Resistance to CD95-mediated apoptosis in breast cancer is not due to somatic mutation of the CD95 gene

Resistance to CD95 (Apo-1/Fas)-mediated apoptosis is a typical feature of breast cancer cells. Recent studies identified deleterious mutations of the CD95 gene not only in a variety of B cell lymphomas but also in a number of solid tumour entities. Therefore, we amplified and sequenced selected regions (including regulatory promoter regions and the last exon coding for the death domain) of the CD95 gene from 48 breast cancer cases and 10 breast cancer cell lines but no mutation was found. In the presence of both polymorphic allele, loss of heterozygosity was excluded in 27 informative cases. We conclude that relevant somatic mutations of the CD95 gene occur, if at all, at a very low frequency and are not the primary cause for resistance to CD95-mediated apoptosis in breast cancer.