Recombinant human erythropoietin, epoetin beta, in patients with relapsed lymphoma treated with aggressive sequential salvage chemotherapy--results of a randomized trial

The aim of the study was to investigate the effects of erythropoietin (epoetin beta) on red blood cell (RBC) transfusions, hemoglobin (Hb) levels, and quality of life (QOL) in patients with relapsed lymphoma treated with an aggressive sequential salvage chemotherapy (SSCT) regimen. Sixty patients with early or late relapsed Hodgkin's disease ( n=39) or first relapse of aggressive non-Hodgkin's lymphoma ( n=21) were randomized to receive epoetin beta 10,000 IE subcutaneously three times a week or no epoetin during salvage chemotherapy. Patients in both study arms received two cycles of DHAP (dexamethasone, high-dose cytarabine, cisplatin); patients in partial remission (PR) or complete remission (CR) then received cyclophosphamide, followed by peripheral blood stem cell (PBSC) harvest, methotrexate plus vincristine, and etoposide. The final myeloablative course was BEAM (carmustine, etoposide, cytarabine, and melphalan) followed by autologous stem cell support. The primary endpoint of the study was the number of RBC units needed during SSCT. In addition, Hb levels and QOL were measured. The mean number of RBC units given in the epoetin beta arm was 4.5 compared to 8.3 in the control arm ( P=0.0134). The mean Hb levels during therapy were 10.4 g/dl in the epoetin beta arm and 9.7 g/dl in the control ( P=0.018). From baseline until BEAM therapy QOL (EORTC QLQ C30) and fatigue (MFI) assessment showed little QOL worsening or stable levels in both arms with a steeper increase of fatigue levels in the control group. Patients with relapsed lymphoma undergoing aggressive chemotherapy and stem cell support benefited from epoetin beta therapy, with a decrease of RBC transfusion requirements and lower rise of fatigue levels.

Chemotherapy in alveolar soft part sarcomas. What do we know?

Alveolar soft part sarcoma (ASPS) is a rare tumour. Published series about treatment and outcome are scarce. Conclusive data about the response to chemotherapy are not available. The aim of this study was to analyse the efficacy of palliative chemotherapeutic treatment options and the incidence and mode of presentation of brain metastases. We retrospectively analysed our own sarcoma data-base and reviewed the literature. From our registry containing 757 patients, we identified 8 patients with ASPS. From the literature, 47 cases of adult patients and 13 children with sufficient data about chemotherapy were identified. Response to first-line chemotherapy in 68 patients was: complete remission (CR) 4%, partial remission (PR) 3%, stable disease (SD) 41%, progressive disease (PD) 51%. 285 patients with stage IV disease were evaluable for the analysis of metastatic sites. The incidence of brain metastases was 30.5% (87/285). Brain metastases were detected at a median interval of 48 months (range 0-396 months) after the primary diagnosis. Median survival after the diagnosis of brain metastases was 12 months. The median survival for patients with stage IV disease treated by chemotherapy was 36+ months (range 10-132 months) (31 patients evaluable) with a median follow-up of 46 months (range 10-135 months). ASPS shows a high incidence of brain metastases, at least 3 times higher than that of other soft tissue sarcomas. Chemotherapeutic regimens used for the treatment of other soft tissue sarcomas lack efficacy in ASPS. Staging investigations for ASPS should routinely include imaging of the brain. ASPS patients should not be treated with chemotherapy outside of controlled clinical trials. New targets for specific biologically-directed therapies need to be developed.

Efficient elimination of chronic lymphocytic leukaemia B cells by autologous T cells with a bispecific anti-CD19/anti-CD3 single-chain antibody construct

Recently, we have shown that a novel recombinant bispecific single-chain antibody construct (bscCD19 x CD3), induces highly efficacious lymphoma-directed cytotoxicity mediated by unstimulated peripheral T lymphocytes. Functional analysis of bscCD19 x CD3 has so far been exclusively performed with human B lymphoma cell lines and T cells from healthy donors. Here we analysed the properties of bscCD19 x CD3 using primary B cells and autologous T cells from healthy volunteers or patients with B-cell chronic lymphocytic leukaemia (B-CLL). We show that bscCD19 x CD3 induces T-cell-mediated depletion of nonmalignant B cells in all four cases and depletion of primary lymphoma cells in 22 out of 25 cases. This effect could be observed at low effector-to-target (E:T) ratios and in the majority of cases without additional activation of autologous T cells by IL-2. Even in samples derived from patients heavily pretreated with different chemotherapy regimens, strong cytotoxic effects of bscCD19 x CD3 could be observed. The addition of bscCD19 x CD3 to patients' cells resulted in an upregulation of activation-specific cell surface antigens on autologous T cells and elevated levels of CD95 on lymphoma B cells. Although anti-CD95 antibody CH-11 failed to induce apoptosis in lymphoma cells, we provide evidence that B-CLL cell depletion by bscCD3 x CD3 is mediated at least in part by apoptosis via the caspase pathway.

Preexistence and evolution of imatinib mesylate-resistant clones in chronic myelogenous leukemia detected by a PNA-based PCR clamping technique

Recently, various mutations within the Abl sequence have been described that negatively affect imatinib binding to Bcr/Abl resulting in cellular resistance of chronic myeloid leukemia (CML) cells. So far, little is known as to whether these mutations are preexisting or develop under imatinib therapy as current mutation analyses are limited by a low sensitivity of approximately 1:2 (50%) to 1:5 (20%). By combining peptide nucleic acid (PNA)-based DNA clamping with a fluorescence hybridization probe assay, we developed a new and highly sensitive technique for the detection of known mutations within the Bcr/Abl kinase domain. With this approach we investigated 19 cases of CML refractory to imatinib treatment before and during therapy. By clamping of wild-type Abl through PNA we could effectively enhance the detection sensitivity for the Bcr/Abl mutations Thr315Ile, Glu255Lys, and Tyr253His such that 1 mutant cDNA molecule could be detected in 500 negatives (0.2%). We observed in one case that a Gly255Lys mutation was detectable before treatment. By DNA analysis of buccal swaps, a genetic polymorphism could be excluded. In two cases clonal evolution of known mutations developed gradually under treatment. In another case an initially detectable Tyr253His mutation disappeared after therapy onset but was again observed after 6 weeks of imatinib treatment. Preexisting and evolving Bcr/Abl mutations associated with an unfavorable prognosis could be safely detected by the presented technique. This may facilitate risk stratification in CML and may serve as a model for individualized molecular monitoring and therapeutic strategies in other malignant diseases.

Combined p53/Bax mutation results in extremely poor prognosis in gastric carcinoma with low microsatellite instability

Gastric cancer is highly refractory to DNA-damaging therapies. We therefore studied both gene mutation and protein expression of p53 and Bax in a cohort of 116 patients with gastric cancer who underwent R0-resection with a curative intent. Bax mutation was independent from severe microsatellite instability (MSI), that is, global mismatch repair deficiency as determined by analysis of BAT-25/BAT-26 microsatellite markers. Thus, Bax-frameshift mutation is a feature of tumors with low MSI. In contrast and as expected, no p53 mutations were observed in the microsatellite instable tumors. p53 Mutation or p53 overexpression did not have an impact on disease prognosis. p53-Inactivation was, however, associated with an extremely poor prognosis in the subgroup of patients with Bax-mutated tumors. Thus, we show for the first time that the combined mutation of p53 and Bax, two key regulators of the mitochondrial apoptosis pathway, results in an extremely aggressive tumor biology and poor clinical prognosis.

Coexpression of p21(WAF1/CIP1) in adenovirus vector transfected human primary hepatocytes prevents apoptosis resulting in improved transgene expression

Replication-deficient adenovirus (Ad vector) is one of the most effective gene transfer systems. However, its employment in human gene therapy trials is hampered by Ad vector associated cytotoxicity and induction of apoptosis of the infected cells. Here, we identify one underlying mechanism as uncoupling of S phase and mitosis of the cell cycle leading to apoptosis and decline of transgene expression. Moreover, we demonstrate a strategy to avoid Ad vector associated cytotoxicity and induction of apoptosis in human primary hepatocytes by coinfection of Ad vector carrying the cDNA of choice and the cell cycle regulator p21(WAF1/CIP1) (p21). In addition, animal experiments were performed using Ad vector directed coexpression of p21 and human alpha 1-antitrypsin. As serum analysis of alpha 1-antitrypsin after Ad vector mediated gene transfer to the liver of mice revealed, this strategy resulted also in the improvement of transgene expression by two orders of magnitude. These data suggest that coexpression of p21 and Ad vector carrying a therapeutic gene may be a promising strategy to avoid cytotoxicity and induction of apoptosis leading to improved safety in human gene therapy.

[Accuracy of the sonographic determination of the splenic weight in comparison with the weight at autopsy]

PURPOSE

The weight of the spleen can be easily calculated from sonographic measurements. This study investigates the correlations between the weight of the spleen determined sonographically and the weight measured at autopsy or after splenectomy.

MATERIALS AND METHODS

The splenic weight at autopsy or after splenectomy was correlated with the calculated sonographic splenic weight in 55 patients who had a sonographic examination within the preceding three weeks.

RESULTS

A significant correlation (r = 0.978) was found between the sonographically calculated splenic weight (460.82 grams) and the measured weight of the removed spleen (average weight 463.18 grams). Spleens weighing more than 1 kg showed a slightly weaker correlation.

CONCLUSION

This study proves that the simple formula of length x transverse diameter x vertical diameter x 0.6 provides a reliable calculation of the weight of the spleen.

Mutation of p53 and consecutive selective drug resistance in B-CLL occurs as a consequence of prior DNA-damaging chemotherapy

Inactivation of p53 has been shown to correlate with poor prognosis and drug resistance in malignant tumors. Nevertheless, few reports have directly shown such effects in primary tumor cells. Here, we investigated the p53 mutational status in 138 B-CLL samples and compared these findings with drug and gamma-irradiation sensitivity profiles. p53 mutations resulted not only in a shorter survival but, notably also in selective resistance to alkylating agents, fludarabine and gamma-irradiation. In contrast, no such effect was observed for vincristine, anthracyclines and glucocorticoids. Thus, these latter compounds induce cell death at least in part by p53-independent pathways. Interestingly, p53 mutations clustered in patients who had received prior chemotherapy. In fact, we show for the first time that treatment with DNA-damaging alkylating agents correlates with occurrence of p53 mutations in a clinical setting. This finding may explain at least to some extent the development of resistance to second-line anticancer chemotherapy.

Reduced intensity conditioning and prophylactic DLI can cure patients with high-risk acute leukaemias if complete donor chimerism can be achieved

23 patients with ALL (n=9) and AML (n=14) underwent nonmyeloablative stem cell transplantation (NST) from an HLA-identical donor after conditioning with fludarabine (180 mg/m(2)), busulfan (8 mg/kg) and anti-T-lymphocyte globulin (40 mg/kg). After NST, 20/23 patients engrafted. Ten out of 14 patients with uncontrolled disease reached complete remission. A multiplex-PCR using short tandem repeats was used for chimerism analysis and detected mixed chimerism (MC) in 14/22 evaluable patients (64%) after NST. Prophylactic donor lymphocyte infusions (DLI) were given to 11/14 patients with MC; MC converted to complete donor chimerism (CC) in 6/11 patients within 2-6 weeks. All patients with persistent MC with or without DLI relapsed during further follow-up. MC predicted impending relapse 4-52 weeks before clinical diagnosis. Ten of 23 patients (43%) are alive 2-34 months after stem cell transplantation. 12 of 23 patients (52%), have died from leukaemia after NST. One out of 23 patients has died from severe sepsis. In conclusion, NST leads to stable engraftment and complete remission in patients with advanced acute leukaemias. NST can cure a substantial proportion of these patients, but the relapse rate is still high. Repeated chimerism analysis is a useful tool to detect recipient cells, especially in patients without molecular markers of disease and can be used to monitor immunomodulatory therapies. MC is unstable in these patients and predicts impending relapse. Prophylactic DLI can convert MC to CC, which seemed to lower relapse risk.

Recurrent gastric adenocarcinoma with unusual metastatic localization and excellent response to docetaxel and 5-FU continuous infusion

BACKGROUND

Metastatic gastric cancer is usually treated with cisplatin- and 5-FU-based chemotherapy regimens. There are good data for the combination regimen ECF (epirubicin, cisplatin and 5-FU), which is therefore often regarded as a reference treatment. Docetaxel shows promising activity against gastric cancer as single agent and in combinations. To develop a well-tolerable combination chemotherapy for an ambulant setting we initiated a randomized phase II study, comparing docetaxel and 5-FU continuous infusion (DF) with ECF.

CASE REPORT

A 66-year-old patient with the history of a curatively resected gastric cancer 2 years previously presented with abdominal masses and lesions in his spleen. Histology proved metastases of gastric adenocarcinoma. The patient was treated with docetaxel (75 mg/m2, d1) and 5-FU continuous infusion (200 mg/m2/d, d1-21, q3w) within our study. Already after 2 cycles of chemotherapy he showed symptomatic improvement and partial remission of his tumor, which was confirmed after the 3rd cycle. In our ongoing study so far 50 patients are evaluable for response. Objective tumor response (CR + PR) could be documented in 44% of patients in the DF arm as well as in the ECF arm.

CONCLUSION

Docetaxel and 5-FU continuous infusion is an active regimen which could possibly be used as an alternative to established treatment protocols.

Basiliximab is well tolerated and effective in the treatment of steroid-refractory acute graft-versus-host disease after allogeneic stem cell transplantation

Basiliximab, a chimeric interleukin-2 receptor (IL-2-R) antagonist, was evaluated in 17 patients with steroid-refractory acute graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT). Patients were transplanted from a related (n = 6) or unrelated (n = 11) HLA-identical donor because of acute lymphoblastic leukemia (n = 4), acute myeloid leukemia (n = 3), chronic myeloid leukemia (n = 7), myelodysplastic syndrome (n = 1), non-Hodgkin's lymphoma (n = 1), and multiple myeloma (n = 1). Basiliximab was given at a dose of 2 x 20 mg on 2 consecutive days after steroid-refractory acute GVHD had developed. Basiliximab was repeated on day 8 in cases of persistent GVHD. A median of four basiliximab infusions (range 1-12) were given to these patients. None had infusion-associated or cytokine-related side-effects after basiliximab. Twelve of 17 patients (71%) responded to basiliximab, 9/17 (53%) had a complete response (CR) of acute GVHD and 3/17 (18%) had a partial response (PR). Five of 17 patients (29%) did not respond. Chronic GVHD developed in 8/13 evaluable patients and only 2/8 had responded to basiliximab before. Five of 13 evaluable patients have no signs of chronic GVHD and all five had a CR or PR after basiliximab. This is the first report on the safety of basiliximab in patients with steroid-refractory acute GVHD. Our data suggest that basiliximab is effective in a substantial proportion of these patients.

Oral trofosfamide: an active and well-tolerated maintenance therapy for adult patients with advanced bone and soft tissue sarcomas. Results of a retrospective analysis

OBJECTIVES

Aim of this study was to evaluate the feasibility and toxicity of oral trofosfamide given as maintenance therapy to adult patients with bone and soft tissue sarcomas following first or later line induction chemotherapy, and to determine the clinical efficacy in terms of impact on progression-free and overall survival.

PATIENTS AND METHODS

49 patients with locally advanced or metastatic high-grade soft tissue and bone sarcomas were identified retrospectively according to the inclusion criteria of the analysis. They were treated with oral trofosfamide at a dose of 100-150 mg per day continuously. All patients were pretreated with one or more lines of chemotherapy resulting in partial remission or stable disease. Patients were treated until progression of disease or unacceptable toxicity occurred. Progression- free and overall survival were measured from the beginning of maintenance therapy.

RESULTS

Median follow-up for all patients was 33 months (range 10-98). Toxicity was mild and predominantly hematologic. Only 1 patient had to stop treatment due to renal toxicity. The median progression-free survival was 7 months with 27% of patients continuing maintenance treatment at 1 year. Median overall survival is 14 months. Patients with metastatic disease showed a median survival of 23 months from diagnosis of metastases. 3 patients with stable disease following induction chemotherapy reached partial remission while under trofosfamide maintenance.

CONCLUSION

Oral maintenance therapy with trofosfamide is well-tolerated and seems to prolong progression-free and overall survival compared to the course of advanced soft tissue and bone sarcomas without maintenance chemotherapy.

[The role of polychemotherapy in the management of malignant bone tumors]

Osteosarcoma,chondrosarcoma and Ewing tumors are the most common primary malignant bone tumors. Due to early hematogenous dissemination, surgery alone is able to cure less than 20% of patients with osteosarcoma. In Ewing-tumors less than 10% of patients will be cured with local treatment alone. By the use of aggressive polychemotherapy, given both pre- and post-surgery, cure rates of more than 50% for Ewing-tumors and about 70% for osteosarcoma could be achieved.Thus,chemotherapy is an indispensable part of the multimodal treatment of these tumor types. Chondrosarcomas are usually more highly differentiated and therefore show a lower rate of metastasis. The use of chemotherapy is not established in these tumors.

Adenoviral transduction of tumor cells induces apoptosis in co-cultured T lymphocytes

Adenoviral gene transfer of immunmodulatory molecules has been employed successfully in tumor vaccination studies to induce rejection of transplanted syngeneic tumors. In contrast, the response observed when treating chemically induced murine tumors is rather limited. The same applies for human malignancies. A number of reasons including poor transduction efficiency or insufficient T cell infiltration have been held accountable for this lack of efficacy. However, little attention has been given to effects of the adenoviral transduction itself on the T cell system. Here, we show that T cells are sensitized for activation-induced cell death after co-culture with adenovirally infected tumor cells. The levels of CD95/Fas ligand or TNF-alpha, both known mediators of activation induced cell death, however were not affected by the presence of adenovirus-infected target cells. Furthermore, supernatant transfer from adenovirally transduced or non-infected tumor cell cultures did not result in increased T cell apoptosis. This suggests that cell contact rather than a soluble factor is responsible for the induction of T cell apoptosis upon co-culture with adenovirally transduced tumor cells. Interestingly, and in line with our previous observations, activation-induced cell death was partially inhibited if T cells were co-cultured with tumor cells adenovirally transduced to express IL-7 and CD80, both molecules having the capacity to prevent T cell apoptosis.

Time-intensified dexamethasone/cisplatin/cytarabine: an effective salvage therapy with low toxicity in patients with relapsed and refractory Hodgkin's disease

BACKGROUND

An important variable affecting outcome in relapsed and refractory Hodgkin's disease (HD) is the potential of conventional salvage chemotherapy to reduce tumor volume before high-dose chemotherapy (HDCT) and autologous stem cell transplantation. Currently, the optimal salvage chemotherapy regimen for these patients is unclear. Since dexamethasone/cisplatin/cytarabine (DHAP) given at 3-4 week intervals has been shown to be very effective in patients with relapsed aggressive non-Hodgkin's lymphoma, we evaluated this regimen given at a median of 16-day intervals in patients with relapsed and refractory HD.

PATIENTS AND METHODS

Patients with relapsed or refractory HD were treated with two cycles of DHAP [dexamethasone 40 mg intravenously (i.v.) day 1-4, cisplatin 100 mg/m(2) i.v. as 24-h continuous infusion day 1, and cytarabine 2 g/m(2) i.v. 12q day 2]. Granulocyte colony-stimulating factor (G-CSF) was given at a dose of 5 micro g/kg from day 4 until day 13. Patients with partial remission (PR) or complete remission (CR) after two cycles of DHAP received sequential HDCT.

RESULTS

The median age of the 102 patients included was 34 years (range 21-64 years). Forty-two percent of the patients had late relapse, 29% early relapse, 12% multiple relapse and 16% primary progressive/refractory disease. The response rate (RR) after two cycles of DHAP was 89% (21% CR, 68% PR). The RRs for patients with late, early, multiple and progressive HD were 91%, 93%, 92% and 65%, respectively. Using the chi-square test for independence, remission status (relapsed HD versus progressive HD) and stage at relapse (stage I/II versus stage III/IV) were significant factors for response to DHAP. WHO grade 4 leukocytopenia and thrombocytopenia were the main toxic- ities occurring in 43% (mean duration 1.1 days, range 0-6) and 48% (mean duration 1.4 days, range 0-11) of all courses, respectively. Neither severe infections nor treatment-related deaths occurred. Peripheral blood stem cells (PBSCs) were collected after the first cycle DHAP in eight patients. The hematopoietic progenitors showed a very rapid increase from day 10 with a synchronous and impressive peak on day 12. A mean of 6.1 x 10(6)/kg CD34(+) cells were collected per apheresis. As originally recommended in the protocol, PBSCs were routinely collected during sequential HDCT in the remaining patients.

CONCLUSIONS

A brief tumor-reducing program with two cycles of DHAP given in short intervals supported by G-CSF is effective and well-tolerated in patients with relapsed and refractory HD. This regimen can be used to mobilize stem cells and select those patients with chemosensitive relapse who should subsequently be treated with HDCT.

Bax expression correlates with cellular drug sensitivity to doxorubicin, cyclophosphamide and chlorambucil but not fludarabine, cladribine or corticosteroids in B cell chronic lymphocytic leukemia

In B-CLL, non-proliferating B cells accumulate due to defective apoptosis. Cytotoxic therapies trigger apoptosis and deregulation of apoptotic pathways contributes to chemoresistance. Loss of the apoptosis-promoting Bax has been implicated in resistance to cytotoxic therapy. We therefore evaluated ex vivo drug sensitivity of CLL, producing chemoresponse data which are prognostic indicators for B-CLL, in particular in the case of purine nucleoside analogs. To analyze the underlying mechanisms of drug resistance, we compared endogenous Bax and Bcl-2 expression to ex vivo response to eight drugs, and to survival in 39 B-CLL patients. We found that reduced Bax levels correlated well with ex vivo resistance to traditional B-CLL therapies - anthracyclines, alkylating agents and vincristine (all P < 0.04). Surprisingly, no such relationship was observed for the purine nucleoside analogs or corticosteroids (all P > 0.5). Mutational analysis of p53 could not explain the loss of Bax protein expression. Levels of Bcl-2 were not associated with sensitivity to any drug. In contrast to the ex vivo data, neither Bax or Bcl-2 expression nor doxorubicin sensitivity were associated with increased survival whereas sensitivity to fludarabine correlated with better overall survival (P = 0.031). These findings suggest that the resistance to purine nucleoside analogs and corticosteroids in B-CLL is due to inactivation of pathways different from those activated by anthracyclines, vinca alkaloids and alkylating agents and may be the molecular rationale for the efficacy of purine analogs in this disease.

Detection of small numbers of cells characteristic for haematological disorders in peripheral blood (the deep diff)

We studied cytocentrifuge preparations of peripheral blood mononuclear leucocytes in haematological patients with nondiagnostic white cell differential counts. This approach (the 'deep diff') enabled the detection of small numbers of diagnostically significant cells in a majority of patients. We found ringed sideroblasts in 5/7 patients with sideroblastic anaemia and megaloblasts in 9/10 patients with megaloblastic anaemia. We observed centrocytes in seven patients with follicular lymphoma, mantle cells in five patients with mantle cell lymphoma and marginal zone cells in five patients with nodal marginal zone lymphoma. We detected small percentages of lymphoma cells in cytospins of mononuclear leucocytes in 12 patients with large B-cell lymphoma, Burkitt's lymphoma and anaplastic large-cell lymphoma. The deep diff was nondiagnostic in 5/6 patients with hairy cell leukaemia and in 9/10 patients with Waldenström's macroglobulinaemia and small lymphocytic lymphoma. In these cases, there were insufficient cells to detect light chain restriction. Increased counts of leukaemic cells were found in 12/13 patients with acute leukaemia with < 3% blasts in the conventional white cell differential. Increased blasts were also observed in six patients with refractory anaemia with excess of blasts (RAEB). Decreased blasts were found in five patients with aplastic anaemia and in nine patients with bone marrow aplasia after intensive chemotherapy. Increased plasma cell counts were observed in 13/14 patients with advanced plasma cell myeloma. We conclude that the 'deep diff', augmented by immunocytochemistry, may be useful in the diagnosis of haematological disorders.

Morphologic diagnosis of leukaemic B-lymphoproliferative disorders and the role of cyclin D1 expression

PURPOSE

This study analysed the morphologic differences between leukaemic mantle cell lymphoma, follicular lymphoma, nodal marginal zone lymphoma, and diffuse large B-cell lymphoma in peripheral blood. Additionally, we investigated the role of cyclin D1 expression in B-lymphoproliferative disorders.

METHODS

The morphologic analysis of the leukaemic cells was performed on cytocentrifuge preparations after separation of mononuclear cells from peripheral blood using a Ficoll-Hypaque density gradient. Cyclin D1 protein expression was studied with the catalyzed signal amplification system. The expression of other markers (CD5, CD23, light chain immunoglobulins) was analysed by the APAAP method.

RESULTS

We describe in detail the morphology of the lymphoma cells in eight patients with mantle cell lymphoma, six patients with follicular lymphoma, 11 patients with nodal marginal zone lymphoma, and seven patients with diffuse large B-cell lymphoma. The morphological distinction between these lymphoma cells is a challenge for the haematologist. The investigation of cytocentrifuge preparations of mononuclear cells allows the detection of lymphoma cells also in cases with nondiagnostic white cell differential. Additionally, the immunotype (light chain restriction, CD5, CD23, and cyclin D1) of 108 patients with leukaemic B-lymphoproliferative disorders was studied. Diffuse nuclear expression of cyclin D1 protein (>20%) was specific for mantle cell lymphoma. However, only 6/8 patients showed cyclin-D1 positivity.

CONCLUSIONS

The morphologic analysis of lymphoma cells in cytocentrifuge preparations of mononuclear leukocytes in combination with immunocytochemical investigation allows the detection of mantle cells, centrocytes of follicular lymphoma, marginal zone cells, and cells of the diffuse large B-cell lymphoma in peripheral blood. The positivity of cyclin D1 protein improves the differentiation of mantle cells from other lymphoma cells.

Piceatannol, a hydroxylated analog of the chemopreventive agent resveratrol, is a potent inducer of apoptosis in the lymphoma cell line BJAB and in primary, leukemic lymphoblasts

The stilbene phytochemicals resveratrol and piceatannol have been reported to possess substantial antitumorigenic and antileukemic activities, respectively. Although recent experimental data revealed the proapoptotic potency of resveratrol, the molecular mechanisms underlying the antileukemic activity have not yet been studied in detail. In the present study, we show that resveratrol, as well as the hydroxylated analog piceatannol, are potent inducers of apoptotic cell death in BJAB Burkitt-like lymphoma cells with an ED50 concentration of 25 microM. Further experiments revealed that treatment of BJAB cells with both substances led to a concentration-dependent activation of caspase-3 and mitochondrial permeability transition. Using BJAB cells overexpressing a dominant-negative mutant of the Fas-associated death domain (FADD) adaptor protein to block death receptor-mediated apoptosis, we demonstrate that resveratrol- and piceatannol-induced cell death in these cells is independent of the CD95/Fas signaling pathway. To explore the antileukemic properties of both compounds in more detail, we extended our study to primary, leukemic lymphoblasts. Interestingly, piceatannol but not resveratrol is a very efficient inducer of apoptosis in this ex vivo assay with leukemic lymphoblasts of 21 patients suffering from childhood lymphoblastic leukemia (ALL).

The IL-6 receptor antagonist SANT-7 overcomes bone marrow stromal cell-mediated drug resistance of multiple myeloma cells

The bone marrow micro-environment produces a number of different survival factors that are important for the malignant growth and drug resistance of multiple myeloma (MM) cells. One of the main factors reported to be essential for survival and growth of MM cells in some experimental systems is IL-6. Therefore, the development and testing of substances that interfere with IL-6 or IL-6 receptor (IL-6R) function might have therapeutic value for the treatment of MM. We analyzed the effect of the IL-6R antagonist SANT-7 on growth and survival of the IL-6--dependent MM cell lines INA-6 and XG-1 as well as primary MM cells from 7 patients co-cultured with bone marrow stromal cells (BMSCs). In particular, we were interested in whether SANT-7 enhances the growth-inhibitory effects of dexamethasone (Dex) and all-trans-retinoic acid (ATRA). None of the drugs when tested as a single substance, including SANT-7, induced major growth inhibition if MM cells were co-cultured with primary human BMSCs. However, when Dex and ATRA were given in combination with SANT-7, strong growth inhibition was achieved in cell lines and primary MM cells. This effect was due to cell-cycle arrest and induction of apoptosis.

Antisense therapy in oncology: new hope for an old idea?

There is a potential role for antisense oligonucleotides in the treatment of disease. The principle of antisense technology is the sequence-specific binding of an antisense oligonucleotide to target mRNA, resulting in the prevention of gene translation. The specificity of hybridisation makes antisense treatment an attractive strategy to selectively modulate the expression of genes involved in the pathogenesis of diseases. One antisense drug has been approved for local treatment of cytomegalovirus-induced retinitis, and several antisense oligonucleotides are in clinical trials, including oligonucleotides that target the mRNA of BCL2, protein-kinase-C alpha, and RAF kinase. Antisense oligonucleotides are well tolerated and might have therapeutic activity. Here, we summarise treatment ideas in this field, summarise clinical trials that are being done, discuss the potential contribution of CpG motif-mediated effects, and look at promising molecular targets to treat human cancer with antisense oligonucleotides.

In vitro susceptibility to TRAIL-induced apoptosis of acute leukemia cells in the context of TRAIL receptor gene expression and constitutive NF-kappa B activity

The TNF-related apoptosis-inducing ligand (TRAIL) is currently under evaluation as a possible (co-)therapeutic in cancer treatment. We therefore examined 129 cell samples from patients with de novo acute leukemia as to their constitutive susceptibility to TRAIL-induced apoptosis In vitro. Only 21 (16%) cell samples revealed at least 10% TRAIL-susceptible cells/sample as detected by flow cytometric annexinV staining after 24 h culture compared with medium control. Precursor B cell ALL samples (11 (27%) of 41) were more TRAIL-susceptible compared with AML (5 (9%) of 54; P < 0.05) but not compared with precursor T cell ALL (5 (15%) of 34; P = 0.20). Furthermore, we examined constitutive mRNA expression levels of TRAIL receptors R1-R4 by semi-quantitative RT-PCR (n = 58). Expression levels were heterogeneous, however, there was no significant correlation between the expression of the signal-transducing receptors (R1, R2) as well as of the decoy receptors (R3, R4) and TRAIL sensitivity in this series. Constitutive NF-kappa B activity has been shown to influence TRAIL susceptibility of leukemic cells. In 39 leukemic cell samples examined, we found a generally high NF-kappa B activity as detected by electrophoretic mobility shift assay which did not differ between TRAIL-susceptible and TRAIL-resistant cases. Finally, 49 acute leukemic cell samples were coincubated with doxorubicin in vitro. Doxorubicin sensitized four of 35 initially TRAIL-resistant samples and augmented TRAIL-induced apoptosis in two of 14 TRAIL-susceptible samples. In summary, constitutive TRAIL susceptibility differs between leukemia subtypes and does not correlate with mRNA expression levels of the TRAIL receptors R1-R4 as well as constitutive NF-kappa B activation status. The observed sensitization of leukemic cells to TRAIL by doxorubicin in vitro indicates that TRAIL should be further evaluated as to its possible role as an in vivo cotherapeutic in acute leukemia.

Overexpression of caspase-3 restores sensitivity for drug-induced apoptosis in breast cancer cell lines with acquired drug resistance

In this study, we asked whether overexpression of caspase-3, a central downstream executioner of apoptotic pathways, might sensitize breast cancer cells with acquired drug resistance (MT1/ADR) to drug-induced apoptosis. As control, we employed caspase-3 negative and caspase-3-transfected MCF-7 cells. Whereas mock-transfected MCF-7 cells were resistant to epirubicin, etoposide and paclitaxel (taxol), the same drugs led to breakdown of nuclear DNA in caspase-3-transfected MCF-7 cells. MT1/ADR cells express low levels of wild type caspase-3 but show defective caspase activation and apoptosis upon drug exposure. These cells also display a less efficient activation of the mitochondrial permeability transition. Caspase-3-transfected MT1/ADR clones showed a 2.8-fold increase in the protein level and a 3.7-fold higher specific enzyme activity. Procaspase-3 overexpression was not toxic and did not affect background apoptosis. Interestingly, procaspase-3-transfected MT1/ADR cells were more sensitive to cytotoxic drugs as compared with vector-transfected controls and DNA fragmentation nearly reached the levels of the original drug sensitive MT1 cells. Thus, overexpression of caspase-3 enhances chemosensitivity especially in situations where activation of the mitochondrial apoptosome is disturbed.