CLONING AND MAPPING OF HUMAN-CHROMOSOME 6Q26-Q27 DELETED IN B-CELL NON-HODGKIN-LYMPHOMA AND MULTIPLE TUMOR TYPES

Frequent deletions of the distal region on the long arm of chromosome 6 have been reported in multiple human tumors including B-cell non-Hod gkin lymphoma (B-NHL), suggesting the presence of one or snore tumor s uppressor genes (TSGs) at this locus. Previously, we identified a regi on of minimal molecular deletion at 6q25-q27 (RMD-1) in B-NHL cases. T o facilitate positional cloning efforts to identify the RMD-1(-) TSG(s ), a yeast artificial chromosome (YAC) contig consisting of 110 clones was constructed across 6q26-q27 by sequence-lagged site/probe content mapping. The contig integrates 79 ordered markers including restricti on fragment length polymorphisms, minisatellites, microsatellites, YAC -insert termini, expressed sequence tags, and known genes. It spans 34 cM and has a minimal tiling path of approximately 12 clones, covering an estimated 9-14 Mlb with nearly every marker on the map showing at least double linkage to its adjacent markers. Dual-color fluorescence in situ hybridization of selected merger pairs on normal pachytene chr omosome 6 further confirmed the YAC-based mappings. Utilizing a loss o f constitutional het; erozygosity assay in the B-NHL tumor panel, 24 a dditional 6q26-q27 polymorphic markers (21 mapping to the contig) furt her defined RMD-1 between markers D6S186 proximally sand D6S227 distal ly, The minimal tiling path of the B-NHL RMD-1 consists of approximate ly 8 YAG clones, providing a size estimate of-g Mb. This interval cont ains, in their entirety, several smaller candidate TSG critical region s previously delimited in other tumor systems. The AF-6 gene, snapping within RMD-1, revealed no mutations in a small subset of B-NHL. The d eletion and physical maps presented herein provide a framework for the identification of the gene(s) involved in B-NHL as well as other mali gnancies and diseases mapped to this region and provide the initial re agents for large-scale genomic sequencing. (C) 1998 Academic Press.