New BAGE (B melanoma antigen) genes mapping to the juxtacentromeric regions of human chromosomes 13 and 21 have a cancer/testis expression profile

Abstract

A first BAGE (B melanoma antigen) gene, BAGE1, was identified because it encodes a human tumour antigen recognised by a cytolytic T lymphocyte. Here, we characterised five new BAGE genes mapping to the juxtacentromeric regions of human chromosomes 13 and 21 and nine BAGE gene fragments mapping to the juxtacentromeric regions of chromosomes 9, 13, 18, and 21. Genes and gene fragments share extensive regions of 90-99% nucleoticle identity. We analysed the expression of BAGE genes on 215 tumours of various histological types and on nine normal tissues. Similar to BAGE1, the new BAGE genes are expressed in melanomas, bladder and lung carcinomas and in a few tumours of other histological types. All the normal tissues were negative, with the exception of testis. Our results show that human juxtacentromeric regions harbour genes, which are transcribed and translated, in addition to gene fragments that are generally not expressed. We suggest that the pattern of expression restricted to cancer/testis is a feature of the few genes mapping to juxtacentromeric regions.