High frequency allelic loss on chromosome 17p13.3-p11.1 in esophageal squamous cell carcinomas from a high incidence area in northern China

Allelic loss on chromosome 17p has been reported frequently in esophageal s quamous cell carcinoma (ESCC) and generally encompasses the p53 locus at 17 p13,1, However, a good correlation between allelic loss on 17p and mutation of p53 has not been found. This suggests the possibility that unknown tumo r suppressor genes near p53 may be involved in the development of ESCC, To evaluate this possibility, we analyzed 30 microsatellite markers covering t he entire short arm of chromosome 17 in 56 ESCC patients from a high risk p opulation in northern China, including 34 with a family history of upper ga strointestinal (UGI) cancer and 22 without a family history of any cancer. Cancer lifestyle risk factors and clinical/pathological characteristics wer e also collected. We found frequent allelic loss (greater than or equal to 65%) at 28 of the 30 markers evaluated in these ESCC patients. The highest frequencies of allelic loss (greater than or equal to 80%) were found in th ree smaller regions: deletion region I located at 17p13,3-p13.2 (between D1 7S849 and D17S1828); deletion region II located at 17p13,2-p13,1 (between D 13S938 and TP53); deletion region III located at 17p13,1-p12 (between D17S8 04 and D17S799), A number of genes have already been identified in these de leted regions, including: OVCA1, OVCA2 and HIC-1 in deletion region I; p53 in deletion region II; ZNF18, ZNn9, ALDH3 and ALDH10 in deletion region III . These results will help us direct future testing of candidate genes and n arrow the search region for major new tumor suppressor genes that may play a role in the pathogenesis of ESCC.