[1] Natl Canc Inst, Clin Expt Oncol Lab, I-70126 Bari, Italy
[2] Univ Pisa, Scuola Med, Dept Internal Med, Div Pharmacol & Chemotherapy, I-56126 Pisa, Italy
[3] AstraZeneca, Canc & Infect Res Area, Macclesfield, Cheshire, England
[4] Regina Elena Inst Canc Res, Expt Chemotherapy Lab, I-00158 Rome, Italy
[5] Azienda Osped Univ Pisana, Clin Pharmacol Ctr Drug Expt, I-56126 Pisa, Italy