Cu(II) Benzoylpyridine Thiosemicarbazone Complexes: Inhibition of Human Topoisomerase IIα and Activity against Breast Cancer Cells

The focus of this research is on the study of a series of copper (II) benzoylpyridine thiosemicarbazone complexes. Of the six benzoylpyridine thiosemicarbazone ligands used in this study, two are reported for the first time;2-benzoylpyridine tert-butyl thiosemicarbazone (BZP-tBTSC), and 2-benzoylpyridine benzyl thiosemicarbazone (BZP-BzTSC). Once characterized by NMR, melting point, and MS, these mono-anionic tridentate ligands were then reacted with Cu2+ to form the new square planar metal complexes [Cu(BZP-tBTSC)Cl] and [Cu(BZP-BzTSC)Cl]. All of the copper complexes display marked inhibition of human topoisomerase IIα. The [Cu(BZP-tBTSC)Cl] complex shows marked activity against human breast cancer cell lines.

Cu(II) Propionyl-Thiazole Thiosemicarbazone Complexes: Crystal Structure, Inhibition of Human Topoisomerase IIα, and Activity against Breast Cancer Cells

Two new thiosemicarbazone ligands, 2-propionylthiazole ethylthiosemicarbazone (PTZ-ETSC), and 2-propionylthiazole tert-butylthiosemicarbazone (PTZ-tBTSC), along with their two copper(II) complexes, [Cu(PTZ-ETSC)Cl] and [Cu(PTZ-tBTSC)Cl], are reported here for the first time. Once characterized by NMR and MS, these mono-anionic tridentate ligands were reacted with Cu2+ to form the square planar metal complexes [Cu(PTZ-ETSC)Cl] and [Cu(PTZ-tBTSC)Cl]. The x-ray crystal structure of the [Cu(PTZ-tBTSC)Cl] complex shows that the complex adopts a square planar arrangement around the copper(II) ion, but forms a sulfur-bridged dimer in the solid state. Both of the copper complexes displayed strong inhibition of human topoisomerase IIα at activities between 2-4 μM for [Cu(PTZ-ETSC)Cl], and between 8-10 μM for the [Cu(PTZ-tBTSC)Cl] complex. The EC50 values for the MDA-MB-231 breast cancer cell line were 82.6 μM for (PTZ-ETSC), 17.9 μM for [Cu(PTZ- ETSC)Cl], 97.8 μM for (PTZ-tBTSC), and 1.41 μM for [Cu(PTZ-tBTSC)Cl]. The EC50 values for the MCF7 breast cancer cell lines were 9.36 μM for (PTZ-ETSC), 0.13 μM for [Cu(PTZ-ETSC)Cl], 0.333 μM for (PTZ-tBTSC), and 0.093 μM for [Cu(PTZ-tBTSC)Cl].

New Copper (II), Palladium (II), and Platinum (II) 2-Acetylpyrazine Tert-Butylthiosemicarbazone Complexes: Inhibition of Human Topoisomerase IIα and Activity against Breast Cancer Cells

The new ligand, 2-acetylpyrazine-tertbutylthiosemicarbazone (APZ-tBTSC), and its Cu(II), Pd(II) and Pt(II) complexes have been synthesized. This ligand coordinates to the metal ions in a tridentate monoanionic fashion forming monometallic complexes with the formula [M(APZ-tBTSC)Cl]. The ligand and the three metal complexes [Cu(APZ-tBTSC)Cl], [Pd(APZ-tBTSC)Cl], and [Pt(APZ-tBTSC)Cl] were tested for anti-proliferative biological behavior with a panel of seven microbes, and the copper and palladium complexes were found to be highly active against Gram positive bacteria. The 4 compounds were also tested in human topoisomerase IIα DNA relaxation assays and all three metal complexes had topoisomerase inhibition at a concentration between 4 - 6 micro-molar. The 4 compounds were also tested for activity with the HEK293T cell line and also the breast cell cancer line, MDA-MB-231. The most effective compound for activity against the HEK293T cell line was the [Cu(APZ-tBTSC)Cl] complex, and the MDA-MB-231 breast cancer cell line was the [Pt(APZ-tBTSC)Cl] complex.

Effects of DNA topoisomerase IIα splice variants on acquired drug resistance

DNA topoisomerase IIα(170 kDa,TOP2α/170)induces transient DNA double-strand breaks in proliferating cells to resolve DNA topological entanglements during chromosome condensation,replication,and segregation.Therefore,TOP2α/170 is a prominent target for anticancer drugs whose clinical efficacy is often compromised due to chemoresistance.Although many resistance mechanisms have been defined,acquired resistance of human cancer cell lines to TOP2αinterfacial inhibitors/poisons is frequently associated with a reduction of Top2α/170 expression levels.Recent studies by our laboratory,in conjunction with earlier findings by other investigators,support the hypothesis that a major mechanism of acquired resistance to TOP2α-targeted drugs is due to alternative RNA processing/splicing.Specifically,several TOP2αmRNA splice variants have been reported which retain introns and are translated into truncated TOP2αisoforms lacking nuclear localization sequences and subsequent dysregulated nuclear-cytoplasmic disposition.In addition,intron retention can lead to truncated isoforms that lack both nuclear localization sequences and the active site tyrosine(Tyr805)necessary for forming enzyme-DNA covalent complexes and inducing DNA damage in the presence of TOP2α-targeted drugs.Ultimately,these truncated TOP2αisoforms result in decreased drug activity against TOP2αin the nucleus and manifest drug resistance.Therefore,the complete characterization of the mechanism(s)regulating the alternative RNA processing of TOP2αpre-mRNA may result in new strategies to circumvent acquired drug resistance.Additionally,novel TOP2αsplice variants and truncated TOP2αisoforms may be useful as biomarkers for drug resistance,prognosis,and/or direct future TOP2α-targeted therapies.

Synthesis of podophyllotoxin derivative GL331 and identification of it binding site on topoisomerase IIα with molecular modeling

A facile one-pot procedure has been developed for the synthesis of GL331 in 26% overall yield.In addition,molecular modeling study was carried out to predict the binding site of GL331 with human topoisomerase IIα.The result showed that GL331 exhibited high affinity for the ATPase domain of human topoisomerase IIα and suggested that GL331 probably acts as a competitor of ATP for binding with the human topoisomerase IIα.

THE ANTICANCER EFFECT AND ANTI－DNA TOPOISOMERASE II EFFECT OF EXTRACTS OF CAMELLIA PTILOPHYLLA CHANG AND CAMELLIA SINENSIS

The cytotoxic effect of extract of camellia ptilophyllachang(ECPC) and extract of camellia sinensis(ECS) onHeLa cell line, poorly differentiated nasopharyngealcarcinoma cell line(CNE2) and gastric cancer cell line(MGC-803 ) in vitro was studied using MIT assay method.The results showed that ECPC and ECS possessed significantcytotoxic effect on above three cell lines. The anticancer testin mice showed that ECPC had marked inhibitory effectagainst Ehrlich solid carcinoma(ESC) with inhibition ratesof 17. 8 48. 3% and with inhibition rates of 28. 3-54. 5% against reticular cell sarcoma(L2), and that ECShad inhibition rates of 31 . 5 -49. 4 % against ESC and 35. 8- 50% against L2. These two extracts had only marginalinhibitory effect against sarcoma- 180. The unknottingactivity of DNA topoisomerase II was inhibited completelyby ECPC and ECS at the concentration of 50 μg/ mlsuggesting that DNA topoisomerase II might be a targetenzyme of these two extracts.

Identification, characteristic and phylogenetic analysis of type II DNA topoisomerase gene in Giardia lamblia

The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a -100 aa longer central domain; a ~200 aa shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the ''amitochondriate'' G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G, lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia.

Synthesis, SAR, and in Silico ADME Screening Studies of Some 9-Amino-3-Phenylacridone Derivatives as Topoisomerase II Inhibitors

Cancer is a leading cause of death globally, claiming about 9.6 million lives and approximately 420 million new cases of cancer will be diagnosed in the world by the year 2025. The aim of this study was to synthesize and computationally evaluate pharmacological potential of some derivatives of 9-amino-3-phenylacridone, as topoisomerase II (Topo II) inhibitors. In this study, 10 derivatives of 3-phenyl-9-aminoacridone were chemically synthesized and characterized, and the potential pharmacological indications of these compounds were computationally predicted by methods such as ADMET prediction, molecular target prediction and molecular docking. The results showed that two derivatives (58e and 58j) were non-permeant of blood-brain barrier, and this property was found similar to that of amsacrine and etoposide. The results of molecular docking of the ten derivatives of 3-phenyl-9-aminoacridone that were synthesized in this work showed that the synthetic compounds (58a-j) and the standard drugs have overall best binding affinities for human acetylcholine esterase than butyrylcholinesterase, and overall best binding affinities for human topo IIα than human topo IIβ. Overall, the results of this study suggest that the synthetic compounds 58a, 58c, 58f, 58g, and 58i could probably inhibit topo IIα by catalytic inhibition as seen with amsacrine, but only 58b and 58e possessed DNA non-intercalation properties as seen with etoposide, serving as topo II poison. In conclusion, this study showed that 3-phenyl-9-aminoacridone derivatives are potential inhibitor of topo IIα/β both by catalytic inhibition and poison as non-intercalator of DNA.

Promoter Methylation, BRAF Mutation Analysis and Topoisomerase IIa Expression for the Detection of Endometrial Carcinoma in Liquid Based Cytology Samples

Cancer of the corpus uteri remains the most common gynecological related cancer in developed countries. Cytology, after the induction of liquid based cytology, has reemerged as a possible first line non-interventional diagnostic procedure with promising results. Apart from slide preparation for cytology diagnosis, LBC allows the application of elaborate molecular tests on the residual material. Samples from 74 symptomatic women were collected in ThinPrep?PreservCyt medium, from witch immunocytochemical and molecular tests were performed. Final diagnosis of 39 endometrioid carcinomas, 20 non-endometrioid carcinomas and 15 non-malignant was set after hysterectomy. Topoisomerase IIa expression was common (42%) in both types of cancer. Promoter methylation analysis revealed that hMLH1 is commonly methylated in cancers (52.7%), CDKN2A and MGMT less often (27.1%) and RARB rarely methylated (8.4%). BRAF activating mutation V600E was a rare event (8.4%) only found in low grade endometrioid carcinomas. Topoisomerase IIa expression correlated with BRAF mutations, hMLH1 and to lesser extent with CDKN2A methylation. Almost none of the biomarkers were positive in cytological negative or hyperplastic without atypia samples. Detection of methylation in any gene displayed sensitivity, specificity, PPV and NPV similar to cytology of cancer. However, inclusion of cytology diagnosis of hyperlasias with atypia increased sensitivity and NPV of cytology outperforming methylation of any gene. Further evaluation of the panel of promoter methylation, especially in cytology diagnoses of hyperplasia with or without atypia should be evaluated since initial results are promising. Even though methylation of MGMT and RARB are rare events, some patients could be benefit from specific chemotherapeutics that target either of them or the more frequently expressed topoisomerase IIa.

Hypersensitive Inhibition of the Proliferation of Cells with Mutated DNA Repair-Related Genes by the Catalytic Topoisomerase II Inhibitor 20-O-IngenolEZ

We previously reported that many ingenol compounds derived from Euphoria kansui exhibit topoisomerase inhibitory activity. 20-O-ingenolEZ in these compounds exerted inhibitory effects on both topoisomerase II (topo II) activity and cell proliferative activity. Topoisomerase II inhibitors can be divided into the poison and catalytic inhibitor types and 20-O-ingenolEZ is a catalytic inhibitor and inhibits topo IIα through inhibition of ATPase activity, but induces topo II-mediated DNA damage and apoptosis in BLM-/- DT40 cells through the induction of the DNA damage checkpoint, similar to the poison type inhibitor adriamycin. The ATPase inhibitor of topo II ICRF-193 also showed poison-like characteristics in the same cell line. However, the inhibitory effects of ICRF-193 on the proliferation of BLM-/- DT40 cells differed from those of 20-O-ingenolEZ, as did the specificity of its inhibition of the proliferation of other cell lines. 20-O-ingenolEZ showed hypersensitive inhibition of the proliferation of MCF-7 cells and BLM-/- DT40 cells with mutated DNA repair-related genes.

Ki-67及TopoisomeraseⅡ在脑胶质母细胞瘤组织中的表达及其生物学意义

目的探讨人胶质母细胞瘤中Ki-67及TopoisomeraseⅡ（TopoⅡ）之间的相关性及其与胶质母细胞瘤病人预后的关系。方法收集O6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）低表达的胶质母细胞瘤标本60例,应用免疫组化法检测Ki-67和TopoⅡ的表达,研究其相关性。结果在MGMT低表达的胶质母细胞瘤中,Ki-67与TopoⅡ表达呈正相关（γ=0.83,P〈0.05）。对本组标本来源的60例胶质母细胞瘤病人随访12~23个月,其中死亡38例,肿瘤复发46例。结论 Ki-67和TopoⅡ在胶质母细胞瘤中的表达强度相对一致;其表达能客观反映肿瘤细胞的增殖活性和恶性程度,且可能影响胶质母细胞瘤病人的预后。

免疫组化检测大肠癌GST-π、TopoisomeraseⅡ-α表达的临床意义

目的 探讨GST -π、TopoisomeraseⅡ -α蛋白与大肠癌病理学特征之间的关系。方法 分别用鼠抗人TopoisomeraseⅡ -α单克隆抗体和兔抗人GST -π抗体对 6 0例大肠癌石蜡标本进行免疫组化研究。结果 1.GST -π、TopoisomeraseⅡ -α蛋白的表达和肿瘤大小、部位及类型无关 (P >0 .0 5 ) ;但与肿瘤的分化程度、临床分期、淋巴结转移有统计学差异 (P <0 .0 0 1)。 2 .GST -π在癌灶及癌旁组织中的表达意义不同 ,在肿瘤组织中低分化组高表达而在癌旁组织中则低表达 ,二者有统计学差异 (P <0 .0 0 1) ;TopoisomeraseⅡ -α在高分化组的表达高于低分化组 (P <0 .0 0 1)。结论 1.GST -π在瘤组织中的表达强度及在癌旁组织中的表达均与肿瘤的分化及临床分期有关 ,可作为肿瘤预后的指标。 2 .Topoi someraseⅡ -α在肿瘤组织中的表达和其分化、淋巴结转移有关 。

TopoisomeraseⅡ-α在大肠癌中的表达和临床意义

目的 探讨TopoisomeraseⅡ α蛋白与大肠癌病理学特征之间 ,耐药之间的关系。 方法 分别用鼠抗人TopoisomeraseⅡ α单克隆抗体对 60例大肠癌石蜡标本进行免疫组化研究。 结果 TopoisomeraseⅡ α蛋白及癌旁组织中的表达和性别、肿瘤大小、部位及类型无关 (P >0 .0 5 ) ;但与肿瘤的分化程度、Dukes分期、TMN分期、临床分期、淋巴结转移有统计学差异 (P <0 .0 0 1)。TopoisomeraseⅡ α在高分化组的表达高于低分化组 (P <0 .0 0 1) ,淋巴结转移组表达则低于无淋巴结转移组 (p <0 .0 0 1)。结论 TopoisomeraseⅡ α在肿瘤组织中的表达 ,强度和肠癌生物学特性密切相关 ,与肿瘤的分化及临床分期、淋巴结转移有关 ,可做为衡量恶性程度 ,耐药性及预后的指标之一。

基于区间毕达哥拉斯犹豫模糊熵和交叉熵的ELECTRE II决策方法

针对属性权重完全未知或部分已知,属性值为区间毕达哥拉斯犹豫模糊数的多属性决策问题,提出了基于区间毕达哥拉斯犹豫模糊熵和交叉熵的ELECTRE II法。首先给出区间毕达哥拉斯犹豫模糊数的区间形式的得分函数和精度函数,定义新的距离测度。然后基于区间毕达哥拉斯犹豫模糊数的模糊因子、直觉因子和幅度因子,给出熵和交叉熵公式,并证明其性质,提出了基于熵和交叉熵确定属性权重的方法。最后提出了区间毕达哥拉斯犹豫模糊环境下的改进的ELECTRE II法,利用综合优势值对方案进行排序,并通过算例和比较分析验证了该方法的可行性和有效性。

基于改进NSGA-II的轨道交通接驳公交线路优化

为解决接驳公交线路规划不合理和时间安排不完善的问题,提出了基于改进NSGA-II算法的环形接驳公交线路优化方法。首先,结合双层规划理论,以乘客出行时间成本最小化、公交企业运营收益和接驳公交服务率最大化为目标函数,以接驳公交线路站点数、线路长度和发车频率作为约束条件构建上层模型,采用Logit模型构建了下层接驳客流分配模型;其次,运用Floyd算法对NSGA-II算法的初始化种群进行了优化,针对所提出的模型设计了模型求解流程;最后,以哈尔滨市轨道交通1号线医大一院轨道交通站为案例,运用笔者提出的多目标双层规划模型和算法进行求解,并与原NSGA-II算法和基于Logistic混沌映射的NSGA-II算法进行对比。研究结果表明:基于Floyd算法改进的NSGA-II算法在多目标双层规划模型求解时,收敛速度更快效果更好,求解结果可以在Pareto前沿得到多个相互非支配的最优解;不同解集对应目标函数值不同,但可以达到接驳公交网络整体效益最优,采用折衷最优解集表述求解结果。

Inhibitory effects of lapachol on rat C6 glioma in vitro and in vivo by targeting DNA topoisomerase Ⅰ and topoisomerase Ⅱ

OBJECTIVE The aim of this study is to investigate the inhibitory effects of lapachol on rat C6 glioma both in vitro and in vivo,as well as the potential mechanisms.METHODS First,the model of C6 glioma in Wistar rats was established and verified by hemotoxylin and eosin staining,immunohistochemical staining and magnetic resonance imaging(MRI).Then different doses of lapachol were gavaged and tumor volumes of the C6 glioma were detected by MRI.The effects of lapachol on C6 cell proliferation,apoptosis and DNA damage were detected by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS)/phen-azinemethosulfate(PMS)assay,Hoechst33358 staining,AnnexinⅤ-FITC/PI staining,and comet assay.Effects of lapachol on topoisomeraseⅠ(TOPⅠ)and topoisomeraseⅡ(TOPⅡ)activities were detected by TOPⅠand TOPⅡmediated supercoiled p BR322 DNA relaxation assay.Molecular docking was used to predict the interaction of lapachol-TOPⅠand lapachol-TOPⅡ.TOP I and TOPⅡexpression levels in C6 cells were determined by Enzymelinked immunosorbent assay kits and real-time polymerase chain reaction(RT-PCR).RESULTS The rat C6 glioma model was successfully established.High dose lapachol showed significant inhibitory effect on the C6 glioma in Wistar rats(P<0.05).MTS/PMS assay,Hoechst 33258 staining,AnnexinⅤ-FITC/PI staining,and comet assay showed that lapachol could inhibit proliferation,induce apoptosis and DNA damage of C6 cells in dose dependent manners.Lapachol could inhibit the activities of both TOPⅠandⅡ.Molecular docking showed that lapachol-TOPⅠshowed relatively stronger interaction than that of lapachol-TOPⅡ.Enzyme-linked immunosorbent assay and RT-PCR showed that lapachol could inhibit TOPⅡexpression levels,but not TOPⅠexpression levels.CONCLUSION These results showed that lapachol could significantly inhibit C6 glioma both in vivo and in vitro,which might be related with inhibiting TOPⅠand TOPⅡactivities,as wel as TOPⅡexpression.

融合NSGA-II和CSA的多目标车间调度

针对在灵活车间系统中调度作业和自动引导车(automated guide vehicle,AGV)的同时调度问题,考虑在有限多个AGV和加工机台的情况下,以最小化最大完工时间、单个AGV搬运消耗时间及所有AGV搬运总消耗时间为目标函数,设计融合NSGA-II(non-dominated sorting genetic algorithms)和克隆选择(clonal selection algorithm,CSA)的改进算法INGCSA来解决此类问题。采用工件、加工机台和AGV三部分编码;引入非支配排序和目标函数值大小排序后总得分进行种群分层,从而有效地保留优秀个体;针对克隆后的种群,对不同等级的种群采取不同的变异概率,并对染色体进行内部交换与均匀交叉混合交换的基因重组,有效地提高了种群的多样性与防止陷入局部最优。通过三组对比实验,验证了该算法在探索最优解时,具有运行时间短、稳定性高和收敛性好等优点。

EFFECT OF ACTIVE COMPOUNDS ISOLATED FROM PTERIS SEMIPINNATA L ON DNA TOPOISOMERASES AND TYROSINE PROTEIN KINASE AND EXPRESSION OF C-MYC IN LUNG ADENOCARCINOMA CELLS

Objective: To study the effect of active compound 6F and A from Pteris semipinnata L.(PsL) on the activities of DNA topoisomerase (TOPO) I and II, activities of cytosolic and membrane TPK, and expression of oncogene c-myc in lung adenocarcinoma cells. Methods: The effect of compound 6F and A on activities of cytosolic and membrane TPK was measured by scintillation counting; the effect of compound A on expression of oncogene c-myc was determined by flow cytometry indirect fluorimetry. Results: compound 6F and A could inhibit the activities of TOPO I, and they strongly inhibited the TOPO II in 0.01 mg/L and 10.0 mg/L respectively. Compound A slightly inhibited the activities of membrane TPK, but not the cytosolic one. Compound A could inhibit the expression of oncogene c-myc. Conclusion: Topoisomerases are target of compound 6F and A. Compound A could slightly inhibit the activities of TPK, and showed an inhibitory effect on the expression of oncogene c-myc.

Inhibition of DNA-Topoisomerase I by Acylated Triterpene Saponins from Pittosporum angustifolium Lodd.

Previous phytochemical investigation of the leaves and seeds of Pittosporum angustifolium Lodd.led to the isolation and structural elucidation of polyphenols and triterpene saponins.Evaluation for cytotoxicity of isolated saponins revealed that the predominant structural feature for a cytotoxic activity are acyl substituents at the oleanane aglycon backbone.The present work reports the results of a screening of 10 selected acylated saponins for their potential to inhibit the human DNA-topoisomerase I,giving rise to IC50 values in a range of 2.8-46.5 lM.To clarify the mode of observed cytotoxic action and,moreover,to distinguish from a pure surfactant effect which is commonly accompanied with saponins,these results indicate an involvement of the topoisomerase I and its role as a possible target structure for a cytotoxic activity.In addition,computational predictions of the fitting of saponins to the topoisomerase I-DNA complex,indicate a similar binding mode to that of clinically used topoisomerase I inhibitors.Graphical Abstract Ten acylated triterpene saponins from Pittosporum angustifolium were investigated for their potential to inhibit the human DNA-topoisomerase I and computational predictions of the fitting of saponins to the topoisomerase I-DNA complex were carried out.