Loss Of Hetrozygosity In Esophageal Squamous Cell Carcinoma And Precursor Lesion

Objective The aim of this study was to investigate the regulation of gene variation and to explor the tumor associated suppressor genes during the developing of esophageal squamous cell carcinoma, through detecting the loss of hetrozygosity (LOH) in esophageal squamous cell carcinoma and high-grade squamous epithelium in same patient. Method microdissection, PCR, electrophoresis and radiograph were selected to detect the LOH in 55 cases esophageal squamous cell carcinoma with high- grade dysplasia and nomal tissue. The changes of LOH at 9p, 13q, 17p total seven miceosatellite markers and ralationship between LOH rate and clinical pathological parameters were analysised.Result Total frequency of LOH in high grade dysplasia was 31% and in esophageal squaraous cell carcinoma was 51%. In the informative cases LOH at D13S802(40%), D13S267(32%), D13S221(31%), D9S942(30%), D17S520(24%) , D9S171(33%) were found whereas D17S1798 LOH was not detected in high-grade dysplasia , LOH were detected among the invasive cancer with marker D13S267 (71%) , D13S802 (58%) , D17S520 (55%) , D13S221 (45%) ,D9S942(43%), 01781798(11%), D9sl71 (33%). In addtion LOH was found in high grade dysplasia in two case but not in invasive tumor. Ralationship between frequency of LOH in seven miceosatellite markers and the pathology grade, clinical stage, metastase of the lymph nodes using SPSS software showed no significant difference(P>0. 05) .Conclusion (1)The study in seven miceosatellite markers showed that the process from normal mucosa to dysplasia to esophageal squamous cell carcinoma were accompanied with accumulation of gene errors. (2) Tumor suppressor gene associated with early stages of esophageal squamous cell carcinoma may be exist near D13S802(13ql2. 12). (3) Tumor suppressor gene associated with invasive carcinoma of esophageal may be exist near D13S267(13ql3. 1). (4) D17S1798 on 17pl3. 3 and D17S520 on17p13.1 may only related to progession of esophageal squamous cell carcinoma. (5) Some cases showed that high grade dysplasis and esophageal squamous cell carcinoma, came from different independent clone which provide some clue for multiple foci carcinoma at genetic level.