BREAKPOINTS OF BURKITTS-LYMPHOMA T(8 22) TRANSLOCATIONS MAP WITHIN A DISTANCE OF 300-KB DOWNSTREAM OF MYC/

The variant translocation t(8;22) in Burkitt's lymphoma (BL) cells joi ns band q24 of chromosome 8 distal to the proto-oncogene MYC to the im munoglobulin lambda locus. The distribution of breakpoints on chromoso me 8 of 11 cell lines with t(8;22) has been investigated by in situ fl uorescence hybridization and pulsed-field gel electrophoresis. We show that these chromosomal breakpoints generally fall within a region of about 300 kb 3' of MYC and that at least 8 out of 11 affect the previo usly characterized transcriptional unit PVT1. Comparable results were obtained in earlier experiments analyzing the variant t(2;8). Recently , in a series of BL cells carrying t(8;14), breakpoints upstream of MY C have been described at a similar distance. Therefore, our results su ggest that deregulation of MYC by the immunoglobulin loci can occur at a distance of up to about 350 kbp of MYC. (C) 1994 Wiley-Liss, Inc.