CDX-2 Protein and mRNA Expression in Canine Intestinal Adenocarcinoma

Caudal-related homeobox transcription factor 2 (CDX-2) is a specific cell marker employed in the diagnosis of human colorectal cancer. Reduced CDX-2 expression is associated with several indicators of poor prognosis in human colorectal cancer. In the present study, CDX-2 protein levels were evaluated and patterns of CDX-2 mRNA accumulation are described for the first time in canine intestinal adenocarcinoma (CIA). Canine intestinal epithelial biopsies from 21 CIAs and 14 non-neoplastic control tissues were retrospectively evaluated for CDX-2 expression and CDX-2 mRNA levels by immunohistochemistry and RNA in-situ hybridization (RNA-ISH), respectively. The mean percentage or intensity of expression was decreased in the CIA group (P = 0.000). RNA-ISH demonstrated a significant correlation between the decrease in CDX-2 mRNA levels and CDX-2 protein expression (P = 0.000). CDX-2 downregulation, in terms of protein as well as mRNA levels, may serve as a diagnostic marker in CIA.