1. ¹State Key Laboratory of Oncology in Southern China, Cancer Center, Sun Yat-Sen University, Guangzhou, China
2. ²Department of Pathology, Cancer Center, Sun Yat-Sen University, Guangzhou, China
3. ³Department of Surgery, The Chinese University of Hong Kong, SAR Hong Kong, China

Correspondence: Dr J-P Yun, Cancer Center, Sun Yat-Sen University, no. 651, East Dongfeng Road, Guangzhou 510060 China. E-mail: yunjp@mail.sysu.edu.cn

⁴These authors contributed equally to this work.

Received 4 October 2006; Revised 28 November 2006; Accepted 28 November 2006; Published online 23 January 2007.

Abstract

Nucleophosmin (NPM, B23, numatrin, NO38) is an abundant nucleolar phosphoprotein involved in multiple cellular functions. Previous evidence indicates that high-level expression of NPM causes uncontrolled cell growth and suggests that NPM may have oncogenic potential. In this study, we examined NPM expression in 103 paired cases of hepatocellular carcinoma (HCC), 12 cases of hepatic focal nodular hyperplasia, 17 cases of liver tissue adjacent to a hepatic haemangioma, and series of array tissues from normal human organs and malignancies using a monoclonal antibody against NPM and reverse transcription–PCR techniques, Western blot analysis, immunohistochemistry, and immunocytofluorescence. Our data indicated that NPM expression was significantly higher in HCC than in the non-malignant hepatocytes (P<0.001). Nucleophosmin was weakly expressed in hepatocytes from a 5-month-old embryo and in stationary hepatocytes of healthy adults. Moreover, enhanced expression of NPM in HCC correlated with the level of PCNA (R²=0.5639) and with the clinical prognostic parameters such as serum alpha fetal protein level, tumour pathological grading, and liver cirrhosis (P<0.05). Our results suggest that NPM may play an important role in the progression of tumorigenesis and that NPM may serve as a potential marker for HCC.