食管癌发生发展过程中GST-π基因表达的研究

Expression of GST π gene in human esophageal carcinogenesis

目的探讨ＧＳＴπ基因在食管癌发生发展过程中的作用。方法采用４８例食管鳞癌标本建立食管癌发生发展多阶段模型，应用免疫组化和原位杂交方法对食管癌发生发展过程中ＧＳＴπ基因表达进行研究。结果在正常粘膜、单纯增生、不典型增生上皮总体及其Ⅰ、Ⅱ、Ⅲ级、原位癌和癌组织中ＧＳＴπ蛋白表达阳性率分别为８７．５％、９５．３％、５５．９％、７３．９％、４７．４％、４１．２％、３６．４％和４５．８％，正常粘膜和单纯增生阳性率较不典型增生总体、原位癌和癌组织差异均有显著性（Ｐ＜０．００５）；ＧＳＴπｍＲＮＡ表达的阳性率分别为８１．２％、９４．４％、６１．９％、７６．５％、６１．５％、４１．７％和５０．０％。ＧＳＴπ蛋白表达阳性率与ｍＲＮＡ表达阳性率差异无显著性。ＧＳＴπ蛋白表达与食管鳞癌组织学分级有关（Ｐ＜０．０５）；原位杂交和免疫组化结果之间差异无显著性（Ｐ＞０．０５）。结论ＧＳＴπ与食管癌的发生发展有关，是食管癌发生过程中早期酶学变化。

Objective To investigate the possible role of GST π in esophageal carcinogenesis. Methods GST π expression at mRNA level was studied by in situ hybridization (ISH) and at protein level by immunohistochemistry (IHC). GST π expression of the esophagus in normal epithelial cells (NC), hyperplastic cells (HC), dysplastic cells (DC) from grade I to III, carcinoma in situ (CIS) and invasive carcionma (IC) was examined in the same esophageal cancer specimens (n=48) which provided a model reflecting the process of esophageal carcinogenesis. Results The positive rate of IHC staining was 87.5% for NC, 95.3% for HC, 55.9% for DC (grade I: 73.9%, grade II: 47.4%, grade III: 41.2%), 36.4% for CIS and 45.8% for IC. The positive rate of GST π mRNA expression was 81.2% for NC, 94.4% for HC, 61.9% for DC (grade I: 76.5%, grade II: 61.5%, grade III: 41.7%), 44.4% for CIS and 83.3% for grade I IC, 30.0% for grade II IC and 0% for grade III IC. There was no statistically significant difference in GST π expression at the mRNA and the protein level. Conclusion There is a decreasing tendency of GST π expression from dysplasia to CIS and IC. The decrease in GST π expression is an early event in esophageal carcinogenesis.