A 700-kb physical map of a region of 16q23.2 homozygously deleted in multiple cancers and spanning the common fragile site FRA16D

We have identified a >600-kb region at 16q23.2 that is homozygously deleted from malignant ovarian ascites using representational difference analysis, Overlapping homozygous deletions were also observed in the colon carcinoma cell Line HCT116 and a xenograft established from the small cell lung canc er cell line WX330. This region coincides with that described previously by others as showing loss of heterozygosity in prostate and breast cancers (C , Li et al., Genes Chromosomes Cancer, 24: 175-182, 1999; A. Latil et al., Cancer Res., 57: 1058-1062, 1997; K. Driouch ef al., Genes Chromosomes Canc er, 19: 185-191, 1997; A. Iida et at, Br, J, Cancer, 75: 264-267, 1997), in addition, the minimally deleted region spans the common fragile site FRA16 D. We have constructed a 700-kb physical map encompassing the deleted regio n. By fluorescence in situ hybridization of aphidicolin-induced metaphase c hromosomes, we have preliminary data to suggest that Pi-derived bacterial a rtificial chromosome clones from the contig he on both sides of FRA16D, Thi s is confirmed by extensive fluorescence bl situ hybridization analysis of the region reported in the accompanying article (M. Mangelsdorf ef at, Canc er Res., 60: 1683-1689, 2000) and is consistent with an involvement of this common fragile site in the loss of 16q23.2 material in various cancer type s. The minimally deleted region of approximately 210 kb has been characteri zed using our own markers and public domain markers. Eleven distinct expres sed sequences mapped to the region, providing a basis for identifying the p redicted tumor suppressor gene in this region.