Decorin gene expression in normal and tumor liver tissue

Abstract

Decorin, a small leucine ‐ rich proteoglycan is involved in a number of cellular processes. Decorin has been shown to suppress proliferation of cancer cells in vitro. Decorin interacts with a number of receptor tyrosine kinases like Met, and Epidermal Growth Factor Receptor. In view of the role of Decorin as a negative regulator of Met and EGFR, we decided to investigate whether Decorin played a role in hepatocyte proliferation, both in vitro and in vivo. Initially we investigated the effects of Decorin on induction of DNA synthesis by HGF and EGF in primary cultures of rat hepatocytes. Addition of Decorin in the culture medium resulted in more than 50% inhibition of DNA synthesis. Decorin gene expression was also found to be regulated during the early stages of liver regeneration in rats following a PHx. Decorin gene expression was found to be suppressed in Liver tissue samples obtained from HCC, Adjacent tissue, Normal and hepatoma cases by microarray analysis. We also investigated Decorin expression by RT‐PCR and western blot analysis in a number of transformed cell lines like HepG3, Hep3b and HuH7, JM1 and JM2. Decorin expression could not be detected by RT‐PCR and western blot analysis in these cell lines. In conclusion, preliminary data indicated that Decorin expression, following a PHx, is significantly suppressed during early phases of liver regeneration and Decorin has a modulating role in hepatocyte proliferation.