Induction of interferon regulatory factors, 2′‐5′ oligoadenylate synthetase, P68 kinase and RNase L in chronic myelogenous leukaemia cells and its relationship to clinical responsiveness

The genes crucially determining the therapeutic response of chronic myelogenous leukaemia (CML) to interferon-alpha (IFN-alpha) are unknown. Recently, two independent IFN-alpha signalling pathways were identified: the classic pathway mediates induction of 2'-5' oligoadenylate synthetase (2-5 OAS), p68 kinase and IFN regulatory factor-2 (IRF-2), whereas the alternate pathway leads to activation of IFN regulatory factor-1 (IRF-1). We investigated whether deficient or imbalanced expression of components of these two pathways is associated with resistance of CML cells to antiproliferative action of IFN alpha/beta. Constitutive and IFN-induced transcript levels of IFN-dependent genes in mononucl…