Serum CD166: a novel hepatocellular carcinoma tumor marker.

Background: We evaluated the diagnostic value of serum-CD166 in patients with hepatocellular carcinoma (HCC).

Methods: Tissue-CD166 was measured using immunohistochemistry. Cell proliferation and migration were evaluated using MTT and Transwell assays, respectively. Serum-CD166 was examined using ELISA and western blotting.

Results: CD166 was up-regulated in HCC compared to those in normal liver tissues. Cell proliferation was positively correlated and cell migration was negatively correlated with endogenous CD166 expression in HCC cells. CD166 inhibition using specific shRNA decreased cell proliferation but increased cell migration. Serum CD166 concentrations were much higher in HCC than in colon cancer, hepatitis B, hepatitis C, cirrhosis, gastric cancer, breast cancer, lung cancer and healthy individuals. Serum CD166 also decreased dramatically after curative surgery. A positive correlation was found between serum CD166 and AFP (R=0.7141, p=0.000). Serum CD166 was also positively correlated with γ-GT, bile acid, ALT, AST, and ALP but was negatively correlated with Alb and pre-Alb. The area under the receiver operating characteristic curve for serum-CD166 was 0.9860, which was better than AFP (AUC-ROC, 0.9354) for the differentiation of HCC patients from healthy individuals, with a cut-off of 261 ng/ml (sensitivity: 100.00%, specificity: 89.41%).

Conclusion: Serum CD166 is a novel diagnostic tumor marker for HCC.