Comparative analysis of Wnt signaling-related proteins in normal, benign, malignant and metastasised human liver tumors

Background and Aims Liver cancer comprises of benign or malignant tumors including hepatocellular carcinoma (HCC), cholangiocarcinoma (CC), hepatoblastoma (HB), and other rarer tumor types. There is evidence of aberrant Wnt signaling during initiation and progression of HCC, CC and HB. Methods We investigated the expression of Wnt/β-catenin transcription related proteins, Cyclin D1, c-Myc, Fra-1 and Pygo-1, in human liver tumors by using an unbiased, quantitative immunohistochemical (qIHC) approach. Results Semi-automated, unbiased quantitation of individual proteins revealed reduced expression of Cyclin D1 and Pygo-1 in CC (P < 0.0001 and P < 0.01, respectively) and HB (P < 0.05 and P 0.8) that discriminates CC from both NL and HCC (P ≤ 0.0001), and Pygo-1 (AUC > 0.7) as a marker for both CC and HCC (P < 0.01) compared to NL. Combining Cyclin D1/Pygo-1 and applying a logistic regression model further improved the diagnostic potential (classifying 84% of NL and CC cases, P < 0.0001). Quantitative co-localisation of tissue samples simultaneously labeled with the four biomarkers, indicated that co-localisation of both Pygo-1/Fra-1 and c-Myc/Fra-1 was also significantly changed in CC and HCC (P < 0.0001) vs NL. Additionally, co-localisation of Pygo-1/Fra-1, in particular, could also distinguish CC from HCC (P < 0.05). Conclusion Our results indicate that measurement of Wnt signaling markers could be used to stratify liver cancer.