Expression Of GST-π And Telomerase In Esophageal Carcinoma And Premalignant Lesions

OBJECTIVES: To explore the expression of GST-π and telomerase activity and investigate a correlation between the expression of GST-πand telomerase activity in esophageal carcinoma and premalignant lesions. METHODS: We sprayed endoscopically Methylene blue and Lugol's iodine in proper order and obtained blue-stained area and brown-stained area and area between blue-stained and brown-stained from 72 patients with esophagpathy. Depending on the pattern of mucosal staining, biopsy specimen was obtained. GST-π and telomerase activity in specimens were examined by immunohistochemistry and PCR based silver staining telomeric repeat amplification protocal (TRAP), respectively.RESULTS: 1. Methylene blue and Lugol's iodine double staining endoscopically. After the Methylene blue and Lugol's iodine staining, area between two colours was obtained in 64 of the 72 patients, including those with 4 normal epitheliums, 6 hyperplasias, 7 low-grade dysplasias, 13 moderate-grade dysplasias, 25 high-grade dysplasias, 1 carcinoma in situ, 8 squamous cell carcinomas; There was blue-stained area in the 72 patients, including those with 2 hyperplasias, 3 low-grade dysplasias, 5 moderate-grade dysplasias, 16 high-grade dysplasias, 43 squamous cell carcinomas, 3 adenocarcinomas; There was brown-stained area in the 72 patients, including those with 49 normal epitheliums, 13 hyperplasias, 7 low-grade dysplasias, 3 mild-grade dysplasias. Association test of two simultaneous ordinal categorical data showed a correlation between the esophageal mucosal staining and the esophageal histology(P<0.005).2. Expression of GST-π in esophageal carcinoma and premalignant lesions. The positive rate of GST-πexpression in normal epithelium, hyperplasia, low-grade dysplasia, moderate-grade dysplasia, high-grade dysplasia, carcinoma in situ, squamous cell carcinoma and adenocarcinoma was 5.7%, 9.5%, 35.3%, 57.1%, 75.6%, 100%, 82.4% and 100%, respectively. GST-πwas expressed in normal epithelium(5.7%,3/53), dysplasia(62.0%,49/79) and carcinoma(83.6%, 46/55)( P<0.005); the expression in hyperplasia was slightly higher than that in normal epithelium( P＞0.9). The expression in low-grade or moderate-grade or high-grade dysplasia was significantly higher than that in normal epithelium( P<0.005). With the lesions progressed from low-grade to moderate-grade to high-grade dysplasia, the positive rate increased(P<0.025). 3. Expression of telomerase activity in esophageal carcinoma and premalignant lesions. The positive rate of telomerase activity expression in normal epithelium, hyperplasia, low-grade dysplasia, moderate-grade dysplasia, high-grade dysplasia, carcinoma in situ, squamous cell carcinoma and adenocarcinoma was 3.8%, 4.8%, 11.8%, 33.3%, 78.0%, 100%, 88.2% and 100%, respectively. Telomerase activity was expressed in normal epithelium(3.8%, 2/53), dysplasia(51.9%, 41/79) and carcinoma(89.1%, 49/55)(P<0.005).The expression in hyperplasia was slightly higher than that in normal epithelium(P=0.998). The expression in low-grade dysplasia was higher than that in normal epithelium (P=0.246); the expression in moderate-grade or high-grade dysplasia was significantly higher than that in normal epithelium (P<0.005). With the lesions progressed from low-grade to moderate-grade to high-grade dysplasia, the positive rate increased; there was significant difference between high-grade dysplasia and low-grade or moderate-grade dysplasia (P<0.005); but no difference between low-grade dysplasia and moderate-grade dysplasia(P＞0.1). 4. Expression of GST-π and telomerase activity in esophageal carcinoma and premalignant lesions. Expression of GST-π correlated with that of telomerase activity in dysplasia and carcinoma (φ=0.4831,P<0.005；φ=0.3031,P<0.025 respectively); but there was not a correlation between the expression of GST-πand telomerase activity in normal epithelium and hyperplasia (P＞0.05)。CONCLUSIONS: 1. Methylene blue and Lugol's iodine double staining endoscopically may help to differen...