Francesca Perut1, Fabrizio Carta2, Gloria Bonuccelli1, Giulia Grisendi3, Gemma Di Pompo1, Sofia Avnet1, Francesca Vittoria Sbrana1, Shigekuni Hosogi1, Massimo Dominici3, Katsuyuki Kusuzaki4, Claudiu T Supuran2, Nicola Baldini1,5. 1. a 1 Istituto Ortopedico Rizzoli, Laboratory for Orthopaedic Pathophysiology and Regenerative Medicine , via di Barbiano 1/10, 40136 Bologna, Italy +39 05 16 36 66 78 ; +39 05 16 36 68 97 ; francesca.perut@ior.it. 2. b 2 University of Florence, Section of Pharmaceutical Chemistry, NEUROFARBA Department , Sesto Fiorentino, FI, Italy. 3. c 3 University of Modena e Reggio Emilia, Department of Medical and Surgical Sciences for Children & Adults , Modena, Italy. 4. d 4 Kyoto Kujo Hospital, Department of Orthopaedic Surgery , Kyoto, Japan. 5. e 5 University of Bologna, Department of Biomedical and Neuromotor Sciences , Bologna, Italy.
Abstract
OBJECTIVE: Hypoxia-inducible factor 1, a regulator of CA IX activity, is often overexpressed in human osteosarcoma (OS) but not in normal tissues, and its expression levels correlate with prognosis. In this study, we investigated the therapeutic potential of newly synthesized CA IX sulfonamide inhibitors in OS. METHODS: CA IX expression was evaluated in OS cell lines and bone marrow stromal cells (BMSC). After treatment with CA IX inhibitors, cell proliferation, apoptosis, cell cycle, extracellular and cytosolic pH changes were evaluated both in vitro and in mouse OS xenografts. RESULTS: CA IX expression levels were significantly higher in OS than in BMSC. Accordingly, CA IX inhibitor 3 induced remarkable cytotoxicity on OS cells without affecting BMSC proliferation. This activity was increased under hypoxia, and was mediated by cell cycle arrest and by the modulation of cytosolic and extracellular pH. In vivo, CA IX inhibitor 3 reduced tumor growth by inducing significant necrosis. CONCLUSIONS: Our results provide a strong rationale for the clinical use of the newly synthesized CA IX inhibitor 3 in human OS.
OBJECTIVE:Hypoxia-inducible factor 1, a regulator of CA IX activity, is often overexpressed in humanosteosarcoma (OS) but not in normal tissues, and its expression levels correlate with prognosis. In this study, we investigated the therapeutic potential of newly synthesized CA IX sulfonamide inhibitors in OS. METHODS:CA IX expression was evaluated in OS cell lines and bone marrow stromal cells (BMSC). After treatment with CA IX inhibitors, cell proliferation, apoptosis, cell cycle, extracellular and cytosolic pH changes were evaluated both in vitro and in mouse OS xenografts. RESULTS:CA IX expression levels were significantly higher in OS than in BMSC. Accordingly, CA IX inhibitor 3 induced remarkable cytotoxicity on OS cells without affecting BMSC proliferation. This activity was increased under hypoxia, and was mediated by cell cycle arrest and by the modulation of cytosolic and extracellular pH. In vivo, CA IX inhibitor 3 reduced tumor growth by inducing significant necrosis. CONCLUSIONS: Our results provide a strong rationale for the clinical use of the newly synthesized CA IX inhibitor 3 in human OS.