Email updates

Keep up to date with the latest news and content from CCS and BioMed Central.

Open Access Research

Global gene expression changes of in vitro stimulated human transformed germinal centre B cells as surrogate for oncogenic pathway activation in individual aggressive B cell lymphomas

Alexandra Schrader1129*, Katharina Meyer1027, Frederike von Bonin1, Martina Vockerodt113, Neele Walther1, Elisabeth Hand110, Antje Ulrich18, Kamila Matulewicz17, Dido Lenze47, Michael Hummel47, Arnd Kieser5, Michael Engelke6, Lorenz Trümper178 and Dieter Kube11078

Author Affiliations

1 Department of Haematology and Oncology, University Medical Centre Göttingen, Göttingen, Germany

2 Computational Diagnostics Group, Institute for Functional Genomics, University of Regensburg, Regensburg, Germany

3 School of Cancer Sciences, University of Birmingham, Birmingham, UK

4 Institute for Pathology, Campus Benjamin Franklin Charité Berlin, Berlin, Germany

5 Research Unit Gene Vectors, Helmholtz Zentrum München - German Research Center for Environmental Health, München, Germany

6 Department of Cellular and Molecular Immunology, University Medical Centre Göttingen, Göttingen, Germany

7 Network “Molecular Mechanism of Malignant Lymphoma” (MMML) of the Deutsche Krebshilfe, Göttingen, Germany

8 FOR942 of the Deutsche Forschungsgemeinschaft at the University Medical Centre Göttingen, Göttingen, Germany

9 GRK 1034 of the Deutsche Forschungsgemeinschaft, Göttingen, Germany

10 Network HaematoSys, Leipzig, Germany

11 Department of Pediatrics I, University Medical Centre Göttingen, Göttingen, Germany

12 Zentrum für Innere Medizin, Abteilung Hämatologie und Onkologie, Universitätsmedizin der Georg-August-Universität Göttingen, 37099, Göttingen, Germany

For all author emails, please log on.

Cell Communication and Signaling 2012, 10:43  doi:10.1186/1478-811X-10-43

Published: 20 December 2012

Abstract

Background

Aggressive Non-Hodgkin lymphomas (NHL) are a group of lymphomas derived from germinal centre B cells which display a heterogeneous pattern of oncogenic pathway activation. We postulate that specific immune response associated signalling, affecting gene transcription networks, may be associated with the activation of different oncogenic pathways in aggressive Non-Hodgkin lymphomas (NHL).

Methodology

The B cell receptor (BCR), CD40, B-cell activating factor (BAFF)-receptors and Interleukin (IL) 21 receptor and Toll like receptor 4 (TLR4) were stimulated in human transformed germinal centre B cells by treatment with anti IgM F(ab)2-fragments, CD40L, BAFF, IL21 and LPS respectively. The changes in gene expression following the activation of Jak/STAT, NF-кB, MAPK, Ca2+ and PI3K signalling triggered by these stimuli was assessed using microarray analysis. The expression of top 100 genes which had a change in gene expression following stimulation was investigated in gene expression profiles of patients with Aggressive non-Hodgkin Lymphoma (NHL).

Results

    α
IgM stimulation led to the largest number of changes in gene expression, affecting overall 6596 genes. While CD40L stimulation changed the expression of 1194 genes and IL21 stimulation affected 902 genes, only 283 and 129 genes were modulated by lipopolysaccharide or BAFF receptor stimulation, respectively. Interestingly, genes associated with a Burkitt-like phenotype, such as MYC, BCL6 or LEF1, were affected by αIgM. Unique and shared gene expression was delineated. NHL-patients were sorted according to their similarity in the expression of TOP100 affected genes to stimulated transformed germinal centre B cells The αIgM gene module discriminated individual DLBCL in a similar manner to CD40L or IL21 gene modules. DLBCLs with low module activation often carry chromosomal MYC aberrations. DLBCLs with high module activation show strong expression of genes involved in cell-cell communication, immune responses or negative feedback loops. Using chemical inhibitors for selected kinases we show that mitogen activated protein kinase- and phosphoinositide 3 kinase-signalling are dominantly involved in regulating genes included in the αIgM gene module.

Conclusion

We provide an in vitro model system to investigate pathway activation in lymphomas. We defined the extent to which different immune response associated pathways are responsible for differences in gene expression which distinguish individual DLBCL cases. Our results support the view that tonic or constitutively active MAPK/ERK pathways are an important part of oncogenic signalling in NHL. The experimental model can now be applied to study the therapeutic potential of deregulated oncogenic pathways and to develop individual treatment strategies for lymphoma patients.

Keywords:
Gene expression pattern; Lymphoma; Pathway activation