Mu X C, Brien T P, Ross J S, Lowry C V, McKenna B J
Department of Pathology and Laboratory Medicine, Albany Medical College, New York, USA.
Cancer. 1999 Apr 25;87(2):93-9.
Telomerase is a ribonucleoprotein that maintains telomeric base pair repeats at the ends of mammalian chromosomes during DNA replication. Telomerase is expressed in various human tumors, some normal tissues, and immortalized cell lines. The assay of telomerase activity has potential as an adjunct for cancer detection in cytologic fluids.
Twenty-four unfixed cytologic fluids, including 13 ascitic fluids, 7 pleural fluids, 3 pelvic washings, and 1 bronchial washing, were prepared for polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (Oncor, Inc., Gaithersburg, MD). Telomerase activity was determined by PCR. The presence of a ladder of products with 6 base pair increments, separated by polyacrylamide gel electrophoresis and detected by phosphoimaging, was considered a positive result. Results were compared with cytologic evaluation of alcohol fixed, Papanicolaou stained smears.
Of the 14 cytologically malignant specimens, 11 (79%) contained detectable telomerase activity. Two cytologically malignant samples could not be evaluated for telomerase activity due to the presence of inhibitory substances of PCR reaction. Of the 10 cytologically negative specimens, 1 (10%) was positive for telomerase activity; this specimen was from a patient with history of both endometrial and lung carcinomas.
Telomerase activity can be detected in malignant cytologic specimens and thus has potential as a diagnostic adjunct in cytopathology.
端粒酶是一种核糖核蛋白，在DNA复制过程中维持哺乳动物染色体末端的端粒碱基对重复序列。端粒酶在多种人类肿瘤、一些正常组织及永生化细胞系中表达。端粒酶活性检测在作为细胞学液体中癌症检测的辅助手段方面具有潜力。
制备24份未固定的细胞学液体，包括13份腹水、7份胸水、3份盆腔冲洗液和1份支气管冲洗液，用于基于聚合酶链反应（PCR）的端粒重复序列扩增法（Oncor公司，马里兰州盖瑟斯堡）。通过PCR测定端粒酶活性。经聚丙烯酰胺凝胶电泳分离并用磷成像检测，出现以6个碱基对递增的产物梯状条带被视为阳性结果。将结果与酒精固定、巴氏染色涂片的细胞学评估结果进行比较。
在14份细胞学诊断为恶性的标本中，11份（79%）含有可检测到的端粒酶活性。由于存在PCR反应抑制物质，2份细胞学诊断为恶性的样本无法评估端粒酶活性。在10份细胞学诊断为阴性的标本中，1份（10%）端粒酶活性呈阳性；该标本来自一位有子宫内膜癌和肺癌病史的患者。
恶性细胞学标本中可检测到端粒酶活性，因此在细胞病理学中作为诊断辅助手段具有潜力。
