【摘要】 目的　为有效地切割端粒酶逆转录酶RNA以使端粒酶活性降低 ,从而使细胞不能维持端粒长度而在有限分裂后进入凋亡 .方法　设计并合成了针对端粒酶逆转录酶RNA的锤头状核酶基因 .将该核酶基因和端粒酶逆转录酶基因分别重组入体外转录质粒 ,经体外转录反应得到核酶RNA和地高辛标记的端粒酶逆转录酶RNA ,将转录产物混合 ,在不同条件下进行体外切割反应后 ,采用地高辛化学分光法检测切割条带 .结果　此核酶对端粒酶逆转录酶组分RNA的切割效率达 6 5% .结论　该核酶具有体外切割端粒酶逆转录酶RNA的活性 ,可望成为有效的端粒酶抑制剂更多还原

【Abstract】 Telomerase activity is th ought to be essential for continuous cell divisio n as seen in malignant tumor cells and its inhibition could be a stratege for anti cancer therapy. Telome rase is a ribonucleoprotein which is composed of t hree components called as human telomerase RNA (hTR) tel omerase protein 1 (TP1) and human telomerase reverse tr anscriptase (hTERT). Among them the hTERT is the catalytic su bunit and a key factor which controls the telomerase act ivity, so it is the best choice to inhibit telomerase th rough controling hTERT expression. In research a hamm er head ribozyme directed against the hTERT RNA (htertRZ) was designed and synthesized to serve as a telomerase inhibitor. In order to test its cleavage activity, two in vitro transcription plasmids containing htert RZ and hTERT gene respectively were constructed. Ribo zyme RNA and DIG Labeled hTERT were synthesized by in vitro transcription. In vitro cleavage reactio n was carried out by mixing the htert RZ with DIG labeled hTERT under different reaction conditions. Cle avage bands were detected by digoxin chemiluminescent ass ay. HTERT RZ showed a specific cleavage activity agai nst the hTERT used as template. The cleavage ratio rea ched about 65%. These findings support the potential app lication of this ribozyme as a new therapeutic agent dire cted against immortalized cancer cell.更多还原