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Objectives:To find out the relation between main clinical character and telomerase activity in oral squamous cell carcinomas. Methods:Telomerase activity was detected by telomerase PCR ELISA assay in 12 cases of oral normal tissue and 45 cases of oral squamous cell carinoma. Results:Telomerase activity was not detectable in 12 cases of oral normal tissue. Telomerase activity was detected in 75.67 percent of oral squamous cell carcinomas. Telomerase activity was present more frequently in advanced oral squamous cell carinoma than in the early stage( P
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Purpose The aim is to obtain the cDNA sequence of encoding extramembrane human FL gene with high level expression in E.coli. Methods The primers were designed based on the known FL cDNA sequence. The total RNA was isolated from fetal liver cells , and then RT-PCR was performed. The fragment was cloned into pUC-18T vector, and further sequenced by automatic sequence analyzer. The gene was inserted into GST fusion expression vector between BamH Ⅰ and EcoR Ⅰ sites. The recombinant plasmid was transformed into E.coli strain DH5 α and induced with 1mmol/L IPTG.Results The 546bp DNA fragment was amplified by RT-PCR method from fetal liver cells and its sequence was identical to the published sequence encoding human FL. The expressed fusion protein, with molecular weight of about 22kD, was about 10% of the total bacteria protein by SDS-PAGE and densitometry analysis.Conclusion cDNA was cloned successfully. This study provided a basis for the further fundamental research and clinical application of FL.
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Objective To study the diagnostic value of pleural fluid telomerase activity in distinguishing a malignant from a benign pleural effusion. Methods Using a PCR-based assay, telomerase activity was examined in the pleural fluid cells obstained from 69 patients with pleural effusions (37 malignant, 32 benign). Results were compared with cytologic evaluation and carcinoembryonic antigen (CEA). Results Of the 37 malignant specimens，26（70.27%）contained detectable telomerase activity. The positive rate in malignant pleural effusions was significantly higher than that in benign origin (2/32). Detection of telomerase in effusions was more sensitive than CEA level evaluation for the identification of pleural malignancy (telomerase assay: sensitivity=70.27%, specificity=93.75%; CEA: sensitivity=51.35%, specificity=96.87%). The consistant rate of telomerase with cytology was 54.05%. Conclusion The detection of telomerase activity may be a useful adjunct to cytopathologic methods in the diagnosis of malignant pleural effusions. It may be useful in differential diagnosis of benign and malignant pleural effusions.