Characterization of an Interferon-Resistant Mutant of the Human Breast Cancer Cell Line BT-20

Abstract
The human breast cancer cells BT-20 were treated for 18 months in the continuous presence of interferon-ύ (HuIFN-ύ; 500 U/ml). These cells have become completely resistant to HuIFN-ύ and interestingly also to IFN-α2. However, the expression of HLA-DR and the regulation of cell adhesion to tissue culture plastic remained partially under the domain of HuIFN-ύ. A reduced number of IFN-ύ binding sites in comparison to the wildtype cells were observed on the IFN-resistant BT-20 cells.