TheProstate68:1105^1115(2008) Vasculature-TargetedTumorNecrosisFactor-Alpha IncreasestheTherapeuticIndexofDoxorubicin AgainstProstateCancer Maria T.S. Bertilaccio, 1,2 Matteo Grioni, 1 Brent W. Sutherland, 3 Elena Degl’Innocenti, 1 Massimo Freschi, 4 Elena Jachetti, 1 Norman M. Greenberg, 2 Angelo Corti, 1,5 and Matteo Bellone 1 * 1 CancerImmunotherapyandGeneTherapyProgram,DepartmentofOncology, Istituto Scientif|co San Raffaele, Milan,Italy 2 Univerista' Vita-Salute San Raffaele, Milan,Italy 3 Clinical Research Division,Fred Hutchinson Cancer Research Center,Seattle,Washington 4 Unita' Operativa Anatomia Patologica,Istituto Scientif|co San Raffaele, Milan,Italy 5 IITNetwork Research Unitof Molecular Neuroscience,Istituto Scientif|co San Raffaele, Milan,Italy BACKGROUND. Poor penetration and uneven distribution of doxorubicin in tumors limits the efficacy of this drug in patients with prostate cancer (PC). Aim of the study was to investigate whether pre-treatment with NGR-TNF, a tumor necrosis factor-a derivative able to target tumor vessels and alter vessel permeability, increases the penetration and the efficacy of doxorubicin in pre-clinical models of PC. METHODS. Wild type C57BL/6 mice bearing androgen-independent TRAMP-C1 PC and transgenic adenocarcinoma of the mouse prostate (TRAMP) mice, which spontaneously develop PC and metastasis, were treated with repeated cycles of doxorubicin, administered either alone or following NGR-TNF. Tumor growth and drug uptake by cancer cells was evaluated. RESULTS. Doxorubicin as a single agent blocked the growth of TRAMP-C1 cells in vitro but not in vivo. Pre-treatment of mice bearing subcutaneous TRAMP-C1 tumors with NGR-TNF favored doxorubicin penetration into the tumor mass, and in both TRAMP-C1 and TRAMP models significantly delayed tumor growth without increasing drug-related toxicity. CONCLUSIONS. Pre-treatment with NGR-TNF significantly expanded the therapeutic index of doxorubicin in mouse models of hormone-dependent and -independent PC. Prostate 68: 1105–1115, 2008. # 2008 Wiley-Liss, Inc. KEY WORDS: TRAMP; mouse model; chemotherapy; cytokines; androgen-independent; CD13 INTRODUCTION Prostate cancer (PC) is one of the leading causes of cancer in men. Even though mortality has significantly decreased over the last decade, PC accounts for approximately 10% of cancer related deaths [1]. Indeed, radical prostatectomy is indicated for organ-confined disease, whereas treatments for advanced and/or metastatic PC have limited efficacy. Prostate tumors are anatomically, histologically and genetically heterogeneous [2], causing variable Grant sponsor: Associazione Italiana per la Ricerca sul Cancro; Grant numbers: 58/2003, 2005-2007; Grant sponsor: Ministero dell’ Universita ` e della Ricerca; Grant number: FIRB-RBIP06LCA9-005. Elena Degl’Innocenti’s present address is 4-Antibody AG, Schwarz- waldallee 215 CH-4002, Basel, Switzerland. *Correspondence to: Matteo Bellone, Cellular Immunology Unit, 3P-A1, Dibit, Istituto Scientifico San Raffaele, Via Olgettina 58, 20132, Milan, Italy. E-mail: bellone.matteo@hsr.it Received 21 November 2007; Accepted 17 March 2008 DOI 10.1002/pros.20775 Published online 24 April 2008 in Wiley InterScience (www.interscience.wiley.com). ß2008Wiley-Liss,Inc.