ABSTRACT
<p><b>OBJECTIVE</b>To detect the expression of Nodal in hepatocellular carcinoma (HCC), and explore its relationship with angiogenesis and epithelial-mesenchymal transition (EMT).</p><p><b>METHODS</b>From September 2006 to June 2010, the 16 self-paired frozen HCC specimens were collected and the expression of Nodal was detected by qPCR and Western blot. The 10 normal liver tissues and 96 cases of HCC tumor and paracarcinomatous tissues were collected. The expression of Nodal and relationship among Nodal, clinicopathological characteristics of HCC and patients' prognosis were detected and analyzed using immunohistochemistry. The expressions of Nodal, Vimentin and CD34 in 96 HCC tumor tissues were detected by immunohistochemistry, and then judgment relationship between the expression of Nodal, EMT and angiogenesis.</p><p><b>RESULTS</b>Immunohistochemistry showed that Nodal mainly expressed in the cytoplasm. The high expression rate of Nodal in HCC tumor tissues was 72.9% (70/96), which was remarkably higher than that in paracarcinomatous tissues (8.3%) and normal liver tissues (0) (χ(2) = 83.001 and 24.470, both P < 0.001). qPCR and Western blot analysis showed that the expression level of Nodal in HCC was significantly higher than that in paracarcinomatous and normal tissues (P < 0.05). The high expression of Nodal in HCC was correlated with tumor size (χ(2) = 15.318, P = 0.000), alpha-fetoprotein (χ(2) = 3.850, P = 0.049), indocyanine green retention rate at 15 minutes (χ(2) = 6.590, P = 0.010), and invasion and metastasis (χ(2) = 17.824, P = 0.000). High expression of Nodal was positively correlated with high microvascular density in HCC (t = 3.070, P = 0.006), but not with Vimentin (r = 0.198, P = 0.053). Survival analysis showed that accumulated survival rate of patients with high expression of Nodal was significantly less than that the low expression (χ(2) = 487.053, P < 0.001). The Cox multivariate analysis demonstrated that high expression of Nodal was independent risk factors for cumulative survival in patients with hepatocellular carcinoma after a curative resection (RR = 2.757, 95%CI: 1.450-5.240, P = 0.002).</p><p><b>CONCLUSIONS</b>Nodal does not participate in EMT of HCC, but can promote angiogenesis, and it could be used as a predictor of poor prognosis.</p>