Fig. 1.

High resolution allelotype of chromosome 16 in breast cancer cell lines using highly polymorphic microsatellite markers. Markers arranged in mapping and linkage order as previously described (Chen et al., 1996). Dark gray blocks indicate that a single allele was observed at the corresponding locus (i.e. hemi or homozygosity), light gray blocks indicate heterozygosity is preserved. Blank blocks were not determined. Numbers at right represent the heterozygosity scores calculated at each specific locus from analyzing this breast cancer panel. Several breast cancer lines showed hemizygosity affecting all or most of the chromosome 16q arm. Areas of high LOH mapped to 16q21, 16q23 and 16q24.2. The most commonly affected area (16q23) was determined to be FRA16D and to contain the WWOX gene. The SUM breast cancer cell lines were a generous gift from Dr. Stephen Ethier (Department of Radiation Oncology, The University of Michigan Health System).