Objective To investigate the expression profiles and their clinical significance of TRAIL receptors (TRAILR) in human hepatocellular carcinoma (HCC). Methods The expression profiles of TRAILR were determined in 60 samples from hepatocellular carcinoma, 20 from normal liver tissue and two HCC cell lines HepG2, SMMC-7721 by in situ hybridization. Results Both DR4 and DR5 were present in all HCC tissues as well as normal hepatic tissues. In contrast, 54 HCC tissues did not express DcR1 and 25 did not express DcR2. But both DcR were detectable in all of the normal liver tissues. The expression patterns of DR and DcR in HCC samples (higher DR expression level and lower DcR expression level) were quite different from those in normal tissue. DR5, DR4, and DcR2 expressed in both cell lines, while no DcR1 expression was detected. The expression level of DR was correlated with HCC differentiation and stage. The weaker expression was more commonly found in HCC with poor differentiation and late stage, while the stronger expression was more common in HCC with middle to high-differentiation and early stage. No relationship was found between DR and gender, age, negative or positive HBsAg, tumor size, grade or metastasis. Multidrug resistance cell lines expressed lower level DR. Conclusion TRAILR expression was prevalent and discrepancy of receptor types was exited in HCC. Loss of DcR1 may contribute for TRAIL therapy for HCC. Key words TRAILR - apoptosis - hepatocellular carcinoma Supported by the Major Fundation of Ministry of Health, NO. 2001–2003
