Telomerase Activity in Benign and Malignant Thyroid Diseases

갑상선 결절의 Telomerase 활성도에 대한 분석

Objective: Telomerase, a specialized ribonucleoprotein polymerase associated with cellular immortality, is expressed by most malignant cells and is inactive in most normal somatic cells. The assays of telomerase activity in various tumors have provided both diagnostic and prognostic information. This study was carried out to determine whether telomerase activity could be useful in distinguishing benign and malignant thyroid diseasees. Materials & Methods: Telomerase activity was determined using Oncor $TRAP_{EZE}^{TM}ELISA$ Telomerase Detection Kit for performing PCR-based telomeric repeat amplification protocol (TRAP) assay followed by ELISA detection in both normal and tumor tissues of 23 adenomatous hyperplasias, 12 follicular adenomas, 4 follicular carcinomas, 16 papillary carcinomas, 4 Hashimoto's thyroiditises and 3 malignant lymphomas. We also examined all cases microscopically to review the status of lymphoid infiltrate. Results: Of the 62 cases, extensive lymphoid infiltrates were contained in 20 tumor tissues(4 Hashimoto's thyroiditises, 3 malignant lymphomas, 6 adenomatous hyperplasias and 7 papillary carcinomas), all of which showed positive telomerase activity. All the normal tissues without lymphoid infiltrates(n=43) did not express telomerase activity. Of 42 tumor tissues without lymphoid infiltrates, 37(88.0%) showed positive telomerase activity: 13 of 17 adenomatous hyperplasias(76.5%), 11 of 12 follicular adenomas(91.7%), 4 of 4 follicular carcinomas(100.0%) and 9 of 9 papillary carcinomas(100.0%). Conclusions: Our methods showed high sensitivity in the detection of telomerase activity and the exclusion of lymphoid infiltrates may be important in telomerase assay. In our work, the measurement of telomerase activity was not useful in distinguishing benign and malignant thyroid diseases.