Increased Expression of Wiskott-Aldrich Syndrome Protein Family Verprolin-Homologous Protein 2 Correlated with Poor Prognosis of Hepatocellular Carcinoma

Abstract

Because of its role in cell migration, the Wiskott-Aldrich syndrome protein family verprolin-homologous protein (WAVE) 2 has been implicated in cancer metastasis. Evidence to support such a role of WAVE2 in human cancer, however, is lacking. We thus examined the expression of WAVE2 in hepatocellular carcinoma (HCC) tissues to test whether the levels of WAVE2 expression correlated to the progression of HCC. Samples of 112 HCC patients were determined immunohistochemically for WAVE2 expression and the correlation of WAVE2 levels with prognosis was analyzed. Among the 112 cases, 31 paired HCC and paracarcinomatous liver tissue specimens were analyzed for WAVE2 levels by reverse transcription-PCR and Western blotting, respectively. Among 112 cases of HCCs, the immunohistochemistry data indicated significant increase of WAVE2 expression levels in 71 cases. Importantly, the increased WAVE2 expression correlated with the multiple tumor nodules (P = 0.008), the absence of capsular formation (P = 0.035), Edmondson-Steiner grade (P = 0.009), vein invasion (P = 0.023), and a shortened median survival time (326 versus 512 days; P = 0.003). Multivariable Cox regression analysis revealed the WAVE2 expression level was an independent factor for prognosis. The immunohistochemistry data were further confirmed by results of reverse transcription-PCR and Western analysis of 31 HCC cases, in which the WAVE2 mRNA and protein in HCC tissues were significantly elevated when compared with paracarcinomatous liver tissue (P < 0.001). WAVE2 expression is elevated in HCC tissues, which correlates with a poor prognosis, suggesting WAVE2 as a candidate prognostic marker of HCC.