The high incidence of acquired drug resistance to STI571 during treatment of chronic myelogenous leukemia (CML) patients in blast crisis has become a problem. We studied the effects of interferon-alpha (IFN-alpha) on a novel STI571-resistant CML cell line and its molecular mechanisms in vitro.
STI571-resistant KT-1 cells are sensitive to interferon-alpha accompanied by the loss of T-cell protein tyrosine phosphatase and prolonged phosphorylation of Stat1.