Original Article


EXPRESSION OF GST-π GENE IN HUMAN ESOPHAGEAL CARCINOGENESIS

Baojin Fu, Yunhan Zhang, Yaohe Wang, Dongling Gao, Shuli Fu, Xiaogang Wen, Sanshen Zhang, Jiang Wang

Abstract

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 in normal epithelial cells (NC) of the esophagus, hyperplastie cells (HC), dysplastie cells (DC) from grade I to IlI, carcinoma in situ (CIS) and all the cells in squamous cell carcinomas (SCC) were 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 SCC. 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 SCC, 30.0% for grade II SCC and 0% for grade III SCC. 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 SCC. The decrease in GST-π expression is an early event in esophageal carcinogenesis.