Up-regulation of Twist induces angiogenesis and correlates with metastasis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a highly invasive tumor characterized by vigorous neovascularization. The purpose of this study is to examine the expression of Twist, a highly conserved bHLH transcription factor that is known to promote EMT, and evaluate its effect on tumor angiogenesis and metastasis of HCC. The mRNA expression of Twist, VEGF, E-cadherin, and N-cadherin was determined by Real-Time RT-PCR in 30 pairs of hepatocellular carcinomas and matched non-cancerous tissues. Immunohistochemistry was carried out to analyze the protein expression of Twist, VEGF, E-cadherin, and N-cadherin in 40 hepatocellular carcinoma cases. The staining of endothelial cells for CD34 was used to evaluate the MVD. We found that Twist mRNA and protein were both increased in HCC as compared to non-cancerous tissues. The HCC specimens showing positive Twist expression had a higher microvessel density than those without Twist expression. And up-regulated Twist protein was significantly associated with intrahepatic and extrahepatic metastasis (p=0.048 and P=0.039 respectively). In addition, patients with Twist expression had poor prognosis. We also found that the expression of Twist positively correlated with up-regulation of VEGF and N-cadherin (P=0.002 and p=0.016 respectively), but not with downregulation of E-cadherin in HCC. Our results demonstrate that Twist may play an important role in the angiogenesis and metastasis of HCC. Twist expression may become a potential novel prognostic factor for the disease survival of HCC.