Study On Telomerase Activity In Human Esophageal Canceration Course

Telomerase, the ribonucleoprotein enzyme that synthesizes telorneric DNA, is repressed in normal human somatic cells but is reactivated during tumor progression. The objectives of this study are as follows: (1) To study the telomerase activity in esophageal canceration course. (2) To probe the relationship between telomerase activity and differentiation, invasiveness, lymphatic metastasis rates. (3) To study the expressions of hTERT mRNA and TP-1 mRNA in esophageal canceration course, and found out the relationship between telomerase activity and the expression of hTERT or TP-l in esophageal cacinoma (EC) tissues. (4) To study the protein expressions of c-myc and bcl-X/L in esophageal canceration course, and found out the relationship between telomerase activity and the protein expression of c-myc or bcl-XIL in EC tissues. Materials and methods: 45 fresh EC specimens surgically resected were collected, which have pathologically proved to be of esophageal carcinoma nature. 3 samples (mucosa of surgical up-edge, paracancerous mucosa and cancer lesions) were taken from each specimens. Each sample was divided into two. One half was made continuously frozen section for detecting telomerase activity and for in situ hybridization. The other half was fixed in 10% formalin, embeded in paraffin, sections were for immunohistochemistry. The microdissection telomeric repeat amplification protocol silver staining assay (inicrodissection-TRAP-silver) was used for detecting telomerase activit)~ In situ hybridization was used for detecting hTERT mRNA and TP- 1 mRNA, Immunohistochemistry was used for detection c-myc and bcl-X/L protein expression. 4 Results: 45 cases were all of esophageal squamous cell carcinoma. 28 of 45 cases had lymphatic metastasis. 1 .Result of telomerase activity detected by microdissection-TRAP-silver: The telomerase activity rates were higher in dysplasia of paracancerous lesion(79.3%), in situ carcinoma(80%), invasive carcinoma(82.2%) than in normal epithelia(5%) and hyperplastic epithilia(9%). The difference of positive rate was found to be highly significant (pO.05) The differences of telomerase activity in same cancerous lesion were neither significant (p>O.O5) between high and low differential lesion nor between surface and deep invasive lesion. In cancerous lesion, telomerase activity was detected in 8 of 12 grade I (66.7%), 22 of 26 grade II (84.6%) and in all of 7 grade 111(100%), but the difference of positive rate was no significant (p>O.O5). The positive rate of telomerase activity was higher in cases with lymphatic metastasis (92.9%) than in cases without lymphatic metastasis (64.7%), and the difference between them was significant (p