Comparative Gene Expression Profiling Identifies Common Molecular Signatures of NF-κB Activation in Canine and Human Diffuse Large B Cell Lymphoma (DLBCL)

Manikhandan A V Mudaliar,Daniel Crowther,Gino Miele,Ilene Kurzman,John R Goodlad,Karen A L Tan,Grant Sellar,Ross D Haggart,David M Vail,David J Argyle,Elspeth Milne

doi:10.1371/journal.pone.0072591

Abstract

We present the first comparison of global transcriptional changes in canine and human diffuse large B-cell lymphoma (DLBCL), with particular reference to the nuclear factor-kappa B (NF-κB) pathway. Microarray data generated from canine DLBCL and normal lymph nodes were used for differential expression, co-expression and pathway analyses, and compared with analysis of microarray data from human healthy and DLBCL lymph nodes. The comparisons at gene level were performed by mapping the probesets in canine microarrays to orthologous genes in humans and vice versa. A considerable number of differentially expressed genes between canine lymphoma and healthy lymph node samples were also found differentially expressed between human DLBCL and healthy lymph node samples. Principal component analysis using a literature-derived NF-κB target gene set mapped to orthologous canine array probesets and human array probesets clearly separated the healthy and cancer samples in both datasets. The analysis demonstrated that for both human and canine DLBCL there is activation of the NF-κB/p65 canonical pathway, indicating that canine lymphoma could be used as a model to study NF-κB-targeted therapeutics for human lymphoma. To validate this, tissue arrays were generated for canine and human NHL and immunohistochemistry was employed to assess NF-κB activation status. In addition, human and canine B-cell lymphoma lines were assessed for NF-κB activity and the effects of NF-κB inhibition.

Highlights

The use of engineered murine cancer models in cancer drug research and development has been criticized as being inadequate for reflecting spontaneous cancers in humans with respect to latency, genomic instability, heterogeneity, cancer recurrence and metastasis1
The three dimensional principal component analysis (PCA) plot, using the first three principal components that captured over 38% of the variance in the dataset showed two distinct clusters: all the 45 diffuse large B-cell lymphoma (DLBCL) samples in one cluster and all the 10 healthy samples in another cluster (Figure 1)
As we looked for differential expression of nuclear factor-kappa B (NF-kB) target genes in the human data, we compared the 4388 differentially expressed probesets against the NF-kB target 259 probesets and found 101 NF-kB target probesets corresponding to 54 genes in the differentially expressed probesets (Table 3 Figure 4)

Summary

Introduction

The use of engineered murine cancer models in cancer drug research and development has been criticized as being inadequate for reflecting spontaneous cancers in humans with respect to latency, genomic instability, heterogeneity, cancer recurrence and metastasis. There has been increasing evidence that spontaneous cancers in dogs could provide model systems to support human cancer drug development [1]. The genetic diversity, phenotypic heterogeneity, anatomical and physiological similarities with humans, large body size, common living environment and sufficient life span supports the dog as a model system for human oncology. Coupled with the high incidence of cancer in this species [2,3,4,5], there is an ideal opportunity to utilize this model of disease

Methods

Results

Discussion

Conclusion