Proteomic Analysis of Canine Hepatobiliary Neuroendocrine Neoplasms

Neuroendocrine neoplasms of the gallbladder and liver occur rarely in dogs and humans. A recent reclassification of human neuroendocrine neoplasms by the World Health Organization has refined categorization of these tumors by morphology, replicative indices, and molecular signatures. In humans, these factors correlate with survival outcomes. Improved characterization of these tumors is needed in dogs to identify diagnostic biomarkers and determine therapeutic strategies. To achieve this objective, the proteome of 3 canine hepatobiliary neoplasms was compared to normal canine adrenal and liver tissue from formalin-fixed paraffin-embedded samples. Thirty-two upregulated and 121 downregulated differentially expressed proteins were identified in the hepatobiliary neuroendocrine neoplasm samples. Among the upregulated proteins is galectin-1, a multivalent carbohydrate binding protein known to play a role in lung and pancreatic neuroendocrine neoplasia development and progression in humans. Drugs targeting the galectin family have shown promise as anticancer therapeutics in cervical cancer, prostate cancer, lung and pancreatic neuroendocrine neoplasia in human medicine. Galectin-1 may represent a novel treatment target in hepatobiliary neuroendocrine neoplasia in both humans and dogs.