Gene amplifications at chromosome 7 of the human gastric cancer genome.

Genetic aberrations at chromosome 7 are known to be related with diverse human diseases, including cancer and autism. In a number of cancer research areas involving gastric cancer, several comparative genomic hybridization studies employing metaphase chromosome or BAC clone microarrays have repeatedly identified human chromosome 7 as containing 'regions of changes' related with cancer progression. cDNA microarray-based comparative genomic hybridization can be used to directly identify individual target genes undergoing copy number variations. Copy number change analysis for 17,000 genes on a microarray format was performed with tumor and normal gastric tissues from 30 patients. A group of 90 genes undergoing copy number increases (gene amplification) at the p11 approximately p22 or q21 approximately q36 region of chromosome 7 is reported. The list of genes includes wingless-type MMTV integration site family member 2 (WNT2), a proto-oncogene and acyloxyacyl hydrolase (AOAH) that was amplified in >80% of the tested cases. The amplified genes are those functioning in the biological processes such as signal transduction pathways, cell proliferation, metabolism, transport, inflammatory response and protein folding or proteolysis. Also found in the list are genes that are targets for drug development, such as maltase-glucoamylase (MGAM), cyclin-dependent kinase 5 (CDK5), neuropeptide Y (NPY) and dopa decarboxylase (DDC). The current dataset can be used as one of the resources in understanding genetic aberrations of chromosome 7 in human gastric cancer.