| Summary: | 碩士 === 國立陽明大學 === 生物醫學影像暨放射科學系 === 102 === Objectives: Thiosemicarbazone compounds (TSC) have anti-microbial, anti-viral and anti-cancer properties, and their copper complexe drugs also have a better activity to inhibit tumor cell. In this study we synthesized several novel thiosemicarbazone-Cu complexes and investigate the in vitro biological activity for topoisomerase II inhibition.
Material and Methods: Thiosemicarbazone-copper complexes were prepared via a multi-step synthesis (total yield > 70%). The crystal structures of three complexes Cu[Q44mT]Cl, Cu[Dp4pT]Cl and Cu[Dp44mT]Cl have been determined by crystal X-ray diffraction technique .The biological character of these complexes were evaluated by in vitro Topoisomerase IIα inhibition assays and antiproliferative activity in LL/2(mouse Lewis lung carcinoma) and MCF-7(human breast adenocarcinoma) cells which expressed different level of Topo-IIα .DNA fragmentation were detected byHoechst33342 staining after 24hr treated with Cu[Dp4pT]Cl (0.25 μM). In DNA distribution , LL/2 cells were analyzed by flow cytometry after 24hr treated Cu[Dp4pT]Cl (0.5 μM).
Results: A series of thiosemicarbazone-Cu complexes were synthesized successfully. In agarose gel TopoII α inhibition assay clearly show the 10 μM Cu[TSC]Cl complexes possessed inhibition activity for Topoisomerase IIα, but the TSC ligands are not suitable. Among, the Cu[Dp4pT]Cl complexe was showed higher Topoisomerase IIα inhibition activity (IC50 0.78±0.14 μM) then others (over 3 μM). The antiproliferation study, the Cu[Dp4pT]Cl was also revealed the higher inhibition activity for high Topoisomerase IIα expressing lung cancer cell (LL2) than low Topoisomerase IIα expressing cells(MCF-7). DNA fragmentation (DAPI staining) study was observed from LL/2 and MCF-7 cancer cells treated with different drug concentration of Cu[Dp4pT]Cl . DNA distribution profiles obtained the percentage of cells in S and G2/M phase had increased significantly.
Conclusions: We have synthesized a serious thiosemicarbazone-Cu complexes successfully. The Cu(TSC)Cl complexes are more effective topoisomerase IIα inhibitor than the free thiosemicarbazone ligands. Among of these complexes, the Cu[Dp4pT]Cl possessed the high anti-topoisomerase II activity and antiproliferation activity of high Topo-IIα expression cell (LL2). Futher the Cu[Dp4pT]Cl might be applied to develop 64Cu-based positron emission tomography probe for noninvasive imaging of Topo-Iiα expresion in vivo.
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