Canine Cutaneous Peripheral Nerve Sheath Tumours versus Fibrosarcomas can be Differentiated by Neuroectodermal Marker Genes in their Transcriptome.. Canis lupus familiaris

The diagnostic differentiation of canine fibrosarcomas and peripheral nerve sheath tumors (PNST) is mainly based on their histopathologic phenotype. Histologic differentiation of these tumors can, however, be difficult and there is a lack of immunohistochemical markers to prove their histogenic origin. To identify possible PNST markers and to further investigate the histogenic origin of the two tumor types, we compared histologically defined canine fibrosarcomas and peripheral nerve sheath tumors by microarray analysis. Forty-five annotated gene products were significantly differentially expressed in both tumor types. Seven of these gene products, known to be specifically expressed in neuroectodermal tissues, showed higher expression in peripheral nerve sheath tumors: FMN2, KIF1B, GLI1, ROBO1, NMUR2, DOK4 and HMG20B. Furthermore, eight genes associated with carcinogenesis were up-regulated in fibrosarcomas: FHL2, PLAGL1, FNBP1L, BAG2, HK1, CSK and Cox5A. Comparison of the fibrosarcoma and PNST transcriptome therefore identified PNST phenotype-associated genes involved in neuroectodermal differentiation which may be potential PNST markers. Furthermore, the identified fibrosarcoma phenotype-associated genes may be potential markers to differentiate fibrosarcomas from other tumor types and may be involved in their pathogenesis. Overall design: The aim of the present study was to examine the differences in global gene expression of histologically prototypic fibrosarcomas and PNST. To this end, complete transcriptome microarray analyses were used to quantify differences in gene expression activity in both tumor types.