The Lysosomotropic Agent, Hydroxychloroquine, Delivered in a Biodegradable Nanoparticle System, Overcomes Drug Resistance of B-Chronic Lymphocytic Leukemia CellsIn Vitro

2010 ◽  
Vol 25 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Eduardo Mansilla ◽  
Gustavo H. Marin ◽  
Luis Nuñez ◽  
Hugo Drago ◽  
Flavio Sturla ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Chronic Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Lysosomotropic Agent ◽  
Nanoparticle System ◽  
Biodegradable Nanoparticle

Standardizing Co-Culture Conditions Between Chronic Lymphocytic Leukemia Cells and Marrow Stromal Cells: Towards a Reliable and Reproducible System to Assess Cell Adhesion-Mediated Drug Resistance

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3149-3149
Author(s):  
Antonina Kurtova ◽  
Maite P. Quiroga ◽  
William G. Wierda ◽  
Michael Keating ◽  
Jan A. Burger
Keyword(s):  
Bone Marrow ◽  
Drug Resistance ◽  
Cell Adhesion ◽  
Chronic Lymphocytic Leukemia ◽  
Stromal Cells ◽  
Lymphocytic Leukemia ◽  
Marrow Stromal Cells ◽  
Hpv E6 ◽  
Induced Apoptosis

Abstract Contact between chronic lymphocytic leukemia (CLL) cells and accessory stromal cells in tissue microenvironments is considered to play a major role in regulating CLL cell survival and disease progression. Stromal cells of various origins and species, and variable stromal-CLL cell ratios have been used in the past to study CLL-stromal cell interactions and to assess cell-adhesion mediated drug resistance (CAM-DR). Because of the heterogeneity of the currently used in vitro systems to study CLL-MSC interactions, and the importance of these co-culture systems for development and testing of novel agents, we tested a panel of murine and human MSC lines for their capacities to support CLL cell survival and CAM-DR, using various CLL-MSC ratios and fludarabine (F-ara-A) to induce CLL cell apoptosis. We tested four murine, non-transformed MSC lines derived from bone marrow: M210B4, KUM4, ST-2 and KUSA-H1. Also, we tested three human transformed cell lines: Stroma-NKtert, derived from bone marrow and immortalized by human telomerase reverse transcriptase (hTERT), UE6E7-T2 derived from bone marrow and transformed with human papilloma viruses (HPV) E6, E7 and hTERT, and UCB408E6E7Tert33 derived from umbilical cord blood and transformed with hTERT and HPV E6, E7. CLL cells were isolated from peripheral blood of untreated patients and each cell line was tested with at least three different patients according to the following protocol: viability of CLL was tested after 24, 48 and 72 hours by flow cytometry after staining with DiOC6 and propidium iodide. The following conditions were assayed on each of the MSC lines: CLL cells in suspension culture, CLL cells in suspension culture with 10 mM F-ara-A, CLL cells in co-culture with MSC, and CLL cells in co-culture with MSC and with 10 mM F-ara-A. Firstly, we performed titration experiments in order to identify the most appropriate ratio between stromal and CLL cells, using CLL-MSC ratios of 5:1, 10:1, 20:1, 50:1 and 100:1. We found a decline in MSC-derived CLL cell protection at the highest ratio of 100:1, suggesting that ratios of 50:1 or lower provide optimal conditions for in vitro assays. Results shown in Table 1 were assayed using a 20:1 ratio and represented relative viabilities when compared to untreated controls (mean±SEM). Regarding the protective effect of different MSC, we found that all MSC lines demonstrated remarkable protection of CLL cells from spontaneous and F-ara-A-induced apoptosis. We also found that stromal cells that had round shape morphology and easily formed confluent monolayer (M210B4, KUSA-H1, Stroma-NKTert) showed more prolonged protective effect in comparison to cell lines with more spindle shaped morphology (ST-2, KUM4, UE6E7-T2). The failure of UE6E7-T2 and UCB408E6E7Tert33 to demonstrate long-term protection of CLL cells could be related to their own sensitivity to F-ara-A. In this comparative study we demonstrated that both murine and human MSC provide substantial and comparable levels of protection from spontaneous and drug-induced apoptosis. CLL:MSC ratios of 50:1 or lower can be considered ideal for co-culture experiments. Further experiments have to be done to determine the levels of MSC-derived protection in a larger series of CLL samples and in different laboratories for validation. Collectively, in these co-culture assays we can study CLL-MSC interactions and CLL drugs under more standardized conditions that may allow us to evaluate the efficacy of new treatments that target the CLL microenvironment. Time points 24 hours 48 hours 72 hours +Flu + MSC + MSC +Flu +Flu + MSC + MSC +Flu +Flu +MSC + MSC +Flu M210B4 85.2±2.4 117.2±5.0 110.5±4.9 30.8±12.6 138.1±9.5 113.0±2.2 5.2±3.1 138.1±5.1 120.4±3.4 ST-2 93.6±3.0 99.9±2.6 103.1±0.5 51.6±9.4 111.9±2.6 89.8±8.7 13.9±6.3 112.6±5.7 87.0±16.4 KUM-4 93.6±3.0 106.4±1.8 104.2±1.9 51.6±9.4 112.4±2.6 100.8±2.8 13.9±6.3 111.8±6.7 88.5±11.4 KUSA-H1 79.4±7.4 125.1±3.7 118.2±2.0 33.9±10.9 136.0±3.6 107.2±7.0 11.3±6.1 133.6±5.4 84.9±7.6 Stroma-NKTert 79.3±7.0 118.6±7.0 111.0±7.0 30.5±9.5 130.7±9.5 115.6±8.0 7.1±4.3 133.0±11.5 122.7±9.0 UE6E7-T2 79.3±7.0 113.4±3.9 109.3±3.0 30.5±9.5 118.4±4.8 85.0±7.1 7.1±4.3 119.2±6.9 51.0±10.1 UCB408 E6E7Tert33 81.5±7.2 120.2±5.4 111.8±2.7 36.7±9.4 123.7±6.3 86.7±7.7 8.5±6.7 119.7±6.1 50.8±13.0 Table 1. Flu: fludarabine (10mM/ml), MSC: marrow stromal cells

ROS-Mediated Upregulation of Noxa Overcomes Drug-Resistance Due to P53-Dysfunction in Chronic Lymphocytic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2382-2382
Author(s):  
Sanne H. Tonino ◽  
Jacoline M van Laar ◽  
Marinus H. J. van Oers ◽  
Jean Y.J. Wang ◽  
Eric Eldering ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Death ◽  
Chronic Lymphocytic Leukemia ◽  
Combination Treatment ◽  
Conflicts Of Interest ◽  
Alkylating Agents ◽  
Single Agent ◽  
Treatment Strategies ◽  
Cd40 Ligand ◽  
Lymphocytic Leukemia

Abstract Abstract 2382 Poster Board II-359 Although recent advances in treatment-strategies for chronic lymphocytic leukemia (CLL) have resulted in increased remission rates and response duration, the disease eventually relapses, which necessitates repeated cycles of therapy. Eventually most patients develop chemo-resistant disease which infers a very poor prognosis. The activity of purine-analogs and alkylating agents, the backbone of current treatment regimens, depends on functional p53 and chemo-resistance is highly associated with a dysfunctional p53-response. P53-independent sensitization of CLL cells to these compounds could represent a novel strategy to overcome chemo-resistance. Platinum-based compounds have been successfully applied in relapsed lymphoma and recently also in high-risk CLL. In various cancer-types, the activity of such compounds has been found to be p53-independent and in part mediated by p73. In this study we investigated the efficacy and mechanism of action of platinum-based compounds in chemo-refractory CLL. Neither cisplatinum nor oxaliplatin as a single agent induced cell death in clinically relevant doses. However, independent of p53-functional status, platinum-based compounds acted synergistically with fludarabine, which was found to be caspase-dependent. Combination-treatment resulted in strong upregulation of the pro-apoptotic BH3-only protein Noxa. We did not find evidence for a role of p73; however, the observed synergy was found to involve generation of reactive oxygen species (ROS). Co-treatment with ROS-scavengers completely abrogated Noxa-upregulation and cell-death upon combination treatment in p53-dysfunctional CLL. Noxa RNA-interference markedly decreased sensitivity to combination treatment, supporting a key role for Noxa as mediator between ROS signaling and apoptosis induction. In addition to these findings, we tested the effects of platinum-based compounds and fludarabine on drug-resistance resulting from CD40-ligand stimulation of CLL cells, which represents a model for CLL cells in the protective micro-environment of the secondary lymph node-tissue (Hallaert et al Blood 2008 112(13):5141). Combination treatment could overcome CD40-ligand induced chemo-resistance and was, at least in part, mediated by the generation of ROS and marked induction of expression of Noxa. Our data indicate that interference with the cellular redox-balance represents an interesting target to overcome drug resistance due to both p53-dysfunction as well as micro-environmental protective stimuli in CLL. Disclosures: No relevant conflicts of interest to declare.

Mapping the Targets of Dasatinib in Chronic Lymphocytic Leukemia Reveals Distinct Roles for Abl and Btk in Drug Resistance and Adhesion, and Explains Clinical Effects On Lymph Node Reduction

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3900-3900
Author(s):  
Eric Eldering ◽  
Christian R Geest ◽  
Martin FM de Rooij ◽  
Nora Liu ◽  
Bogdan I Florea ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Lymph Node ◽  
Chronic Lymphocytic Leukemia ◽  
Broad Spectrum ◽  
Kinase Inhibitor ◽  
Conflicts Of Interest ◽  
Lymphocytic Leukemia ◽  
Clinical Effects ◽  
Open Label

Abstract Abstract 3900 In the lymph node (LN) microenvironment, chronic lymphocytic leukemia (CLL) cells are protected from apoptosis by upregulation of anti-apoptotic proteins. In vitro, this can be mimicked via CD40-stimulation of CLL cells, which also provides resistance to various chemotherapeutics. Novel drugs that target kinases involved in B cell signalling, including the broad spectrum kinase inhibitor dasatinib, are currently in clinical development for CLL. We have shown previously that dasatinib prevents CD40-mediated anti-apoptotic changes in CLL (Hallaert et Blood 2008). However, the kinase(s) involved remain unidentified. Here, we coupled dasatinib to an affinity matrix and pulled down its targets from CD40-stimulated CLL cells. By mass-spectrometry and Western blotting, Abl and Btk were identified as dominant targets of dasatinib. Functional analysis revealed that CD40-mediated anti-apoptotic signals and drug-resistance could be overcome both by dasatinib and the Abl inhibitor imatinib, but not by the novel Btk inhibitor PCI-32765 (ibrutinib), whereas BCR- and chemokine-controlled adhesion could be abolished by dasatinib and ibrutinib, but not by imatinib. Thus, dasatinib combines two key aspects that are clinically relevant: inhibition of Abl overrides chemoprotective survival signals, whereas inhibition of Btk impairs integrin-mediated adhesion of CLL cells in the microenvironmental niche. This combined inhibition of Abl and Btk was put to an initial test in an open-label phase 2 trial of dasatinib combined with fludarabine in twenty refractory CLL patients. As might be expected based on the in vitro data, reductions in lymph node size were observed in most patients. A LN reduction of ≥20% provided a significant improved PFS (256 days) and OS (510 days) as compared to non-responders (80 days and 158 days respectively). Details of the clinical study will be presented separately. In conclusion, in agreement with in vitro molecular studies, dasatinib seems to have clinical efficacy in heavily pretreated refractory CLL patients. Combined, these data encourage further studies on a broad-spectrum kinase inhibitor like dasatinib in combination with other classes of drugs in relapsed and refractory CLL. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Targeting PAK1 Overcomes Resistance to Ibrutinib in Chronic Lymphocytic Leukemia

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1546-1546
Author(s):  
Zijuan Wu ◽  
LEI Fan ◽  
Luqiao Wang ◽  
Hanning Tang ◽  
Yi Miao ◽  
...  
Keyword(s):  
Drug Resistance ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
High Throughput ◽  
Combination Index ◽  
Lymphocytic Leukemia ◽  
Chromatin Conformation ◽  
Rna Seq ◽  
Ibrutinib Resistance

Abstract Objective: Chronic lymphocytic leukemia (CLL) is a lymphoproliferative disorder that mainly affects the elderly and is characterized by the expansion of small mature B-cells. New targeted drugs, such as the BTK inhibitor ibrutinib, have greatly improved patient survival but have also posed the challenge of drug resistance. The three-dimensional (3D) spatial structure of chromatin is highly dynamic and varies greatly between cell types and developmental stages, with the maintenance of chromatin homeostasis being of major significance in disease prevention. Accumulating evidence has suggested that changes in 3D genomic structures play an important role in cell development and differentiation, disease progression, as well as drug resistance. Nevertheless, the characteristics and functional significance of chromatin conformation in the resistance of CLL to ibrutinib remain unclear. In this study, we aimed to investigate the mechanism underlying ibrutinib resistance through multi-omics profiling, including the study of chromatin conformation. Thus, we would be able to demonstrate the importance of chromatin spatial organization in CLL and highlight the oncogenic factors contributing to CLL development and mediating ibrutinib resistance. Methods: An ibrutinib-resistant cell line was established by exposing cells to increasing doses of ibrutinib. High-throughput chromosome conformation capture (Hi-C), assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq), bulk RNA sequencing (RNA-seq), and Tandem Mass Tag (TMT) were performed to explore differences between ibrutinib-resistant and parental cells. Peripheral blood mononuclear cells (PBMCs) from 53 CLL patients were collected for RNA-seq. Mitochondrial respiration and glycolysis were assessed via Seahorse analysis. The growth-inhibitory effects of tested drugs were evaluated via a CCK8 assay, and the combination index (CI), indicating synergy, was calculated using CompuSyn software. Apoptosis was detected via annexin V staining. Results: Between ibrutinib-resistant and parental cells changes in some chromosomes, including chr11 were observed (Figure 1A). p21-activated kinase 1 (PAK1), which is located on chr11 and frequently overexpressed or excessively activated in almost all cancer types and involved in almost every stage of cancer progression, was first explored for its role in CLL progression and drug resistance. The oncogene PAK1 was observed locate in a region where B-to-A compartment switching occurred (Figure 1B). Consistent with the results of ATAC-seq, RNA-seq, and TMT, Hi-C analysis revealed a transcriptional upregulation of PAK1 in ibrutinib-resistant CLL cells (Figure 1C). Functional analysis demonstrated that PAK1 overexpression significantly promoted cell proliferation, while knockdown markedly suppressed cell viability (Figure 1D). Cell viability assays indicated that the depletion of PAK1 increased ibrutinib sensitivity (Figure 1E). In addition, PAK1 positively regulates glycolysis and oxidative phosphorylation in CLL cells (Figure 1F and G). To verify the results of sequencing and further explore the role of PAK1 in CLL, B-cells from healthy volunteers and PBMCs from CLL patients were collected. The level of PAK1 mRNA expression was significantly higher in CLL primary cells than in B-cells from healthy volunteers (Figure 1H). Kaplan-Meier survival analysis of qRT-PCR data confirmed that patients with high PAK1 expression had a significantly lower OS (Figure 1I). IPA-3, the small molecular inhibitor of PAK1 suppressed the proliferation of ibrutinib-resistant and parental CLL cells in a dose-dependent manner. The combination of IPA-3 and ibrutinib exerted potent cell growth inhibition (Figure 1J), and the combination index (CI) calculated using the CompuSyn software confirmed the synergistic effect (CI<1) of this combinatorial therapy (Figure 1K). Conclusions: In the current study, we have provided a genome-wide view of alterations in 3D chromatin organization between ibrutinib-resistant and parental CLL cells and confirmed the oncogenic role of PAK1 in CLL. Most importantly, our research provides promising therapeutic targets for overcoming ibrutinib resistance. In particular, the treatment of CLL patients with a combination of IPA-3 and ibrutinib may improve clinical outcomes. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals p53 gene mutation in B-cell chronic lymphocytic leukemia is associated with drug resistance and is independent of MDR1/MDR3 gene expression

Blood ◽  
1993 ◽  
Vol 82 (11) ◽  
pp. 3452-3459 ◽  
Author(s):  
S el Rouby ◽  
A Thomas ◽  
D Costin ◽  
CR Rosenberg ◽  
M Potmesil ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Gene Mutations ◽  
P53 Gene ◽  
Lymphocytic Leukemia ◽  
P53 Mutations ◽  
P53 Gene Mutation ◽  
P53 Gene Mutations ◽  
Cell Chronic Lymphocytic Leukemia

We studied 53 patients with B-cell chronic lymphocytic leukemia (B-CLL) and found mutations of the p53 gene in 15%. Patients with p53 gene mutations were found to have an aggressive form of B-CLL disease characterized by advanced Rai stage, rapid lymphocyte doubling time (LDT), and resistance to chemotherapy. While 27 of 29 treated patients (93%) without p53 mutations achieved a partial remission, only one of seven treated patients (14%) with p53 mutations achieved a partial remission (P = .00009). Adjusting for prognostic factors (age, sex, race, and Rai stage), patients with p53 gene mutations had a 13-fold greater risk of death than patients without p53 mutations (P = .013). In addition to examining the clinical relevance of p53 gene mutations in B-CLL, we investigated the possible role of p53 gene regulation in the expression of the multidrug resistance genes MDR1 and MDR3. We quantitated MDR1 and MDR3 mRNA expression by reverse transcription- polymerase chain reaction (RT-PCR). Expression of both the MDR1 and MDR3 genes was independent of p53 gene mutation or prior drug treatment, and did not predict for clinical response. Our findings indicate that p53 gene mutations in B-CLL are associated with a poor clinical outcome and may be a prognostic indicator for drug resistance.

scholarly journals Ibrutinib in Chronic Lymphocytic Leukemia: Clinical Applications, Drug Resistance, and Prospects

2020 ◽  
Vol Volume 13 ◽  
pp. 4877-4892
Author(s):  
Hong Zhou ◽  
Pan Hu ◽  
Xiyue Yan ◽  
Yaping Zhang ◽  
Wenyu Shi
Keyword(s):  
Drug Resistance ◽  
Chronic Lymphocytic Leukemia ◽  
Clinical Applications ◽  
Lymphocytic Leukemia

scholarly journals Dual TORK/DNA-PK inhibition blocks critical signaling pathways in chronic lymphocytic leukemia

Blood ◽  
2016 ◽  
Vol 128 (4) ◽  
pp. 574-583 ◽  
Author(s):  
Rachel Thijssen ◽  
Johanna ter Burg ◽  
Brett Garrick ◽  
Gregor G. W. van Bochove ◽  
Jennifer R. Brown ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Chronic Lymphocytic Leukemia ◽  
Signaling Pathways ◽  
Lymphocytic Leukemia ◽  
Clinical Effects ◽  
Key Points

Key Points TORK/DNA-PK inhibition induces cytotoxicity and blocks signaling pathways important for CLL survival, proliferation, and drug resistance. Preliminary clinical effects of TORK/DNA-PK inhibition show 7 of 8 CLL patients with decreased lymphadenopathy.

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