Background: Physiological angiogenesis occurs during liver regeneration, leading to the formation of new functional sinusoids. Pathological angiogenesis occurs in hepatocellular carcinoma (HCC). We aimed to evaluate the expression of angiogenic factors in hepatitis C virus (HCV)-HCC tissues and the utility of angiogenesis soluble factors as noninvasive markers of HCC and tumor growth.

Methods: Thirty-eight HCV-HCC tumors with 10 corresponding nontumor cirrhotic tissues, as well as 42 independent HCV cirrhotic and 6 normal liver tissues were studied using high-density oligonucleotide arrays. Human angiogenesis microarray was used for the protein detection of EGF, TIMP-1, TIMP-2, HGF, angiopn-1, angiopn-2, VEGF-A, IP-10, PDGF, KGF, angiogenin, VEGF-D, ICAM-1, and FGF in plasma samples from 40 patients (30 HCCs and 10 HCV cirrhosis).

Results: From the gene expression analysis of the HCV-HCC tumors compared to normal livers, we found an important number of genes related to angiogenesis differentially expressed (alpha=0.01), including VEGF, PDGF, AGPTL2, ANG, EGFL6, EGFR, angiopn-1, angiopn-2, ICAM2, TIMP-2, among others. Moreover, angiogenic genes were also differentially expressed when HCV-HCC samples were compared to HCV cirrhotic tissues (alpha=0.01; VEGF, EGFL3, EGFR, VEGFB, among others). Ten out of 14 angiogenic proteins analyzed were statistically differentially expressed between HCV cirrhosis and HCV-HCC groups (TIMP-1, TIMP-2, HGF, angiopn-1, angiopn-2, VEGF-A, IP-10, PDGF, KGF, and FGF; P<0.05). In addition, we observed that angiopn-2 was the most significant predictor (area under the curve: 0.83).

Conclusion: Differentially expressed angiogenesis genes were observed between HCV patients with and without HCC. Soluble angiogenic factors might be useful for monitoring high-risk HCV patients.