Loss of heterozygosity at microsatellite marker sites for tumour suppressor genes in oesophageal adenocarcinoma

Aims Loss of cell cycle control is an important step in the development of human tumours. A number of tumour suppressor genes are involved in cell cycle control, including p16, p53 and Rb. The aim of this study was to seek evidence of deletions of these genes in oesophageal adenocarcinoma. Methods Paired (tumour and normal squamous epithelium) frozen tissue samples from 12 patients were analysed by polymerase chain reaction (PCR) for loss of heterozygosity (LoH) at five microsatellite marker sites (two each for p16 and Rb, one for p53). Aneuploid tumour cell populations were sorted by flow cytometry prior to PCR, to eliminate stromal cell contamination. Results Of the 12 tumours, 11 (92%) had LoH at one or more loci. LoH at the p53 locus occurred in nine of 12 tumours, at one or both p16 loci in seven of 11 tumours, and at one or both Rb loci in eight of 12 tumours. Five tumours had LoH at two tumour suppressor gene loci, and a further four tumours had LoH at loci for all three genes. Conclusions Allelic deletions of p53, p16 and Rb are common in oesophageal adenocarcinoma, and may be important in the development of this disease.