Cripto-1 promotes tumor invasion and predicts poor outcomes in hepatocellular carcinoma

Cripto-1 (CR1), an oncofetal protein, had been implied to reactivate in some cancers. However, the relationship between CR1 expression and patient outcomes and the tumor biological function of CR1 contributing to invasion and metastasis in hepatocellular carcinoma (HCC) is poorly defined. In this study, we demonstrated that CR1 was expressed in over 80% of HCCs in a training cohort (n = 242) and a validation cohort (n = 159). High CR1 expression was significantly correlated with aggressive HCC phenotypes (i.e. portal vein tumor thrombus, microscopic vascular invasion, multiple tumors and poor tumor differentiation). In both the training and validation cohorts, patients with high CR1 expression had remarkably shorter disease-free survival and overall survival rates than those with low CR1 expression. A series in vitro and in vivo assays showed that CR1 substantially promoted HCC cell migration, invasion and metastasis. Mechanistically, we demonstrated that CR1 induced HCC cells to undergo epithelial-mesenchymal transition through activating the Akt/NF kappa B/p65 signaling. Chromatin immunoprecipitation assay showed that NF kappa B/p65 enhanced CR1 expression by binding its promoter. Thus, CR1 and NF kappa B/p65 form a positive feedback loop that sustained the process of migration and invasion of HCC. Therefore, CR1 plays an important role in HCC invasion and metastasis and may be an effective and reliable prognostic biomarker for HCC recurrence after resection. Targeting CR1 may be a promising treatment for HCC.