Background: Disorders of histiocytic origin affecting humans and dogs share various similarities. Canine disseminated histiocytic sarcoma (DHS) (formerly known as malignant histiocytosis) is an aggressive neoplasm of interstitial dendritic cells (DCs). The receptor for glycation end products (RAGE) and the high mobility group box1 protein (HMGB1) have been shown to be required for the maturation and migration of DCs. Thus, deregulation of the expression of these genes could have a major effect on the progression of histiocytic disorders.
Materials and methods: Neoplastic canine DHS samples and non-neoplastic control samples were analysed immunohistochemically and via real-time PCR.
Results: Significant down-regulation of RAGE in the lung tumour samples and down-regulation of HMGB1 in the lung, lymph node and spleen tumour samples were detected compared to their non-neoplastic counterparts.
Conclusion: RAGE and HMGB1 expression down-regulation in canine DHS points to a role in the progression of histiocytic disorders.