DNA topoisomerases are essential nuclear enzymes in correcting topological DNA errors and maintaining DNA integrity.Topoisomerase inhibitors are a significant class of cancer chemotherapeutics with a definite curative...DNA topoisomerases are essential nuclear enzymes in correcting topological DNA errors and maintaining DNA integrity.Topoisomerase inhibitors are a significant class of cancer chemotherapeutics with a definite curative effect.Natural products are a rich source of lead compounds for drug discovery,including anti-tumor drugs.In this study,we found that narciclasine(NCS),an amaryllidaceae alkaloid,is a novel inhibitor of topoisomerase I(topo I).Our data demonstrated that NCS inhibited topo I activity and reversed its unwinding effect on p-HOT DNA substrate.However,it had no obvious effect on topo II activity.The molecular mechanism of NCS inhibited topo I showed that NCS did not stabilize topo-DNA covalent complexes in cells,indicating that NCS is not a topo I poison.A blind docking result showed that NCS could bind to topo I,suggesting that NCS might be a topo I suppressor.Additionally,NCS exhibited a potent anti-proliferation effect in various cancer cells.NCS arrested the cell cycle at G_(2)/M phase and induced cell apoptosis.Our study reveals the antitumor mechanisms of NCS and provides a good foundation for the development of anti-cancer drugs based on topo I inhibition.展开更多
目的：探讨DNA拓扑异构酶Ⅱα（TopoⅡα）蛋白在宫颈癌前病变及宫颈癌中的表达及其在宫颈癌发生发展中的作用。方法选取2007-2008年在山西省肿瘤医院行宫颈病变诊治的患者，其中包括慢性宫颈炎，低级别和高级别宫颈上皮内瘤变（CIN）...目的：探讨DNA拓扑异构酶Ⅱα（TopoⅡα）蛋白在宫颈癌前病变及宫颈癌中的表达及其在宫颈癌发生发展中的作用。方法选取2007-2008年在山西省肿瘤医院行宫颈病变诊治的患者，其中包括慢性宫颈炎，低级别和高级别宫颈上皮内瘤变（CIN）和宫颈浸润性鳞癌（SCC）的患者分别21、33、30、73例，制作组织芯片，应用免疫组织化学法（SP）检测宫颈组织中TopoⅡα蛋白的表达情况。结果结果TopoⅡα蛋白在慢性宫颈炎上皮组织、CINⅠ、CINⅡ～Ⅲ、SCC中的表达率分别是5％，12％，90％，97％，表达率逐渐增加，高级别CIN和浸润性鳞癌的表达显著高于低级别CIN和正常宫颈组织，差异有统计学意义；而高级别CIN与浸润性癌之间、低级别CIN与正常宫颈上皮之间的表达差异均无统计学意义。结论 TopoⅡα蛋白表达随着宫颈癌前病变的严重程度的加重而增加，因此T o poⅡα蛋白可能参与了宫颈上皮的异常增生和恶性转变。展开更多
基金the National Natural Science Foundation of China(Grant Nos.21907044,81460559 and 82160697)Yunnan Fundamental Research Projects(Grant Nos.202101AT070155 and 202201AS070086)+2 种基金Basic Research Plan of Yunnan Provincial Science and Technology Department-Kunming Medical University(Grant Nos.202101AY070001-011,202201AY070001-003 and 202101AY070001-041)the Ten Thousand Talent Plans for Young Top-notch Talents of Yunnan Province(Hongyu Zhou,Dandan Liu),Yunnan Academician Expert Workstation(Grant No.202305AF150054)Basic Research Project of Yunnan Provincial Department of Education(Grant No.2022J0213).
文摘DNA topoisomerases are essential nuclear enzymes in correcting topological DNA errors and maintaining DNA integrity.Topoisomerase inhibitors are a significant class of cancer chemotherapeutics with a definite curative effect.Natural products are a rich source of lead compounds for drug discovery,including anti-tumor drugs.In this study,we found that narciclasine(NCS),an amaryllidaceae alkaloid,is a novel inhibitor of topoisomerase I(topo I).Our data demonstrated that NCS inhibited topo I activity and reversed its unwinding effect on p-HOT DNA substrate.However,it had no obvious effect on topo II activity.The molecular mechanism of NCS inhibited topo I showed that NCS did not stabilize topo-DNA covalent complexes in cells,indicating that NCS is not a topo I poison.A blind docking result showed that NCS could bind to topo I,suggesting that NCS might be a topo I suppressor.Additionally,NCS exhibited a potent anti-proliferation effect in various cancer cells.NCS arrested the cell cycle at G_(2)/M phase and induced cell apoptosis.Our study reveals the antitumor mechanisms of NCS and provides a good foundation for the development of anti-cancer drugs based on topo I inhibition.
文摘目的：探讨DNA拓扑异构酶Ⅱα（TopoⅡα）蛋白在宫颈癌前病变及宫颈癌中的表达及其在宫颈癌发生发展中的作用。方法选取2007-2008年在山西省肿瘤医院行宫颈病变诊治的患者，其中包括慢性宫颈炎，低级别和高级别宫颈上皮内瘤变（CIN）和宫颈浸润性鳞癌（SCC）的患者分别21、33、30、73例，制作组织芯片，应用免疫组织化学法（SP）检测宫颈组织中TopoⅡα蛋白的表达情况。结果结果TopoⅡα蛋白在慢性宫颈炎上皮组织、CINⅠ、CINⅡ～Ⅲ、SCC中的表达率分别是5％，12％，90％，97％，表达率逐渐增加，高级别CIN和浸润性鳞癌的表达显著高于低级别CIN和正常宫颈组织，差异有统计学意义；而高级别CIN与浸润性癌之间、低级别CIN与正常宫颈上皮之间的表达差异均无统计学意义。结论 TopoⅡα蛋白表达随着宫颈癌前病变的严重程度的加重而增加，因此T o poⅡα蛋白可能参与了宫颈上皮的异常增生和恶性转变。
