Chronic lymphocytic leukemia and the central nervous system: a clinical and pathological study.

Chronic lymphocytic leukemia is the most common human leukemia but infrequently causes neurologic symptoms. We have reviewed all previously reported cases of chronic lymphocytic leukemia in the CNS along with three new cases; one patient was diagnosed antemortem and treated with immediate improvement and 4-year survival. In addition, we reviewed all autopsy cases since 1972 and available lumbar puncture data on patients with chronic lymphocytic leukemia admitted to the Massachusetts General Hospital. Invasion of the CNS by chronic lymphocytic leukemia often leads to confusional state, meningitis with cranial nerve abnormalities, optic neuropathy, or cerebellar dysfunction. Lumbar puncture shows a lymphocytosis consisting of monoclonal B cells, but CSF cytology studies are of limited value in establishing the diagnosis. Long-term survival may be related to the stage of chronic lymphocytic leukemia at the time of CNS disease and may be associated with intrathecal chemotherapy. A mild, asymptomatic infiltration of the brain, frequently noted in late-stage chronic lymphocytic leukemia in autopsy series, may explain the CSF lymphocytosis in some patients with late-stage chronic lymphocytic leukemia

Questions and answers about leukemia

Leukemia is cancer of the white blood cells. It develops in the bone marrow and spreads into the blood and to other organs. There are several types of leukemia. They are grouped in two ways: by how rapidly the disease develops (acute vs. chronic leukemia) and by the type of blood cell involved (lymphocytic and myeloid leukemia being the most common). In acute leukemia, bone marrow cells are immature and are unable to function normally. The number of abnormal cells increases rapidly. In chronic leukemia, cells are more mature and can carry out some of their normal functions. The number of abnormal cells increases more slowly. The most common types of leukemia are acute lymphocytic leukemia, acute myeloid leukemia, chronic lymphocytic leukemia, and chronic myeloid leukemia. In children leukemia is the most common cancer, and acute lymphocytic leukemia is the most common type of leukemia. In adults, acute myeloid leukemia is the most common occurring type, followed by chronic lymphocytic leukemia.Publication date from document properties.mleukemi.pd

The prohibitin-binding compound fluorizoline induces apoptosis in chronic lymphocytic leukemia cells through the upregulation of NOXA and synergizes with ibrutinib, 5-aminoimidazole-4-carboxamide riboside or venetoclax

Fluorizoline is a new synthetic molecule that induces apoptosis by selectively targeting prohibitins. In the study herein, the pro-apoptotic effect of fluorizoline was assessed in 34 primary samples from patients with chronic lymphocytic leukemia. Fluorizoline induced apoptosis in chronic lymphocytic leukemia cells at concentrations in the low micromolar range. All primary samples were sensitive to fluorizoline irrespective of patients' clinical or genetic features, whereas normal T lymphocytes were less sensitive. Fluorizoline increased the protein levels of the pro-apoptotic B-cell lymphoma 2 family member NOXA in chronic lymphocytic leukemia cells. Furthermore, fluorizoline synergized with ibrutinib, 5-aminoimidazole-4-carboxamide riboside or venetoclax to induce apoptosis. These results suggest that targeting prohibitins could be a new therapeutic strategy for chronic lymphocytic leukemia

Targeting the Ataxia Telangiectasia Mutated-null Phenotype in Chronic Lymphocytic Leukemia with Pro-oxidants

Inactivation of the Ataxia Telangiectasia Mutated gene in chronic lymphocytic leukemia results in resistance to p53-dependent apoptosis and inferior responses to treatment with DNA damaging agents. Hence, p53-independent strategies are required to target Ataxia Telangiectasia Mutated-deficient chronic lymphocytic leukemia. As Ataxia Telangiectasia Mutated has been implicated in redox homeostasis, we investigated the effect of the Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia genotype on cellular responses to oxidative stress with a view to therapeutic targeting. We found that in comparison to Ataxia Telangiectasia Mutated-wild type chronic lymphocytic leukemia, pro-oxidant treatment of Ataxia Telangiectasia Mutated-null cells led to reduced binding of NF-E2 p45-related factor-2 to antioxidant response elements and thus decreased expression of target genes. Furthermore, Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia cells contained lower levels of antioxidants and elevated mitochondrial reactive oxygen species. Consequently, Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia, but not tumours with 11q deletion or TP53 mutations, exhibited differentially increased sensitivity to pro-oxidants both in vitro and in vivo. We found that cell death was mediated by a p53- and caspase-independent mechanism associated with apoptosis inducing factor activity. Together, these data suggest that defective redox-homeostasis represents an attractive therapeutic target for Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia

Effects of miRNA-15 and miRNA-16 expression replacement in chronic lymphocytic leukemia : implication for therapy

This work was supported by: Associazione Italiana Ricerca sul Cancro (AIRC) Grant 5 x mille n.9980, (to M.F., F.M. A. N., P.T. and M.N.) ; AIRC I.G. n. 14326 (to M.F.), n.10136 and 16722 (A.N.), n.15426 (to F.F.). AIRC and Fondazione CaRiCal co-financed Multi Unit Regional Grant 2014 n.16695 (to F.M.). Italian Ministry of Health 5x1000 funds (to S.Z. and F.F). A.G R. was supported by Associazione Italiana contro le Leucemie-Linfomi-Mielomi (AIL) Cosenza - Fondazione Amelia Scorza (FAS). S.M. C.M., M.C., L.E., S.B. were supported by AIRC.Peer reviewedPostprin

B-cell chronic lymphocytic leukemia-associated nuclear antigens

One- and two-dimensional polyacrylamide gel electrophoresis were used to compare the composition of nuclear polypeptides from normal and В-cell chronic lymphocytic leukemia mononuclear cells. Against two electrophoretically-specific nuclear proteins with molecular weight of 38/39 and 44/46 kD a from leukemic cells rabbit sera were obtained. As it was analyzed by Western blot technique the available antisera recognized the 38/39 kDa antigen in 53 of the 56 (94.6%), while the 44/46 kDa in 46 of the 49 (93.9%) of examined В-CLL nuclear fraction preparations, but not in normal ones. The pi values of described leukaemia-specific antigens were determined; p38/39 had pi in the range of pH 6.55 -7.00 and p44/46 - in the range of pH 6.2-6.4.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę

Cirmtuzumab inhibits Wnt5a-induced Rac1 activation in chronic lymphocytic leukemia treated with ibrutinib.

Signaling via the B cell receptor (BCR) plays an important role in the pathogenesis and progression of chronic lymphocytic leukemia (CLL). This is underscored by the clinical effectiveness of ibrutinib, an inhibitor of Bruton's tyrosine kinase (BTK) that can block BCR-signaling. However, ibrutinib cannot induce complete responses (CR) or durable remissions without continued therapy, suggesting alternative pathways also contribute to CLL growth/survival that are independent of BCR-signaling. ROR1 is a receptor for Wnt5a, which can promote activation of Rac1 to enhance CLL-cell proliferation and survival. In this study, we found that CLL cells of patients treated with ibrutinib had activated Rac1. Moreover, Wnt5a could induce Rac1 activation and enhance proliferation of CLL cells treated with ibrutinib at concentrations that were effective in completely inhibiting BTK and BCR-signaling. Wnt5a-induced Rac1 activation could be blocked by cirmtuzumab (UC-961), an anti-ROR1 mAb. We found that treatment with cirmtuzumab and ibrutinib was significantly more effective than treatment with either agent alone in clearing leukemia cells in vivo. This study indicates that cirmtuzumab may enhance the activity of ibrutinib in the treatment of patients with CLL or other ROR1+ B-cell malignancies

Targeting the CXCR4 pathway using a novel anti-CXCR4 IgG1 antibody (PF-06747143) in chronic lymphocytic leukemia.

BackgroundThe CXCR4-CXCL12 axis plays an important role in the chronic lymphocytic leukemia (CLL)-microenvironment interaction. Overexpression of CXCR4 has been reported in different hematological malignancies including CLL. Binding of the pro-survival chemokine CXCL12 with its cognate receptor CXCR4 induces cell migration. CXCL12/CXCR4 signaling axis promotes cell survival and proliferation and may contribute to the tropism of leukemia cells towards lymphoid tissues and bone marrow. Therefore, we hypothesized that targeting CXCR4 with an IgG1 antibody, PF-06747143, may constitute an effective therapeutic approach for CLL.MethodsPatient-derived primary CLL-B cells were assessed for cytotoxicity in an in vitro model of CLL microenvironment. PF-06747143 was analyzed for cell death induction and for its potential to interfere with the chemokine CXCL12-induced mechanisms, including migration and F-actin polymerization. PF-06747143 in vivo efficacy was determined in a CLL murine xenograft tumor model.ResultsPF-06747143, a novel-humanized IgG1 CXCR4 antagonist antibody, induced cell death of patient-derived primary CLL-B cells, in presence or absence of stromal cells. Moreover, cell death induction by the antibody was independent of CLL high-risk prognostic markers. The cell death mechanism was dependent on CXCR4 expression, required antibody bivalency, involved reactive oxygen species production, and did not require caspase activation, all characteristics reminiscent of programmed cell death (PCD). PF-06747143 also induced potent B-CLL cytotoxicity via Fc-driven antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity activity (CDC). PF-06747143 had significant combinatorial effect with standard of care (SOC) agents in B-CLL treatment, including rituximab, fludarabine (F-ara-A), ibrutinib, and bendamustine. In a CLL xenograft model, PF-06747143 decreased tumor burden and improved survival as a monotherapy, and in combination with bendamustine.ConclusionsWe show evidence that PF-06747143 has biological activity in CLL primary cells, supporting a rationale for evaluation of PF-06747143 for the treatment of CLL patients

Lenalidomide interferes with tumor-promoting properties of nurse-like cells in chronic lymphocytic leukemia

Lenalidomide is an immunomodulatory agent clinically active in chronic lymphocytic leukemia patients. The specific mechanism of action is still undefined, but includes modulation of the microenvironment. In chronic lymphocytic leukemia patients, nurse-like cells differentiate from CD14(+) mononuclear cells and protect chronic lymphocytic leukemia cells from apoptosis. Nurse-like cells resemble M2 macrophages with potent immunosuppressive functions. Here, we examined the effect of lenalidomide on the monocyte/macrophage population in chronic lymphocytic leukemia patients. We found that lenalidomide induces high actin polymerization on CD14(+) monocytes through activation of small GTPases, RhoA, Rac1 and Rap1 that correlated with increased adhesion and impaired monocyte migration in response to CCL2, CCL3 and CXCL12. We observed that lenalidomide increases the number of nurse-like cells that lost the ability to nurture chronic lymphocytic leukemia cells, acquired properties of phagocytosis and promoted T-cell proliferation. Gene expression signature, induced by lenalidomide in nurse-like cells, indicated a reduction of pivotal pro-survival signals for chronic lymphocytic leukemia, such as CCL2, IGF1, CXCL12, HGF1, and supported a modulation towards M1 phenotype with high IL2 and low IL10, IL8 and CD163. Our data provide new insights into the mechanism of action of lenalidomide that mediates a pro-inflammatory switch of nurse-like cells affecting the protective microenvironment generated by chronic lymphocytic leukemia into tissues

Wnt5a causes ROR1 to complex and activate cortactin to enhance migration of chronic lymphocytic leukemia cells.

Chronic lymphocytic leukemia cells (CLL) migrate between the blood and lymphoid tissues in response to chemokines. Such migration requires structured cytoskeletal-actin polymerization, which may involve the protein cortactin. We discovered that treatment of CLL cells with Wnt5a causes Receptor tyosin kinase-like orphan receptor 1 (ROR1) to bind cortactin, which undergoes tyrosine phosphorylation at Y421, recruits ARHGEF1, and activates RhoA, thereby enhancing leukemia-cell migration; such effects could be inhibited by cirmtuzumab, a humanized mAb specific for ROR1. We transfected the CLL-cell-line MEC1 with either full-length ROR1 or various mutant forms of ROR1 to examine the structural features required for binding cortactin. We found that the proline-rich domain (PRD) was necessary for ROR1 to recruit cortactin. We generated MEC1 cells that each expressed a mutant form of ROR1 with a single amino-acid substitution of alanine (A) for proline (P) in potential SH3-binding sites in the ROR1-PRD at positions 784, 808, 826, 841, or 850. In contrast to wild-type ROR1, or other ROR1P=>A mutants, ROR1P(841)A failed to complex with cortactin or ARHGEF1 in response to Wnt5a. Moreover, Wnt5a could not induce MEC1-ROR1P(841)A to phosphorylate cortactin or enhance CLL-cell F-actin polymerization. Taken together, these studies show that cortactin plays an important role in ROR1-dependent Wnt5a-enhanced CLL-cell migration