C-Abl Regulates Mcl-1 Gene Expression In Chronic Lymphocytic Leukaemia Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3579-3579
Author(s):  
John C Allen ◽  
Mirko Zuzel ◽  
Ke Lin ◽  
Joseph R Slupsky
Keyword(s):  
Gene Expression ◽  
Chronic Lymphocytic Leukaemia ◽  
Lymphocytic Leukaemia ◽  
Conflicts Of Interest ◽  
Strong Relationship ◽  
Chemotherapeutic Agents ◽  
Disease Prognosis ◽  
Stat3 Phosphorylation ◽  
Definition Of

Abstract Abstract 3579 Chronic lymphocytic leukaemia (CLL) is a prevalent malignancy characterised by the clonal expansion of mature B cells that are resistant to apoptosis. This resistance to apoptosis will partly be due to Mcl-1 expression because high levels of this protein in CLL cells correlate with poor disease prognosis and resistance to chemotherapy. Thus, understanding the mechanism(s) regulating Mcl-1 expression in CLL cells may be useful in the development of new therapies for this incurable disease. In the present study we show a strong relationship between c-Abl and Mcl-1 expression in CLL cells. We show that treatment of CLL cells with Abl-specific siRNA or with imatinib, to inhibit c-Abl activity, results in the downregulation of Mcl-1 protein and mRNA. A major regulator of Mcl-1 gene expression is STAT3. Our data show that CLL cells expressing high levels of c-Abl also show elevated levels of phospho-STAT3, and that STAT3 phosphorylation in CLL cells is dependent on c-Abl activity. However, STAT3 phosphorylation by c-Abl is not direct, and requires activation of NFkB, secretion of autocrine IL6 and active PKC. Taken together, our results provide clearer definition of the pathobiological role of c-Abl in CLL cells. Given that high NFkB activation, plasma IL6 levels and Mcl-1 all correlate with poor disease prognosis in CLL, our work potentially connects several features of CLL cells that are important to their pathophysiology by suggesting a central role of c-Abl in their regulation. Since CLL cells expressing high levels of c-Abl and Mcl-1 belong to the unmutated, poor prognostic group of CLL, c-Abl inhibition may have therapeutic application in the treatment of this disease, especially for those patients who are resistant to conventional chemotherapeutic agents. Disclosures: No relevant conflicts of interest to declare.

The Local Sanarelli-Shwartzman Phenomenon in Rats Induced by Human Leukaemic Cells

1973 ◽  
Vol 29 (02) ◽  
pp. 353-362
Author(s):  
J Lisiewicz ◽  
A Pituch ◽  
J. A Litwin
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Intravenous Injection ◽  
Peripheral Blood ◽  
Lymphocytic Leukaemia ◽  
Acute Myeloblastic Leukaemia ◽  
Demarcation Line ◽  
E Coli ◽  
Leukaemic Cells ◽  
Shwartzman Phenomenon

SummaryThe local Sanarelli-Shwartzman phenomenon (SSP-L) in the skin of 30 rats was induced by an intr a cutaneous sensitizing injection of leukaemic leucocytes isolated from the peripheral blood of patients with chronic lymphocytic leukaemia (CLL), acute myeloblastic leukaemia (AL) and chronic granulocytic leukaemia (CGL) and challenged by an intravenous injection of 100(μ of E. coli endotoxin. SSP-L was observed in 7 rats after injection of CLL lymphocytes and in 6 and 2 rats after AL myeloblasts and the CGL granulocytes, respectively. The lesions in the skin after AL myeloblasts appeared in a shorter time and were of longer duration compared with those observed after CLL lymphocytes and CGL granulocytes. Histologically, the lesions consisted of areas of destruction in the superficial layers of the skin ; the demarcation line showed the presence of neutrophils, macrophages and erythrocytes. Haemorrhages and fibrin deposits near the demarcation line were larger after injection of CLL lymphocytes and AL myeloblasts than after CGL granulocytes. The possible role of leucocyte procoagulative substances in the differences observed have been discussed.

The Role of Continuous Flow Centrifuge Leucapheresis in the Management of Chronic Lymphocytic Leukaemia

1976 ◽  
Vol 32 (4) ◽  
pp. 609-616 ◽  
Author(s):  
I. E. Fortuny ◽  
D. C. Hadlock ◽  
B. J. Kennedy ◽  
A. Theologides ◽  
J. McCullough
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Continuous Flow ◽  
Lymphocytic Leukaemia ◽  
Continuous Flow Centrifuge

scholarly journals Prognostic role of CD4 T-cell depletion after frontline fludarabine, cyclophosphamide and rituximab in chronic lymphocytic leukaemia

BMC Cancer ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Martin Gauthier ◽  
Françoise Durrieu ◽  
Elodie Martin ◽  
Michael Peres ◽  
François Vergez ◽  
...  
Keyword(s):  
T Cell ◽  
Chronic Lymphocytic Leukaemia ◽  
Lymphocytic Leukaemia ◽  
Cd4 T Cell ◽  
Cell Depletion ◽  
Prognostic Role ◽  
T Cell Depletion

Gene expression profiling in chronic lymphocytic leukaemia

2009 ◽  
Vol 22 (2) ◽  
pp. 211-222 ◽  
Author(s):  
Carles Codony ◽  
Marta Crespo ◽  
Pau Abrisqueta ◽  
Emili Montserrat ◽  
Francesc Bosch
Keyword(s):  
Gene Expression ◽  
Chronic Lymphocytic Leukaemia ◽  
Gene Expression Profiling ◽  
Expression Profiling ◽  
Lymphocytic Leukaemia

Characterisation of B Cell Receptor-Induced NF-KB Activation In Chronic Lymphocytic Leukaemia Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 375-375 ◽  
Author(s):  
Fatima Talab ◽  
Victoria Thompson ◽  
John C Allen ◽  
Ke Lin ◽  
Joseph R Slupsky
Keyword(s):  
B Cells ◽  
Tyrosine Kinase ◽  
Chronic Lymphocytic Leukaemia ◽  
B Cell ◽  
Cell Cultures ◽  
Lymphocytic Leukaemia ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Nfkb Pathway

Abstract Abstract 375 B cell receptor (BCR) signaling promotes survival of the malignant clone in chronic lymphocytic leukaemia (CLL) through its ability to stimulate NFkB pathway signaling. In lymphoid cells, antigen receptor stimulation of this pathway is achieved by engaging the Carma-1 – Bcl10 – MALT1 (CBM) complex for eventual activation of I-kB kinases (IKKs). In B cells, protein kinase C beta (PKCbeta) is an important mediator of CBM complex activation. However, in CLL cells we found that PKCs do not appear to have a role in BCR-mediated NFkB pathway signaling, despite high expression levels of PKCbeta, because the presence of specific inhibitors of this kinase (LY379196 and bisindolylmaleimide-I) has no effect on the induction of IKK phosphorylation during BCR crosslinking. Examination of CBM complex expression suggests an explanation for this phenomenon; the expression levels of Carma-1 and MALT-1 are largely similar in CLL and normal B cells, but the expression of Bcl10 is much reduced in CLL cells. These findings, taken together with the established role of Bcl10 in the pathway of BCR-induced NFkB activation, suggest that CLL cells may employ a different mechanism to activate this pathway during BCR stimulation. Tyrosine kinases are known to play a role in BCR-induced IKK activation in CLL cells because compounds like dasatinib and PP2 inhibit NFkB pathway activation by BCR. One possible tyrosine kinase is c-Abl because we have shown this protein to be overexpressed in CLL cells, where it plays a role in activation of the NFkB pathway. To investigate the role of c-Abl in BCR-induced IKK activation, we used the inhibitor imatinib and found that the presence of this compound partially inhibited IKK phosphorylation in BCR-stimulated CLL cells. However, imatinib can also inhibit Lck, a T cell-specific src-family tyrosine kinase that is expressed by CLL cells. To differentiate between Lck- and c-Abl-mediated BCR signals we used the specific inhibitor 4-amino-5-(4-phenoxyphenyl)-7H-pyrrolo[3,2d] pyrimidin-7-yl-cyclopentane (Lck-i). We found that the presence of this compound in CLL cell cultures undergoing BCR stimulation almost completely inhibited the induction of IKK activation. Investigation of Lck-i specificity revealed this compound did not inhibit either c-Abl or Lyn at the concentration used to inhibit Lck in CLL cell cultures. Further investigation of the effects of Lck-i showed that this compound was also effective in inhibiting BCR-induced activation of the Akt and ERK signaling pathways. Taken together, these data suggest a major role for Lck in BCR-mediated signaling in CLL cells, and question the existing paradigm on the importance of Lyn. Disclosures: No relevant conflicts of interest to declare.

Defining The Role Of Microrna-146a In B Cell Lymphomagenesis

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3805-3805
Author(s):  
Jorge Contreras ◽  
Jayanth Kumar Palanichamy ◽  
Tiffany Tran ◽  
Dinesh S. Rao
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
B Cell ◽  
Conflicts Of Interest ◽  
Cell Lymphoma ◽  
Expression Patterns ◽  
Significant Proportion ◽  
B Cell Lymphoma ◽  
Gene Expression Patterns

Abstract Diffuse large B cell lymphoma (DLBCL) is one of the most common Non-Hodgkin lymphomas among adults. It is a heterogeneous disease characterized by multiple mutations and translocations. Gene expression profiling studies have revealed several characteristic gene expression patterns, with two main patterns emerging, namely Germinal Center(GC) type, and Activated B Cell (ABC) type. ABC-type DLBCL shows gene expression patterns that resemble activated B-cells, with increased expression of anti-apoptotic, and pro-proliferative genes. Critically, upregulation of the NF-κB the pathway is a hallmark of ABC-type DLBCL and has been shown to be necessary for survival, and is caused by several different mutations at different levels within the pathway. Recent work has revealed the critical importance of a new class of small RNA molecules, namely microRNAs, in gene regulation. Of these, microRNA-146a (miR-146a) was discovered as an NF-κB induced microRNA that plays a role as a negative feedback regulator of this pathway by targeting adaptor proteins. To further characterize miR-146a, mice deficient for this miRNA were created, and were found to develop lymphadenopathy, splenomegaly, and myeloid proliferation. As expected, immune cells in these mice have an upregulated NF-κB pathway and many of the phenotypes can be ameliorated by inhibition of the NF-κB pathway. Importantly, a significant proportion of the animals develop B-cell lymphoma at older ages. In this study, we examined the role of miR-146a in the development of malignancy in B-cells. To accelerate the role of miR-146a in tumor formation we overlaid the miR-146a deficient allele onto the Eμ-Myc like mouse model. Eμ-Myc mice develop tumors on average by 14weeks of age. The transgenic status of animals was verified by genotyping, RNA and protein expression analyses. miR-146a sufficient and deficient animals on the Eμ-Myc background were followed for tumor latency by peripheral blood analysis and careful physical examination. Based on approved humane criteria for animal discomfort, animals were sacrificed and hematopoietic tissue was harvested for analysis. Mice deficient for miR-146a had a statistically reduced survival in comparison with miR-146a sufficient animals with a p-value of .0098 (Kaplan Meir survival analysis). Complete Blood Count of animals at time of death revealed an increase leukemia presentation in the miR-146a deficient background. FACS analysis of tumor tissue from both groups revealed an increase in the number of IgM positive tumors in the miR-146a-deficient background indicating skewing towards more mature B cell neoplasms when miR-146a is lacking. Lineage analysis of tumors verified them to be of B cell origin although a subset of miR-146a sufficient tumors had higher numbers of infiltrating myeloid cells compared to deficient animals. Furthermore, histologic analysis of hematopoietic organs showed that while infiltration remained similar in kidneys and liver, more spleens in the miR-146a deficient background tended to be less involved. Our extensive histopathologic and immunophenotypic analyses indicate that miR-146a deficiency drives a more aggressive malignant phenotype in the B-cell lineage. In keeping with this, our profiling studies of human DLBCL suggest that a subset of DLBCL show decreased expression of miR-146a. We are currently examining the status of NF-κB in the murine tumors and using high throughput sequencing approaches to delineate gene expression differences between miR-146a sufficient and deficient tumors. We anticipate the discovery of novel gene targets of miR-146a and expect that these studies will lead to improved diagnostic and therapeutic options for patients of B-cell malignancies. Disclosures: No relevant conflicts of interest to declare.

The Multimerization Domain of Cbfß-SMMHC Is Required for Leukemogenesis

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3666-3666 ◽  
Author(s):  
Ling Zhao ◽  
Lemlem Alemu ◽  
Jun Cheng ◽  
Tao Zhen ◽  
Alan D. Friedman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Peripheral Blood ◽  
Conflicts Of Interest ◽  
Fusion Gene ◽  
Fetal Liver ◽  
Core Binding Factor ◽  
Binding Factor ◽  
Definitive Hematopoiesis

Abstract Among acute myeloid leukemia (AML) with cytogenetic abnormalities, core binding factor (CBF) leukemia acounts for 20-30% of adult AML, and 20-30% of pediatric AML. The chromosome 16 inversion (inv(16)), which results in a fusion gene CBFB -MYH11 and an encoded chimeric protein CBFβ-SMMHC (core binding factor β - smooth muscle myosin heavy chain), is observed primarily in AML subtype M4Eo. Using Cbfb-MYH11 knock-in mouse models we previously demonstrated that CBFβ-SMMHC needs its C terminal domains for leukemogenesis (Kamikubo et al, Blood 121:638, 2013). In this study we generated a new CBFB-MYH11 knock-in mouse model to determine the role of the multimerization domain at the C terminus of CBFβ-SMMHC for hematopoietic defects and leukemogenesis. Previous studies have shown that the C-terminal 29-residue assembly competent domain (ACD) is essential for multimerization of SMMHC. Within ACD, clustered point mutations in helices D and E specifically disrupts multimerization of CBFβ-SMMHC without interfering with the repression function of CBFβ-SMMHC (Zhang et al., Oncogene 25:7289, 2006). Therefore, we generated knock-in mice expressing CBFβ-SMMHC with mutated helices D and E (mDE) to study the role of the multimerization domain in vivo. Heterozygous embryos (Cbfb+/mDE) were viable and showed no defects in fetal liver definitive hematopoiesis, while homozygous embryos (CbfbmDE/mDE) showed complete blockage of definitive hematopoiesis, hemorrhage in the central nervous system and midgestation lethality, similar to the phenotype in Cbfb+/MYH11 mice and the Cbfb or Runx1 null mice. This phenotype is also similar to that in the homozygous knockin embryos expressing C-terminally-deleted CBFβ-SMMHC (Kamikubo et al, Blood 121:638, 2013). The fetal liver of E12.5 CbfbmDE/mDE embryos gave no colonies while the fetal liver of Cbfb+/mDE mice generated similar number of colonies as the WT controls. We further looked at the peripheral blood of E10.5 CbfbmDE/mDE embryos and found that the primitive hematopoiesis was not affected, while E10.5 Cbfb+/MYH11 embryos showed a developmental delay at this stage. Analysis of peripheral blood showed decreased B cell population in young adult Cbfb+/mDE mice, while the myeloid compartment was unchanged. In aged mice (>12 months), however, there was an increase of immature myeloid cells in the peripheral blood. Importantly, there was no leukemia development in the Cbfb+/mDE mice one year after ENU treatment (to induce cooperating mutations), while Cbfb+/MYH11 micedied of leukemia within 2 months of ENU treatment. Notably bone marrow cells in the Cbfb+/mDE and Cbfb+/MYH11 mice expressed their respective fusion proteins at similar levels. Overall our data suggest that the C terminal multimerization domain is required for the defects in primitive and definitive hematopoiesis caused by CBFβ-SMMHC, and the domain is essential for leukemogenesis by CBFβ-SMMHC. Further mechanistic studies of this domain may lead to new drug targets for treating inv(16) leukemia. For this purpose we have performed gene expression profiling with microarray and RNA-seq technologies, comparing gene expression changes in adult bone marrow c-Kit+ cells as well as embryonic primitive blood cells from Cbfb+/mDE and Cbfb+/MYH11 mice. Preliminary analysis indicates that the gene expression profile of the hematopoietic cells from the Cbfb+/mDE mice was much similar to that of Cbfb+/+ than Cbfb+/MYH11 mice. Validation and pathway analysis of those differentially expressed genes are ongoing and the results will be presented at the annual meeting. Disclosures No relevant conflicts of interest to declare.

To Treat or Not to Treat: Metabolomics Reveals Biomarkers for Treatment Indication in Chronic Lymphocytic Leukaemia Patients

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5286-5286
Author(s):  
Jaroslaw Piszcz ◽  
Emily Grace Armitage ◽  
Ferrarini Alessia ◽  
Francisco Javier Ruperez ◽  
Agnieszka Kulczynska ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Lymphocytic Leukaemia ◽  
Conflicts Of Interest ◽  
Disease Onset ◽  
Disease Status ◽  
Analytical Technique ◽  
Fatty Acid Amides ◽  
Staging Systems ◽  
Disease Staging ◽  
Patient Survival Time

Abstract In chronic lymphocytic leukaemia (CLL) clinical course of patients is heterogeneous. Some present an aggressive disease onset and require immediate therapy, while others remain without treatment for years. Current disease staging systems developed by Rai and Binet may be useful in forecasting patient survival time, but do not discriminate between stable and progressive forms of the disease in the early stages. Recently ample attention has been directed towards identifying new disease prognostic markers capable of predicting clinical aggressiveness at diagnosis. In this research we reached for LC-MS metabolic fingerprinting method to analyse serum of stable (n=51) and progressive (n=42) CLL patients and controls (n=45) with aim to discover metabolic indicators of disease status. A panel of markers discriminating aggressive from indolent patients was discovered. Ten of them were selected for validation on larger population (45 controls and 92 CLL) with an independent analytical technique. Linoleamide (p=0.002) in addition to various acylcarnitines (p=0.001-0.000001) showed to be significant markers of CLL in its aggressive form. Acetylcarnitine (p=0.05) and hexannoylcarnitine (p=0.005) were also distinguishable markers of indolent subjects. Forming a panel of selected acylcarnitines and fatty acid amides, it was possible to reach a highly specific and sensitive diagnostic approach (AUC=0.766). Disclosures No relevant conflicts of interest to declare.

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