Novel expressed sequences obtained by means of a suppression subtractive hybridisation analysis from the 6q21 region that is frequently deleted in gastric cancer.

In our search for genomic regions that are involved in the development of gastric cancer, we recently identified a 2-cM minimal region of overlapping heterozygous deletions in 6q16.3-q23.1. Here, we describe an application of the suppression subtraction method (SSH) to search for genes in this small region of the genome, taking advantage of the fact that many human genes present on yeast artificial chromosomes (YACs) are expressed in yeast. Subtraction was performed with two virtually contiguous YACs that cover a region of approximately 2.5 Mb. Combined forward and reversed subtractions resulted in the identification of 12 clones of human origin, all of which could be confirmed by sequence analysis as originating from the 6q21 region. Expression in human tissues could be confirmed by Northern analysis for two of the clones, one of them showing a high level of expression in stomach tissue.