Microarray Analysis of Differentially Expressed Genes of Primary Tumors in the Canine Central Nervous System

Abstract

Abstract. The pathophysiologic similarities of many human and canine cancers support the role of the domestic dog as a model for brain tumor research. Here we report the construction of a custom canine brainspecific cDNA microarray and the analysis of gene expression patterns of several different types of canine brain tumor. The microarray contained 4000 clones from a canine brain specific cDNA library including 2161 clones that matched known genes or expressed sequence tags (ESTs) and 25 cancer-related genes. Our study included 16 brain tumors (seven meningiomas, five glial tumors, two ependymomas, and two choroid plexus papillomas) from a variety of different dog breeds. We identified several genes previously found to be differentially expressed in human brain tumors. This suggests that human and canine brain tumors share a common pathogenesis. In addition, we also found differentially expressed genes unique to either meningiomas or the glial tumors. This report represents the first global gene expression analysis of different types of canine brain tumors by cDNA microarrays and might aid in the identification of potential candidate genes involved in tumor formation and progression.

Characterization of Gene Expression Profiles of Normal Canine Retina and Brain Using a Retinal cDNA Microarray

“…Compared to the total number of genes with preferential expression, we found higher frequencies of proliferation and cell death genes expressed in the brain than retina, and nucleic acid processing genes in retina than brain. Among the transcripts preferentially expressed in the brain were many known and unknown genes not previously reported to have a preferential expression pattern in different regions of the brain [5,29]. We demonstrated also that expression patterns are quite restricted to individual cortex areas, as few differential expressed genes showed overlap between the examined brain regions (Figure 2).…”

Advances in Diagnostic and Treatment Modalities for Intracranial Tumors

“…Overexpression of surface markers previously defined in human tumors, suitable for tumor targeting strategies, has been demonstrated for IL‐13RA2, EphA2, and alpha3‐beta1 integrin in a variety of canine brain tumors (Fig 4). 127, 128, 129, 130 To date, global expression studies have utilized relatively limited microarray platforms and have shown some similarities to differentially expressed genes found in human tumors 131. At the epigenetic level, preliminary studies profiling genome‐wide methylation status of canine glioma suggest that hypermethylation patterns in developmentally regulated genes may be similar to those in human gliomas 132…”

Faithful Companions: A Proposal for Neurooncology Trials in Pet Dogs

“…For example, canine glioblastomas show immunoreactivity for glial fibrillary acidic protein (11)(12)(13), and epidermal growth factor receptor and vascular endothelial growth factor overexpression has been observed in canine astrocytic tumors, as has p53 deregulation (11,13). Finally, microarray analysis indicates similar patterns of differentially expressed genes in canine and human brain tumors (14). Chemo-and radiosensitivity similarities are less well documented.…”