Regulation of Berg-36 Gene Expression by Survival and Apoptotic Stimuli in B-Chronic Lymphocytic Leukaemia Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4767-4767
Author(s):  
Andrew P. Jewell ◽  
Maria Baou ◽  
Kwee L. Yong ◽  
Robert Carr ◽  
John Murphy
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Calcium Ionophore ◽  
Early Response ◽  
Lymphocytic Leukemia ◽  
Apoptotic Cells ◽  
Cd20 Antibody ◽  
Induced Apoptosis ◽  
Anti Cd20

Abstract Chronic lymphocytic leukemia is characterized by the accumulation of monoclonal malignant CD5+ B cells that show resistance to apoptosis in vivo. Berg 36 (ZFP36L1, TIS11b, BRF1, cMG1, ERF1) is a zinc finger containing early response gene that was cloned from PMA-stimulated B chronic lymphocytic leukemia cells. Induced expression of this gene has been linked to calcium ionophore and anti-CD20-induced apoptosis of human B lymphoma cells. Berg36 protein has, in common with two other members of the small gene family (TIS11, TIS11d), been reported to function as an mRNA-binding protein that may promote instability of cytokine mRNAs. We have therefore studied the regulation of Berg36 expression in B-CLL cells in vitro, in response to cytokines and other signals that regulate apoptosis. B-CLL cells from 12 patients were purified and incubated with the following agents either alone or in combinations for a number of hours; IL-4, CD40 ligand, PMA or anti-CD20 antibody (rituximab). Apoptosis was measured after 24 hours by Annexin/PI staining and Berg-36 expression by Northern blot analysis. Spontaneous apoptosis in unstimulated B-CLL cells was 20.9±5.1%. Co-incubation of B-CLL cells with IL-4 reduced the percentage of apoptotic cells to 6.2±1.2%, but had no effect on Berg-36 expression. In contrast, both PMA and CD40 stimulation reduced the percentage of apoptotic cells (to 14.8±3.4% and 10.2±4.2% respectively), and markedly induced Berg36 expression. On the other hand, anti-CD20 antibody induced apoptosis (36.2±6.6%), but also induced Berg36 expression. Specific inhibitors of various intracellular signalling molecules confirmed that induction of Berg36 by different agents was mediated through different signalling pathways. In conclusion, expression of Berg36 can be induced in B-CLL cells by stimuli that induce either survival or apoptosis in these cells.

scholarly journals IL-21 mediates apoptosis through up-regulation of the BH3 family member BIM and enhances both direct and antibody-dependent cellular cytotoxicity in primary chronic lymphocytic leukemia cells in vitro

Blood ◽  
2008 ◽  
Vol 111 (9) ◽  
pp. 4723-4730 ◽  
Author(s):  
Aruna Gowda ◽  
Julie Roda ◽  
Syed-Rehan A. Hussain ◽  
Asha Ramanunni ◽  
Trupti Joshi ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Family Member ◽  
Lymphocytic Leukemia ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Bh3 Domain ◽  
Induced Apoptosis ◽  
Primary Chronic Lymphocytic Leukemia

Abstract Interleukin-21 (IL-21) is a recently identified γ-chain receptor cytokine family member that promotes B-cell apoptosis as well as activation of innate immune system. Based on this, we hypothesized that IL-21 might enhance the apoptosis induced by fludarabine and rituximab and also play a role in augmenting immune-mediated clearance of the chronic lymphocytic leukemia (CLL) cells. Our studies demonstrate that the majority of CLL patients have surface IL-21 receptor-α, and its expression correlates with apoptosis, tyrosine phosphorylation of STAT1, and up-regulation of the proapoptotic BH3 domain protein BIM. IL-21–induced BIM up-regulation is critical for apoptosis because inhibition of BIM expression using small interfering RNA prevented IL-21–induced apoptosis. IL-21 treatment of CLL cells but not normal T cells with fludarabine or rituximab additively enhanced the direct cytotoxic effect of these therapies. In addition to its proapoptotic effect, IL-21 promoted STAT1 and STAT5 phosphorylation in natural killer cells with concurrent enhanced antibody-dependent cellular cytotoxicity against rituximab-coated CLL cells in vitro. These data provide justification for combination studies of IL-21 with fludarabine and rituximab in CLL and suggest that BIM up-regulation might serve as relevant pharmacodynamic end point to measure biologic effect of this cytokine in vivo.

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.

Evaluation of vecabrutinib as a model for non-covalent BTK/ITK inhibition for treatment of chronic lymphocytic leukemia

Blood ◽  
2021 ◽  
Author(s):  
Billy Michael Chelliah Jebaraj ◽  
Annika Müller ◽  
Rashmi Priyadharshini Dheenadayalan ◽  
Sascha Endres ◽  
Philipp M. Roessner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
Inhibitory Effect ◽  
Lymphocytic Leukemia ◽  
Transfer Model ◽  
Treatment Benefit ◽  
Btk Inhibitors

Covalent Bruton tyrosine kinase (BTK) inhibitors such as ibrutinib have proven to be highly beneficial in the treatment of chronic lymphocytic leukemia (CLL). Interestingly, the off-target inhibition of IL-2-inducible T-cell kinase (ITK) by ibrutinib may also play a role in modulating the tumor microenvironment, potentially enhancing the treatment benefit. However, resistance to covalently binding BTK inhibitors can develop by a mutation in cysteine 481 of BTK (C481S), which prevents the irreversible binding of the drugs. In the present study we performed pre-clinical characterization of vecabrutinib, a next generation non-covalent BTK inhibitor, with ITK inhibitory properties similar to those of ibrutinib. Unlike ibrutinib and other covalent BTK inhibitors, vecabrutinib showed retention of the inhibitory effect on C481S BTK mutants in vitro, similar to that of wildtype BTK. In the murine Eµ-TCL1 adoptive transfer model, vecabrutinib reduced tumor burden and significantly improved survival. Vecabrutinib treatment led to a decrease in CD8+ effector and memory T-cell populations, while the naïve populations were increased. Of importance, vecabrutinib treatment significantly reduced frequency of regulatory CD4+ T-cells (Tregs) in vivo. Unlike ibrutinib, vecabrutinib treatment showed minimal adverse impact on activation and proliferation of isolated T-cells. Lastly, combination treatment of vecabrutinib with venetoclax was found to augment treatment efficacy, significantly improve survival and lead to favourable reprogramming of the microenvironment in the murine Eµ-TCL1 model. Thus, non-covalent BTK/ITK inhibitors such as vecabrutinib may be efficacious in C481S BTK mutant CLL, while preserving the T-cell immunomodulatory function of ibrutinib.

Chronic lymphocytic leukemia: revelations from the B-cell receptor

Blood ◽  
2004 ◽  
Vol 103 (12) ◽  
pp. 4389-4395 ◽  
Author(s):  
Freda K. Stevenson ◽  
Federico Caligaris-Cappio
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Cell Of Origin ◽  
Regulatory B Cell ◽  
V Genes

Abstract The finding that chronic lymphocytic leukemia (CLL) consists of 2 clinical subsets, distinguished by the incidence of somatic mutations in the immunoglobulin (Ig) variable region (V) genes, has clearly linked prognosis to biology. Antigen encounter by the cell of origin is indicated in both subsets by selective but distinct expression of V genes, with evidence for continuing stimulation after transformation. The key to distinctive tumor behavior likely relates to the differential ability of the B-cell receptor (BCR) to respond. Both subsets may be undergoing low-level signaling in vivo, although analysis of blood cells limits knowledge of critical events in the tissue microenvironment. Analysis of signal competence in vitro reveals that unmutated CLL generally continues to respond, whereas mutated CLL is anergized. Differential responsiveness may reflect the increased ability of post-germinal center B cells to be triggered by antigen, leading to long-term anergy. This could minimize cell division in mutated CLL and account for prognostic differences. Unifying features of CLL include low responsiveness, expression of CD25, and production of immunosuppressive cytokines. These properties are reminiscent of regulatory T cells and suggest that the cell of origin of CLL might be a regulatory B cell. Continuing regulatory activity, mediated via autoantigen, could suppress Ig production and lead to disease-associated hypogammaglobulinemia. (Blood. 2004;103:4389-4395)

Triggering of CD40 Antigen Inhibits Fludarabine-Induced Apoptosis in B Chronic Lymphocytic Leukemia Cells

Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 990-995 ◽  
Author(s):  
Maria Fiammetta Romano ◽  
Annalisa Lamberti ◽  
Pierfrancesco Tassone ◽  
Fiorella Alfinito ◽  
Silvia Costantini ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Consensus Sequence ◽  
Significant Proportion ◽  
Lymphocytic Leukemia ◽  
Antiapoptotic Effect ◽  
Apoptotic Effect ◽  
American Society ◽  
Induced Apoptosis ◽  
Decoy Oligonucleotide

Abstract We analyzed the effect of CD40 triggering on the fludarabine-induced apoptosis of B chronic lymphocytic leukemia (B-CLL) cells. Peripheral blood samples obtained from 15 patients were incubated with fludarabine in the absence or the presence of the anti-CD40 monoclonal antibody (MoAb) G28-5. In 12 patients a significant proportion of apoptotic cells, ranging from 22% to 38% (mean ± SE: 28.5 ± 1.6), were detected after 3 days of culture. In 9 of these samples, the addition of G28-5 reduced apoptosis by at least 30.1% and by 57.1% ± 7.8% on average (P = .0077). Because the CD40 antigen activates NF-κB/Rel transcription factors in B cells, and NF-κB/Rel complexes can inhibit cell apoptosis, we investigated whether the antiapoptotic effect of G28-5, in our system, could be related to modulation of NF-κB/Rel activity. As expected, B-CLL cells displayed significant levels of nuclear NF-κB/Rel activity; p50, RelA, and c-Rel components of the NF-κB/Rel protein family were identified in these complexes. After exposure to fludarabine, NF-κB/Rel complexes were decreased in the nuclei. The addition of G28-5 upregulated the NF-κB/Rel levels. To determine the involvement of NF-κB/Rel activity in the G28-5–mediated inhibition of apoptosis, we blocked the transcription factor with a decoy oligonucleotide, corresponding to the NF-κB/Rel consensus sequence. Cells incubated with the anti-CD40 MoAb in the presence of the decoy oligonucleotide but not a control oligonucleotide displayed a complete impairment of the G28-5 antiapoptotic effect, indicating that NF-κB/Rel activity was required for the inhibition of apoptosis. These results suggest that CD40 triggering in vivo could counteract the apoptotic effect of fludarabine on B-CLL cells and that its neutralization, or the use of NF-κB/Rel inhibitors, could improve the therapeutic effect of fludarabine. © 1998 by The American Society of Hematology.

scholarly journals ATR inhibition induces synthetic lethality and overcomes chemoresistance in TP53- or ATM-defective chronic lymphocytic leukemia cells

Blood ◽  
2016 ◽  
Vol 127 (5) ◽  
pp. 582-595 ◽  
Author(s):  
Marwan Kwok ◽  
Nicholas Davies ◽  
Angelo Agathanggelou ◽  
Edward Smith ◽  
Ceri Oldreive ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Synthetic Lethality ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Selective Cytotoxicity ◽  
Key Points ◽  
Synthetically Lethal

Key PointsATR inhibition is synthetically lethal to TP53- or ATM-defective CLL cells. ATR targeting induces selective cytotoxicity and chemosensitization in TP53- or ATM-defective CLL cells in vitro and in vivo.

Nurture versus Nature: The Microenvironment in Chronic Lymphocytic Leukemia

Hematology ◽  
2011 ◽  
Vol 2011 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Jan A. Burger
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Tyrosine Kinase ◽  
B Cell ◽  
Disease Progression ◽  
Drug Testing ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
In Vivo Models

Abstract Intrinsic factors such as genetic lesions, anti-apoptotic proteins, and aberrant signaling networks within leukemia cells have long been the main focus of chronic lymphocytic leukemia (CLL) research. However, over the past decade, it became increasingly clear that external signals from the leukemia microenvironment make pivotal contributions to disease progression in CLL and other B-cell malignancies. Consequently, increasing emphasis is now placed on exploring and targeting the CLL microenvironment. This review highlights critical cellular and molecular pathways of CLL-microenvironment cross-talk. In vitro and in vivo models for studying the CLL microenvironment are discussed, along with their use in searching for therapeutic targets and in drug testing. Clinically, CXCR4 antagonists and small-molecule antagonists of B cell receptor (BCR)-associated kinases (spleen tyrosine kinase [Syk], Bruton's tyrosine kinase [Btk], and PI3Kδ) are the most advanced drugs for targeting specific interactions between CLL cells and the miocroenvironment. Preclinical and first clinical evidence suggests that high-risk CLL patients can particularly benefit from these alternative agents. These findings indicate that interplay between leukemia-inherent and environmental factors, nature and nurture determines disease progression in CLL.

scholarly journals Functional and clinical relevance of VLA-4 (CD49d/CD29) in ibrutinib-treated chronic lymphocytic leukemia

2018 ◽  
Vol 215 (2) ◽  
pp. 681-697 ◽  
Author(s):  
Erika Tissino ◽  
Dania Benedetti ◽  
Sarah E.M. Herman ◽  
Elisa ten Hacken ◽  
Inhye E. Ahn ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Progression Free Survival ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Clinical Activity ◽  
Independent Manner ◽  
Btk Inhibitor

The Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, which antagonizes B cell receptor (BCR) signals, demonstrates remarkable clinical activity in chronic lymphocytic leukemia (CLL). The lymphocytosis experienced by most patients under ibrutinib has previously been attributed to inhibition of BTK-dependent integrin and chemokine cues operating to retain the tumor cells in nodal compartments. Here, we show that the VLA-4 integrin, as expressed by CD49d-positive CLL, can be inside-out activated upon BCR triggering, thus reinforcing the adhesive capacities of CLL cells. In vitro and in vivo ibrutinib treatment, although reducing the constitutive VLA-4 activation and cell adhesion, can be overcome by exogenous BCR triggering in a BTK-independent manner involving PI3K. Clinically, in three independent ibrutinib-treated CLL cohorts, CD49d expression identifies cases with reduced lymphocytosis and inferior nodal response and behaves as independent predictor of shorter progression-free survival, suggesting the retention of CD49d-expressing CLL cells in tissue sites via activated VLA-4. Evaluation of CD49d expression should be incorporated in the characterization of CLL undergoing therapy with BCR inhibitors.

Relationship between in vitro and in vivo Radiosensitivity of Lymphocytes in Chronic Lymphocytic Leukemia

1988 ◽  
Vol 80 (3) ◽  
pp. 129-133 ◽  
Author(s):  
Robert Schrek ◽  
William R. Best ◽  
Stefano Stefani
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Lymphocytic Leukemia

scholarly journals Effect of a thymic factor on T lymphocytes in B cell chronic lymphocytic leukemia: in vitro and in vivo studies

Blood ◽  
1984 ◽  
Vol 64 (3) ◽  
pp. 667-671 ◽  
Author(s):  
F Lauria ◽  
D Raspadori ◽  
S Tura
Keyword(s):  
T Cell ◽  
Chronic Lymphocytic Leukemia ◽  
T Lymphocytes ◽  
B Cell ◽  
Proliferative Response ◽  
Lymphocytic Leukemia ◽  
Before And After ◽  
Cell Chronic Lymphocytic Leukemia

Abstract Abnormalities of T lymphocytes in B cell chronic lymphocytic leukemia (B-CLL) have been extensively documented by several immunologic investigations. Following recent studies pointing to the favorable effect of TP-1, a partially purified extract of calf thymus, on the T cell-mediated immunity of several diseases, including Hodgkin's disease, we have used monoclonal antibodies and the enriched T lymphocytes of 16 untreated B-CLL patients to evaluate the proportion of T cell subsets before and after the administration of TP-1. In addition, the proliferative response to phytohemagglutinin (PHA) and the helper function in a pokeweed mitogen (PWM) system were assessed. In ten cases, the effect of TP-1 was also studied in vitro by evaluating the same parameters before and after incubation of B-CLL T cells with the drug. The study demonstrated that in vivo administration of TP-1 increases significantly (P less than .001) the proportion of the defective helper/inducer T cell population (OKT4-positive cells) in B-CLL, leading to a near normal OKT4/OKT8 ratio. Furthermore, the improved phenotypic profile was accompanied by an increased proliferative response to PHA and, in particular, by a significant increase (P less than .01) of T helper capacity; this increase was, however, insufficient to enable the normalization of the serum immunoglobulin levels. The in vitro incubation of B-CLL T lymphocytes did not succeed in producing significant modifications in distribution and function.

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