Received: 07.08.2008 Accepted: 12.10.2008 J Gastrointestin Liver Dis December 2008 Vol.17 No 4, 411-417 Address for correspondence: Cezar Stroescu, MD Fundeni Clinical Institute Sos. Fundeni no 258 Bucharest, Romania Email: cezar.stroescu@gmail.com Expression of p53, Bcl-2, VEGF, Ki67 and PCNA and Prognostic Significance in Hepatocellular Carcinoma Cezar Stroescu 1 , Adrian Dragnea 2 , Bogdan Ivanov 1 , Catalin Pechianu 3 , Vlad Herlea 3 , Olivia Sgarbura 1 , Andra Popescu 1 , Irinel Popescu 1 1) Fundeni Clinical Institute - Department of General Surgery and Liver Transplantation, Bucharest; 2) Military County Hospital “Ion Jianu” - General Department, Pitesti; 3) Fundeni Clinical Institute - Department of Pathology, Bucharest, Romania Abstract Background. Hepatocellular carcinoma is one of the most common malignant tumors that carry a poor prognosis. To improve the long-term outlook for HCC, an accurate prognosis is important. Aims. To study the immunohistochemical expressions of p53, Ki67, Bcl-2, VEGF and PCNA and their potential role as prognostic factors in patients with radical resection of hepatocellular carcinoma. Patients and methods. Forty-seven formalin- fixed paraffin-embedded tumor samples from patients with HCC receiving liver resection were investigated immunohistochemically for the expression of cellular proliferation markers PCNA, Ki67, p53, Bcl-2 and VEGF and their correlation with tumor characteristics and survival time after resection. Results. p53 was expressed in a higher percentage (85.7 vs. 42.1%) in undifferentiated histological tumor grades (Edmondson Steiner G3/G4 vs. G1/G2). Patients with p53 accumulating tumors showed a worse survival than patients with p53 non-accumulating tumors (median 9.5 vs. 16.5 months). Over-expression of VEGF was found in 38.3% of all HCCs. VEGF expression was significantly correlated with p53 expression and recurrence rates. The results showed that the labeling index of PCNA and expression of p53 are correlated. The high labeling index of PCNA or over-expression of p53 resulted in high risk of tumor recurrence, more aggressive growth and poor survival. Conclusion. High labeling index of PCNA, p53 nuclear accumulation and VEGF high expression are associated with poor survival in patients with HCC. Key words Immunohistochemistry – p53 – PCNA – VEGF – prognosis – hepatocellular carcinoma. Introduction With the development of diagnostic techniques many primary liver cancers can benefit from resection at an early stage [1, 2]. Because of the biological behavior of HCC, the recurrence rate after hepatectomy is very high [3-5]. Some authors described influencing factors such as tumor size, capsule formation, differentiation of tumor cells, clinico-pathological stage, proliferating cell nuclear antigen (PCNA), mutation of p53 [5-10]. The most commonly observed genetic alteration in human cancers has been reported to be the mutation of the p53 gene [1]. This gene has the features of a recessive oncosuppressor in its wild-type (wt) form and can be a dominant oncogene in its mutated form. The p53 gene product acts as a genetic sentinel, initiating cell cycle arrest or apoptosis. A defective copy of p53 behaves as a dominant negative, resulting in a cell that is resistant to undergoing apoptosis. Indeed, cancers presenting mutations of p53 tend to be more aggressive and resist chemotherapy [9, 10]. The vascular endothelial growth factor (VEGF) is the most important angiogenesis factors and a hot spot for study at present. It has been reported that VEGF, a dimeric glycoprotein with a structural homology with PDGF [7, 8] is a highly specific mitogen for blood vessel endothelial cells that can stimulate endothelial cells of microvessels to proliferate and increase permeability, resulting in tumor angiogenesis [9]. The most widely used proliferation-associated marker is Ki-67, which is a nuclear antigen present only in proliferating cells. A detailed cell cycle analysis showed that the Ki-67 antigen is expressed in cells during the G1, S, and G1–M phases but not during the G0 phase of the cell cycle [10, 11]. In HCC, Ki-67 expression was found to be in close relation to tumor growth rate [12] and was an independent prognostic indicator of patient disease-free and overall survival rates [13]. Proliferating cell nuclear antigen (PCNA) is a highly conserved nuclear protein that is expressed during cell replication and DNA repair [11, 14]. The protein encoded by the Bcl-2 (B cell lymphoma/