RECIPROCAL TRANSLOCATION AT 1P36.2 DIS160 IN A NEUROBLASTOMA CELL-LINE - ISOLATION OF A YAC CLONE AT THE BREAK/

Band 1p36.1-1p36.2 is frequently involved in chromosomal aberrations o f neuroblastoma cells, and therefore thought to harbour genetic inform ation which may be involved in tumorigenesis. To map this putative neu roblastoma locus, we screened neuroblastoma cell lines for reciprocal translocations at 1p36.1-2 which may signal the site of an affected ge ne. We identified a reciprocal 1;15 translocation in cell line NGP by fluorescence in situ hybridisation (FISH). As a strategy to clone the translocation breakpoint, we isolated yeast artificial chromosomes (YA Cs) specific for loci at 1p36. Screening of cell line NGP by FISH iden tified a YAC, 1050 kbp in size, which hybridised to both derivative 1; 15 and 15;1 chromosomes. We conclude that this YAC, which maps to D1S1 60, covers the break. This chromosomal position is within the smallest region of overlap (SRO) found in neuroblastoma tumours and within the region of a constitutional interstitial deletion of a neuroblastoma p atient. The YAC we describe here should serve as a DNA source for gene cloning approaches towards the isolation of candidates for the putati ve neuroblastoma suppressor gene.