Objectives. 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) ...Objectives. 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. Methods. 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. Results. 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. Conclusion. 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.展开更多
Cytokinesis-block micronucleus method is used to evaluate the radiosensitivity of a nasopharyngeal carcinoma cell line (CNE-1) and biopsies obtained from 31 patients with nasopharyngeal carcinoma. The number of micro...Cytokinesis-block micronucleus method is used to evaluate the radiosensitivity of a nasopharyngeal carcinoma cell line (CNE-1) and biopsies obtained from 31 patients with nasopharyngeal carcinoma. The number of micronuclei increases with theradiation dose. A good correlation was found between the radiosensitivity determined by the micro-nucleus assay and that measured by the colony-forming assay in CNE-1 cell line (r=-0.998). Moreover, the results of micronucleus assay for tumor cells from biopsies of patients with primary carcinoma look promising for the prediction of tumor radiosensitivity. These results are encouraging but fleed to be confirmed with a larger number of patients with a longer follow-up.展开更多
文摘Objectives. 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. Methods. 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. Results. 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. Conclusion. 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.
文摘Cytokinesis-block micronucleus method is used to evaluate the radiosensitivity of a nasopharyngeal carcinoma cell line (CNE-1) and biopsies obtained from 31 patients with nasopharyngeal carcinoma. The number of micronuclei increases with theradiation dose. A good correlation was found between the radiosensitivity determined by the micro-nucleus assay and that measured by the colony-forming assay in CNE-1 cell line (r=-0.998). Moreover, the results of micronucleus assay for tumor cells from biopsies of patients with primary carcinoma look promising for the prediction of tumor radiosensitivity. These results are encouraging but fleed to be confirmed with a larger number of patients with a longer follow-up.
