Expression and prognostic role of tumor suppressor gene PTEN/MMAC1/TEP1 in hepatocellular carcinoma.

Abstract

Inactivation of the tumor suppressor gene PTEN/MMAC1/TEP1, located on chromosome 10q23, is a common event in advanced stages of diverse human malignancies. However, the prognostic role of PTEN expression in patients with hepatocellular carcinoma (HCC) has not been characterized. One hundred five resected specimens were collected from patients with HCC. Expression levels of PTEN and p53 in clinical samples were analyzed by immunohistochemistry. Immunohistochemical analysis of 105 HCC tissue specimens revealed that decreased or absence of PTEN immunostaining was found in 43 specimens (40.9%). Reduced PTEN expression levels were correlated with increased tumor grade (P = 0.017), advanced disease stage (P = 0.016), and elevated serum alpha-fetoprotein (alphaFP) levels (P = 0.001). Kaplan-Meier analysis indicated that patients with reduced PTEN levels had shorter overall survival (P = 0.001) and higher recurrence rates (P = 0.0007) compared with patients who had intact PTEN expression. Examining p53 expression unveiled an inverse correlation between p53 overexpression and reduced PTEN expression in patients with HCC (P = 0.004). In addition, patients with p53 overexpression had shorter overall survival compared with patients who were without p53 overexpression (P = 0.0014). Univariate and multivariate analyses revealed that reduced PTEN expression was an independent prognostic factor for survival in patients with HCC. The current study demonstrated that reduced PTEN expression levels are involved in the pathogenesis of HCC. Moreover, decreased PTEN expression was correlated with tumor progression, high alphaFP levels, p53 overexpression, and poor prognosis in patients with HCC.