Prognostic significance of Beclin 1-dependent apoptotic activity in hepatocellular carcinoma

Abstract

Autophagy is believed to be important in tumorigenesis and tumor progression. However, the role of autophagy in hepatocellular carcinoma (HCC), and especially the prognostic value of autophagic proteins, has not been investigated. Our studies described here show decreased basal expression of autophagic genes and their corresponding autophagic activity under conditions of starvation in HCC cell lines, and the autophagy defect correlated well with the highly malignant phenotype of HCC. In addition, in a tissue microarray study of HCC patients who underwent resection, the expression of the autophagy-related protein Beclin 1 was extremely low in tumors, where Beclin 1 could predict the prognosis of HCC patients only in a Bcl-XL-positive expression background. Based on our results, we propose that autophagy defects that synergize with altered apoptotic activity might facilitate tumor progression and poor prognosis of HCC, due to the fact that autophagy may interact with apoptosis in the regulation of HCC. © 2009 Landes Bioscience.