The loss of phenol sulfotransferase 1 in hepatocellular carcinogenesis.

Biomarkers for the detection of early hepatocellular carcinoma (HCC) are urgently needed. To identify biomarkers of HCC, we performed a comparative proteomics analysis, based on 2-DE of HCC tissues and surrounding non-tumor tissues. Six xenobiotic enzymes were significantly down-regulated in the HCC tissue. Among these, phenol sulfotransferase (SULT1A1) was confirmed by Western blot analysis in 105 HCC patients. SULT1A1 showed a significant decrease in 98.1% of the HCC tissues, with 88.6% sensitivity and 66.7% specificity for the detection of HCC. Immunohistochemistry for SULT1A1 was performed and compared with glypican-3, which is a well-known marker of HCC. The results showed down-regulation of SULT1A1 and up-regulation of glypican-3 in 52.6 and 71.9% of the HCCs, and the use of both markers improved the sensitivity up to 78.9%. Moreover, SULT1A1 was useful in differentiating early HCC from benign dysplastic nodules. Clinically, the down-regulation of SULT1A1 was closely associated with an advanced International Union Against Cancer stage and high levels of serum alpha-fetoprotein. In conclusion, the results of this study demonstrate that the loss of SULT1A1 appears to be a characteristic molecular signature of HCC. SULT1A1 might be a useful biomarker for the detection of early HCC and help predict the clinical outcome of patients with HCC.