Antiangiogenic gene therapy for liver cancer via systemic administration of adenoviral vector expressing pigment epithelium derived factor (PEDF)

Parallel Session 3: Viral Hepatitis cacy and safety of propranolol plus isosorbide mononitrate and endoscopic variceal ligation (EVL) for prevention of vaficeal rebleeding. Methods: Patients in the pharmacotherapy group (N = 51) received propranolol at a dose sufficient to decrease the base line heart rate to 55 beats/min followed by isosorbide mononitrate in a dose of 20 mg twice daily once the target heart rate was achieved. Patients in the EVL group (N = 53) underwent ligation within 24 hours of randomization. The primary outcomes were rebleeding, death, and withdrawal from treatment due to treatment related complications. Data were analyzed according to intention-to-treat strategy. The actuarial probabilities of rebleeding and of death were calculated by the Kaplan-Meier method and comparisons made using log-rank test. Results: Ten patients (19%) in the EVL and 13 patients (26%) in the pharmacotherapy group rebled during a median follow-up of 18 and 16 months, respectively. In the EVL group, 5 of 10 rebleeds (50%) occurred from post-EVL ulcers. At 30 months, the actuarial probability of rebleeding was 25% in the EVL and 37% in the pharmacotherapy group, (p = 0.31). Seven patients died in each group (p = 0.75 for the difference in the actuarial probability of survival at 30 months). Four patients (8%) had to be withdrawn from treatment in the pharmacotherapy group. Condusions: (i) Both propranolol plus isosorbide mononitrate and EVL provide comparable efficacy and safety for the prevention of vaficeal rebleeding. (ii) A combination of the two modalities should be evaluated to decrease post-EVL ulcer related bleed. GENE THERAPY FOR LIVER CANCER VIA • 2ANTIANGIOGENIC - ] SYSTEMIC ADMINISTRATION OF ADENOVIRAL VECTOR EXPRESSING PIGMENT EPITHELIUM DERIVED FACTOR (PEDF) Lin Wang 1, Volker Schmitz I , Alberto Perez-Mediavilla 2, Inigo Izal 2, Jesus Pfieto ] , Cheng Qian I . 1Division of Hepatology and Gene Therapy,

Department of Medicine, Medical School, University of Navarra, Pamplona; 2Department of Biochemistry, Medical School, University of Navarra, Pamplona, Spain Tumor angiogenesis plays a key role in progression and metastasis of malignant tumors. Inhibition of tumor angiogenesis provides a potent strategy for effective treatment of cancer. PEDE was identified from retinal pigment epithelial cells and has been shown to display neurotrophic effects. In addition it has been found to induce a potent inhibition of angiogenensis. In this study we have explored whether overexpression of PEDF by gene transfer approach can block tumor angiogenesis and reduce tumor growth. Method: Adenoviral vector with PEDF driven by CMV promoter was constructed (AdPEDF). Transgene expression was monitored by western blotting and activity of PEDF was measured by inhibition of migration and tube formation of endothelial cells. Antitumor effect was carded out in animal models with hepatocellular carcinoma (HCC) and lung carcinoma. Results: Our data showed that AdPEDF infected cells produced PEDF as demonstrated by western blotting and that secreted PEDF had strong inhibitory effect on migration and tube formation of endothelial cells induced by vascular endothelial growth factor (VEGF). The systemic admininstration of AdPEDF could inhibit angiogenesis in Matrigel assay in vivo. Treatment of established HCC tumor in nude mice resulted in strong suppression of tumor growth. This anti-tumor effect could also be seen in lung carcinoma model in immuno-competent or immuno-defficient mice. The anti-tumor effect was related to decrease of density of microvessel in tumors after treatment with AdPEDE Conclusion: These data suggests that PEDF is a tumor-suppressive mediator with antiangiogenic properties allowing it to target growing endothelium and limit establishment of neovasculature.

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LONG TERM FOLLOW-UP OF A LARGE COHORT OF ASYMPTOMATIC HBEAG-NEGATIVE CHRONIC HEPATITIS B CARRIERS

Mafia Raptopoulou-Gigi ], Ioannis Goulis 1, Helen Orphanou 1 Thalia Lalla 1, Emmanuel Sinakos 1, Ioannis Vakolas 1, Helen Vrettou 2.

14th Medical Dept., Aristotle University of Thessaloniki; 2Dept. of Pathology, Aristotle University of Thessaloniki, Greece A total of 404 asymptomatic HBeAg-negative chronic hepatitis B patients were followed-up every 6-12 months, for a period of 3 to 21 years. 288 patients (71.3%) who had initially normal liver function tests for at least two clinic visits of follow-up were termed healthy carders. However in 84 patients out of 288 (29.2%) healthy carriers, a flare of ALT levels and HBVDNA(+) were recorded after 2 to 16 years of follow-up. 32 out of the 84 patients (38%) who developed persistently abnormal ALT levels underwent liver biopsy. Moderate or severe activity (HAI > 9) was found in 14 patients (44%) while 6 out of 32 (19%) had severe fibrosis or cirrhosis. 24 out of 404 asymptomatic patients (5.9%) of the original cohort showed loss of HbsAg after 3 to17 years of follow-up. In two of these patients (8.33%) HBVDNA remained positive despite the loss of HbsAg. In conclusion our data has shown that the course of HbeAg ( - ) chronic hepatitis B with initial normal liver function tests is not as benign as it was often considered. The term healthy carrier state should be replaced by inactive carrier state. These patients should be followed-up for life as reactivation of the disease can occur, even after 16 years of follow-up.

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PREVALENCE OF HBV PRECORE AND CORE PROMOTOR VARIANTS IN THE UNITED STATES - RESULTS OF A NATION-WIDE STUDY

Chu Chi-Jen l , Emmet B. Keeffe 2, Steven-Huy Han 3, Robert Perrillo 4, Albert D. Min 5, William Carey 6, Consuelo Soldevila-Pico 7, Velimir A. Luketic s , Robert S. Brown, Jr 9, Norah Terrault l°, Donald Jensen II , Anna S. Lok 1. 1University of Michigan Medical Center, Ann Arbor,

Michigan; 2Stanford University Medical Center, Palo Alto, California; 3UCLA School of Medicine, Los Angeles, California; 40chsner Clinic, New Orleans, Louisiana; 5Mount Sinai Medical School, New York, New York; 6Cleveland Clinic, Cleveland, Ohio; 7University of Florida Health Science Center, Gainesville, Florida; 8Virginia Commonwealth University, Richmond, Virginia; 9Columbia-Presbyterian Medical Center, New York, New York; WUCSF Division of Gastroenterology, San Francisco, California; 11Rush Presbyterian-St Luke's Medical Center, Chicago, Illinois, USA Background & Aims: Previous studies based on small numbers of patients reported that the prevalence of HBV precore (PC) and core promoter (CP) variants is extremely low in the United States. Data from Europe and Asia suggest that these variants are becoming more common. This study was designed to determine the prevalence of HBV PC and CP variants in the U.S. and their association with patient demographics, clinical status and HBV genotypes. Methods: Consecutive patients with chronic HBV infection seen in 17 U.S. Liver Centers were enrolled into this ongoing cross-sectional study. Patients currently receiving antiviral therapy and those with recurrent hepatitis B after OLT were excluded. Demographic, clinical and laboratory data were collected during clinic visits. Sera were tested for HBV genttyping, PC (G1896A) and CP (A1762T, G1764A) variants by line probe assays (Innogenetics). Results: To date, 571 patients have been enrolled, and HBV testing has been completed on 468 patients. Demographics were as follows: 67% men;