Michael Hundemer

The role of IGF-1 as a major growth factor for myeloma cell lines and the prognostic relevance of the expression of its receptor.

A plethora of myeloma growth factors (MGFs) has been identified, but their relative importance and cooperation have not been determined. We investigated 5 MGFs (interleukin-6 [IL-6], insulin-like growth factor type 1 [IGF-1], hepatocyte growth factor [HGF], HB-epidermal growth factor [HB-EGF], and a proliferation-inducing ligand [APRIL]) in serum-free cultures of human myeloma cell lines (HMCLs). In CD45(-) HMCLs, an autocrine IGF-1 loop promoted autonomous survival whereas CD45(+) HMCLs could not survive without addition of MGFs, mainly IGF-1 and IL-6. IGF-1 was the major one: its activity was abrogated by an IGF-1R inhibitor only, whereas IL-6, HGF, or HB-EGF activity was inhibited by both IGF-1R- and receptor-specific inhibition. APRIL activity was inhibited by its specific inhibitor only. Of the investigated MGFs and their receptors, only expressions of IGF-1R and IL-6R in multiple myeloma cells (MMCs) of patients delineate a group with adverse prognosis. This is mainly explained by a strong association of IGF-1R and IL-6R expression and t(4;14) translocation, but IGF-1R expression without t(4;14) can also have a poor prognosis. Thus, IGF-1-targeted therapy, eventually in combination with anti-IL-6 therapy, could be promising in a subset of patients with MMCs expressing IGF-1R.

Induction of angiogenesis by normal and malignant plasma cells

Abundant bone marrow angiogenesis is present in almost all myeloma patients requiring therapy and correlated to treatment response and survival. We assessed the expression of 402 angiogenesis-associated genes by Affymetrix DNA microarrays in 466 samples, including CD138-purified myeloma cells (MMCs) from 300 previously untreated patients, in vivo microcirculation by dynamic contrast-enhanced magnetic resonance imaging, and in vitro angiogenesis (AngioKit-assay). Normal bone marrow plasma cells (BMPCs) express a median of 39 proangiogenic (eg, VEGFA, ADM, IGF-1) and 28 antiangiogenic genes (eg, TIMP1, TIMP2). Supernatants of BMPCs unlike those of memory B cells induce angiogenesis in vitro. MMCs do not show a significantly higher median number of expressed proangiogenic (45) or antiangiogenic (31) genes, but 97% of MMC samples aberrantly express at least one of the angiogenic factors HGF, IL-15, ANG, APRIL, CTGF, or TGFA. Supernatants of MMCs and human myeloma cell lines induce significantly higher in vitro angiogenesis compared with BMPCs. In conclusion, BMPCs express a surplus of proangiogenic over antiangiogenic genes transmitting to the ability to induce in vitro angiogenesis. Aberrant expression of proangiogenic and down-regulation of antiangiogenic genes by MMCs further increases the angiogenic stimulus, together leading to bone marrow angiogenesis at various degrees in all myeloma patients.

Cancer/Testis Genes in Multiple Myeloma: Expression Patterns and Prognosis Value Determined by Microarray Analysis

Cancer-testis (CT) Ags are expressed in testis and malignant tumors but rarely in nongametogenic tissues. Due to this pattern, they represent attractive targets for cancer vaccination approaches. The aims of the present study are: 1) to assess the expression of CT genes on a pangenomic base in multiple myeloma (MM); 2) to assess the prognosis value of CT gene expression; and 3) to provide selection strategies for CT Ags in clinical vaccination trials. We report the expression pattern of CT genes in purified MM cells (MMC) of 64 patients with newly diagnosed MM and12 patients with monoclonal gammopathy of unknown significance, in normal plasma cell and B cell samples, and in 20 MMC lines. Of the 46 CT genes interrogated by the Affymetrix HG-U133 set arrays, 35 are expressed in the MMC of at least one patient. Of these, 25 are located on chromosome X. The expression of six CT genes is associated with a shorter event-free survival. The MMC of 98% of the patients express at least one CT gene, 86% at least two, and 70% at least three CT genes. By using a set of 10 CT genes including KM-HN-1, MAGE-C1, MAGE-A3/6/12, MAGE-A5, MORC, DDX43, SPACA3, SSX-4, GAGE-1–8, and MAGE-C2, a combination of at least three CT genes—desirable for circumventing tumor escape mechanisms—is obtained in the MMC of 67% of the patients. Provided that the immunogenicity of the products of these 10 CT genes is confirmed, gene expression profiling could be useful in identifying which CT Ags could be used to vaccinate a given patient.

Inhibition of aurora kinases for tailored risk-adapted treatment of multiple myeloma

Genetic instability and cellular proliferation have been associated with aurora kinase expression in several cancer entities, including multiple myeloma. Therefore, the expression of aurora-A, -B, and -C was determined by Affymetrix DNA microarrays in 784 samples including 2 independent sets of 233 and 345 CD138-purified myeloma cells from previously untreated patients. Chromosomal aberrations were assessed by comprehensive interphase fluorescence in situ hybridization and proliferation of primary myeloma cells by propidium iodine staining. We found aurora-A and -B to be expressed at varying frequencies in primary myeloma cells of different patient cohorts, but aurora-C in testis cell samples only. Myeloma cell samples with detectable versus absent aurora-A expression show a significantly higher proliferation rate, but neither a higher absolute number of chromosomal aberrations (aneuploidy), nor of subclonal aberrations (chromosomal instability). The clinical aurora kinase inhibitor VX680 induced apoptosis in 20 of 20 myeloma cell lines and 5 of 5 primary myeloma cell samples. Presence of aurora-A expression delineates significantly inferior event-free and overall survival in 2 independent cohorts of patients undergoing high-dose chemotherapy, independent from conventional prognostic factors. Using gene expression profiling, aurora kinase inhibitors as a promising therapeutic option in myeloma can be tailoredly given to patients expressing aurora-A, who in turn have an adverse prognosis.

High-dose melphalan with autologous stem cell transplantation after VAD induction chemotherapy for treatment of amyloid light chain amyloidosis: a single centre prospective phase II study

Amyloid light chain (AL) amyloidosis is the result of a clonal plasma cell expansion, in which monoclonal light chains transform to amyloid deposit in various tissues and can lead to organ dysfunction and organ failure. The median survival of patients with AL amyloidosis without therapy is 10–14 months. With high‐dose melphalan (HDM) and autologous stem cell transplantation (ASCT), haematological and clinical remission rates of up to 50% of treated patients have been reported from phase II studies. HDM followed by ASCT appears to prolong survival in patients, if haematological remission can be reached. In this phase II study, we evaluated vincristine, adriamycin and dexamethasone (VAD) as induction chemotherapy prior to stem cell mobilization and HDM with ASCT. The regimen was, in general, feasible in patients with AL amyloidosis, but VAD chemotherapy had a considerable World Health Organization (WHO) grade III–IV toxicity (25%) and mortality (7%) rate. VAD pretreatment did not interfere with stem cell mobilization and HDM with ASCT was possible in 86% of patients. The overall treatment efficacy was comparable with reported results of HDM and ASCT without preceding chemotherapy. We could not show an additional benefit of VAD induction in terms of increasing haematological response rate; however the 13% mortality rate after HDM and ASCT in our series was lower than the previous report.

Autologous stem cell transplantation for elderly patients with newly diagnosed multiple myeloma in the era of novel agents

BACKGROUND High-dose therapy (HDT) with autologous stem cell transplantation (ASCT) is considered the standard of care for multiple myeloma (MM) patients <65 years. Safety and outcome of ASCT for patients >65 years is currently uncertain, especially since the introduction of novel agents for induction and maintenance therapy. Furthermore, there are no conclusive data available on risk assessment in elderly patients treated with HDT. PATIENTS AND METHODS We retrospectively analyzed 202 patients ≥60 years with newly diagnosed MM who underwent ASCT at our institution. Patients were stratified by age into three groups (60-64, 65-69 and 70-75 years). For safety assessment, we compared data about hospitalization, hematopoetic reconstitution and early mortality. Remission before and after ASCT was analyzed according to age and application of novel agents. Event-free (EFS) and overall survival (OS) were analyzed to identify impact of age, remission before/after ASCT and maintenance therapy as well as ISS score and cytogenetic aberrations on outcome in elderly patients. RESULTS The assessment of safety, remission before/after ASCT as well as EFS and OS showed no significant differences between the three groups (median EFS: 60-64 years: 27 months; 65-69 years: 23 months; 70-75 years: 23 months; median OS: not reached). Patients receiving novel agents as part of induction therapy achieved significantly higher nCR + CR rates than patients treated without novel agents. In Cox regression analysis, ISS and cytogenetics as well as remission after ASCT had the highest prognostic impact on EFS and OS. Maintenance therapy was associated with longer EFS in uni- and multivariate analyses. CONCLUSION ASCT is feasible for selected patients >65 and >70 years without increased mortality. Age at transplantation has no prognostic significance on outcome after ASCT. Novel agents during induction therapy and maintenance therapy improves outcome of older patients eligible for ASCT. ISS and cytogenetic analysis should be carried out routinely for risk assessment.

Lack of CD56 expression on myeloma cells is not a marker for poor prognosis in patients treated by high-dose chemotherapy and is associated with translocation t(11;14).

Lack of CD56 expression was reported to be associated with a poor prognosis in multiple myeloma (MM) patients treated with conventional chemotherapy. Aim of our retrospective study was to analyse whether CD56 expression on MM cells reveals as a prognostic factor in patients treated with high-dose chemotherapy. MM cells of 99 patients prior to treatment with high-dose chemotherapy were analysed for CD56 expression by flow cytometry. Multivariable analysis of event-free survival in these patients showed no statistically significant difference between the CD56− (n=28) and the CD56+ (n=71) group. The lack of CD56 expression on MM cells of these patients correlated significantly with the presence of translocation (11;14) (t(11;14)) (estimated correlation coefficient=0.655 95%, confidence interval (0.481; 0.779)). In summary, our results indicate that lack of CD56 expression on MM cells is not a prognostic marker in patients treated with high-dose chemotherapy, but is associated with t(11;14).

Lenalidomide Enhances Antigen-Specific Activity and Decreases CD45RA Expression of T Cells from Patients with Multiple Myeloma

The aim of this study was to investigate whether the specific T cell response against the multiple myeloma Ag HM1.24 is enhanced by the immunomodulatory drug lenalidomide (Revlimid). Ag-specific CD3+CD8+ T cells against the HM1.24 Ag were expanded in vitro by dendritic cells in 29 healthy donors and 26 patients with plasma cell dyscrasias. Ag-specific activation was analyzed by IFN-γ, granzyme B, and perforin secretion using ELISA, ELISPOT assay, and intracellular staining, and generation of Ag-specific T cells was analyzed by tetramer staining. Expression of T cell maturation markers (CD45RA, CD45R0, CCR7, and CD28) was investigated by flow cytometry. We found that activation of HM1.24-specific T cells from healthy donors and patients with plasma cell dyscrasias was enhanced significantly by lenalidomide and furthermore that the impact of lenalidomide on T cells depends on the duration of the exposure. Notably, lenalidomide supports the downregulation of CD45RA on T cells upon activation, observed in healthy donors and in patients in vitro and also in patients during lenalidomide therapy in vivo. We showed for the first time, to our knowledge, that lenalidomide enhances the Ag-specific activation of T cells and the subsequent downregulation of CD45RA expression of T cells in vitro and in vivo.

Risk stratification in cardiac amyloidosis: novel approaches.

Amyloidosis is a term for diseases with extracellular deposition of insoluble beta-fibrillar proteins in different organs. The heart is primarily involved in more than half of patients with immunoglobulin light-chain amyloidosis or hereditary amyloidosis and associated with poor prognosis. Different traditional diagnostic tools that have been described for risk stratification lack of sufficient sensitivity and specificity for patient survival. Until November 2004 in 50 consecutive patients with light chain amyloidosis and 15 patients with hereditary amyloidosis electrocardiography, echocardiography, Holter monitoring, cardiopulmonary exercise test, lung function testing, tilt-test, and laboratory investigations have been performed at our department. Cardiac amyloidosis was found in 32 patients. Interventricular septum (14.3±0.5 mm vs. 12.3±0.7 mm, P<0.05), plasma NT-proBNP (7154±2122 ng/l vs. 380±113 ng/l; P<0.01), cardiac Troponin T (0.105±0.030 vs. 0.019±0.010 &mgr;g/l; P<0.05) were increased in patients with cardiac amyloidosis as compared to patients light chain amyloidosis but no cardiac involvement. Maximal inspiratory (Pimax) and expiratory (Pemax) mouth pressure were decreased with CA compared to controls. Correlation of NT-proBNP and interventricular septum thickness (r=0.53, P=0.029) as well as and Pimax (r=0.72, P<0.01) or Pemax (r=0.69; P<0.01) was noticed. A correlation of grade of arrhythmias in Holter monitoring and syncopes was not observed.Cardiac involvement of amyloid disease carries a poor prognosis and is not well characterized by classic heart failure determinants. Heart transplantation based on novel risk markers including NT-proBNP might be a suitable therapeutic approach for patients with manifest cardiac amyloidosis, but will require alternative patient selection and listing criteria.

Melan-A/MART1 Analog Peptide Triggers Anti-myeloma T-cells Through Crossreactivity With HM1.24

The Melan-Aaa26–35 (EAAGIGILTV) peptide is a human leukocyte antigen (HLA)-A2-restricted T-cell epitope within the Melan-A/MART-1 tumor antigen expressed on malignant melanoma cells. Melan-A and Melan-A analog (ELAGIGILTV, Melan-Aaa26–35*A27L) specific T-cells can be expanded reliably for immunotherapeutic approaches in vitro. We studied the ability of Melan-A analog (ELAGIGILTV, Melan-Aaa26–35*A27L) specific T-cells to recognize the HM1.24aa22−30 (LLLGIGILV) peptide within the HM1.24 antigen presented by normal and malignant plasma cells. Peripheral blood mononuclear cells from HLA-A2+ healthy donors and HLA-A2+ multiple myeloma (MM) patients were stimulated with Melan-A analog peptide-loaded autologous dendritic cells, and expanded in vitro. T-cell activation was assessed by interferon-γ specific enzyme-linked immunosorbent spot and cytotoxicity by 51Chromium-release-assays. The frequency of Melan-A analog specific CD8+ T-cells was detected by using tetramers. Melan-A analog specific T-cells from HLA-A2+ healthy donors and HLA-A2+ MM patients showed a interferon-γ secretion mediated by HM1.24aa22−30 peptide-pulsed T2 cells and lysed the HLA-A2+ HM1.24+ U266 and XG-1 human myeloma derived cell-lines as well as the B-lymphoblastoid cell-line IM-9. Melan-A analog specific T-cells from MM patients specifically lysed autologous MM cells. The current data demonstrate that Melan-A analog specific T-cells crossreact with HM1.24aa22−30. They might be a tool for the future use in immunotherapy against MM.