结肠灌洗脱落细胞端粒酶活性诊断结肠癌的价值

目的端粒酶作为核糖核酸蛋白酶能使端粒延长而克服细胞衰老，与细胞永生和癌变密切相关，正常的躯体细胞无端粒酶活性，大多人类原发肿瘤均可探及端粒酶阳性．本研究旨在探讨结肠脱落细胞端粒酶检测对结肠癌的临床诊断价值．方法采用端粒重复序列扩增法（ＴＲＡＰ）检测１６例结肠癌外科手术新鲜标本、相邻的正常组织及其肠腔灌洗物，６例ＩＢＳ患者的结肠镜抽取物的端粒酶活性．结果结肠癌组织１６例，端粒酶强阳性１０例，弱阳性３例和阴性３例，阳性率为８１３％；结肠癌远端正常肠粘膜组织的端粒酶强阳性、弱阳性和阴性分别为０，２和１４例，阳性率为１２５％，两组Ｐ＜００１．结肠癌结肠灌洗液１６例中有５例端粒酶阳性，而６例ＩＢＳ结肠镜抽取液全部为端粒酶阴性，其诊断的敏感性和特异性分别为３１３％和１００％，阳性预测值和阴性预测值分别为１００％和６４７％．结论结肠灌洗脱落细胞的端粒酶检测对结肠癌有良好的诊断价值．

Telomerase activity of exfoliated cancer cells in colonic luminal washings *

AIM To detect the value of telomerase activity in exfoliated cancer cells in colonic luminal washings. METHODS Telomerase activity in 16 cases of colorectal tumor, their corresponding normal tissues, exfoliated cancer cells in colonic luminal washings in 16 cases of colorectal tumor and 6 cases of irritable bowel syndrome (IBS) were detected by polymerase chain based telomeric repeat amplification protocol (TRAP) respectively. RESULTS Telomerase activity was strongly positive in 10, weak positive in 3 and negative in 3 cases of tumor tissues, while there was weak positive in 2 and negative in 14 cases in 16 matched normal colonic tissue specimens. The positive rates of telomerase activity in colorectal tumor tissues and normal colonic tissue specimens were 81 3% and 12 5% respectively ( P <0 01). Telomerase activity was detected in washings from 5 (31 3%) of the 16 colon carcinoma cases but not in any cases with IBS. The sensitivity, specificity, positive predictive value and negative predictive value of detection of telomerase activity in luminal exfoliated cancer cells were 31 3%, 100%, 100% and 64 7% respectively. CONCLUSION Telomerase activity in exfoliated cancer cells in colonic luminal washings is a good marker for the detection of colon carcinoma.