Effect of CD37 small modular immuno-pharmaceutical (SMIP) on direct apoptosis in chronic lymphocytic leukemia cells via transcriptional up-regulation of the BH3 family member BIM

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 3035-3035
Author(s):  
J. C. Byrd ◽  
R. Lapalombella ◽  
A. Ramanunni ◽  
L. A. Andritsos ◽  
J. M. Flynn ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Mitochondrial Membrane ◽  
Membrane Depolarization ◽  
Lymphocytic Leukemia ◽  
Luciferase Reporter ◽  
Clinical Activity ◽  
Physical Interaction ◽  
Mrna Levels ◽  
Primary Role ◽  
Mitochondrial Membrane Depolarization

3035 Background: CD37 is a tetraspan transmembrane family protein selectively expressed on normal and transformed B-cells. A novel CD37SMIP was previously demonstrated to mediate superior direct apoptosis and NK-cell mediated killing of chronic lymphocytic leukemia (CLL) and other B-cell malignancies. Methods: Given the superior in vitro apoptosis observed with CD37SMIP treatment and early clinical activity observed in highly refractory CLL patients, we hypothesized that a unique mechanism of cell killing was utilized by CD37SMIP. This was pursued in preclinical studies outlined below. Results: Unlike many other agents utilized to treat CLL, death mediated by CD37SMIP does not depend upon caspase activation. Nonetheless, CD37SMIP treatment of CLL cells promotes time-dependent induction of mitochondrial membrane depolarization, mitochondrial translocation of Bax, and up-regulation of Bim protein. CD37SMIP Bim protein induction occurred concomitantly with an increase in BIM mRNA levels. Electrophoretic mobility shift assay using oligonucleotides of the BIM promoter demonstrated increased protein binding activity in nuclear extracts derived from CD37SMIP treated cells and the physical interaction of FoxO3a transcription factor with the FoxO3a responsive element in the BIM promoter was demonstrated using a “protein pull down” assay and confirmed by chromatin immunoprecipitation assays. Furthermore, CD37SMIP treatment significantly increased BIM promoter regulated luciferase reporter expression in B-CLL cells. Consistent with a primary role of Bim up-regulation in mitochondrial membrane destabilization and apoptosis, transfection of CLL cells with BIM siRNA resulted in inhibition of CD37SMIP-induced mitochondrial membrane depolarization and apoptosis. Conclusions: These studies demonstrate CD37SMIP mediated apoptosis in CLL cells occurs via FoxO3a-dependent transcriptional up-regulation of BIM protein. This distinct mechanism of apoptosis utilized by CD37SMIP contrasts it with other agents used for CLL treatment. Additionally, it provides a mechanism for the promising clinical activity of TRU-016 (humanized CD37SMIP) observed to date in refractory CLL patients. [Table: see text]

scholarly journals CHOP and c-JUN up-regulate the mutant Z α1-antitrypsin, exacerbating its aggregation and liver proteotoxicity

2020 ◽  
Vol 295 (38) ◽  
pp. 13213-13223
Author(s):  
Sergio Attanasio ◽  
Rosa Ferriero ◽  
Gwladys Gernoux ◽  
Rossella De Cegli ◽  
Annamaria Carissimo ◽  
...  
Keyword(s):  
Liver Disease ◽  
Er Stress ◽  
Proteinase Inhibitors ◽  
Pediatric Population ◽  
Transcriptional Response ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Primary Role ◽  
Loss Of Function ◽  
Human Livers

α1-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation. Its primary role is to protect lung tissue by inhibiting neutrophil elastase. The Z allele of SERPINA1 encodes a mutant AAT, named ATZ, that changes the protein structure and leads to its misfolding and polymerization, which cause endoplasmic reticulum (ER) stress and liver disease through a gain-of-function toxic mechanism. Hepatic retention of ATZ results in deficiency of one of the most important circulating proteinase inhibitors and predisposes to early-onset emphysema through a loss-of-function mechanism. The pathogenetic mechanisms underlying the liver disease are not completely understood. C/EBP-homologous protein (CHOP), a transcription factor induced by ER stress, was found among the most up-regulated genes in livers of PiZ mice that express ATZ and in human livers of patients homozygous for the Z allele. Compared with controls, juvenile PiZ/Chop−/− mice showed reduced hepatic ATZ and a transcriptional response indicative of decreased ER stress by RNA-Seq analysis. Livers of PiZ/Chop−/− mice also showed reduced SERPINA1 mRNA levels. By chromatin immunoprecipitations and luciferase reporter–based transfection assays, CHOP was found to up-regulate SERPINA1 cooperating with c-JUN, which was previously shown to up-regulate SERPINA1, thus aggravating hepatic accumulation of ATZ. Increased CHOP levels were detected in diseased livers of children homozygous for the Z allele. In summary, CHOP and c-JUN up-regulate SERPINA1 transcription and play an important role in hepatic disease by increasing the burden of proteotoxic ATZ, particularly in the pediatric population.

scholarly journals Targeted inhibition of eIF4A suppresses B-cell receptor-induced translation and expression of MYC and MCL1 in chronic lymphocytic leukemia cells

2021 ◽  
Author(s):  
Sarah Wilmore ◽  
Karly-Rai Rogers-Broadway ◽  
Joe Taylor ◽  
Elizabeth Lemm ◽  
Rachel Fell ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Mrna Translation ◽  
Cell Receptor ◽  
Memory B Cells ◽  
B Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Mrna Levels ◽  
Mrna Stabilization

AbstractSignaling via the B-cell receptor (BCR) is a key driver and therapeutic target in chronic lymphocytic leukemia (CLL). BCR stimulation of CLL cells induces expression of eIF4A, an initiation factor important for translation of multiple oncoproteins, and reduces expression of PDCD4, a natural inhibitor of eIF4A, suggesting that eIF4A may be a critical nexus controlling protein expression downstream of the BCR in these cells. We, therefore, investigated the effect of eIF4A inhibitors (eIF4Ai) on BCR-induced responses. We demonstrated that eIF4Ai (silvestrol and rocaglamide A) reduced anti-IgM-induced global mRNA translation in CLL cells and also inhibited accumulation of MYC and MCL1, key drivers of proliferation and survival, respectively, without effects on upstream signaling responses (ERK1/2 and AKT phosphorylation). Analysis of normal naïve and non-switched memory B cells, likely counterparts of the two main subsets of CLL, demonstrated that basal RNA translation was higher in memory B cells, but was similarly increased and susceptible to eIF4Ai-mediated inhibition in both. We probed the fate of MYC mRNA in eIF4Ai-treated CLL cells and found that eIF4Ai caused a profound accumulation of MYC mRNA in anti-IgM treated cells. This was mediated by MYC mRNA stabilization and was not observed for MCL1 mRNA. Following drug wash-out, MYC mRNA levels declined but without substantial MYC protein accumulation, indicating that stabilized MYC mRNA remained blocked from translation. In conclusion, BCR-induced regulation of eIF4A may be a critical signal-dependent nexus for therapeutic attack in CLL and other B-cell malignancies, especially those dependent on MYC and/or MCL1.

scholarly journals Combination chemoimmunotherapy with pentostatin, cyclophosphamide, and rituximab shows significant clinical activity with low accompanying toxicity in previously untreated B chronic lymphocytic leukemia

Blood ◽  
2006 ◽  
Vol 109 (2) ◽  
pp. 405-411 ◽  
Author(s):  
Neil E. Kay ◽  
Susan M. Geyer ◽  
Timothy G. Call ◽  
Tait D. Shanafelt ◽  
Clive S. Zent ◽  
...  
Keyword(s):  
Prognostic Factors ◽  
Chronic Lymphocytic Leukemia ◽  
Minimal Residual Disease ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
Clinical Activity ◽  
Hematologic Toxicity ◽  
Color Flow ◽  
Significant Clinical Activity ◽  
Minimal Residual

Abstract Building on the prior work of use of pentostatin in chronic lymphocytic leukemia (CLL), we initiated a trial of combined pentostatin (2 mg/m2), cyclophosphamide (600 mg/m2), and rituximab (375 mg/m2) for 65 symptomatic, previously untreated patients. Of 64 evaluable patients, 34 (53%) were high Rai risk, 71% were nonmutated for the immunoglobulin heavy-chain variable region gene, 34% were CD38+, and 34% were ZAP-70+. Thirty patients (52%) had one anomaly detected by fluorescence in situ (FISH) hybridization, and 21 (36%) had complex FISH defects. Thirty-eight patients (58%) had grade 3+ hematologic toxicity but minimal transfusion needs and no major infections. Responses occurred in 58 patients (91%), with 26 (41%) complete responses (CRs), 14 (22%) nodular partial responses (nodular PRs), and 18 (28%) partial responses (PRs). Many patients with a CR also lacked evidence of minimal residual disease by 2-color flow cytometry. Examination of prognostic factors demonstrated poor response in the 3 patients with del(17p). In contrast, we found this regimen was equally effective in young versus older (> 70 years) patients and in del(11q22.3) versus other favorable prognostic factors. Thus, this novel regimen of pentostatin, cyclophosphamide, and rituximab for previously untreated patients with CLL demonstrated significant clinical activity despite poor risk-based prognoses, achievement of minimal residual disease in some, and modest toxicity.

scholarly journals Akt Inhibitors Induce Apoptosis in Chronic Lymphocytic Leukemia Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1731-1731
Author(s):  
Mercè de Frias ◽  
Daniel Iglesias-Serret ◽  
Ana M Cosialls ◽  
Llorenç Coll-Mulet ◽  
Antonio F Santidrián ◽  
...  
Keyword(s):  
T Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Conflicts Of Interest ◽  
Therapeutic Option ◽  
Mrna Level ◽  
Lymphocytic Leukemia ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Healthy Donors ◽  
Induced Apoptosis

Abstract Abstract 1731 Poster Board I-757 Phosphatidylinositol-3-kinase (PI3K)/Akt pathway has been described to be critical in the survival of chronic lymphocytic leukemia (CLL) cells. Here, we have analyzed the effect of two selective chemical inhibitors of Akt (Akti-1/2 and A-443654) in the survival of CLL cells. We studied by cytometric analysis the cytotoxic effects of Akt inhibitors on peripheral B and T lymphocytes from patients with CLL and from healthy donors. Both inhibitors induced apoptosis in CLL cells in a dose-dependent manner. Moreover, B cells from CLL samples were more sensitive to Akt inhibitors than T cells from CLL samples, and B or T cells from healthy donors. Survival factors for CLL cells, such as IL-4 and SDF-1a, were not able to block the apoptosis induced by both Akt inhibitors. We studied the changes induced by Akti-1/2 and A-443654 at mRNA level by performing reverse transcriptase multiplex ligation–dependent probe amplification (RT-MLPA). Akti-1/2 did not induce any change in the mRNA expression profile of genes involved in apoptosis, while A-443654 induced some changes, including an increase in NOXA and PUMA mRNA levels, suggesting the existence of additional targets for A-443654. We also studied the changes induced by both Akt inhibitors in some BCL-2 protein family members on CLL cells by Western blot. Both inhibitors induced an increase in PUMA and NOXA protein levels, and a decrease in MCL-1 protein level. Moreover, Akti-1/2 and A-443654 induced apoptosis irrespective of TP53 status. These results demonstrate that Akt inhibitors induce apoptosis of CLL cells and might be a new therapeutic option for the treatment of CLL. Disclosures No relevant conflicts of interest to declare.

scholarly journals CD6 Ligation Modulates the Bcl-2/Bax Ratio and Protects Chronic Lymphocytic Leukemia B Cells From Apoptosis Induced by Anti-IgM

Blood ◽  
1997 ◽  
Vol 89 (8) ◽  
pp. 2833-2841 ◽  
Author(s):  
Lyda M. Osorio ◽  
Angelina De Santiago ◽  
Miguel Aguilar-SantelisesHå ◽  
kan Mellstedt ◽  
Mikael Jondal
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
T Cell Activation ◽  
Cell Activation ◽  
Scavenger Receptor ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
Small Subset ◽  
Mrna Levels ◽  
Membrane Glycoproteins

Abstract CD6 and CD5 belong to a scavenger-receptor cysteine-rich (SRCR) super family of membrane glycoproteins that are expressed on chronic lymphocytic leukemia B (B-CLL) cells, normal T cells, and a small subset of normal B cells. CD6 configures in the membrane in relation to the cellular activation level and can act as a coreceptor for T-cell activation. We have examined a group of progressive and nonprogressive B-CLL cells. Most B-CLL cells were positive for CD6 and the expression of CD6 was increased after activation with Staphylococcus aureus Cowan I plus interleukin-2 or 12-O-tetradecanoylphorbol 13-acetate, although anti-CD6 antibodies did not increase proliferative responses to these stimuli. However, anti-CD6 stimulation was found to protect against anti-IgM–induced apoptosis in B-CLL. baxα upregulation and bcl-2 downregulation were found in anti-IgM– and glucocorticoid (GCC)-induced apoptotic cells, respectively. Furthermore, CD6 cross-linking downregulated baxα mRNA levels in anti-IgM–treated cells, resulting in an increased bcl-2/baxα ratio. CD6 activation also prevented bcl-2 mRNA downregulation and apoptosis induced by GCC in one of six GCC-sensitive patients. These data suggest that an interaction between CD6 and its ligand might contribute to B-CLL survival through the modulation of the Bcl-2/Bax ratio.

scholarly journals Phase I and Pharmacologic Study of SNS-032, a Potent and Selective Cdk2, 7, and 9 Inhibitor, in Patients With Advanced Chronic Lymphocytic Leukemia and Multiple Myeloma

2010 ◽  
Vol 28 (18) ◽  
pp. 3015-3022 ◽  
Author(s):  
Wei-Gang Tong ◽  
Rong Chen ◽  
William Plunkett ◽  
David Siegel ◽  
Rajni Sinha ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Chronic Lymphocytic Leukemia ◽  
Phase I ◽  
Clinical Efficacy ◽  
Stable Disease ◽  
Single Agent ◽  
Tumor Lysis Syndrome ◽  
Lymphocytic Leukemia ◽  
Clinical Activity ◽  
Dose Escalation Study

Purpose SNS-032 is a highly selective and potent inhibitor of cyclin-dependent kinases (Cdks) 2, 7, and 9, with in vitro growth inhibitory effects and ability to induce apoptosis in malignant B cells. A phase I dose-escalation study of SNS-032 was conducted to evaluate safety, pharmacokinetics, biomarkers of mechanism-based pharmacodynamic (PD) activity, and clinical efficacy. Patients and Methods Parallel cohorts of previously treated patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) received SNS-032 as a loading dose followed by 6-hour infusion weekly for 3 weeks of each 4-week course. Results There were 19 patients with CLL and 18 with MM treated. Tumor lysis syndrome was the dose-limiting toxicity (DLT) for CLL, the maximum-tolerated dose (MTD) was 75 mg/m2, and the most frequent grade 3 to 4 toxicity was myelosuppression. One patient with CLL had more than 50% reduction in measurable disease without improvement in hematologic parameters. Another patient with low tumor burden had stable disease for four courses. For patients with MM, no DLT was observed and MTD was not identified at up to 75 mg/m2, owing to early study closure. Two patients with MM had stable disease and one had normalization of spleen size with treatment. Biomarker analyses demonstrated mechanism-based PD activity with inhibition of Cdk7 and Cdk9, decreases in Mcl-1 and XIAP expression level, and associated CLL cell apoptosis. Conclusion SNS-032 demonstrated mechanism-based target modulation and limited clinical activity in heavily pretreated patients with CLL and MM. Further single-agent, PD-based, dose and schedule modification is warranted to maximize clinical efficacy.

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.

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