TUMOR DEVELOPMENT AND TELOMERASE ACTIBITY IN HUMAN COLORECTAL TUMORS

端粒酶维持端粒末端染色体的不稳定性，对肿瘤的发生和细胞的不朽起着重要作用。我们研究了端粒酶在结直肠癌发生中的表达机制。采用端粒重复扩增技术对结直肠癌患者手术切除的13例腺瘤、9例早期癌、32例进展期癌、5例转移瘤和30例正常粘膜进行了检测。正常粘膜端粒酶阳性率为13.3%、18.0，腺瘤为15.4%、29.9，早期癌为77.8%、65.8，进展期癌为93.8%、97.0，转移性肿瘤为100%、161.3。在直径大于6 cm的癌、低分化癌和粘液癌（p=0.009,0.001）和侵犯固有肌的癌（p=0.08）中显示高活性。端粒酶活性按正常粘膜平均活性的2倍切断，计算为肿瘤标志物。灵敏度为0.89，特异度为0.98，准确度为0.93。端粒酶在肿瘤的发生发展中起着重要的作用，被认为是一种有用的肿瘤标志物。

Telomerase keeps instability of chromosomes with telomere in terminals of them and plays a important role for development of carcinomas and immortality of cells. We investigated a mechanism of telomerase-expression in carcinogenesis of colorectal carcinomas. Thirteen adenomas, nine carcinomas in early stage, 32 carcinomas in progressive stage, five metastatic tumors, and 30 normal mucosae resected surgically from the patients with colorectal cancer were examined with the telomeric repeat amplification protocol. The results of the positivity and mean activity of telomerase are 13.3% and 18.0 in normal mucosae, 15.4%, 29.9 in adenomas, 77.8%, 65.8 in carcinomas in early stage, 93.8%, 97.0 in carcinomas in progressive stage, and 100%, 161.3 in metastatic tumors. High activity was shown in carcinomas whose diameter is larger than six cm, in poorly defferentiated carcinomas and mucus carcinomas (p=0.009,0.001 respectively), in carcinomas invades proprial muscle (p=0.08). Telomeraseactivity was cut off by the two times of mean activity of normal mucosae and calculated as a tumor marker. Its sensitivity is 0.89, its specificity 0.98, and its accuracy 0.93. Telomerase plays a important role for carcinogenesis and development of carcinomas as well as it is considered as a useful tumor marker.