Sub theme 2.1.4
Identification of diagnostic and therapeutic targets and therapeutic development

Goals of research: general outline
Scientific achievements
Future plans: special goals and approach
Running projects
Associated staff

Goals of research: general outline
Within this theme we link the identification of the molecular mechanisms in the development of hematopoietic neoplasm (in retroviral models and high througput analysis of clinical samples) to developmental diagnostics and therapeutics and we evaluate and implement clinical investigational procedures. This program focusses mainly on myeloid leukemias and myeloma.

Scientific achievements
  • Generation and analyses of expression profiles of >550 de novo AMLs.
  • Identification of a novel AML subtype with a unique gene expression signature, CEBPA hypermethylation and a mixed myeloid/T-lymphoid phenotype.
  • We demonstrated double mutations in CEBPA-double (Biallelic) as a marker for favourable prognosis, in contrast to AML patients with a single mutation in CEBPA.
  • A diagnostic assay detecting multiple EVI1 splice variants was developed to determine the relative EVI1 expression by a single real-time quantitative PCR. EVI1 expression in AML is unequally distributed in cytogenetic subtypes. It predicts poor outcome, particularly among intermediate cytogenetic risk AML. Patients with EVI1+ AML seem to benefit from allogeneic transplantation in first CR. Pretreatment EVI1 screening has now been included as a standard assay in protocolysed AML studies.
  • We have now established an extensive analysis of 750 patients treated in prospective trials in Multiple Myeloma for the role of genomic SNPs in disease outcome and treatment effects, using a custom build Affymetrix platform. Significant associations have been established of Bortezomib and Thalidomide with typical toxicities such as polyneuropathy. These are now subject to bioinformatics analysis for classifier determination. 

Future plans: special goals and approach
  • By means of high throughput sequencing, gene array analysis and real-time PCR we will continue the study in a large cohort of AML (± 600 cases) the involvement of novel “leukaemia disease” genes identified by retroviral insertional mutagenesis. Novel disease genes based on the mouse and primary AML screen and, which predict unique pathways and mechanisms of transformation, will be selected for further study. Inducible in vitro and in vivo models will be applied to unravel the exact mechanism of transformation by the distinct transforming genes that have been or will be identified. 
  • New assays will be developed (e.g. EVI1 expression and CEBPA-mutation) and applied on a routine basis in AML clinical studies.
  • To assess the clinical significance (prognostic) of findings from high throughput expression profiling and mutational analyses and implement these in clinical molecular diagnostics, and identify targets for treatment intervention
  • Integration of high throughput approaches, next generation sequencing, gene expression profiling, microRNA profiling, DNA methylation profiling and histone profiling to further dissect the molecular en clinical heterogeneity of AML
  • Through the European Myeloma Network (EU-FW6 program) we have organized standardization for GEP and SNP. We have access  to patient samples from HOVON and international trials in exchange programs.  We will perform a combined analysis of GEP with LOH in a large patient cohort using standardized diagnostic work-up procedures, on which the development of a BioChip can be based.
  • The department of hematology coordinates the development of a nation-wide biobank for hematological malignancies (“Parelsnoer”).

Most recent publications
  1. Bas Wouters and Ruud Delwel: CEBPA promoter hypermethylation in a subset of myeloid/T-lymphoid leukemias with a distinct gene expression profile Blood, Feb 2009; 113: 1866.
  2. Bas J. Wouters, Bob Lowenberg, Claudia A.J. Erpelinck-Verschueren, Wim L.J. van Putten, Peter J.M. Valk, and Ruud Delwel: Double CEBPA mutations, but not single CEBPA mutations, define a subgroup of acute myeloid leukemia with a distinctive gene expression profile that is uniquely associated with a favorable outcome. Blood, Mar 2009; 113: 3088 - 3091.
  3. Bas Wouters, Bob Lowenberg and Ruud Delwel: A decade of genome-wide gene expression profiling in ac ute myeloid leukemia: flashback and prospects. Blood. 2009 Jan 8;113(2):291-8
  4. Sanne Lugthart, Antoinette van Hooven-Bijen, Bob Lowenberg, Peter Valk and Ruud Delwel:  High EVI1 levels predict adverse outcome in acute myeloid leukemia: prevalence of EVI1 overexpression and chromosome 3q26 abnormalities underestimated. Blood 2008 111: 4329-4337
  5. Breems DA, Van Putten WL, De Greef GE, Van Zelderen-Bhola SL, Gerssen-Schoorl KB, Mellink CH, Nieuwint A, Jotterand M, Hagemeijer A, Beverloo HB, Löwenberg B. Monosomal karyotype in acute myeloid leukemia: a better indicator of poor prognosis than a complex karyotype. J Clin Oncol. 2008 Oct 10;26(29):4791-7.
  6. Jongen-Lavrencic M, Sun SM, Dijkstra MK, Valk PJ, Löwenberg B. MicroRNA expression profiling in relation to the genetic heterogeneity of acute myeloid leukemia. Blood. 2008 May 15;111(10):5078-85.
  7. Löwenberg B. Diagnosis and prognosis in acute myeloid leukemia--the art of distinction. N Engl J Med. 2008 May 1;358(18):1960-2.
  8. Johnson DC, Corthals S, Ramos C, Hoering A, Cocks K, Dickens NJ, Haessler J, Goldschmidt H, Child JA, Bell SE, Jackson G, Baris D, Rajkumar SV, Davies FE, Durie BG, Crowley J, Sonneveld P, Van Ness B, Morgan GJ. Genetic associations with thalidomide mediated venous thrombotic events in myeloma identified using targeted genotyping. Blood. 2008 Dec 15;112(13):4924-34.
  9. Meijer E, Sonneveld P.Hematology: Lenalidomide plus dexamethasone is effective in multiple myeloma. Nat Rev Clin Oncol. 2009 May;6(5):247-8.
  10. B. Lowenberg, GJ Ossenkoppele, W. van Putten et al.  High-Dose Daunorubicin in Patients with Acute Myeloid Leukemia Older Than 60 years of Age, NEJM, september 24 2009, in press.