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PubMed1994

Serum macrophage colony-stimulating factor (M-CSF) levels correlate with clinical response to interferon-alpha in patients with early-stage B-CLL.

Interferon-alpha (IFN-alpha) reduces peripheral lymphocyte counts in B-CLL (CLL). In eight patients with stage 0 CLL on IFN-alpha therapy, peripheral lymphocyte counts fell to 61.7 +/- 19.5% of baseline at week 2 (P < 0.01), while serum M-CSF levels rose from 455 +/- 183 U/ml to 686 +/- 110 U/ml (P < 0.05). Neopterin levels also showed a significant rise. M-CSF levels were correlated with clinical response in these patients. Increased production of M-CSF and the activation of mononuclear phagocytes may be involved in clinical responses to IFN-alpha in early-stage CLL.

Biopterins↗

PubMed1995

Deletion of chromosome 13 (band q14) but not trisomy 12 is a clonal event in B-chronic lymphocytic leukaemia (CLL).

Chromosomal abnormalities are detected by conventional cytogenetic or FISH analysis in 50% of chronic lymphocytic leukaemias (CLL). Trisomy 12 and del 13q14 account for 70% of these abnormalities. The incidence of these two abnormalities was studied in CLL patients by Southern blot analysis using a highly purified B-cell malignant population (CD5 > 95%, CD3 < 5%). Probes for the D13S25 marker on chromosome 13 band q14 and for the RBTN3 gene on chromosome 12 band p12-13, were used. Deletion of the D13S25 was detected in 17/42 patients (43%) in a homozygous (9.5%) or heterozygous (30%) configuration. Deletion of the D13S25 marker appears to be a clonal and early event in CLL development since it is detected in > 95% of the malignant clonal population. Conversely, trisomy 12 is rarely a clonal event (5/33 patients, 15%) and a varying proportion of cells carrying this abnormality can be demonstrated in 30% of CLL patients (10/33 patients).

Blotting, Southern↗

PubMed1978

CLL and diffuse histiocytic lymphoma in one patient: clonal proliferation of two different B cells.

A case report is presented of a 77-year-old woman suffering from a composite lymphoma, known as Richter's Syndrome, consisting of chronic lymphocytic leukaemia (CLL) and diffuse histiocytic lymphoma. Light-microscopic investigation revealed the presence of CLL cells in the blood and bone marrow and a combination of CLL cells and large immunoblastic cells in the lymph node. Immunological investigation showed that both malignant cell types were B cells. The CLL cells carried a monoclonal surface immunoglobulin (S-Ig) micron lambda, and the immunoblastic cells had a monoclonal S-Ig micron K. These findings indicated that both clonal lymphoproliferative diseases were probably derived from different tumour stem cells.

Aged↗

PubMed1989

Immunophenotype analysis of B-CLL lymphoma and immunocytoma.

The differential diagnosis between lymphocytic lymphoma of the B-CLL type and immunocytoma (IC) can be difficult when it is based only upon morphological criteria. With the aim of improving the distinction between these subgroups, frozen sections of lymph nodes or other biopsied tissues from 14 cases of B-CLL and 16 cases of IC were investigated according to immunophenotype. A panel of 13 B cell-associated and 2 T cell-associated monoclonal antibodies was used. All but one of the B-CLL cases were FMC7-, while 14/16 IC cases were FMC7+ (p less than 0.001). The two negative IC cases were both of the lymphoplasmacytic type, claimed to be "more differentiated" than the lymphoplasmacytoid type. We suggest that the cells in these cases are mature enough to have lost their FMC7 positivity, similar to plasma cells. There was also a statistically significant (p less than 0.01) difference, although not as pronounced, for the anti-CD38 antibody (Leu-17, B-CLL: 3/14, IC: 10/16 positive). No significant difference in expression of determinants was found for any of the other antibodies.

ADP-ribosyl Cyclase↗

PubMed2004

Vdelta1 T lymphocytes from B-CLL patients recognize ULBP3 expressed on leukemic B cells and up-regulated by trans-retinoic acid.

We analyzed 38 untreated patients with chronic lymphocytic leukemia of B-cell type (B-CLL): 24 low-, 8 intermediate-, and 6 high-risk stage. In 15 patients (13 low risk and 2 intermediate risk), circulating Vdelta1 T lymphocytes were significantly increased (100 to 300 cells/muL) compared with most intermediate, all high-risk stage, and 15 healthy donors (50 to 100 cells/muL). We studied these Vdelta1 T lymphocytes and observed that they proliferated in vitro and produced tumor necrosis factor alpha or IFN-gamma in response to autologous leukemic B cells but not to normal lymphocytes. However, they were unable to kill resting autologous B cells, which lack the MHC-related MIC-A antigen and express low levels of the UL16-binding protein (ULBP) 3 and undetectable levels of ULBP1, ULBP2, and ULBP4. All these molecules are reported ligands for the NKG2D receptor, which is expressed by gammadelta T cells and activates their cytolytic function. The Vdelta1 T lymphocytes studied were able to lyse the ULBP3(+) C1R B-cell line upon transfection with MIC-A. More importantly, they also lysed autologous B-CLL cells when transcription and expression of MIC-A or up-regulation of ULBP3 were achieved either by activation or by exposure to trans-retinoic acid. The NKG2D receptor expressed on Vdelta1 T cells was involved in the recognition of B-CLL. Finally, in six patients with low numbers of circulating Vdelta1 T cells and undetectable ULBP3, the disease progressed over 1 year, whereas no progression occurred in patients with high Vdelta1 T lymphocytes and detectable/inducible ULBP3. These data suggest that Vdelta1 T lymphocytes may play a role in limiting the progression of B-CLL.

Aged↗

PubMed2006

New prognostic markers in CLL.

The individual prognosis of patients with chronic lymphocytic leukemia (CLL) is extremely variable. Although clinical stages remain the basis for assessing prognosis in CLL, a number of biological markers, particularly serum markers, cytogenetic abnormalities, IgVH mutations, CD38 and ZAP-70 expression in leukemic cells offer important, independent prognostic information. Before being incorporated into daily practice, however, these markers require standardization and validation in large, prospective trials. Meanwhile, treatment of patients with CLL not included in clinical studies should be decided on the basis of classical NCI/CLL Working Group criteria. An important area of research in CLL prognostication is the identification of markers useful for predicting response to therapy and its duration. Among them, del(17p), reflecting P53 abnormalities, is particularly important. Also relevant is del(11q), which points to ATM defects. There is also some correlation between IgVH mutational status, ZAP-70 and CD38 expression and response to therapy and its duration, although these relationships need further investigation. Finally, there is increasing evidence that response to therapy, particularly in those cases in which minimal residual disease is eradicated, is associated with longer survival.

Biomarkers↗

PubMed2004

Quantitative analysis of nucleoside transporter and metabolism gene expression in chronic lymphocytic leukemia (CLL): identification of fludarabine-sensitive and -insensitive populations.

Resistance to fludarabine is observed in the clinic, and molecular predictive assays for benefit from chemotherapy are required. Our objective was to determine if expression of nucleoside transport and metabolism genes was associated with response to fludarabine therapy in patients with chronic lymphocytic leukemia (CLL). CLL cells from 56 patients were collected prior to treatment with fludarabine. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was performed on sample RNA to determine the relative levels of mRNA of 3 nucleoside transporters that mediate fludarabine uptake (human equilibrative nucleoside transporter 1 [hENT1], human equilibrative nucleoside transporter 2 [hENT2], and human concentrative nucleoside transporter 3 [hCNT3]), deoxycytidine kinase (dCK), and 3 5'-nucleotidases (ecto-5'nucleotidase [CD73], deoxynucleotidase-1 [dNT-1], and cytoplasmic high-Km 5-nucleotidase [CN-II]). Two-dimensional hierarchical cluster analysis of gene expression identified 2 distinct populations of CLL. Cluster 2 patients experienced a 3.4-fold higher risk of disease progression than cluster 1 patients (P = .0058, log-rank analysis). Furthermore, independent analysis of the individual genes of interest revealed statistically significant differences for risk of disease progression (adjusted hazard ratios [HRs]) with underexpression of dNT-1 (HR = 0.45; P = .042), CD73 (HR = 0.40; P = .022), and dCK (HR = 0.0.48; P = .035), and overexpression of hCNT3 (HR = 4.7; P = .0007) genes. Subjects with elevated hCNT3 expression experienced a lower complete response rate to fludarabine therapy (11% vs 69%; P = .002). No hCNT3-mediated plasma membrane nucleoside transport was detected in CLL samples expressing hCNT3 message, and hCNT3 protein was localized to the cytoplasm with immunohistochemical and confocal microscopy.

Adult↗

PubMed2004

A novel celecoxib derivative, OSU03012, induces cytotoxicity in primary CLL cells and transformed B-cell lymphoma cell line via a caspase- and Bcl-2-independent mechanism.

Chronic lymphocytic leukemia (CLL) is an incurable adult leukemia characterized by disrupted apoptosis. OSU03012 is a bioavailable third-generation celecoxib derivative devoid of cyclooxygenase-2 inhibitory activity that potently induces apoptosis in prostate cancer cell lines and is being developed as an anticancer therapy in the National Cancer Institute (NCI) Rapid Access to Intervention Development (RAID) program. We assessed the ability of OSU03012 to induce apoptosis in primary CLL cells and the mechanism by which this occurs. The LC50 (lethal concentration 50%) of OSU03012 at 24 hours was 7.1 microM, and this decreased to 5.5 microM at 72 hours. Additionally, we have demonstrated that OSU03012 mediates apoptosis by activation of the intrinsic, mitochondrial pathway of apoptosis but also activates alternative cell death pathways that are caspase independent. The early activation of both caspase-dependent and -independent pathways of apoptosis is novel to OSU03012 and suggests it has great potential promise for the treatment of CLL. Moreover, unlike the great majority of therapeutic agents used to treat leukemia or other forms of cancer, OSU03012 induces cell death entirely independent of bcl-2 expression. Overall, these data provide justification for further preclinical development of OSU03012 as a potential therapeutic agent for CLL.

Apoptosis↗

PubMed2002

The alternative transcript of CD79b is overexpressed in B-CLL and inhibits signaling for apoptosis.

The B-cell receptor (BCR) for antigen is composed of surface immunoglobulin (sIg), which provides antigen specificity, and a noncovalently associated signaling unit, the CD79a/b heterodimer. Defects in CD79 can influence both BCR expression and signaling and may explain why cells from certain malignancies, such as B-chronic lymphocytic leukemia (B-CLL), often express diminished and inactive BCR. Recently, an alternative transcript of CD79b (DeltaCD79b) has been reported that is up-regulated in B-CLL and may explain this diminished BCR expression. Here we assess the expression of DeltaCD79b in B-CLL and other lymphoid malignancies and investigate its function. High relative expression of DeltaCD79b was confirmed in most cases of B-CLL and found in 6 of 6 cases of splenic lymphomas with villous lymphocytes (SLVLs) and hairy cell leukemia. In a range of Burkitt lymphoma cell lines, expression of DeltaCD79b was relatively low but correlated inversely with the ability of the BCR to signal apoptosis when cross-linked by antibody (Ab). Interestingly, when Ramos-EHRB cells, which express low DeltaCD79b, were transfected with this transcript, they were transformed from being sensitive to anti-Fcmu-induced apoptosis to being highly resistant. Although DeltaCD79b was expressed as protein, its overexpression did not reduce the level of cell surface BCR. Finally, we showed that the inhibitory activity of DeltaCD79b depended on an intact leader sequence to ensure endoplasmic reticulum (ER) trafficking and a functional signaling immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic tail. These results point to DeltaCD79b being a powerful modulator of BCR signaling that may play an important role in normal and malignant B cells.

Alternative Splicing↗

PubMed2005

In B-CLL, the codon 72 polymorphic variants of p53 are not related to drug resistance and disease prognosis.

BACKGROUND: A common sequence polymorphism at codon 72 of the p53 gene encoding either arginine or proline was recently shown to be functionally relevant for apoptosis induction in vitro. In B-type chronic lymphocytic leukemia (B-CLL), p53 gene mutations occur in a subset of patients and are associated with impaired survival and drug resistance. Here, we address the functional relevance of the codon 72 single nucleotide (SNP) polymorphism for cell death sensitivity following exposure to clinically employed cytotoxic drugs and gamma-irradiation. METHODS: 138 B-CLL samples were analysed by SSCP-PCR and sequencing for single nucleotide polymorphism at codon 72 of the p53 gene. The in vitro cytotoxicity assay (DiSC-assay) was performed with 7 drugs (chlorambucil, mafosfamide, fludarabine phosphate, methylprednisolone, doxorubicin, vincristine) or gamma-irradiation. RESULTS: Of the 138 B-CLL samples, 9 samples were homozygous for proline (Pro/Pro), 78 samples homozygous for arginine (Arg/Arg), and 49 samples heterozygous (Arg/Pro). No differences were found for patient survival and cell death triggered by 7 cytotoxic drugs or gamma-irradiation. CONCLUSION: These data indicate that polymorphic variants of p53 codon 72 are not clinically relevant for apoptosis induction or patient survival in B-CLL.

Aged↗

PubMed2002

Immunological effects and safe administration of alemtuzumab (MabCampath) in advanced B-cLL.

Alemtuzumab (MabCampath) can purge both B- and T-cells in a variety of clinical situations, as seen in the treatment of autoimmune disorders and of lymphoid malignancies such as B-cell chronic lymphocytic leukemia (B-CLL). One of the characteristics of advanced B-CLL is an increased susceptibility to infection, which may improve in patients whose disease responds to alemtuzumab, particularly when immune reconstitution by non-malignant stem cells is successful. However, at initiation of treatment, patients with advanced disease are likely to have poor immune function, and need careful management during and after treatment. Here, we present results showing the nature of immune reconstitution after alemtuzumab and the ways in which alemtuzumab may affect white cell counts during and after treatment. The management of B-CLL patients is discussed both in the context of minimizing acute "first-dose" events and with reference to the health risks already existing in this patient population. With protocols in place for dose escalation, for dose postponement in the event of cytopenia, and for anti-infective prophylaxis, alemtuzumab can be used effectively and safely in high-risk B-CLL patients.

Alemtuzumab↗

PubMed2005

Signaling molecules and cytokine production in T cells of patients with B-cell chronic lymphocytic leukemia (B-CLL): comparison of indolent and progressive disease.

T-cell dysfunction in B-CLL patients might be attributed to altered expression of components of the TCR/CD3 complex and associated intracellular tyrosine kinases. Four-color flow cytometry was applied to the expression of these molecules as well as the T-cell regulatory cytokines (IFN-gamma and IL-4) in B-CLL patients with indolent and progressive disease. Intracellular levels [mean fluorescent intensity (MFI)] of IFN-gamma and IL-4 in both CD4 and CD8 T cells of both patient groups were significantly higher than in healthy donors. Absolute number of IL-4 producing CD4 T cells in patients with indolent was significantly higher than in healthy donors. The expression level (MFI) of the CD3-zeta chain was higher in patients than in normal donors as well as ZAP-70 in patients with indolent disease as compared to healthy donors and progressive patients. No significant difference was noted in the expression of p56lck, p59fyn, and PI3-kinase between healthy donors and patients or between the patient subgroups. The results indicate multiple T-cell abnormalities especially in indolent-stage B-CLL suggesting a state of chronic and aberrant activation. This information might be of significance when studying the immunobiology of B-CLL as well as developing new therapeutic approaches.

Aged↗

PubMed2001

Impaired transendothelial migration of B-CLL lymphocytes: a defect linked to low L-selectin expression.

The emigration of lymphocytes from blood into lymph nodes is regulated by the expression of the adhesion molecule, L-selectin on the lymphocyte surface which arrests the rolling of the cell on the vessel wall and allows firmer adhesive interactions to develop. The expression of L-selectin on B-CLL lymphocytes is less than half that on normal lymphocytes and this difference correlates with an impaired capacity of B-CLL lymphocytes to migrate beneath a monolayer of human umbilical vein endothelial cells. Both the B-cell and T-cell lymphocytes from normal subjects and B-CLL patients show down-regulation of L-selectin and CD23 after transendothelial migration. The reduced expression of L-selectin on B-CLL lymphocytes leads to a relative "trapping" of these cells in the vascular space and is one factor contributing to the elevation of peripheral lymphocyte count.

B-Lymphocytes↗

PubMed1993

Cytokines and intracellular signals involved in the regulation of B-CLL proliferation.

Cytokines play an important role in the regulation of both normal and malignant B cells. In this paper we give a brief overview of the major cytokines involved in the regulation of B-CLL proliferation. In vitro experiments have indicated that there is an antagonistic interaction between TNF-alpha as a growth-enhancing factor and IL-4, which inhibits the growth of B-CLL. We have extended these findings with recent experiments on the intracellular signals which might be involved in these processes. We show that increased levels of intracellular cAMP dose-dependently inhibit the TNF-alpha-induced proliferation of B-CLL. On the basis of these results, we propose a model for the signals involved in the regulation of B-CLL proliferation. The implications for possible new ways of treatment are discussed.

Apoptosis↗

PubMed1993

Proliferating cell nuclear antigen (PCNA) expression in chronic lymphocytic leukemia (CLL).

Chronic Lymphocytic Leukemia (CLL) is usually an indolent disorder which in some patients assumes an aggressive clinical course. In order to assess at presentation the prognosis of a given patient, several staging systems and prognostic variables have been proposed including the expression of the Proliferating Cell Nuclear Antigen (PCNA). PCNA is a 36 kd nuclear protein, the regulation of which is cell cycle-dependent. In CLL, PCNA levels correlate with cell proliferation, clinical stage and the lymphocyte doubling time (LDT). Furthermore, preliminary data suggests that PCNA expression may also predict response to Fludarabine-based chemotherapy. Since PCNA is a cofactor for Delta DNA polymerase, PCNA overexpression in CLL may also reflect the intrinsic DNA repair activity of the leukemic cells and thus their resistance to chemotherapy. Further studies aiming at modulation of PCNA expression in CLL cells may clarify this issue and may offer a future new therapeutic strategy with which to treat this disorder.

Antigens, Neoplasm↗

PubMed1994

B-CLL in PLL transformation associated with hypercalcemia.

A 64-year-old woman is reported with Stage I (Rai) chronic lymphocytic leukaemia (CLL), in whom hypercalcemia developed when an increased proportion of prolymphocytic cells characterized a transformation of CLL in prolymphocytoid leukaemia (CLL/PL). Although hypercalcemia is more frequently found in T-cell leukaemia associated with human T lymphotropic lymphocyte type I, scattered reports indicate that patients with B-CLL can also be affected with this metabolic disturbance. The case described here, progressed with an indolent course of CLL for 26 months, when she was admitted with a very aggressive disease characterized by a high WBC count, splenomegaly and hypercalcemia. Despite an effort to achieve a clinical remission, she failed treatment and death was attributed to unresponsive hypercalcemia. The mechanism of hypercalcemia in such cases is unclear as no parathyroid adenoma or second malignant tumor was found ante mortem. This electrolytic disturbance would appear to be a direct consequence of the transforming leukaemia and a possible mechanism involving a secreted humoral factor that could lead to altered calcium metabolism.

Antigens, CD↗

PubMed1996

Differentiating agents do not induce a true hairy cell phenotype in B-CLL cells in vitro.

B-Chronic lymphocytic leukemia (B-CLL) and hairy cell leukemia (HCL) are both differentiated B-cell lymphoproliferative disorders. Prior studies have suggested that phorbol esters and the macrocyclic lactone Bryostatin-1, which are both protein kinase-C activators, can induce the differentiation of B-CLL cells into HCL cells in vitro, as evidenced by morphology, phenotype and TRAP activity. The differentiating effect of all-trans retinoic acid on B-CLL cells has been less extensively studied. We studied the effects of incubating adherence purified B-CLL cells with phorbol myristic acetate (PMA), all-trans retinoic acid (ATRA), and Bryostatin-1. None of these agents induced a true HCL phenotype (CD5-, CD11c/CD25 coexpression) under the conditions studied.

Acid Phosphatase↗

PubMed1996

Nuclear NF-ATp is a hallmark of unstimulated B cells from B-CLL patients.

B lymphocytes from the peripheral blood of patients with chronic lymphocytic leukaemia (CLL) were analysed for the nuclear presence and DNA binding of a panel of transcription factors which are involved in the gene control of lymphoid cells. The following transcription factors were studied: the Octamer factors Oct-1 and Oct-2, members of the AP-1 factor family, NF-AT factors, in particular NF-ATp, and members of the Rel/NF-kB family. We show that the constitutive nuclear translocation of NF-ATp, a member of the growing family of NF-AT factors, is a hallmark of nonstimulated B cells from CLL patients that distinguishes B-CLL cells from 'normal' B lymphocytes. Constitutive nuclear appearance was also observed for NF-kB2/p52. Constitutive binding of further factor proteins to DNA, such as JunD, c-Fos and FosB, was detected in several patients whereas the localisation and DNA binding of other factors such as c-Jun, RelA/p65 and c-Rel was unaltered. It is remarkable that in B-CLL cells the nuclear appearance and DNA binding of specific transcription factors is dramatically affected whereas other members of the same factor family remained unaltered in these leukemic cells. It remains to be shown which molecular events lead to the specific 'pre-activation', i.e. constitutive nuclear translocation and DNA binding, of these members of NF-AT, NF-kB and AP-1 factor families.

B-Lymphocytes↗