Gradual upregulation of OCI-5 expression during occurrence and progression of rat hepatocellular carcinoma.

BACKGROUND: OCI-5, the rat homologene of human glypican 3 (GPC3), is confirmed upregulated in hepatocellular carcinoma (HCC). The present study was undertaken to detect gene expression change of OCI-5 during occurrence and progression of rat HCC. METHODS: Male Sprague-Dawley rats were given diethylnitrosamine (DENA) to induce HCC. Three DENA-induced rats and one control rat were sacrificed every week for 18 weeks during the development of HCC. Tissues specimens were snap-frozen in liquid nitrogen and total RNA was isolated. Sk-Hep1 cells were treated with DENA at different concentrations. The gene expression levels of OCI-5 and GPC3 were detected with the RT-PCR method. RESULTS: OCI-5 was not expressed in normal rat liver tissues. When HCC occurred and aggravated, OCI-5 expression was gradually elevated to a very high level. GPC3 was not expressed in the DENA-treated Sk-Hep1 cells. CONCLUSIONS: OCI-5 was not expressed in normal rat liver tissues but in rat HCC tissues. High-expression of OCI-5 in DENA-induced rat HCC model was the gene expression change of HCC not the DENA-induced gene expression. The expression level of OCI-5 was not only elevated in rat HCC but also gradually along the occurrence and progression of HCC, indicating that GPC3 might serve as a sensitive marker of early stage HCC.