Characteristics of extracellular cyclic AMP-dependent protein kinase as a biomarker of cancer in dogs

Objective: Early and proper diagnosis of cancer is the most critical factor for the survival and treatment of veterinary cancer patients. In this study, we evaluated extracellular cyclic AMP-dependent protein kinase A (ECPKA) level in serum as a useful cancer biomarker in dogs. Methods: ECPKA levels were detected in sera from dogs with cancers (n = 48), benign tumours (n = 18), and non-tumour diseases (n = 102) as well as healthy control dogs (n = 54) utilizing enzyme-linked immunosorbent assay (ELISA). Results: Sera from dogs bearing various types of cancer exhibited markedly increased levels of ECPKA by up to 7.1-, 8.8-, and 10.9-fold compared with those from dogs harbouring benign tumours, dogs with non-tumour diseases, and healthy control dogs, respectively (P <.0001). In addition, serum ECPKA level did not show statistically significant correlation with gender, breed, or age of dogs or their non-cancerous disease conditions. Conclusion: Our data strongly propose that detection of serum ECPKA level is a potential and specific diagnostic tool for cancer in dogs.