Zhu H, Xiong S, Cheng W
Shanghai Institute of Radiation Medicine, Department of Immunology, Shanghai Medical University, Shanghai 200032.
Chin Med Sci J. 2001 Jun;16(2):63-6.
In order to identify the relationship between telomerase and the biological effect of radiation injury, and investigate the role of human telomerase catalytic subunit gene (hEST2) reverse transcriptase(RT) segment in the expression of telomerase activity.
Tumor HeLa cells, KB cells and A431 cells were employed to measure the change in telomerase activity after 60Co-ray irradiation at RNA level and protein level. Quantitative PCR and Northern blotting were used to determine the expression of hEST2 RT segment that encodes seven motifs of the human telomeres, a PCR-based telomeric repeat amplification protocol (TRAP) was used to assay telomerase activity after exposure to radiation.
Both of telomerase activity and the expression hEST2 RT segment were decreased with increasing dosage of radiation. In addition, testing the expression of motifs domain is similar to the measurement of telomerase activity.
The detection of the hEST2 RT segment by Northern blotting and quantitative PCR are new methods for testing telomerase activity. Furthermore, radiation can cause a dose-dependent decrease in telomerase activity. The effect of radiation on telomerase is one possible reason for the death of cancer cells after irradiation.
为明确端粒酶与辐射损伤生物学效应之间的关系，探讨人端粒酶催化亚基基因（hEST2）逆转录酶（RT）片段在端粒酶活性表达中的作用。
采用肿瘤HeLa细胞、KB细胞和A431细胞，在RNA水平和蛋白质水平上检测60Co射线照射后端粒酶活性的变化。运用定量PCR和Northern印迹法测定编码人端粒七个基序的hEST2 RT片段的表达，采用基于PCR的端粒重复序列扩增法（TRAP）检测辐射暴露后端粒酶活性。
随着辐射剂量增加，端粒酶活性和hEST2 RT片段的表达均降低。此外，检测基序结构域的表达与端粒酶活性的测定相似。
通过Northern印迹法和定量PCR检测hEST2 RT片段是检测端粒酶活性的新方法。此外，辐射可导致端粒酶活性呈剂量依赖性降低。辐射对端粒酶的影响是癌细胞照射后死亡的一个可能原因。
