Recent Progress of Wnt Pathway Inhibitor Dickkopf-1 in Liver Cancer.

Hepatocellular carcinoma (HCC) is one of the most common cancers around the world. Multiple etiologic factors such as virus and environment can lead to HCC. It is a challenge for us to successfully detect early HCC due to the lack of effective characterized and specific biomarkers. However, if the early diagnosis is successfully realized, it provides crucial chance for HCC patients to receive effective treatment as early as possible. Dickkopf-1 (DKK-1) is a secretary glycoprotein, which negatively regulates Wnt pathway through binding to surface receptors LRP5/6 and Kremen 1/2. The expression of DKK-1 is regulated by p53, V-Myc avian myelocytomatosis viral oncogene neuroblastoma derived homolog (MYCN), beta-catenin, etc. Ectopic expression of DKK-1 can inhibit cell proliferation, or induce apoptosis with apoptosis enhancing factors. DKK-1 is low-expressed in many tumors, but overexpressed in others. Growing evidences show that DKK-1 plays complex and different roles in tumorigenesis, tumor progression and metastasis of different cancers. We herein review the recent progress in the expression and function of DKK-1 in hepatocellular carcinoma.