may further rationalize the addition of SOR to our ART838 plus ABT199 antileukemic regimen. We had previously observed strong in vitro synergy between ART838 and SOR (PMID: 26771236). Treatment of acute leukemia xenografts with the ART838 plus SOR combination reduced leukemia xenograft growth rates and prolonged survivals, compared to single drugs. Mice bearing luciferase-labelled acute leukemia xenografts were treated (PO daily x5) with single drug or 2-drug or 3-drug combinations of ART838, ABT199, and SOR, each at their individual maximally tolerated doses. Treatment with this 3-drug combination caused rapid regression of luciferase-labelled MV4;11 AML xenografts (Fig 1A). The 5-day treatment cycles were repeated every other week, and mice receiving this 3-drug combination survived >4 times longer than vehicle-treated mice (Fig 1B). Mouse body weights were stable during treatment. Although myelosuppression is the human clinical dose-limiting toxicity of each of these 3 drugs, mouse blood cell counts during 3-drug combination treatment were in the normal range. Treatment of a luciferase-labelled primary AML leukemia xenograft with this 3-drug combination reduced leukemia growth more than the single drugs or 2-drug combinations (Fig 1C). Assessment of efficacy and pharmacokinetics-pharmacodynamics against diverse acute leukemia xenografts will test this combination of ART838, ABT199 plus SOR as a rational low-toxicity drug triad for treatment of acute leukemias and potentially other cancers. Disclosures Fox: Intrexon Corporation: Employment. Tyner:Genentech: Research Funding; Janssen: Research Funding; AstraZeneca: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Constellation: Research Funding; Array: Research Funding; Takeda: Research Funding; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; Aptose: Research Funding. Civin:ConverGene LLC: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; GPB Scientific LLC: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; 3DBioWorks Inc: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; BD (Becton Dickinson): Honoraria.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2498-2498
Author(s):  
Jeffrey L. Cleland ◽  
Alvin Wong ◽  
Susan E. Alters ◽  
Peter A. Harris ◽  
Chris R. Dunk ◽  
...  

Abstract An ideal treatment for lymphoma and leukemia is the use of highly selective compounds to eliminate diseased cells with minimal systemic toxicity to normal tissues (cf. imatinib mesylate; Gleevec). AQ4N (1,4 bis[[2-(dimethylamino)ethylamino}-5,8-hydroxyanthracene-9,10-dione bis N-oxide) is designed to have little or no toxicity until selectively activated by bioreduction in hypoxic cells to AQ4 (reduced AQ4N), a highly potent DNA topoisomerase II inhibitor. In a series of studies, AQ4 has been shown to have potent cytotoxicity on lymphoma and leukemia cell lines in vitro and AQ4N has selective activity in lymphatic tissues in vivo. The IC50 of AQ4, was 0.63, 12.0, 90.5 and 150 nM in Namalwa, Daudi, Ramos, and Raji human lymphoma cell lines and 1.0, 6.0, and 20 nM in HL-60, KG1a and K562 human leukemia cell lines. On several of the tumor lines the activity of AQ4 was more potent than doxorubicin (i.e. IC50 for Dox was 20.3 nM on Namalwa). AQ4N also had anti-proliferative activity at μM levels indicating a potential mechanism for activation by these cell lines. In repeat dose toxicology studies of AQ4N in pigmented rats and cynomolgus monkeys, the maximum tolerated doses (MTD; rats: 20 mg/kg/wk x 6; monkeys 6 mg/kg/wk x 6) resulted in lymphoid tissue atrophy. A decrease in lymphocyte levels and atrophy of the spleen, thymus, and mandibular and mesenteric lymph nodes were observed at terminal sacrifice of the animals. In contrast, there was an absence of myelosuppression and only mild neutropenia and minor bone marrow atrophy at the MTD. Administration of radiolabeled AQ4N (14C-benzene) to pigmented rats and cynomolgus monkeys indicated persistence of AQ4N radioactivity in lymphoid tissues for several weeks after a single dose (rats: 20 mg/kg (130–140 μCi/kg); monkeys: 10 mg/kg (135 μCi/kg)). For example, in rats the half-life of radioactive AQ4N in the spleen was 538 hrs with 0.9 μg AQ4N/g tissue (spleen) remaining one week after dosing. Monkeys demonstrated a similar effect with 76.5–86.8 μg AQ4N/g tissue observed in the spleen one week after treatment. Other tissues contained significantly less radioactive AQ4N with the exception of the liver (67.9–78.6 μg AQ4N/g tissue) and adrenal cortex (78.7–86.6 μg AQ4N/g tissue). While some hypertrophy and eosinophila was observed in the adrenal glands, liver toxicity was not observed at the MTD in the repeat dose cynomolgus monkey toxicology study. Overall, these initial findings indicate that AQ4N is active in vitro against human lymphoma and leukemia cell lines and selectively targets lymphoid tissues in vivo suggesting the potential benefit of AQ4N in the treatment of lymphoproliferative diseases.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Farideh Namvar ◽  
Heshu Sulaiman Rahman ◽  
Rosfarizan Mohamad ◽  
Abdullah Rasedee ◽  
Swee Keong Yeap ◽  
...  

Gold nanoparticles were grown onSargassum muticumwater extract (S-GNPs) using the green biosynthetic approach. The nanoparticles were characterized using UV-visible spectroscopy, zeta potential, and transmission electron microscopy (TEM). The resulting S-GNPs were spherical and crystalline with a size of <10 nm. Thein vitroanticancer activity was demonstrated in human leukemia cell lines. The cancer cells were treated with different concentrations of S-GNPs, and calorimetric (MTT) assay used for the cytotoxicity test, which resulted in an IC50value of 4.22 ± 1.12, 5.71 ± 1.4, 6.55 ± 0.9, and 7.29 ± 1.7 μg/mL for each of the K562, HL-60, Jurkat, and CEM-ss cells, respectively. Thus, the K562 was selected for the next experiments. Furthermore, apoptosis induction was confirmed by Hoechst 33342, annexin V staining, and caspase-3/-9 activity tests. The cell cycle analysis exhibited a significant increase in the accumulation of S-GNPs treated cells at the sub-G1 phase, demonstrating the induction of apoptosis by S-GNPs. The nature of the inhibition of cancer cell growth by S-GNPs could open the way for further research in the design of green synthesis therapeutic agents, particularly in nanomedicine, for the treatment of cancer.


2017 ◽  
Vol 54 (5) ◽  
pp. 263-270 ◽  
Author(s):  
Neslihan Tekin ◽  
Kamile Öztürk ◽  
Talat Baran ◽  
Barış Kerimoğlu ◽  
Mehtap Tarhan ◽  
...  

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4936-4936
Author(s):  
Pritesh R. Patel ◽  
Dolores Mahmud ◽  
Damiano Rondelli

Abstract The alkylator Busulfan (Bu) is used in conditioning regimens for acute leukemia prior to allogeneic stem cell transplant. Multiple DNA repair mechanisms including mismatch repair and base excision repair have been implicated in resistance to Bu. The enzyme PARP is central to base excision repair. We hypothesized that treatment of acute leukemia cell lines with both ABT888 (Veliparib), an inhibitor of PARP 1 and 2, and Bu would lead to synergistic cell kill and that this effect is maximal in mismatch repair deficient cells. Two mismatch repair proficient cell lines (K562 and HL60) and 2 mismatch repair deficient cell lines (NB4 and REH) were treated with ABT888 alone, Bu alone or a combination of both. In single drug experiments, doses of drug treatment ranged from 0-400mcg/ml. In combination experiments a fixed dose of ABT888 of 1.25mcg/ml was utilized with Bu doses varying from 0-200mcg/ml. This dose of ABT888 was chosen as it approximated to patient blood levels in clinical trials. After 24 hours of treatment, cells were washed and resuspended in fresh medium. Proliferation of cells was measured by standard 3H-thymidine uptake assay at 48 hours. Sigmoidal dose response curves and GI50 values were then calculated. In addition, cells were tested for apoptosis by flow cytometry using activated caspase 3 and annexin/ PI staining at 24 and 48 hours after treatment. All 4 cell lines were found to be resistant to single agent ABT888. Despite mismatch repair deficiency in REH cells, therapeutic doses of ABT888 did not cause significant decreases in proliferation. The effect of ABT888 was, as expected, much less evident in the mismatch repair proficient K562 cells. These cells were also relatively resistant to single agent Bu in vitro. The combination of Bu and ABT888 was synergistic in all cell lines with GI50 (micromoles/ml) for Bu decreasing from 67.8 to 45.7 in K562, from 23.3 to 8.0 in HL60, from 46.6 to 36.1 in NB4 and from 34.4 to 17.0 in REH cells. The Combination Index was <1 in all cell lines indicating synergy. Dose Reduction Index, indicating the factor by which the dose of Bu can be decreased to achieve the same treatment effect size, ranged from 1.45 to 3.1. The synergistic effect was greatest in the mismatch repair deficient cell line REH (Combination Index 0.53, Dose Reduction Index 3.1). As expected, the synergistic effect observed did not correlate with increased apoptotic death of leukemic cells implying an alternative mechanism for the derease in proliferation. To our knowledge, this is the first study to show synergy of a clinically available PARP inhibitor with Bu. We believe this data warrants further study with the potential clinical application of increasing the antileukemic effect of stem cell transplantation conditioned with Bu containing preparative regimens. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2002 ◽  
Vol 100 (12) ◽  
pp. 3968-3974 ◽  
Author(s):  
Hiroshi Nishihara ◽  
Masae Maeda ◽  
Atsushi Oda ◽  
Masumi Tsuda ◽  
Hirofumi Sawa ◽  
...  

The CDM (ced-5 of Caenorhabditis elegans,DOCK180 [downstream of Crkwith molecular weight of 180 kDa] of humans, andmyoblast city of Drosophila melanogaster) family of proteins has been shown to play a pivotal role in the integrin-mediated signaling pathway under the regulation of an adaptor moleculec-CT10–related kinase II (c–Crk-II) in adherent cells. Recently, hematopoietic cell–specific CDM protein DOCK2 has been shown to be indispensable for lymphocyte migration. However, the regulatory mechanism for DOCK2 is still unknown because DOCK2 lacks a c–Crk-II binding consensus motif. In this study, we demonstrated that DOCK2 bound to CrkL, which is present exclusively in hematopoietic cells both in vivo and in vitro, and we also found that 2 separate regions of DOCK2 contributed to its binding to Src homology 3 (SH3) domain of CrkL. Colocalization of DOCK2 with Crk-like (CrkL) and F-actin was shown by immunocytochemical analysis with the use of Jurkat cells. We also found that CrkL-induced activation of small guanine triphosphatase (GTPase) Rac1 was significantly inhibited by the DOCK2-dCS mutant in 293T cells. Furthermore, the association of DOCK2 and Vav, the guanine-nucleotide exchanging factor (GEF) for Rac1, was demonstrated in Jurkat cells. Finally, the stable expression of DOCK2-dCS mutant in Jurkat cells was shown to reduce cell attachment. These data suggest the presence of a novel protein complex of CrkL, DOCK2, and Vav to regulate Rac1 in leukemia cell lines.


2021 ◽  
Vol 5 (3) ◽  
pp. 711-724
Author(s):  
Blake S. Moses ◽  
Samantha McCullough ◽  
Jennifer M. Fox ◽  
Bryan T. Mott ◽  
Søren M. Bentzen ◽  
...  

Abstract Artemisinins are active against human leukemia cell lines and have low clinical toxicity in worldwide use as antimalarials. Because multiagent combination regimens are necessary to cure fully evolved leukemias, we sought to leverage our previous finding that artemisinin analogs synergize with kinase inhibitors, including sorafenib (SOR), by identifying additional synergistic antileukemic drugs with low toxicity. Screening of a targeted antineoplastic drug library revealed that B-cell lymphoma 2 (BCL2) inhibitors synergize with artemisinins, and validation assays confirmed that the selective BCL2 inhibitor, venetoclax (VEN), synergized with artemisinin analogs to inhibit growth and induce apoptotic cell death of multiple acute leukemia cell lines in vitro. An oral 3-drug “SAV” regimen (SOR plus the potent artemisinin-derived trioxane diphenylphosphate 838 dimeric analog [ART838] plus VEN) killed leukemia cell lines and primary cells in vitro. Leukemia cells cultured in ART838 had decreased induced myeloid leukemia cell differentiation protein (MCL1) levels and increased levels of DNA damage–inducible transcript 3 (DDIT3; GADD153) messenger RNA and its encoded CCATT/enhancer-binding protein homologous protein (CHOP), a key component of the integrated stress response. Thus, synergy of the SAV combination may involve combined targeting of MCL1 and BCL2 via discrete, tolerable mechanisms, and cellular levels of MCL1 and DDIT3/CHOP may serve as biomarkers for action of artemisinins and SAV. Finally, SAV treatment was tolerable and resulted in deep responses with extended survival in 2 acute myeloid leukemia (AML) cell line xenograft models, both harboring a mixed lineage leukemia gene rearrangement and an FMS-like receptor tyrosine kinase-3 internal tandem duplication, and inhibited growth in 2 AML primagraft models.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3462-3462
Author(s):  
Xi Jiang ◽  
Hao Huang ◽  
Zejuan Li ◽  
Yuanyuan Li ◽  
Ping Chen ◽  
...  

Abstract Abstract 3462 Acute myeloid leukemia (AML) bearing MLL (mixed lineage leukemia) translocations are associated with poor survival, and only fewer than 50% of the patients survive longer than 5 years. Thus, an improved strategy leading to a higher cure rate is urgently needed to treat MLL-associated AML. MicroRNAs (miRNAs), a class of small non-coding RNAs, have been postulated to be important gene expression regulators in all biology including human leukemia. Through large-scale, genome-wide miRNA expression profiling assays, we determined that miR-495 is significantly down-regulated in the majority of human AML samples, particularly, in those with MLL rearrangements. More interestingly, through correlating the expression signature of miR-495 with clinical outcome of AML patients, we revealed that a low expression level of miR-495 is a predictor of poor prognosis in most AML patients. Our further qPCR assays confirmed that the expression of miR-495 is even more significantly downregulated in MLL-rearranged AML primary patient samples and cell lines. Through in vitro colony-forming/replating assays and in vivo bone marrow transplantation studies, we found that forced expression of miR-495 significantly inhibits the capacity of the MLL-AF9 fusion gene to support colony formation in mouse bone marrow progenitor cells in vitro and to induce leukemia in vivo. In leukemia cell lines, overexpression of miR-495 greatly inhibits the viability of the cells, while increasing apoptosis. Furthermore, by using 3 algorithms for miR-495 3'UTR binding sites, we identified several well-known MLL leukemia-related genes, e. g. BMI1, MEF2C, BID and MEIS1, as potential targets of miR-495. Results of qPCR revealed that forced expression of miR-495 significantly inhibits the expression levels of these genes in leukemia cell lines, mouse bone marrow progenitor cells, as well as mouse peripheral blood cells with MLL fusion genes. Therefore we hypothesize that miR-495 may function as a tumor suppressor in AML with MLL rearrangements by targeting essential tumor-related genes. Further studies will focus on: 1) effects of miR-495 on the functions of target genes studied in vitro and in vivo; 2) the epigenetic mechanisms and the signaling pathways involved in regulating the expression level of miR-495 in human leukemia. Disclosures: No relevant conflicts of interest to declare.


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