Expression and Regulation of Telomerase Subunits in both Cutaneous Neoplasms and Cultured Melanoma Cell Line

• Main Authors: Sindy Hu, 胡倩婷
• Other Authors: Jong-Hwei S.Pang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/60615887474039909146

碩士 === 長庚大學 === 臨床醫學研究所 === 90 === Background: Telomerase is a specialized ribonucleoprotein polymerase that ensures the chromosomal stability. Three major components of telomerase complex: human telomerase RNA (hTR), telomerase-associated protein (TP1) and human telomerase reverse transcriptase (hTERT) have been identified and the regulation of these subunits is multifactorial and implicated in telomerase activation, which is an important step in human carcinogenesis. Purpose: To detect and compare the mRNA expression of 3 major telomerase subunits in different skin diseases biopsy specimens and try different agents on cultured melanoma cells for screening out the inhibitors of telomerase and its subunits. Methods: Fresh biopsy skin specimens from 62 clinical cases were collected in out patient department. Total RNA was isolated from tissue followed by reverse transcriptase-polymerase chain reaction (RT-PCR) for the expression of telomerase subunits. We also detected the activity of telomerase and the expression of hTERT of human MeWo melanoma cell line after addition of different cell-damaging agents. Results: TP1 was detected in 61 of 62 cases (98.38%). hTR was found in 58 of 62 cases (93.55%). There was no significant difference in the expression of hTR between benign tumors (92.6%) and malignant tumors (95.65%)(P=1). We observed a higher positive rate of hTERT in malignant and premalignant tumor group (73.91%) when compared to benign tumor group (7.41%) (P=0.001). We concluded that hTERT was more specific for malignant cutaneous lesions when comparing with TP1 and hTR. Among the tested agents in the cultured melanoma cell line,H7(1-(5-Isoquinolinesulfonyl)-2-methylpiperazineDihydrochloride) had inhibition of both telomerase activity and the expression of hTERT with dosage-dependence. Conclusion: The study of telomerase has implication of our understanding about the molecular mechanism of the telomerase activation. Since hTERT is found to have higher specificity to malignant cutaneous tumors and melanoma, development of new anticancer regimens may be considered focusing on targeting this rate-limiting determinant.