【摘要】 背景与目的:肿瘤细胞的端粒长度、端粒酶活性与其增殖能力和恶性程度关系密切,而且端粒和端粒酶还可能参与放射诱导的DNA损伤的修复;由此推测肿瘤细胞的端粒长度、端粒酶活性与放射敏感性之间可能存在联系。本研究旨在探讨人喉鳞癌细胞端粒长度、端粒酶活性与放射敏感性的关系。方法:体外长期传代的人喉鳞癌细胞系Hep鄄2经0、2、4、8、12Gy剂量照射3次后的存活后代体外培养20代,以克隆形成实验测定其放射敏感性参数SF2,Southernblot法测定其端粒长度(meanlengthoftelomererestrictionfragments,TRF),TRAP鄄ELISA法测定其端粒酶活性(telomeraseactivity,TA)。结果:人喉鳞癌细胞不同放射剂量存活后代的SF2:0.47～0.64,TRF:3.76～9.43kb,TA:2.606～1.761,且它们各自的SF2、TRF、TA存在差异(P均<0.05);而且,SF2与TRF呈现明显的正相关(r=0.921,P<0.01),SF2与TA呈现明显的负相关(r=-0.929,P<0.01),TRF与TA呈现明显的负相关(r=-0.944,P<0.01)。结论:人喉鳞癌细胞接受不同放射剂量存活后代的放射敏感性与其端粒长度和端粒酶活性具有一定的相关性,提示端粒长度与端粒酶活性检测对预测肿瘤细胞放射敏感性有一定意义。更多还原

【Abstract】 BACKGROUND & OBJECTIVE: Many studies showed that telomere length and telomerase activity closely correlate with proliferation and malignant degree of tumor cells, and both of them might be involved in the repair of radiation-induced DNA damage. So it was speculated that telomere length and telomerase activity maybe correlate to radiosensitivity of carcinoma cells. This study was designed to investigate the correlations of telomere length and telomerase activity to radiosensitivity of human laryngeal squamous carcinoma cell line Hep-2. METHODS: Hep-2 cells were irradiated with 0, 2, 4, 8, or 12 Gy of γ-ray for 3 times. Survival cells were subcultured for 20 generations. Radiosensitivity index, survival fraction at 2 Gy (SF2), was measured by clone formation assay. Telomere length (mean length of telomere restriction fragments, TRF) was examined by Southern blot; telomerase activity (TA) was detected by polymerase chain reaction-based telomeric repeat amplification protocol (PCR-TRAP) coupled with ELISA. RESULTS: After different doses of irradiation, SF2 of Hep-2 cells was 0.47-0.64; TRF was 3.76-9.43 kb; TA was 1.761-2.606. Each parameter had significant differences among the survival progenies (P<0.05). SF2 was positively correlated with TRF (r=0.921, P<0.01), and negatively correlated with TA (r=-0.929, P<0.01); TRF was negatively correlated with TA (r=-0.944, P<0.01). CONCLUSION: Radiosensitivity of Hep-2 cells negatively correlates with telomere length, and positively correlates with telomerase activity, which suggest that both telomere length and telomerase activity may be used to predict cellular radiosensitivity.更多还原