Chromosome 11q13 abnormalities in human breast cancer.

Amplification of markers centred on band q13 of human chromosome 11 is a consistent feature in a subset of oestrogen receptor positive breast cancers. Although the amplification was initially scored via FGF3/INT2, which has strong credentials as a mammary oncogene, current data suggest that some other gene on 11q13 provides the driving force for amplification. Here we have reviewed our understanding of the amplified DNA, the genes it encompasses and the evidence in favour of two candidate oncogenes, CCND1 and EMS1. As well as being among the most frequently amplified markers in the region, these genes are expressed at elevated levels as a consequence of amplification, and their predicted functions would be consistent with a role in tumorigenesis. Irrespective of the final conclusions regarding their biological relevance, the overexpression of CCND1 or EMS1 should provide a more amenable assay for the amplification and help to clarify its clinical significance.