Gene Amplification in Human Cancer

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Gene amplification is one of the basic mechanisms that lead to overexpression of oncogenes. We examined the amplification status in 32 esophageal squamous cell carcinomas (ESCCs) and 13 ESCC cell lines on 51 frequently amplified loci in a variety of cancers by both DNA array CGH and Southern blot analyses. Eight out of 51 loci (15.7%) were found to be amplified in at least one of the 32 primary ESCCs or the 13 ESCC cell lines, suggesting that chromosomal loci frequently amplified in a type of human cancer may also be amplified in other types of cancers. We previously reported that CAB1 and c-ERBB-2 genes were found to be located in a core amplified region of the 17q12 locus, which is frequently amplified in various cancers. During an identification process of this core region, CAB2, a human homologue of the yeast COS16 required for the repair of DNA double-strand breaks was cloned. This is the first report identifying all of the genes on the core amplified region of the 17q12 locus in breast and gastric cancers.