scholarly journals Notch2 Increases the Resistance to Venetoclax-Induced Apoptosis in Chronic Lymphocytic Leukemia B Cells by Inducing Mcl-1

2022 ◽  
Vol 11 ◽  
Author(s):  
Stefania Fiorcari ◽  
Rossana Maffei ◽  
Claudio Giacinto Atene ◽  
Nicolò Mesini ◽  
Monica Maccaferri ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Acquired Resistance ◽  
Lymphocytic Leukemia ◽  
Drug Induced ◽  
Effective Response ◽  
Incurable Disease ◽  
Trisomy 12 ◽  
Leukemic Clone ◽  
Induced Apoptosis ◽  
Interferon Regulatory Factor 4

Chronic lymphocytic leukemia (CLL) has experienced a clinical revolution—thanks to the discovery of crucial pathogenic mechanisms. CLL is still an incurable disease due to intrinsic or acquired resistance of the leukemic clone. Venetoclax is a Bcl-2 inhibitor with a marked activity in CLL, but emerging patterns of resistance are being described. We hypothesize that intrinsic features of CLL cells may contribute to drive mechanisms of resistance to venetoclax. We analyzed the expression of Interferon Regulatory Factor 4 (IRF4), Notch2, and Mcl-1 in a cohort of CLL patients. We evaluated CLL cell viability after genetic and pharmaceutical modulation of Notch2 expression in patients harboring trisomy 12. We tested venetoclax in trisomy 12 CLL cells either silenced or not for Notch2 expression or in combination with an inhibitor of Mcl-1, AMG-176. Trisomy 12 CLL cells were characterized by low expression of IRF4 associated with high levels of Notch2 and Mcl-1. Notch2 and Mcl-1 expression determined protection of CLL cells from spontaneous and drug-induced apoptosis. Considering the involvement of Mcl-1 in venetoclax resistance, our data demonstrated a contribution of high levels of Notch2 and Mcl-1 in a reduced response to venetoclax in CLL cells carrying trisomy 12. Furthermore, reduction of Mcl-1 expression by silencing Notch2 or by treatment with AMG-176 was able to restore the response of CLL cells to venetoclax. The expression of Notch2 identifies a subset of CLL patients, mainly harboring trisomy 12, characterized by high levels of Mcl-1. This biological mechanism may compromise an effective response to venetoclax.

scholarly journals Nurse-Like Cells and Chronic Lymphocytic Leukemia B Cells: A Mutualistic Crosstalk inside Tissue Microenvironments

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 217
Author(s):  
Stefania Fiorcari ◽  
Rossana Maffei ◽  
Claudio Giacinto Atene ◽  
Leonardo Potenza ◽  
Mario Luppi ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Hematological Disease ◽  
Drug Induced ◽  
Comprehensive Overview ◽  
Leukemic Clone ◽  
Immunosuppressive Microenvironment ◽  
Induced Apoptosis ◽  
Adult Leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in Western countries and is an example of hematological disease where cooperation between genetic defects and tumor microenvironmental interaction is involved in pathogenesis. CLL is a disease that is considered as “addicted to the host”; indeed, the crosstalk between leukemic cells and the tumor microenvironment is essential for leukemic clone maintenance supporting CLL cells’ survival, proliferation, and protection from drug-induced apoptosis. CLL cells are not innocent bystanders but actively model and manipulate the surrounding microenvironment to their own advantage. Besides the different players involved in this crosstalk, nurse-like cells (NLC) resemble features related to leukemia-associated macrophages with an important function in preserving CLL cell survival and supporting an immunosuppressive microenvironment. This review provides a comprehensive overview of the role played by NLC in creating a nurturing and permissive milieu for CLL cells, illustrating the therapeutic possibilities in order to specifically target and re-educate them.

BMS-936564 (MDX1338): A Fully Human Anti-CXCR4 Antibody Induces Apoptosis in an in Vitro Model of Stromal – Leukemia Cell Interaction for Chronic Lymphocytic Leukemia.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2887-2887
Author(s):  
Manoj Kumar Kashyap ◽  
Deepak Kumar ◽  
Harrison Jones Jones ◽  
Michael Y. Choi ◽  
Johanna Melo-Cardenas ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Stromal Cells ◽  
Leukemia Cell ◽  
Cell Interaction ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Drug Induced ◽  
Induced Apoptosis ◽  
Cells Cultured

Abstract Abstract 2887 Chronic lymphocytic leukemia (CLL) remains incurable despite advances in the biology and treatment of this disease. Current data support the notion that resistance to therapy is promoted by a “protective” tumor microenvironment in which non-leukemia cells produce factors that enhance the resistance of CLL cells to spontaneous or drug-induced apoptosis. One such factor is the chemokine CXCL12, which interacts with its receptor CXCR4 on CLL cells to promote cancer cell survival. To examine the therapeutic potential of blocking CXCL12-CXCR4 interactions, we studied the effect of BMS-936564, a fully human IgG4 anti-CXCR4 antibody, using an in vitro co-culture model of human bone marrow derived stomal-NKter cells – leukemia cell interaction. Such stromal-NKter cells secrete CXCL12 and enhance the resistance of CLL cells to apoptosis in vitro. We observed that primary CLL cells co-cultured with stromal-NKter cells had significantly greater viability than CLL cells cultured alone (20–60% above baseline at 48 hours). Moreover, CLL cells co-cultured with stromal cells had enhanced resistance to drug-induced apoptosis. We found that BMS-936564 antibody at concentrations of 2–200nM could enhance the rate of apoptosis of CLL cells cultured alone or in the presence of stromal cells. CLL cells that expressed unmutated IgVH genes or ZAP-70 appeared equally susceptible to treatment with BMS-936564 as did CLL cells that lack these adverse prognostic markers, as did CLL cells that harbored deletions in 17p13.2 and that were resistant to chemotherapeutic agents, such a fludarabine monophosphate. BMS-936564 antibody inhibited CXCL12 mediated F-Actin polymerization in CLL cells at lower concentrations (20–200nM) compared to AMD-3100 (Mozobil), a small molecule CXCR4 inhibitor (50–150μM). In addition, AMD-3100 did not induce apoptosis in CLL cells (10–300μM). In summary, we observed that the anti-CXCR4 antibody BMS-936564 inhibited CXCL12 mediated activation of the CXCR4 receptor in CLL cells and induced apoptosis in leukemia cells. The pro-apoptotic activity of BMS-936564 was observed in cells cultured alone or together with stromal cells suggesting that this antibody had direct cytotoxic effect on leukemia cells and that it can overcome the protective tumor microenvironment. More over, the activity of BMS-936564 was independent of the presence of poor prognostic factors such as del(17p) suggesting that its mechanism of action is P53 independent. These findings show evidence that the CXCR4-CXCL12 pathway is a valid therapeutic target in CLL and provide additional biological rationale for ongoing clinical trials in CLL and other hematological malignancies using BMS-936564. Disclosures: Kuhne: Bristol-Myers Squibb: Employment. Sabbatini:Bristol-Myers Squibb: Employment. Cohen:Bristol-Myers Squibb: Employment. Shelat:Bristol-Myers Squibb: Employment. Cardarelli:Bristol-Myers Squibb: Employment. Kipps:Abbott: Consultancy, Research Funding.

Sildenafil and vardenafil, types 5 and 6 phosphodiesterase inhibitors, induce caspase-dependent apoptosis of B-chronic lymphocytic leukemia cells

Blood ◽  
2003 ◽  
Vol 101 (1) ◽  
pp. 265-269 ◽  
Author(s):  
Marika Sarfati ◽  
Véronique Mateo ◽  
Sylvie Baudet ◽  
Manuel Rubio ◽  
Christine Fernandez ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Phosphodiesterase Inhibitors ◽  
Inhibitory Effect ◽  
Lymphocytic Leukemia ◽  
Interleukin 4 ◽  
Drug Induced ◽  
Pde Inhibitors ◽  
Induced Apoptosis

Abstract Type 4 phosphodiesterase (PDE4) inhibitors reportedly induce apoptosis in chronic lymphocytic leukemia (CLL) cells. Following clinical improvement of one previously untreated CLL patient with sildenafil therapy, we evaluated the in vitro induction of apoptosis in CLL cells by 4 PDE5/6 inhibitors, including sildenafil, vardenafil, zaprinast, and methoxyquinazoline (MQZ). After 24 hours of culture, the various PDE inhibitors differed in their ability to induce apoptosis, with zaprinast displaying no killing effect. Normal B cells isolated from control donors were totally resistant to PDE-induced apoptosis. Vardenafil was 3 and 30 times more potent an inducer of apoptosis than sildenafil and MQZ, respectively. Both vardenafil and sildenafil failed to elevate adenosine 3′5′ cyclic monophosphate (cAMP) levels, largely excluding an inhibitory effect on cAMP-PDE3, -PDE4, and -PDE7. Vardenafil- or sildenafil-treated B-CLL cells displayed up to 30% intracellular active caspase 3. Drug-induced apoptosis was inhibited by the caspase inhibitor z-VAD.fmk, prevented by interleukin-4 (IL-4), and significantly reduced by stromal-derived factor1-α (SDF-1α). We conclude that vardenafil and sildenafil induce caspase-dependent apoptosis of B-CLL cells in vitro and thus might be considered in the treatment of CLL patients. However, further in vivo investigations should be warranted.

Spontaneous and drug-induced apoptosis is mediated by conformational changes of Bax and Bak in B-cell chronic lymphocytic leukemia

Blood ◽  
2002 ◽  
Vol 100 (5) ◽  
pp. 1810-1816 ◽  
Author(s):  
Beatriz Bellosillo ◽  
Neus Villamor ◽  
Armando López-Guillermo ◽  
Silvia Marcé ◽  
Francesc Bosch ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Conformational Changes ◽  
Intracellular Localization ◽  
Reactive Oxygen Species Generation ◽  
Lymphocytic Leukemia ◽  
Drug Induced ◽  
Mitochondrial Potential ◽  
Induced Apoptosis ◽  
Cell Chronic Lymphocytic Leukemia

The role of Bax and Bak, 2 proapoptotic proteins of the Bcl-2 family, was analyzed in primary B-cell chronic lymphocytic leukemia (CLL) cells following in vitro treatment with fludarabine, dexamethasone, or the combination of fludarabine with cyclophosphamide and mitoxantrone (FCM). A strong correlation was found between the number of apoptotic cells and the percentage of cells stained with antibodies recognizing conformational changes of Bax (n = 33;r = 0.836; P < .001) or Bak (n = 10;r = 0.948; P < .001). Preincubation of CLL cells with Z-VAD.fmk (N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone), a broad caspase inhibitor, abolished caspase-3 activation, exposure of phosphatidylserine residues, and reactive oxygen species generation; partially reversed the loss of transmembrane mitochondrial potential (ΔΨm); but did not affect Bax or Bak conformational changes. These results indicate that the conformational changes of Bax and Bak occur upstream of caspase activation or are caspase independent. Following drug-induced apoptosis, Bax integrates into mitochondria, as demonstrated by fluorescence microscopy and Western blot, without changes in the total amount of Bax or Bak protein. Fludarabine and FCM induce p53 stabilization, but do not seem to be essential in inducing Bax and Bak conformational changes, as they are also observed in dexamethasone-treated CLL cells. These results demonstrate that, in CLL cells, the change in the intracellular localization of Bax from cytosol to mitochondria and the conformational changes of Bax and Bak are among the early steps in the induction of cell death.

scholarly journals IRF4 mutations in chronic lymphocytic leukemia

Blood ◽  
2011 ◽  
Vol 118 (10) ◽  
pp. 2827-2829 ◽  
Author(s):  
Violaine Havelange ◽  
Yuri Pekarsky ◽  
Tatsuya Nakamura ◽  
Alexey Palamarchuk ◽  
Hansjuerg Alder ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Genome Wide Association Study ◽  
Interferon Regulatory Factor ◽  
Good Prognosis ◽  
B Cell Development ◽  
Lymphocytic Leukemia ◽  
Regulatory Factor ◽  
Genome Wide ◽  
Trisomy 12 ◽  
Interferon Regulatory Factor 4

Abstract Interferon regulatory factor 4 (IRF4) is a member of the interferon regulatory factor family of transcription factors and has been shown to have critical functions at several stages of B-cell development. Genome-wide association study identified a polymorphism in the 3′ untranslated region of IRF4 as a chronic lymphocytic leukemia risk locus. In this study, we report a recurrent heterozygous somatic mutation in the DNA-binding domain of IRF4 detected in 7 of 457 chronic lymphocytic leukemia patients (1.5%). Patients with IRF4 mutation have a good prognosis, and 4 of 6 have a trisomy 12. We also found that IRF4 mRNA expression is higher in the patients with the mutation.

Lysophosphatidic Acid (LPA) Protects Primary Chronic Lymphocytic Leukemia (CLL) Cells from Apoptosis: Role for LPA as a Survival Factor in CLL.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4788-4788
Author(s):  
Spencer B. Gibson ◽  
Xiaojie Hu ◽  
Neil Haney ◽  
Albert F. Kabore ◽  
James B. Johnston
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Protective Effect ◽  
Cell Line ◽  
Lysophosphatidic Acid ◽  
Lymphocytic Leukemia ◽  
Drug Induced ◽  
Lpa Receptor ◽  
Survival Factor ◽  
Induced Apoptosis ◽  
Primary Chronic Lymphocytic Leukemia

Abstract Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of CD19+/CD5+ lymphocytes, and this is achieved primarily through a block in apoptosis. The mechanisms underlying this defect are not fully understood. Several proteins have been shown to protect CLL cells from apoptosis and one of these is albumin that solublizes lipids in the plasma. A lipid found in plasma, lysophosphatidic acid (LPA), protects epithelial and fibroblast cells from apoptosis. We investigated whether LPA could be a survival factor in CLL. Herein, we demonstrate that LPA effectively protects the B cell line BJAB and the CLL-like cell line I-83 from etoposide, fludarabine, and chlorambucil-induced apoptosis. In primary CLL cells, plasma from either healthy or CLL patients significantly reduces spontaneous and drug-induced apoptosis. However, delipidation of the plasma reduces its protective effect. In addition, LPA protects primary CLL cells but not healthy lymphocytes from apoptosis. By western blotting, the LPA receptor 1 (LPA1) expression is increased in primary CLL cells compared to normal lymphocytes. Treatment of primary CLL cells with the LPA receptor antagonist diacylglycerol pyrophosphate (DGPP) reverses the protective effect of LPA against apoptosis. Over expression of the LPA1 receptor protects cells from apoptosis and downregulation of the receptor blocks LPA mediated protection against spontaneous apoptosis. The protective effect of LPA is inhibited by blocking activation of the PI-3K/AKT signaling pathway. These results indicate that LPA is a survival factor in primary CLL cells and that drugs targeting the LPA receptors might be an effective therapy for this disease.

Chronic Lymphocytic Leukemia Cells Have Increased Expression of Cyclic Nucleotide Phosphodiesterase 7B, Which May Serve as Disease-Specific Therapeutic Target.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2802-2802
Author(s):  
Lingzhi Zhang ◽  
Fiona Murray ◽  
Joan R. Kanter ◽  
Daisy Chou ◽  
Laura Rassenti ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Cyclic Nucleotides ◽  
Cyclic Nucleotide ◽  
Lymphocytic Leukemia ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Target Cells ◽  
Drug Induced ◽  
Induced Apoptosis

Abstract Non-specific inhibition of cyclic nucleotide phosphodiesterase (PDE) in chronic lymphocytic leukemia (CLL) cells leads to intracellular accumulation of cyclic nucleotides, which in turn can sensitize the CLL cells to spontaneous and/or drug-induced apoptosis. Recent studies have identified at least 11 isoforms of PDE, each of which catalyzes the hydrolysis of cAMP and/or cGMP and regulates the intracellular levels of cyclic nucleotides. The finding that various tissues differentially express selected PDE isoforms has prompted development of isoform-specific inhibitors that can selectively increase intracellular levels of cyclic nucleotides in target cells that over-express the inhibited PDE isoform. Accordingly, we examined for differential expression of PDE isoforms by CLL B cells by assessing the levels of mRNA encoding each of the 11 different PDE isoforms in CLL cells and normal blood lymphocytes using quantitative real-time RT-PCR. CLL cell samples (n = 24) and lymphocytes of healthy adults (n = 16) each expressed detectable levels of PDE isoforms 1A, 1B, 2A, 3A, 3B, 4A, 4B, 4C, 4D, 5A, 7A, 7B, 8A, 8B, and 9A. However, we discovered that CLL cells of each patient had significantly higher levels of PDE7B mRNA (2.8-fold to 368-fold) and significantly lower levels of PDE3B mRNA (5-fold to 138 fold) than did lymphocytes from healthy donors (n = 16). As such, the ratios of PDE7B/PDE3B in CLL cell samples were >3 (ranging from 3 to 1019), whereas normal lymphocytes had ratios of < 0.3 (ranging from 0.006 to 0.23). The mean PDE7B/PDE3B ratio for CLL cells (123.6 ± 45.0, S.D., n=24) was significantly higher than that for B-lymphocytes of normal donors (3.8 ± 1.1, n=10) (P<0.0001). Immunoblot analyses demonstrated that CLL cells uniformly expressed high levels of PDE7B and low levels of PDE3B relative to those of normal lymphocytes. Moreover, we found that PDE7B contributed predominantly to the total PDE activity in CLL cells but not in normal lymphocytes. We thus studied effect of a selective PDE7 inhibitor (BRL-50481) on CLL cells and normal lymphocytes in vitro and found that BRL-50481 dose-dependently promoted apoptosis of CLL cells, but not normal lymphocytes. Collectively these findings indicate that CLL B cells selectively over-express PDE7B and under-express PDE3B relative to normal lymphocytes or isolated blood B cells and suggest that selective inhibitors of PDE7B may be effective in the treatment of this disease.

Importance of PI3 Kinase Family for Crosstalk between Chronic Lymphocytic Leukemia B Cells and the Stromal Microenvironment: Therapeutic Implications.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1125-1125
Author(s):  
Matthias T.W. Niedermeier ◽  
Justyna Rawluk ◽  
Zachary Knight ◽  
Kevan Shokat ◽  
William G. Wierda ◽  
...  
Keyword(s):  
Cell Migration ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Stromal Cells ◽  
Therapeutic Potential ◽  
Dominant Role ◽  
Lymphocytic Leukemia ◽  
Drug Induced ◽  
Cxcr4 Signaling ◽  
Induced Apoptosis

Abstract Nontumoral accessory cells such as marrow stromal cells (MSC) or nurselike cells (NLC), which constitute the leukemia microenvironment, constitutively secrete the chemokine stromal cell-derived factor-1 (SDF-1/CXCL12). CXCL12 transduces signals via its receptor CXCR4, which is expressed at high levels by Chronic Lymphocytic Leukemia (CLL) B cells. Via the CXCL12-CXCR4 axis, CLL cells migrate and adhere to stromal cells. Adhesion to stromal cells protects CLL cells from spontaneous and drug-induced apoptosis in a contact-dependent fashion. Signaling pathways regulating these processes in CLL B cells are largely unknown. Here, we examined the importance of phosphatidyl-inositide 3-kinases (PI3-K) for migration and viability of CLL B cells using non-specific and isoform-specific PI3-K inhibitors. The importance of PI3-K for migration of CLL cells to CXCL12 was determined by transwell chemotaxis and pseudoemperipolesis (PEP) assays. Inhibition of PI3-K resulted in a significant reduction of CLL cell migration in chemotaxis and PEP assays. In comparison to untreated CLL cells, Ly 294002 inhibited chemotaxis to 65 ± 4.6% of untreated controls. Using a panel of isoform-specific PI 3-K inhibitors (PI-103, PIK-90, IC87114, TGX-115, ZK-75), we observed inhibition of chemotaxis by the multi-targeted compounds PI-103 (51.4 ± 0.2%) and PIK-90 (57.5 ± 8.9%), whereas p110beta and delta inhibition had no effect. We conclude from this part of the study that PI3-kinases play an important role for CXCR4 signaling in CLL B cells, mediating migratory responses and protection from apoptosis. Experiments with inhibitors of PI3-K with higher target selectivity suggest a dominant role for the class I PI3-K p110alpha for migration in response to CXCL12. Because adhesion to stroma mediates protection from chemotherapeutic drugs, we tested PI3-K inhibitors alone and in combination with fludarabine in CLL-stroma co-cultures. Pre-treatment of CLL cells with the PI3-K inhibitors Ly 294002, PI-103, and PIK-90 resulted in a significant decrease in viability of CLL cells co-cultured with and without stroma. Moreover, PI3-K isoform specific inhibitors enhance the cytotoxicity of Fludarabine and partially reverse the protective effect of stromal cells on fludarabine-induced apoptosis. Collectively, this study establishes that PI3-Ks play an important role in CXCR4 signaling for CLL cell migration and adhesion to stromal cells. New, isoform-specific PI3-K inhibitors enhance the cytotoxicity of fludarabine in suspension cultures and in co-cultures with stromal cells. Therefore, the therapeutic potential of PI3-K inhibitors alone or in combination with fludarabine should further be investigated. Figure. Figure.

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