Novel endothelial cell markers in hepatocellular carcinoma

Abstract

Hepatocellular carcinoma is characterized by hypervascularity and a propensity for vascular invasion. Detailed analysis of complementary DNA (cDNA) microarray global gene expression data and further validation on a smaller independent sample set by reverse transcription-polymerase chain reaction established the presence of two endothelial gene clusters in hepatocellular carcinoma. Cluster I, consists of 20 cDNA clones, representing 15 unique genes. Cluster II consists of nine unique genes. The expression of the cluster I genes appeared to be significantly upregulated in hepatocellular carcinoma compared with normal liver, cirrhotic liver, or nontumor liver tissues adjacent to the hepatocellular carcinoma. The pattern of gene expression of cluster I genes correlated positively with the 'proliferation gene cluster' and 'stromal cells cluster 2'. Expression of cluster II genes, in contrast, was not significantly different between hepatocellular carcinoma and non-neoplastic liver tissues. Studies conducted to localize the protein products of these genes by immunohistochemical staining of tissue arrays with up to 350 cores of tissues, and by in situ hybridization led to the discovery of novel sinusoidal endothelial cell markers in hepatocellular carcinoma: podocalyxin-like and regulator of G protein signaling-5. Our results underscore fundamental differences not only between neoplastic vs non-neoplastic liver cells but also between the hepatic sinusoidal endothelium of hepatocellular carcinoma and normal liver.

Hedgehog signaling in human hepatocellular carcinoma

“…Immunohistochemical staining was performed on liver tissue sections using DAKO envision plus kit (DakoCytomation, Carpinteria, CA) as described previously. 42 Cell proliferation assays. To test for cyclopamine responsiveness, HCC cell lines were grown for five days in control medium or medium containing DMSO/ethanol (50:50, v/v), or containing tomatidine (10 µM), or containing cyclopamine (10 µM).…”

Sprouty 2, an Inhibitor of Mitogen-Activated Protein Kinase Signaling, Is Down-Regulated in Hepatocellular Carcinoma

“…The hybridization probes for Spry2 were prepared as previously described (22) and used in nonradioactive in situ hybridization as detailed in Chen et al (28). Arrays were scored using a four-tier scale: 0, negative; 1, insufficient or equivocal; 2, weak staining; 3, strong staining.…”

Regulator of G‑protein signaling 5 enhances portal vein invasion in hepatocellular carcinoma

“…Integrins are a family of transmembrane receptors and SPP1 is a ligand of integrin α V β 3 , which is a combination of integrin subunit α V and β 3 . RGS5 has been reported to be a marker of cancer-associated endothelial cells (15) and is an endothelial cell marker that is highly expressed in HCC (16). Therefore, ITGB3, SPP1, RGS5, MT1 G and MT1H were focused on by the present study.…”

“…Silini et al (15) reported higher levels of RGS5 mRNA in endothelial cells isolated from carcinomas, primarily ovarian carcinomas, compared with endothelial cells isolated from non-neoplastic tissue. In a study of hepatic tissue, Chen et al (16) used ISH to demonstrate that RGS5 was not expressed in sinusoidal endothelial cells in non-tumor liver tissues, detected RGS5 mRNA in the sinusoidal endothelial cells in the HCC samples. The present study used immunohistochemical staining to reveal that RGS5 was expressed in the cytoplasm of HCC cells.…”