Down-regulation of retinol binding protein 5 is associated with aggressive tumor features in hepatocellular carcinoma

Abstract

Purpose: Acyclic retinoid (ACR) has been shown to be a promising chemopreventive agent for hepatocellular carcinoma (HCC) after curative resection. The effects of retinoid are mediated by retinol-binding proteins (RBPs) through regulating cell proliferation and differentiation. Patients and methods: This study investigated the clinical significance of RBP5 in HCC. RBP5 mRNA level was examined by real-time quantitative PCR on 52 matched tumor and adjacent non-tumor liver tissues, and on ten normal livers. Expression of RBP5 protein was examined using Western blotting analysis and immunohistochemistry. Results: Down-regulation of RBP5 was found in HCC tissues at both mRNA and protein levels. Decreased RBP5 level was closely related to poor differentiation (P = 0.02) and large tumor size (P = 0.01). Low level of RPB5 was associated with poor overall survival (P = 0.02), and was an independent prognostic factor for HCC. Conclusions: Our study revealed that RBP5 down-regulation in HCC was associated with aggressive tumor features, suggesting an important role of RPB5 in HCC progression. © 2007 Springer-Verlag.