A phase II study of alemtuzumab, fludarabine, cyclophosphamide, and doxorubicin (Campath-FCD) in peripheral T-cell lymphomas.

The clinical course of peripheral T-cell lymphoma (PTCL) is usually aggressive and the prognosis unfavorable. Therefore, there is a need for improvement of treatment options. Patients with newly diagnosed (n = 27) or refractory/relapsed (n = 11) PTCL received a combination of alemtuzumab, fludarabine, cyclophosphamide, and doxorubicin.

Src kinase inhibitors induce apoptosis and mediate cell cycle arrest in lymphoma cells.

Src kinases are involved in multiple cellular contexts such as proliferation, adhesion, tumor invasiveness, angiogenesis, cell cycle control and apoptosis. We here demonstrate that three newly developed dual selective Src/Abl kinase inhibitors (SrcK-I) (AZM559756, AZD0530 and AZD0424) are able to induce apoptosis and cell cycle arrest in BCR-ABL, c-KIT and platelet-derived growth factor-negative lymphoma cell lines. Treatment of DOHH-2, WSU-NHL, Raji, Karpas-299, HUT78 and Jurkat cells with SrcK-I revealed that the tested substances were effective on these parameters in the cell lines DOHH-2 and WSU-NHL, whereas the other tested cell lines remained unaffected.

The tyrosine kinase inhibitor AMN107 (Nilotinib) exhibits off-target effects in lymphoblastic cell lines.

The aminopyrimidine inhibitor AMN107 (Nilotinib) was rationally designed to antagonize the aberrant tyrosine kinase activity of Bcr-Abl-positive cells. We here evaluated, whether AMN107 is also able to induce apoptosis in Bcr-Abl-negative cells of lymphatic origin. The B-cell lines DOHH-2 and WSU-NHL and the T-cell lines Jurkat and HUT78 were incubated with increasing amounts of AMN107 corresponding to clinically achievable dosages.

Dexa-BEAM as salvage therapy in patients with primary refractory aggressive non-Hodgkin lymphoma.

Although aggressive NHL in relapse after remission can still be cured by second-line treatment followed by high-dose therapy and autologous stem cell transplantation, the long-term prognosis of patients who fail to obtain remission after first-line therapy remains extremely poor. We retrospectively evaluated a series of 29 consecutive patients with primary refractory high-grade NHL who were treated with Dexa-BEAM (DB) as uniform salvage therapy at a single institution. Twenty-nine patients with aggressive NHL primary refractory to CHOP or CHOP-like induction therapy with a median age of 47 (range, 22 - 64) years received 1 - 2 cycles of DB and were candidates for subsequent autologous stem cell (PBSC) mobilization and transplantation (PBSCT).

The molecular biology of TRAIL-mediated signaling and its potential therapeutic exploitation in hematopoietic malignancies.

Tumor necrosis factor apoptosis ligand (TRAIL) is a type II membrane-bound ligand displaying expression in a broad range of tissues and exhibiting a high grade of homology with the cytotoxic Fas ligand. Interest in TRAIL grew after evidence emerged, that induction of TRAIL-mediated signaling destroyed malignant cells while sparing normal cells. Employing the extrinsic pathway of apoptosis, TRAIL-stimulation is characterized by initial adaptor recruitment and the subsequent activation of caspases.

Prostate-apoptosis-response-gene-4 increases sensitivity to TRAIL-induced apoptosis.

The capacity of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) to preferentially induce apoptosis in malignant cells while sparing normal tissues renders it an attractive therapeutic agent. Nevertheless, the molecular determinants governing sensitivity towards TRAIL remain to be defined. Acknowledging the previously demonstrated deregulation of prostate-apoptosis-response-gene-4 (par-4) in ex vivo cells of patients suffering from acute and chronic lymphatic leukemia, we here tested the hypothesis that expression of par-4 influences sensitivity to TRAIL.

Acquired immunodeficiency syndrome-related lymphoma: simultaneous treatment with combined cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy and highly active antiretroviral therapy is safe and improves survival--results of the German Multicenter Trial.

Background: Highly active antiretroviral therapy (HAART) has improved the survival of patients with acquired immunodeficiency syndrome-related lymphoma (ARL). The German ARL Study Group investigated whether HAART administered concomitantly with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy compromised the course of immune parameters during and after chemotherapy and exerted a positive effect on remission and survival.

Methods: From 1997 to 2001, 72 patients with ARL were stratified prospectively into a standard-risk group (n = 48 patients) and a high-risk group (n = 24 patients) with either 0-1 or 2-3 of the following risk factors: CD4 < 50/microL, prior opportunistic infection, and/or a World Health Organization performance status > or = 3.

Novel agents aiming at specific molecular targets increase chemosensitivity and overcome chemoresistance in hematopoietic malignancies.

In hematologic neoplasias primary or secondary resistance of malignant cells towards the applied treatment presents the major clinical obstacle in the induction of remission and definite cure. Evaluation of the underlying molecular mechanisms determining response or resistance not only enables the clinician to define prognostic markers, but moreover facilitates the design of molecularly targeted agents potentially reversing the causative lesion. Deregulation of apoptosis is considered to contribute to the emergence and propagation of the malignant clone, and several molecular alterations hindering programmed cell death and thus leading to chemoresistance have been defined.

In vivo drug-response in patients with leukemic non-Hodgkin's lymphomas is associated with in vitro chemosensitivity and gene expression profiling.

Only a few approaches are available to address the mechanisms of cell death in vivo which are induced by anticancer treatment in patients with malignancies. In this study in vitro chemosensitivity testing of primary peripheral blood leukemic cells of five patients suffering from different leukemic non-Hodgkin's lymphomas was combined with the analysis of the in vivo rate of apoptosis by flow-cytometry (Annexin V and depolarisation of mitochondrial membrane potential (MMP) by JC-1). Furthermore, changes in expression patterns of apoptosis related proteins during chemotherapeutic treatment were detected by Western Blot.

Bendamustine plus rituximab is effective and has a favorable toxicity profile in the treatment of mantle cell and low-grade non-Hodgkin's lymphoma.

Purpose: The aim of this multicenter-study was to evaluate the progression-free survival, response rate and toxicity of the combination of bendamustine and rituximab (BR) in patients with mantle cell or low-grade lymphomas in first to third relapse or refractory to previous treatment.

Patients And Methods: A total of 245 courses (median, four courses per patient) were administered to 63 patients. Bendamustine was given at a dose of 90 mg/m2 as a 30-minute infusion on days 1 and 2, combined with 375 mg/m2 rituximab on day 1, for a maximum of four cycles every 4 weeks.

Upon drug-induced apoptosis expression of prostate-apoptosis-response-gene-4 promotes cleavage of caspase-8, bid and mitochondrial release of cytochrome c.

Par-4 functions as a tumor suppressor antagonizing the transforming capacity and the resistance of malignant cells towards apoptotic stimuli. After demonstrating that par-4 promotes apoptosis by activating signaling of the intrinsic pathway of apoptosis, we hypothesized that par-4 also impacts on key molecules of the extrinsic pathway without the requirement of a receptor/ligand interaction. Here, we provide first evidence, that expression of par-4 increases cleavage of caspase-8, truncation of Bid and its translocation to the mitochondria, resulting in an augmentation of cytochrome c and AIF efflux into the cytosol, effects par-4-positive cells are able to retain to a higher extent than par-4-negative cells upon inhibition of caspase-3 activation.

Expression of Daxx sensitizes Jurkat T-cells to the apoptosis-inducing effect of chemotherapeutic agents.

Background: The role of Daxx, in particular its ability to promote or hinder apoptosis, still remains controversial. In order to elucidate the functional relevance of Daxx in the extrinsic signaling of malignant lymphocytes Jurkat T-cells were stably transfected with a Daxx-expressing vector or with the respective Daxx-negative control vector.

Results: Assessing first the impact of Daxx expression on the rate of proliferation we demonstrate that overexpression of Daxx alone is not sufficient to alter proliferation in neoplastic lymphocytes.

Daxx overexpression in T-lymphoblastic Jurkat cells enhances caspase-dependent death receptor- and drug-induced apoptosis in distinct ways.

The role of Daxx, in particular, its ability to promote or hinder apoptosis, still remains controversial. In order to elucidate the functional relevance of Daxx in apoptosis signaling of malignant lymphocytes, Jurkat T-cells were stably transfected with a Daxx-expressing vector or with the respective Daxx-negative control vector. We thus demonstrate that ectopic expression of Daxx substantially increases the rate of apoptosis upon incubation with death receptor agonists such as Fas and TRAIL as well as upon incubation with the cytotoxic drug doxorubicin (DOX).

Changing incidence and prognostic factors of survival in AIDS-related non-Hodgkin's lymphoma in the era of highly active antiretroviral therapy (HAART).

Non-Hodgkin's lymphoma is an AIDS-defining disease. The impact of HAART on the epidemiology and prognosis is debated controversially. A retrospective analysis has been performed in order to determine the influence of HAART.

In vitro chemosensitivity to gemcitabine, oxaliplatin and zoledronic acid predicts treatment response in metastatic gastric cancer.

Individual response of disseminated cancer to chemotherapy is unpredictable. In vitro chemotherapy-induced apoptosis can be measured and might be a method to evaluate in vivo activity of tested drugs. In this report, tumor cells of a patient with signet cell carcinoma of the stomach and diffuse bone marrow infiltration were cultured and tested for in vitro chemosensitivity.

In malignant myeloid cells expression of Daxx downregulates expression of p53 and of the inhibitors of apoptosis proteins.

The role of Daxx, in particular its ability to promote or hinder proliferation, still remains controversial. In order to elucidate the functional relevance of Daxx in malignant myelocytes, the erythroleukemia cell line HEL was stably transfected with a Daxx-expressing vector or with the respective Daxx-negative control vector. Assessing the molecular consequences of ectopic Daxx-expression, we present evidence that Daxx downregulates p53.

Expression of ZAP-70 protein correlates with disease stage in chronic lymphocytic leukemia and is associated with, but not generally restricted to, non-mutated Ig VH status.

The mutational status of immunoglobulin variable region genes (Ig VH) is a well established prognostic parameter in chronic lymphocytic leukemia (CLL). Recently, a subset of genes with a characteristic expression profile correlating with the mutational status of B-CLLs has been identified. One of the overexpressed genes in the prognostically unfavorable group of CLL patients with unmutated Ig VH genes encodes for the protein tyrosine kinase ZAP-70, which is physiologically involved in T-cell signaling.

In the erythroleukemic cell line HEL Prostate-apoptosis-response-gene-4 (par-4) fails to down-regulate Bcl-2 and to promote apoptosis.

In a variety of malignant cells Prostate-apoptosis-response-gene-4 (Par-4) exhibits a pro-apoptotic influence sensitizing these cells to apoptosis-inducing agents by downregulating expression of Bcl-2. Considering the crucial role of Bcl-2 in the development of chemoresistance of acute myeloid leukemia (AML) cells, we here assessed the potential of Par-4 to down-regulate Bcl-2 and to induce apoptosis in the erythroleukemic cell line HEL. Testing a potential pro-apoptotic role of Par-4 upon incubation with various conventional chemotherapeutic drugs, novel agents such as the signal transduction inhibitor STI 571 and the histone deacetylase (HDAC)- inhibitor trichostatin A (TSA), as well as with the experimental substances Fas and TRAIL, we provide evidence that in the erythroleukemic cell line HEL expression of Par-4 is not sufficient to sensitize to any of these pro-apoptotic stimuli.

Upon drug-induced apoptosis in lymphoma cells X-linked inhibitor of apoptosis (XIAP) translocates from the cytosol to the nucleus.

The X-linked inhibitor of apoptosis (XIAP) and cellular inhibitor of apoptosis-1 (cIAP-1) are emerging as versatile proteins in programmed cell death with a scope of possible functions reaching far beyond their well known inhibitory effects on caspases. We previously demonstrated that the ability of drugs to modify expression and cleavage of the IAPs are crucial for the synergistic effects achieved by the combinations of different cytotoxic drugs employed to treat malignant lymphomas. In order to more clearly assess the underlying molecular mechanisms, we here evaluated the consequences of drug-induced apoptosis on the localization and aggregation of XIAP and cIAP-1.

Prostate apoptosis response gene-4 sensitizes neoplastic lymphocytes to CD95-induced apoptosis.

Evaluating the functional consequences of prostate apoptosis response gene-4 (par-4) expression in CD95-induced apoptosis of neoplastic lymphocytes, we demonstrate that par-4 increases apoptosis by upregulating the CD95 receptor on the cell surface and--with a concomitant decrease of the FLICE-like inhibitory protein (FLIP)--by promoting cleavage of the initiator caspases-8 and -10. This results in an enforced activation of the executioner caspases-6, -7, and -3 as well as in an activation of the mitochondrial pathway. Upon inhibition of caspase-8, overexpression of par-4 enables Jurkat cells to maintain a higher sensitivity to CD95-induced apoptosis by downregulating cIAP-2 and XIAP and by enforcing activation of the initiator caspase-10 as well as of the executioner caspases-6, -7, and -3.

Prostate apoptosis response gene-4 (par-4) abrogates the survival function of p185(BCR-ABL) in hematopoietic cells.

Objective: Prostate apoptosis response gene-4 (par-4) is deregulated in acute and chronic lymphatic leukemia. Given its pro-apoptotic role in neoplastic lymphocytes and evidence that par-4 antagonizes oncogenic Ras in solid tumors, we hypothesized that par-4 may act as a tumor suppressor impairing transformation induced by p185(BCR-ABL).

Materials And Methods: The capacity of par-4 to interfere with factor independence induced by p185(BCR-ABL) and V12ras was evaluated by analysis of factor-independent growth of p185(BCR-ABL)/ par-4 and V12ras/par-4 transduced cells.

In bcr-abl-positive myeloid cells resistant to conventional chemotherapeutic agents, expression of Par-4 increases sensitivity to imatinib (STI571) and histone deacetylase-inhibitors.

In a variety of malignant cells the prostate-apoptosis-response-gene-4 (Par-4) induces increased sensitivity towards chemotherapeutic agents by down-regulating anti-apoptotic B-cell lymphoma-gene 2 (Bcl-2). Hypothesizing that Par-4 also influences apoptosis in myeloid cell lines, we tested this hypothesis by stably transfecting bcr-abl transformed-K562 cells with a Par-4-expressing vector. Here we demonstrate that over-expression of Par-4 in K562 cells up-regulates expression levels of Bcl-2 and death-associated protein (Daxx).

Positron emission tomography in patients with Hodgkin's disease: correlation to histopathologic subtypes.

The aim of this study was to evaluate the initial staging and restaging of Hodgkin's disease (HD) according to histopathologic subtype (HST) using fluorine-18-deoxyglucose-positron emission tomography (PET). Special attention was paid to the accuracy of PET for detection of bone marrow infiltration (BMI). 44 patients with HD (m:f = 28:16, mean age 36 +/- 15 years) underwent PET; 16 were primary stagings and 28 restaging examinations.

Synergistic effects of chemotherapeutic drugs in lymphoma cells are associated with down-regulation of inhibitor of apoptosis proteins (IAPs), prostate-apoptosis-response-gene 4 (Par-4), death-associated protein (Daxx) and with enforced caspase activation.

Cytotoxic drugs mediate apoptotic tumor cell death by influencing key regulator proteins of programmed cell death. In clinical practice cytotoxic drug combinations are desired to potentiate tumor cell kill and to minimize side effects. Nevertheless, the molecular mechanisms underlying synergistic and antagonistic effects on tumor cells are still poorly understood.

In AML cell lines Ara-C combined with purine analogues is able to exert synergistic as well as antagonistic effects on proliferation, apoptosis and disruption of mitochondrial membrane potential.

The pyrimidine analogue Ara-C and the purine analogues fludarabine and cladribine (2-CdA) are essential compounds in the treatment of acute myeloid leukemia (AML). Inhibition of cell proliferation and induction of apoptosis are the major mechanisms of cytotoxic agents to cause tumor cell death. Therefore, we studied whether Ara-C in combination with the purine analogues exerts synergistic or antagonistic effects on cell proliferation, phosphatidylserine exposure and disruption of mitochondrial membrane potential (MMP) in the AML cell lines HL60 and HEL.