Increased DJ-1 and Its Prognostic Significance in Hepatocellular Carcinoma

Background/aims: To investigate the expression profile of DJ-1 gene and its clinical relevance and prognostic value in hepatocellular carcinoma (HCC).

Methodology: Specimens from 149 HCC patients were applied for DJ-1 expression through immunohistochemistry. The correlation of DJ-1 levels with clinicopathologic variables and prognosis was analyzed. 32 paired HCC and para-carcinomatous liver tissue (PCLT) specimens from 149 HCC patients plus 10 hepatic cirrhosis specimens and 10 normal liver specimens were detected by semi-quantitative polymerase chain reaction (PCR) and Western blot.

Results: DJ-1 was up-regulated significantly in HCC by semi-quantitative PCR and Western blot. DJ-1 expression closely correlated with preoperative AFP, liver cirrhosis, vein invasion, differentiation and Edmondson grade in HCCs by Pearson Chi-square test. Both of tumor-free survival time and overall survival time in the DJ-1 high expression group were shorter than those in the low expression group. DJ-1 was adopted as an independent prognostic factor for overall survival of HCC patients through multivariate Cox proportional hazard model analysis (HR, 2.568; p = 0.003). Additionally, immunohistochemistry analysis revealed that expression of DJ-1 negatively correlated with expression of tumor suppressor gene phosphatase and tensin homolog deleted on chromosome ten (PTEN) in HCC (r = -0.836; p < 0.001).

Conclusions: DJ-1 expression is significantly upregulated in HCC, and its expression level correlates with clinicopathological variables and prognosis of HCC patients, which suggests that DJ-1 maybe a candidate prognostic biomarker of HCC.