Alterations of glutathione S-transferase and matrix metalloproteinase-9 expressions are early events in esophageal carcinogenesis

AIM: To investigate the role of glutathione S-transferase (GST) and matrix meta lloproteinase-9 (MMP-9) expressions in the development and progression of reflux esophagitis-Barrett's meta plasia-dysplasia-adenocarcinoma sequence in the esophagus. METHODS: GST and MMP-9 expressions were analyzed in 51 paraffin-embedded tissue samples by immunohistochemistry including patients with reflux esophagitis (n = 7), Barrett's metaplasia (n = 14), Barrett and esophagitis (n = 8), Barrett and dysplasia (n = 7), esophageal adenocarcinoma (n = 8) and a control group without any histological changes (n = 7). Immunostaining was determined semiquantitatively. Statistical analysis with one-way ANOVA, LSD test and correlation analysis were performed. P value of < 0.05 was considered significant. RESULTS: GST expression was significantly higher while MMP-9 expression was significantly lower in control group compared to Barrett's metaplasia and the other groups. No major changes were observed between Barrett, esophagitis, and Barrett and concomitant esophagitis. Barrett and concomitant dysplasia, and adenocardnoma revealed a significant lower expression of GST and higher levels of MMP-9 compared to all other groups. Adenocarcinoma showed almost no expression of GST and significantly higher levels of MMP-9 than Barrett and concomitant dysplasia. Alterations of GST and MMP-9 were inversely correlated (r 0.82). CONCLUSION: Decreased GST and increased expression of MMP-9 in Barrett's meta plasia-clysplasiaadenocarcinoma sequence as compared to normal tissue suggest their association with esophageal tumorigenesis. Loss of GST and gain of MMP-9 in Barrett with dysplasia compared to non-clysplastic metaplasia indicate that these alterations may be early events in carcinogenesis. Quantification of these parameters in Barrett's esophagus might be useful to identify patients at higher risk for progression to cancer. (c) 2007 The WJG Press. All rights reserved