DETAILED MAP OF A REGION COMMONLY AMPLIFIED AT 11Q13-]Q14 IN HUMAN BREAST-CARCINOMA

Amplification of loci present on band q13 of human chromosome 11 is a feature of a subset of estrogen receptor positive breast carcinomas pr one to metastasis. As many as five distinct amplification units have b een described on 11q13. They include particularly a genomic area encom passing the GARP gene at 11q13.5-->q14.1. We have reassessed our curre nt knowledge of this region, located telomeric to CCND1 and EMS1, whic h is amplified in 7-10% of mammary tumors. The loose definition of the driving forces of these amplification events led us to map accurately the boundaries of the amplifiable region, and thus to contribute a ph ysical and transcriptional map of a 3-Mb region of chromosome 11. Four new genes were placed on the regional map, namely CBP2, CLNS1A, UVRAG , and PAK1. We have narrowed the core of the 11q13-->q14 amplicon to a 350-kb area encompassing D11S533, mostly on its telomeric side. The m ap reported here represents an indispensable step toward sequencing th e entire region, and thus toward uncovering gene(s) which play(s) a cr itical role in breast cancer progression.