Spleen Size Is Significantly Influenced by Body Height and Sex: Establishment of Normal Values for Spleen Size at US with a Cohort of 1200 Healthy Individuals

PURPOSE

To define height- and sex-corrected normal values for spleen length and volume determined with ultrasonography (US).

MATERIALS AND METHODS

The authors performed a retrospective data review of stem cell donors who had provided written informed consent for stem cell donation and use of anonymized data and biologic materials for scientific and quality control purposes. Spleen length, spleen volume, and anthrophometric data were correlated in 1230 healthy volunteers to identify variables that affect spleen size. Multiple linear regression analysis was performed to weight effects of various variables on spleen size. Linear regression through the 95th percentile for men and women of different height cohorts generated the formula for the upper limit of normal for spleen length and volume. For validation, the upper limit of normal was calculated for each volunteer and compared with the observed value. Formulae to calculate the additional percentiles were similarly generated and validated. A cohort of 75 volunteers was analyzed twice to assess the stability of spleen length and volume over time.

RESULTS

Spleen length and volume were significantly and independently associated with sex (length: P < .001; volume: P = .012), body height (P < .001 for both), and weight (P < .001 for both), with men and taller and heavier individuals having longer and larger spleens. The spleen length of 20 of 324 women (6%) and 234 of 906 men (26%) exceeded the previously reported upper limit of normal of 12 cm. Repeat measurements indicated that spleen length (median difference, 0.10 cm; range, -1.8 to 1.7 cm) and volume (median difference, 3 cm(3); range, -106 to 142 cm(3)) were quite stable. A mobile application that performs these calculations is available for download.

CONCLUSION

The authors define height- and sex-corrected normal values for spleen length and volume for women with a body height of 155-179 cm and men with a body height of 165-199 cm and propose validated algorithms to gauge the percentile of an individual's spleen size.

Synergistic Effects of Valproic Acid and Mitomycin C in Adenocarcinoma Cell Lines and Fresh Tumor Cells of Patients with Colon Cancer

Valproic acid has been demonstrated to mediate cytotoxic effects against tumor cells by acting as a histone-deacetylase inhibitor. However, to date, there are only limited data on the effects of valproic acid in colon cancer. Moreover, information regarding combinations of the drug with chemotherapeutic agents is very limited. The latter is of interest as there is increasing evidence for synergism between so-called "molecular targeting drugs" and chemotherapy. We first demonstrated that valproic acid dose-dependently reduced the viability of adenocarcimona cell lines. After co-incubation with a variety of chemotherapeutic agents, only valproic acid in combination with mitomycin C consistently induced synergistic growth inhibition in all cell lines. To confirm these results in an ex vivo situation, five samples of fresh colon cancer cells were studied. Again, the effect of valproic acid on the viability of the fresh tumor cells was dose dependent. In four of five samples of freshly isolated colon cancer cells, the synergistic effect of valproic acid and mitomycin C on the inhibition of cell growth was confirmed by calculation of the combination index by multiple drug effect analysis. In conclusion, this is the first demonstration that valproic acid as a model substance for histone-deacetylase inhibitors is effective in tumor cells freshly isolated from patients with colon cancer and that the combination of mitomycin C and valproic acid synergistically decreases viability of colon cancer cells.

Clinical case reports raise doubts about the therapeutic equivalence of an iron sucrose similar preparation compared with iron sucrose originator

Intravenous iron sucrose has been used to treat iron deficiency and iron deficiency anaemia associated with different chronic diseases for several decades. Despite the complex structure of iron sucrose, copies called iron sucrose similars (ISSs) have been approved according to the generic approach and therefore, therapeutic equivalence is taken for granted. In February 2011, three patients who previously tolerated well the prescribed iron sucrose originator experienced urticaria, oedema and headache within 1 hour after infusion of an ISS that had been substituted for the originator at the pharmacy level. One patient collapsed due to severe hypovolaemic dysregulation and required hospitalisation. Due to emerging evidence that ISSs differ from the iron sucrose originator in safety and efficacy profiles, it seems prudent for physicians as well as patients who require intravenous (i.v.) iron to have available data on therapeutic equivalence of new ISS preparations versus the originator. This may be especially important in patients who are chronically ill and need iron supplementation on a regular, long-term basis.

Clinical efficacy of immunochemotherapy with fludarabine, epirubicin and rituximab in the treatment for chronic lymphocytic leukaemia and prolymphocytic leukaemia

Despite some considerable progress in the therapy for chronic lymphocytic leukaemia (CLL) owing to fludarabine-based regimens and rituximab, no curative treatment is available so far. We conducted an explorative phase II study in patients with CLL, prolymphocytic leukaemia (PLL) and leukaemic lymphoplasmacytic lymphoma (LL) with the combination of fludarabine, epirubicin and rituximab (FER) to improve the complete remission (CR) rate and progression-free survival (PFS). Fludarabine 25 mg/m(2) was administered i.v. on days 1-5 and epirubicin 25 mg/m(2) i.v. on days 4 and 5, and rituximab was added at a dose of 375 mg/m(2) i.v. day 1 in the first cycle and at a dose of 500 mg/m(2) in all consecutive cycles. Patients exhibiting responsive disease after FER were eligible to receive maintenance therapy of up to 12 cycles of rituximab 375 mg/m(2) bimonthly. Forty-four patients (38 CLL, 4 PLL and 2 LL) with a median age of 65 yrs (43-84 yrs) were evaluable. Seventeen patients with CLL had stage Binet C, 14 Binet B and seven symptomatic or rapid progressive stage Binet A. Cytogenetic features showed normal karyotype in nine cases, an isolated deletion (del) 13q in 12 patients, trisomy 12 in 7, del 11 in two and del 17p in 4. Half of the patients (48%) had mutated IgVH genes. Treatment with FER achieved an overall response rate of 95%, including 63% CRs and 32% PRs. Haematological toxicity was considerable. After a median follow-up period of 34 months (range: 8-84 months), median PFS was 61 months and overall survival was yet not reached. All patients with PLL and LL achieved CR. The data support the high efficacy of the combination of rituximab with chemotherapy (FE) and are suggestive of possible benefit with rituximab maintenance therapy for PFS and DFS.

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. The influence of drug-induced apoptosis on localization of IAPs was investigated using immunofluorescence microscopy as well as western blot analysis. Apoptosis was induced by chemotherapeutic drugs with different modes of action (bendamustine, cladribine, fludarabine, doxorubicin and mitoxantrone) and assessed by flow-cytometry using Annexin V. We demonstrate that XIAP and cIAP-1 are downregulated and/or cleaved in a dose-dependent manner upon treatment with a variety of anti-cancer drugs. Moreover we provide evidence that in the context of drug-induced apoptosis XIAP, its BIR3-RING cleavage product and cIAP-1 undergo an extensive change of subcellular localization. Immunofluorescence microscopy reveals that XIAP, in contrast to cIAP-1, is located in discrete cytosolic protein aggregates and-upon induction of apoptosis with cytotoxic drugs--redistributes into large nuclear inclusions. This translocation of XIAP and its BIR3-RING cleavage product from the cytosol into the nucleus is confirmed by cell fractionation and western blot analyses. Of note, in this experimental setting putative interaction partners of XIAP-such as Apaf-1, caspase-3 and -7--do not co-localize with XIAP. These results imply a new unknown function of XIAP and its BIR3-RING fragment in the nucleus in the context of drug-induced apoptosis. The localization of cIAP-1 in mitochondria and its liberation from these indicate a profoundly different function of this protein despite its similar modular structure to XIAP.

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. Subsequently, induced molecular changes were assessed by FACS analysis, Western blot, and enzyme activity assays. Although AMN107 exhibited only a minor apoptosis-inducing effect in the T-cell lines, it exerted a considerable, dose-dependent cytotoxicity in the B-cell lines. Using selective caspase-inhibitors, we show that apoptosis in responder cell lines critically relies on activation of caspase-6 and caspase-9. Cell lines sensitive and resistant towards AMN107 can be discriminated by their differential expression of Src-kinases. Although the AMN107-sensitive cell lines DOHH-2 and WSU-NHL exhibited low or no expression of the Src-kinases Lck, phosphorylated Lck, and Yes with a concomitant high expression of Hck, Lyn, and phosphorylated Lyn, the expression pattern of these kinases was inverse in the AMN107-resistant T-cell lines. In conclusion, this is the first report providing evidence that activity of AMN107 is not restricted to Bcr-Abl, c-Kit, or PDGFR-positive cells, but also extends to lymphatic cell lines of B-cell origin.

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. We collected data of 214 cases of AIDS-related Lymphoma (ARL) treated at our centre from January 1984 until May 2003 and analysed them using the Kaplan-Meier-, log rank- and Cox proportional hazard-model. The incidence of ARL increased between 1991 and 1994 up to a peak of 14.83 per 1000 patient years. In the subsequent periods from 1995 onwards however, it decreased to 3.7 in 1000 patient years. The incidence of AIDS-related primary CNS lymphomas (PCNSL) took a comparable, yet more pronounced development. Using the univariate Kaplan-Meier analysis prolonged survival was significantly associated with the achievement of a complete remission as well as with a favourable virological response to HAART. No significant differences could be shown for the use of protease inhibitors as well as for virological response being achieved before the diagnosis of NHL. When using the Cox model, complete remission overrides viral response and thus remained the only independent prognostic factor. Classical prognostic factors (CD4 count, prior Kaposi Sarcoma, extranodal manifestation, staging and histological subtype of NHL) were no longer significant for HAART patients in the multivariate analysis. These results illustrate the requirement for new prospective studies in order to determine the best options and ideal timing of coadministering chemotherapy and the type of HAART. Furthermore this study demonstrates that HAART decreases the incidence of ARL, and that achievement of a complete remission in patients suffering from ARL is--according to the multivariate analysis--the single most important prognostically relevant factor with respect to the time of survival.

Expression of a CD20-specific chimeric antigen receptor enhances cytotoxic activity of NK cells and overcomes NK-resistance of lymphoma and leukemia cells

Despite the clinical success of CD20-specific antibody rituximab, malignancies of B-cell origin continue to present a major clinical challenge, in part due to an inability of the antibody to activate antibody-dependent cell-mediated cytotoxicity (ADCC) in some patients, and development of resistance in others. Expression of chimeric antigen receptors in effector cells operative in ADCC might allow to bypass insufficient activation via FcgammaRIII and other resistance mechanisms that limit natural killer (NK)-cell activity. Here we have generated genetically modified NK cells carrying a chimeric antigen receptor that consists of a CD20-specific scFv antibody fragment, via a flexible hinge region connected to the CD3zeta chain as a signaling moiety. As effector cells we employed continuously growing, clinically applicable human NK-92 cells. While activity of the retargeted NK-92 against CD20-negative targets remained unchanged, the gene modified NK cells displayed markedly enhanced cytotoxicity toward NK-sensitive CD20 expressing cells. Importantly, in contrast to parental NK-92, CD20-specific NK cells efficiently lysed CD20 expressing but otherwise NK-resistant established and primary lymphoma and leukemia cells, demonstrating that this strategy can overcome NK-cell resistance and might be suitable for the development of effective cell-based therapeutics for the treatment of B-cell malignancies.

Inhibition of osteosarcoma cell proliferation by the Hedgehog-inhibitor cyclopamine

Osteosarcomas (OS) are the most frequent primary malignant bone tumors in humans. Even though OS are chemosensitive, about 30% of patients must be considered poor responders and consequently have a dismal long term prognosis. The Hedgehog (Hh) gene is crucial in the signalling pathways of proliferation and differentiation during embryonic development. There is evidence that uncontrolled activation of this pathway results in specific types of cancer and that inhibition of Hh signalling is able to suppress tumour growth and to induce apoptosis of neoplastic cells. This study investigates the impact of the steroidal alkaloid and Hh-inhibitor cyclopamine on osteosarcoma cells. Thus we demonstrate the drug's impact on cellular proliferation, cell cycle cell death as well as the cells' metabolism. We here demonstrate that cyclopamine exhibits a high efficacy against the osteosarcoma cell lines HOS, SaOS and OS-KA, a self-established primary osteosarcoma cell line. In particular, cyclopamine is able to inhibit proliferation and to promote cell death. Our results provide evidence for the potency of the Hh-inhibitor cyclopamine as a future treatment of osteosarcomas.

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. Phosphorylation of Lyn and in particular Lck were affected most heavily by treatment with the SrcK-I. Extrinsic as well as intrinsic apoptosis pathways were activated and elicited unique expressional patterns of apoptosis-relevant proteins such as downregulation of survivin, Bcl-XL and c-FLIP. Protein levels of c-abl were downregulated and Akt phosphorylation was decreased by treatment with SrcK-I. Basal expression levels of c-Myc were notably lower in sensitive cell lines as compared with nonsensitive cell lines, possibly providing an explanation for sensitivity versus resistance against these novel substances. This study provides the first basis for establishing novel SrcK-I as weapons in the arsenal against lymphoma cells.

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. Besides promoting apoptosis, stimulation of the TRAIL receptors may also activate survival signals via the transcription factor NF-kappaB. Moreover, evaluation of the physiological roles of TRAIL-mediated signaling pathways provides evidence for a regulatory function within the immune system. Thus a complex picture of TRAIL-mediated signaling evolves, underscoring the necessity to define its modes of action while assessing its therapeutic potential. This review outlines the current knowledge on the physiological role of TRAIL and discusses its therapeutic potential with particular focus on malignancies of the hematopoietic system.

Highly active antiretroviral therapy (HAART) improves survival in HIV-associated Hodgkin's disease: results of a multicenter study

BACKGROUND

The purpose of the study was to evaluate the outcome of Hodgkin's disease (HD) in patients infected with the human immunodeficiency virus (HIV) with respect to the use of highly active antiretroviral therapy (HAART).

MATERIALS AND METHODS

This cohort study included patients with HIV-HD diagnosed from June 1984 to February 2004. Patients treated in the pre-HAART era (1984-1996) were compared with those belonging to the HAART era (1997-2004).

RESULTS

Of 66 patients with HIV-HD, 47 (71%) presented with stage III/IV disease and 38 patients (58%) with an AIDS-defining illness. Fifty-nine of 66 patients (89.4%) underwent curative intended chemotherapy. Patients receiving HAART (n = 34) had a significantly better 2-year overall survival (OS) than those not receiving HAART (74% versus 30%, P <0.001). The 2-year OS of HAART-responders was 88% compared with 19% in patients without HAART-response (P = 0.0002). By multivariate analysis patients without HAART had a 5.6-fold higher risk for 3-year mortality [HR 5.6, 95% confidence interval (CI) 2.20-14.26]. Three-year mortality was significantly higher in patients without complete remission (HR 4.40, CI 1.77-10.99), with stage III/IV HD (HR 4.64, CI 1.31-16.49) and with CD4 cells <200/microl (HR 2.69, CI 0.99-7.33).

CONCLUSIONS

Use of HAART significantly improved the overall survival in patients with HIV-HD.

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. Evaluating this hypothesis we show, that par-4-transfected T-lymphoblastic Jurkat cells exhibit a considerably increased rate of apoptosis upon incubation with an agonistic TRAIL-antibody as compared to their mock-transfected counterparts. Defining the underlying molecular mechanisms we provide evidence, that par-4 enhances sensitivity towards TRAIL by employing crucial members of the extrinsic pathway. Thus, par-4-overexpressing Jurkat clones show an enforced cleavage of c-Flip(L) together with an increased activation of the initiator caspases-8 and -10. In addition, expression of par-4 enables cells to down-regulate the inhibitor-of-apoptosis proteins cIAP-1, cIAP-2, XIAP and survivin with a concomitantly enhanced activation of the executioner caspases-6 and -7. Supporting the crucial role of caspase-8 in par-4-promoted apoptosis we demonstrate that inhibition of caspase-8 considerably reduces TRAIL-induced apoptosis in par-4 and mock-transfected Jurkat clones and reverses the described molecular changes. In conclusion, we here provide first evidence that expression of par-4 in neoplastic lymphocytes augments sensitivity to TRAIL-induced cell death and outline the responsible molecular mechanisms, in particular the crucial role of caspase-8 activation.

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. While reviewing these molecular alterations this article moreover focuses on the impact of new therapeutic agents, which specifically exploit the knowledge of the molecular characteristics of malignant hematopoetic cells.

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. Gene expression profiling (HG-U133A, Affymetrix, Santa Clara, CA) was employed to identify common marker genes of in vivo drug response. In vitro chemosensitivity was tested using the cytotoxic agents which the patients were scheduled to receive and was strongly correlated with effective reduction of leukemic lymphoma cells in patients resulting in complete remissions in all five cases. Due to the rapid clearance of apoptotic tumor cells in vivo neither the analysis of the in vivo rate of apoptosis and depolarisation of MMP nor the assessment of expression of regulators of apoptosis showed concordant results concerning the drug response. However, assessment of gene expression during therapy could identify a set of 30 genes to significantly discriminate between samples from patients before treatment compared to samples from the same patients after receiving cytotoxic therapy. Among these 30 genes we found a high proportion of genes associated with apoptotic cell death, cell proliferation and cell cycle signalling including complement lysis inhibitor (clusterin/CLU), beta-catenin interacting protein (ICAT), peroxisome proliferator activated receptor alpha (PPARalpha), TNF alpha converting enzyme (ADAM17/TACE), homeo box A3 (HOX1), inositol polyphosphatase 5-phosphatase type IV (PPI5PIV) and inhibitor of p53 induced apoptosis alpha (IPIA-Alpha/NM23-H6). These results indicate that in vitro chemosensitivity testing and gene expression profiling can successfully be utilised to analyse in vivo drug response in patients with leukemic NHL's and can be used to explore new pathway models of drug-induced cell death in vivo which are independent of different lymphoma subtypes and different treatment regimens.

Deregulated expression of prostate apoptosis response gene-4 in less differentiated lymphocytes and inverse expressional patterns of par-4 and bcl-2 in acute lymphocytic leukemia

INTRODUCTION

Prostate apoptosis response gene-4, known as par-4, is a new proapoptotic factor functionally required but not sufficient for apoptosis. Since there is evidence from prostate cancer cells that par-4 is involved in regulation of bcl-2 we assessed expression of par-4 and bcl-2 in different populations of normal and neoplastic lymphocytes.

MATERIALS AND METHODS

Expression of par-4 mRNA and protein in different subpopulations of normal and neoplastic lymphocytes was assessed by reverse transcription polymerase chain reaction and Western blot.

RESULTS

Par-4 mRNA was not detectable in lymphocytes of healthy volunteers (n = 10), but was present in the majority of samples of chronic lymphocytic leukemia (n = 30), chronic lymphocytic leukemia/prolymphocytic leukemia (n = 6) and acute lymphocytic leukemia (n = 10). Par-4 protein was expressed unanimously in samples of mononuclear cells from healthy volunteers and patients with CLL, but less frequently in immature lymphocytes, including neoplastic cells of CLL/PLL and ALL. The decreased frequency of par-4 expression in immature subpopulations was confirmed by results on lymphocytic cell lines at various stages of maturation. Comparing the expressional patterns of par-4 and bcl-2 there was an inverse relationship of both proteins in ALL and different lymphocytic cell lines, indicating a functional relationship of par-4 and bcl-2.

CONCLUSIONS

This study establishes par-4 as a factor expressed in the majority of normal and neoplastic lymphocytic cells, demonstrating a decreased frequency of protein expression in less differentiated lymphocytes and an inverse expressional pattern of par-4 and bcl-2 in lymphocytic cell lines and ALL.

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). Analysis of the molecular changes induced in the extrinsic and intrinsic apoptosis pathways reveals that augmentation of apoptosis by Daxx overexpression is conveyed by distinctly different mechanisms. Although enforced apoptosis caused by ectopic Daxx expression is caspase-dependent in both cases, major differences between Fas/TRAIL-induced apoptosis and doxorubicin-induced apoptosis are observed in expression patterns of X-linked inhibitor of apoptosis (XIAP), p53, Bid, ZIP kinase, and prostate apoptosis response gene 4 (Par-4). Moreover, we could show that addition of a CD95 blocking antibody to the clones treated with doxorubicin was able to increase apoptosis as compared to doxorubicin treatment alone and was accompanied by an enhancement of the mitochondrial branch of apoptosis. In conclusion, we here outline the major molecular mechanisms underlying the apoptosis-promoting effect of Daxx in neoplastic lymphocytes and demonstrate fundamental molecular differences elicited by the overexpression of Daxx in the extrinsic and intrinsic signaling pathways.

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 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. Since ZAP-70 has been described to be prognostically relevant in CLL, we analyzed the possible relationship of its expression to the mutational status of Ig VH genes as well as to other prognostic factors in CLL and indolent lymphomas. The mutational status of Ig VH genes was analyzed by seminested PCR, direct sequencing and comparison with the sequences of the EMBL databases in 60 samples of patients with B-CLL and 18 samples of patients with indolent B-cell malignancies. ZAP-70 protein expression was assessed in all samples by immunoblotting and for semiquantitative analysis the ratio of ZAP-70 to tubulin expression was calculated. ZAP-70 protein was found to be expressed in all investigated B-cell malignancies. Expression levels varied within a wide range in each entity. The highest mean level of ZAP-70 expression was observed in unmutated B-CLLs, however, with broad expression variability. High levels of ZAP-70 expression correlated with higher stage Binet B or C and with unmutated Ig VH genes. Overall survival rates estimated by Kaplan-Meier curves did not differ among patients with high or low ZAP-70 expression. We conclude that ZAP-70 is associated with the mutational status of Ig VH genes, but this expression pattern is not present in all individual cases. Furthermore, high levels of ZAP-70 correlated with Binet stages B or C indicating an involvement of ZAP-70 in mechanisms promoting growth of B-CLL cells.

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. Nevertheless, expression of Daxx down-regulates anti-apoptotic Bcl-2 and up-regulates pro-apoptotic BID. In addition, Daxx-overexpressing Jurkat cells exhibit a decreased expression of the pro-caspase-8, -10, -9 and -3 and a concomitant increase of the inhibitors of apoptosis proteins survivin, XIAP, cIAP-1 and -2. We further demonstrate, that upon incubation with various chemotherapeutic agents these Daxx-induced molecular alterations sensitize Jurkat T-cells to the apoptosis-inducing effects of specific chemotherapeutic agents.

CONCLUSIONS

We here outline the molecular changes elicited by Daxx on major components of the apoptotic cascade of malignant lymphocytes and demonstrate the capacity of Daxx to sensitize these cells to the apoptosis-inducing effect of various chemotherapeutic agents.

Antioxidative treatment prevents activation of death-receptor- and mitochondrion-dependent apoptosis in the hearts of diabetic rats

AIMS/HYPOTHESIS

The mechanisms by which glucose injures cells of the cardiovascular system include generation of reactive oxygen species and induction of cellular apoptosis. To date, little is known about the molecular events of hyperglycaemia-induced apoptosis in the heart in vivo.

METHODS

Male Sprague-Dawley rats were rendered diabetic by a single intraperitoneal injection of 60 mg/kg body weight streptozotocin. Caspase activities in cardiac ventricular tissue were determined using fluorometric and immunoassay caspase-activity assay kits respectively. Expression levels of proteins of the apoptotic cascade were determined with western blot analyses using specific antibodies.

RESULTS

Four weeks of hyperglycaemia induced significant apoptosis in cardiac tissue. Determining the initiators of death-receptor-dependent apoptosis revealed induction of CD95/Fas and caspase-8. Examination of the activities of effector caspases revealed increased activity of caspase-6, but not caspase-3 and -7. On evaluating inhibitors of apoptosis, we found up-regulation of caspase-3 and -7-inhibiting X-linked inhibitors of apoptosis in diabetic rats. Hyperglycaemia also induced significant mitochondrion-dependent apoptosis. Our evaluation of expression levels of Bcl-2 family members showed increased expression of pro-apoptotic Bak and Bax in diabetic rats. Antioxidative treatment with lipoic acid significantly suppressed apoptosis and down-regulated caspase-6, -8 and -9 activity, as well as expression levels of pro-apoptotic Bcl-2 proteins without changing blood glucose levels.

CONCLUSIONS/INTERPRETATION

The present study indicates that reactive oxygen species induced by high glucose are involved in both death-receptor- and mitochondrion-dependent apoptosis in the heart in vivo. It also suggests that antioxidants may be a therapeutic option for preventing cardiovascular damage in diabetes mellitus in humans.

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. Moreover, we demonstrate that Daxx overexpressing myelocytes downregulate the proapoptotic Bcl-2 family member Bax, while expression of antiapoptotic Bcl-2 is not influenced. Furthermore, expression of Daxx diminishes expression levels of the initiator-procaspase-8 and -10, and the executioner procaspase-7, whereas the procaspase-3, -6 and -9 remain unaltered. The altered protein levels of the caspases in Daxx overexpressing myelocytes are accompanied by a decrease of expression levels of the inhibitor of apoptosis proteins (IAPs) cIAP-1, -2 and survivin. Despite the described impact of Daxx expression on major molecules of the apoptotic cascade, expression of Daxx in neoplastic myelocytes does not impact on the rate of proliferation. Upon a proapoptotic stimulus such as serum withdrawal Daxx is unable to maintain its influence on expression levels of p53, Bax, IAPs and the procaspase-8, -10 and -7.

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. We further demonstrate that--in contrast to previous reports in non-AML cells--Par-4 expression in HEL cells leads to an upregulation of Bcl-2. Moreover, Par-4-positive HEL cells exhibit a decreased level of the proapoptotic protein Bax as compared to Par-4- negative cells. In addition, Par-4 increases the expression of Daxx--whose downregulation is associated with augmented chemosensitivity--as well as expression of the procaspases-8, -9 and -10, whereas the levels of the procaspases-3 and -7 remain unaltered. In conclusion we here demonstrate that in the erythroleukemic cell line HEL--in contrast to other cell types Par-4 fails to promote apoptosis and outline the underlying molecular mechanisms.

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). Upon treatment with different chemotherapeutic agents, Fas- or TRAIL agonistic antibodies, Par-4-positive cells did not exhibit an increased rate of apoptosis as compared to Par-4-negative control cells. However, incubation with histone deacetylase (HDAC)-inhibitors Trichostatin A (TSA) and LAQ824 or the tyrosinkinase inhibitor Imatinib (STI571) increased the rate of apoptosis in Par-4-positive K562 cells. Assessing the underlying molecular mechanisms for the Par-4-induced response to HDAC-inhibitors and STI571 we provide evidence, that these effects are associated with a down-regulation of Daxx, enforced activation of caspases and enhanced cleavage of cellular inhibitor of apoptosis (cIAP)-1 and -2.

Strong impact of highly active antiretroviral therapy on survival in patients with human immunodeficiency virus-associated Hodgkin's disease

Hodgkin's disease (HD) is the most common non-acquired immunodeficiency syndrome (AIDS)-defining malignancy in human immunodeficiency virus (HIV)-infected patients. We analysed the outcome of patients with HIV-associated HD (HIV-HD) with respect to the use and efficacy of highly active antiretroviral therapy (HAART) and other prognostic factors. To evaluate the effects of several variables on overall survival (OS), Kaplan-Meier statistics and extended Cox regression analysis were performed. Response to HAART was used as a time-dependent variable and was defined as an increase of >0.1 x 10(9) CD4 cells/l and/or at least one viral load <500 copies/ml during the first 2 years following diagnosis of HIV-HD. Fifty-seven patients with HIV-HD diagnosed between 1990 and 2002 were included in the study. In the Cox model, the only factors independently associated with OS were HAART response [relative hazard (RH) 0.19; 95% confidence interval (CI) 0.06-0.60], complete remission (RH 0.30, 95% CI 0.13-0.72), and age <or=45 years (RH 0.23; 95% CI 0.09-0.60). Median survival time in patients without HAART response was 18.6 months, whereas the median survival time in patients with HAART response was not reached (89% OS at 24 months). In this cohort, a significant improvement in survival was found in patients with HIV-HD who responded to HAART.

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 order to elucidate these molecular mechanisms we established models of synergistic and antagonistic drug combinations within the same lymphoma cell lines. By combination index method we demonstrated that bendamustine in combination with either doxorubicin or mitoxantrone caused antagonistic effects on disruption of mitochondrial membrane potential as well as on the rate of apoptosis. In contrast the combination of bendamustine with cladribine acted synergistically on these parameters. By using the IC(50) (dosages causing 50% rate of apoptosis) the synergistic effect of the combination of bendamustine and cladribine was associated with an enhanced mitochondrial release of cytochrome c and Smac/DIABLO, by down-regulation of x-linked inhibitor of apoptosis (XIAP), cIAP1, Par-4 and Daxx as well as by a significantly increased activation of caspases-3, -6, -7, -8 and -9. At the same rate of apoptosis (IC(50)), the antagonistic combinations did not increase the release of cytochrome c or Smac/DIABLO, nor down-regulate the expression of XIAP, cIAP1, Par-4 and Daxx, nor increase the activation of caspases. The role of down-regulation of IAPs and of enforced caspase activation for synergism in this model was supported by the observation, that broad spectrum inhibition of caspases re-established expression of XIAP. Our study is the first to outline the molecular alterations caused by synergistic and antagonistic drug combinations within the same lymphoma cell model. The above described mechanisms were already assessable at a point where the effects of synergistic or antagonistic combinations could not yet be discriminated quantitatively by the level of apoptosis rate of the lymphoma cells.

Reduced-dose cladribine (2-CdA) plus mitoxantrone is effective in the treatment of mantle-cell and low-grade non-Hodgkin's lymphoma

Cladribine (2-chlorodeoxyadenosine) (2-CdA) has been shown to be effective in mantle-cell (MCL) and low-grade lymphomas (lgNHL). The aim of this multicentre study was to evaluate the rate and duration of remissions and to examine the toxicity of the combination of reduced-dose 2-CdA and mitoxantrone (CdM) in MCL and lgNHL as first-line therapy or for patients in their relapse. A total of 285 courses, median of five courses per patient, were administered to 62 evaluable patients (42 previously untreated, 20 relapsed) with 5 mg/m(2) 2-CdA per day given as an intermittent 2-h infusion over 3 consecutive days combined with 8 mg/m(2) mitoxantrone on days 1 and 2 for the untreated patients or 12 mg/m(2) mitoxantrone on day 1 for patients in their first relapse for a maximum of six cycles every four weeks. 32 follicular, 18 MCL, 9 lymphoplasmacytoid, 2 marginal zone and 1 unclassified low-grade B-cell lymphoma were involved in the study. 56 of the 62 patients responded to CdM resulting in an overall response rate of 90% (95% confidence interval (CI), 80-96%) with a complete remission (CR) rate of 44% (95% CI, 31-57%) and a median duration of remission of 25 months (range 6-42+). The overall survival rate at 48 months was 80%. For 42 previously untreated patients, the overall response rate was 88% (95% CI, 74-96%) with a CR rate of 38% (95% CI, 24-54%), whereas the response rate for the group of 20 previously treated patients was similar with a 95% overall response (95% CI, 75-100%) and a CR rate of 55% (95% CI, 32-77%). In MCL, CdM showed a high activity, achieving a response rate of 100% (95% CI, 81-100%) with a CR rate of 44% and a median duration of remission of 24 months (range 6-35+). Myelosuppression was the major toxicity with 23% grade 3 granulocytopenia and 50% grade 4. Thrombocytopenia was less commonly observed, with only 8% grades 3 and 4. These results demonstrate that the combination of reduced-dose 2-CdA and mitoxantrone is a highly active regimen in the treatment of low-grade lymphomas, and in particular of MCL.

In vitro induction of apoptosis of neoplastic cells in low-grade non-Hodgkin's lymphomas using combinations of established cytotoxic drugs with bendamustine

BACKGROUND AND OBJECTIVES

Regulation of apoptotic cell death is being increasingly recognized as a mechanisms by which cytostatic agents mediate tumor cell death. Preliminary clinical studies with bendamustine, an alkylating agent with a purine nucleus, provide strong evidence that this drug is a highly effective cytostatic in low grade lymphomas. Therefore, we investigated the in vitro activity of bendamustine in combination with other established cytotoxic drugs.

DESIGN AND METHODS

2 lines (DOHH-2, WSU-NHL) and mononuclear cells (MNC) from patients with leukemic low-grade B-non-Hodgkin's lymphoma (NHL) (n=10), T-NHL (n=7) and chronic lymphocytic leukemia (CLL) (n=12). Apoptosis (7-AAD), depolarization of mitochondrial membrane potential (MMP, JC-1), caspase-3-activity (FIENA) and cell proliferation (XTT/WST-1) were determined. Several incubation times and drug dosages (for IC(30/50/75/90)) were studied. Synergistic, additive or antagonistic effects were calculated by a median plot effect and the combination index (CI) method.

RESULTS

In general, combinations of bendamustine with mitoxantrone or doxorubicin resulted in antagonistic effects in the tested cell lines and the MNC from the patients. CI-calculation failed in these cases since there was not a sufficient dose response. On the other hand, the combination of bendamustine with 2-CdA showed synergistic in vitro activity on the tested cell lines, neoplastic lymphocytes from patients with peripheral T-cell lymphomas and partially on MNC from patients with CLL and B-NHL. The antagonism of the combination of bendamustine and anthracyclines appeared to be due to inhibition of depolarization of mitochondrial-membrane potential and caspase-3-activity during apoptosis of the studied cell lines.

INTERPRETATION AND CONCLUSIONS

In conclusion, our results suggest that schedules using combinations of bendamustine and anthracyclines should not be recommended for the treatment of low-grade NHL, whereas bendamustine combined with 2-CdA could be considered for the development of future treatment strategies.

Treatment of aggressive, or progressing indolent peripheral T- and NK-cell neoplasias by combination of fludarabine, cyclophosphamide and doxorubicine

BACKGROUND

Regarding standardization of treatment, classification, and pathophysiology of peripheral T- and NK-cell neoplasias the current knowledge is markedly behind that of B-cell lymphomas, which are approximately 10 times more frequent. In May 2000, the study group 'Peripheral T- and NK-cell Neoplasias' was founded in Frankfurt/M. This group decided on a clinical protocol and a scientific program for research on the pathophysiology of these entities. Rationales for the therapeutic regimen are the efficacy of cyclophosphamide and doxorubicine as shown in protocols for treatment of high grade lymphoma, the synergism of cyclophosphamide and fludarabine, and reports demonstrating the efficacy of fludarabine in T-cell neoplasias.

PATIENTS AND METHODS

Patients will be treated with a combination of fludarabine (30 mg/m(2) days 1-3), cyclophosphamide (1000 mg/m(2) day 1) doxorubicine (25 mg/m(2) day 2+3) (FCD). For patients > or =65 years a dose-reduced FCD regimen will be administered. In patients included in the treatment study and additionally in patients with indolent disease not requiring therapy, scientific projects on the biology of peripheral T- and NK-cell neoplasias will be performed.

CONCLUSIONS

Expected conclusions of the projected study are the establishment of treatment and diagnostic standards, and improvement of classification of these entities by clinical, morphologic and biologic parameters.

Changing incidence and survival in patients with aids-related non-Hodgkin's lymphomas in the era of highly active antiretroviral therapy (HAART)

To determine role of highly active antiretroviral therapy (HAART) and additional factors in incidence and outcome of patients with AIDS-related non-Hodgkin's lymphomas (NHL) we retrospectively analyzed 257 cases of AIDS-related NHL (24 low-grade, 168 high-grade B-cell, 6 high-grade T-cell, and 59 primary CNS lymphomas (PCNSL) among 2004 patients with HIV-infection treated at the University Hospital of Frankfurt, Germany from January 1983 to May 1999. Data were evaluated by univariate and multivariate analyses, using overall survival as end point. Patients received CHOP-like therapy as standard treatment. Until May 1999 incidence of all diagnosed cases of NHL was decreasing (1991-94: 14.2% versus 1995-5/99: 12.8%). Mainly, the incidence of low-grade NHL and PCNSL clearly decreased whereas the incidence of high-grade B-cell NHL increased compared to all diagnosed cases of NHL (1983-86: 53.3% versus 1995-5/99: 78.6%). One-year survival probability of all screened patients with AIDS related NHL was 54%, while 5-year survival rate remained 5%. We found age <25 years, development of NHL in the years before 1990, IVDU, CD4 counts <150/microl, PCNSL as well as NHL as the AIDS index disease, to be highly significant independent predictors of poor survival, including increased hazard ratios. In the era of HAART incidence of NHL is decreasing, mainly the incidence of low-grade NHL and PCNSL. Overall survival of patients has been prolonged with HAART. This development is mainly due to improvement of antiretroviral therapy, rather than to any fundamental changes in the chemotherapeutic treatment of NHL. Therefore, new treatment approaches for AIDS-related NHL should focus on more efficient antiretroviral therapy in association with combination chemotherapy.

T-large granular lymphocyte leukaemia with natural killer cell-like cytotoxicity and expression of two different alpha- and beta-T-cell receptor chains

We describe a case of cytotoxic T-large granular lymphocyte leukaemia showing typical morphological features, expressing antigens characteristic for cytotoxic T cells and exhibiting marked natural killer-like cytotoxicity towards different target cells. Moreover, characterization of the T-cell receptors revealed simultaneous expression of two different types of beta-chains as well as alpha-chains by the malignant cell clone. The patient had an 8 year history of indolent disease, before progressing to an aggressive clinical course hardly responsive to chemotherapeutic treatment. This is the first description of a peripheral T-cell neoplasm expressing four distinct types of T-cell receptor molecules.

Induction of apoptosis using 2',2' difluorodeoxycytidine (gemcitabine) in combination with antimetabolites or anthracyclines on malignant lymphatic and myeloid cells. Antagonism or synergism depends on incubation schedule and origin of neoplastic cells

Induction of apoptosis in vitro using gemcitabine (dFdC) in combination with cladribine (2-CdA) and other cytotoxic drugs on malignant mononuclear cells (MNCs) of patients with acute myeloid leukemia (AML, n=20) and chronic lymphocytic leukemia (CLL, n =20) in myeloid (HL60, HEL) and lymphatic cell lines (HUT78, JURKAT) was investigated using different incubation conditions (simultaneous and consecutive). Furthermore, the influence of dFdC on the level of intracellular metabolites of 2-CdA was studied using high-performance liquid chromatography (HPLC). Apoptosis was evaluated using flow cytometry with 7-aminoactinomycin D. In MNCs of patients with CLL, dFdC + 2-CdA showed an antagonistic effect when applied simultaneously. This antagonism was reduced by consecutive application. The combination of dFdC with doxorubicin was synergistic, independent of incubation schedule. In blasts from newly diagnosed patients with de novo AML, all drug combinations (dFdC+2-CdA, doxorubicin, or cytosine arabinoside) were antagonistic by simultaneous incubation. Reduced antagonism or even synergism was shown (P<0.001) by consecutive incubation. The simultaneous combination of dFdC with 2-CdA in all tested cell lines resulted in a competitive inhibition on the rate of apoptosis. By changing the incubation period to a consecutive schedule, the antagonism was diminished or synergism of apoptosis was measured (P< 0.001). Using similar incubation conditions, these experiments were supported by HPLC measurement of intracellular metabolites of 2-CdA influenced by dFdC application. In conclusion, we demonstrated that the efficacy of dFdC in vitro in combination with other cytotoxic drugs depends on the incubation condition and on the origin of neoplastic cells (lymphatic vs myeloid). The data suggest that simultaneous combination therapy with purine and pyrimidine analogues may not improve the clinical efficacy of one or the other drug administered alone.

Induction of apoptosis by 2-chloro-2'deoxyadenosine (2-CdA) alone and in combination with other cytotoxic drugs: synergistic effects on normal and neoplastic lymphocytes by addition of doxorubicin and mitoxantrone

2-CdA is active as a single agent in the treatment of low-grade lymphomas. We analyzed the induction of apoptosis by 2-CdA alone (n=5) and in combination with other drugs in peripheral lymphocytes from 25 patients with leukemic low-grade lymphomas and from 25 healthy volunteers. 2-CdA was tested in 4 escalating concentrations (0.05 microg/ml to 0.4 microg/ml). Linear regressions showed a dose dependent apoptosis rate of 0.29 x microg 2-CdA/ml + 0.11 (r2=0.88, p=0.006) in normal cells and 0.41 x microg 2-CdA/ml + 0.15 (r2=0.88, p=0.005) in leukemic cells. Intracellular metabolization of 2-CdA into 2-CdA-5'mono-, -di- and the active metabolite -triphosphate was analyzed by HPLC and paralleled the dose dependent increase of apoptosis. The combination of 2-CdA with doxorubicin or mitoxantrone had a synergistic effect on the induction of apoptosis (p<0.001) in both normal and neoplastic lymphocytes, whereas 2-CdA plus etoposide or cytosine arabinoside were only additive. Due to the flat slope of the dose response of 2-CdA concentration on apoptosis we assume that higher in vivo dosages of 2-CdA in the treatment of low-grade lymphomas may not result in a higher clinical efficacy. The synergistic lymphocytotoxic effect of 2-CdA combined with doxorubicin or mitoxantrone may be relevant for new treatment approaches.

Intermittent 2-hour-infusion of cladribine as first-line therapy or in first relapse of progressive advanced low-grade and mantle cell lymphomas

Aim of this multicenter-study was to evaluate rate and duration of remissions and to examine toxicity of cladribine in low-grade lymphomas as first-line therapy or in first relapse using intermittent 2-hour-infusion of cladribine. A total of 294 courses, median of 5 courses per patient, were administered to 66 evaluable patients (53 previously untreated, 13 relapsed) with 5 mg/m2 cladribine given as intermittent 2-hour-infusion over 5 consecutive days for a maximum of 6 cycles every four weeks. Entities: 26 follicle center, 20 lymphoplasmacytoid, 12 mantle cell, 6 T-cell, 2 marginal zone lymphomas. Fifty of 66 patients responded to cladribine corresponding to an overall response rate of 76% (95% confidence interval (95% CI): 64%-85%) with 38% CR (95% CI: 26%-51%) and a median time of remission duration of 23 months (range 6-45+). The overall survival rate at 48 months was 72%. For 49 previously untreated patients with B-cell lymphomas the overall response rate was 86% (95% CI: 73%-94%) with a high CR rate of 43% (95% CI: 29%-58%). Response rate for the group of 23 previously untreated patients with follicle center lymphomas was high with 96% overall response (95% CI: 78%-100%) and 57% CR rate (95% CI: 34%-77%). Cladribine also showed activity in patients with mantle cell lymphomas achieving a response rate of 58% (95% CI: 28%-85%). Myelosuppression was the major toxicity with 17% neutropenia grade 3 and 4. Thrombocytopenia was rare with only 2% grade 3 and 4. A prolonged CD4-lymphocytopenia was observed in all patients. Life threatening complications were not observed. These results confirm the major single-agent activity of cladribine in a large cohort of patients with untreated low-grade lymphomas using the intermittent 2-hour-infusion dosage-regimen. To improve treatment results furthermore, cladribine should be combined with other agents active in low-grade lymphomas.

Positron emission tomography (PET) for staging and evaluation of response to treatment in patients with Hodgkin's disease

Forty two examinations utilizing F-18 FDG-PET were performed in 23 patients with Hodgkin's disease to study for involved lymphoma regions and compared to conventional staging procedures. Twenty stagings were performed at diagnosis of untreated Hodgkin's disease or at first relapse, and 22 restagings during and after chemoradiotherapy. At diagnosis in 5 of 20 patients PET and other procedures revealed different extranodal manifestations and in 3 patients established different clinical staging. PET seemed to be accurate in the assessment of lymphoma involvement in nodal sites. During follow up, in 10 out of 22 investigations different results and discrepancy were recorded, mostly due to the different extent of F-18-FDG metabolism in residual masses in lymphatic tissues compared to CT, X-ray or ultrasonography. The results indicate that PET may have advantages in the assessment of remissions in nodal sites. Less conclusive results were observed with regard to extranodal involvement or inflammatory disease. In conclusion PET may be sufficient for the staging of the majority of patients with Hodgkin's disease and particularly for assessing remission status in nodal sites, but PET may have disadvantages in the evaluation of extranodal lymphoma and inflammatory disease.

Treatment of mantle-cell lymphomas with intermittent two-hour infusion of cladribine as first-line therapy or in first relapse

PURPOSE

Cladribine (2-chlorodeoxyadenosine, 2-CdA) has been reported to be effective in the treatment of low-grade lymphomas. The objective of this multicenter study was to evaluate the activity of cladribine in mantle-cell lymphomas as first-line therapy or in first relapse using an intermittent two-hour infusion of cladribine.

PATIENTS AND METHODS

A total of 47 courses, or an average of four courses per patient, were administered to 12 patients (seven untreated, five relapsed) with 5 mg/m2 cladribine given as an intermittent two-hour infusion over five consecutive days for a maximum of six cycles every four weeks.

RESULTS

Cladribine showed activity in patients with mantle-cell lymphomas, achieving a response rate of 58% (95% confidence interval (95% CI): 28%-85%). Myelosuppression was the major toxicity with 17% of grade 3 and 4 neutropenia. Thrombocytopenia was rare with only 2% of grade 3 and 4.

CONCLUSION

These results demonstrate single-agent activity of cladribine in mantle-cell lymphomas using the intermittent two-hour infusion dosage regimen. To further improve treatment results, cladribine should be combined with other agents active in mantle-cell lymphomas.

Spirometric gated quantitative computed tomography of the lung in healthy smokers and nonsmokers

RATIONALE AND OBJECTIVES

The authors investigated the influence of cigarette smoking on healthy, asymptomatic smokers and nonsmokers with the help of spirometric triggered quantitative computed tomography. In our prospective study, the authors compared conventional lung function parameters with the computed tomography values (lung attenuation, lung area).

METHODS

The study group comprised 40 healthy volunteers consisting of 20 smokers and nonsmokers (20 females and 20 males). The corresponding groups have been matched concerning their age, height, body mass, (cigarette) pack years. Computer tomography scans were triggered at 35%, 50%, 70% and 95% of vital capacity at a defined apical and a basal level.

RESULTS

Functional residual capacity (FRC), total lung capacity and airway resistance showed close correlations to lung parenchymal attenuation values especially at full inspiration and expiration. For example, the authors found a correlation coefficient of r = -0.845 (P < or = 0.001) concerning the FRC and lung attenuation values in the apical lung at 35% of vital capacity in male smokers. Male smokers proved to have a significantly higher pulmonary lung density at all inspiratory states than the other groups (P < or = 0.05; Student's t test). Although male smokers had a higher vital capacity they showed a smaller cross-sectional area increase of the lung during inspiration than nonsmokers. This phenomenon is a result of the decreasing compliance of the smoker's lung, due to small airways disease and hypoxic vasoconstriction.

CONCLUSIONS

Spirometric-triggered quantitative computed tomography has proved to be a sensitive diagnostic device for the investigation of early pathomorphologic changes in healthy, asymptomatic cigarette smokers.