• 【UCN-01和喜树碱可在p53突变肿瘤细胞中诱导DNA双链断裂,但在正常或p53阴性上皮细胞中则不会。】 复制标题 收藏 收藏
    DOI:10.3892/ijo.17.5.1043 复制DOI
    作者列表:Jones CB,Clements MK,Redkar A,Daoud SS
    BACKGROUND & AIMS: :Previous research has shown synergistic growth inhibition between UCN-01 and camptothecin (CPT) in tumor cells with mutant p53 versus tumor cells with wild-type p53. To determine the possible role of p53 in this drug combination, we tested the hypothesis that the synergistic growth inhibition is due to the absence of p53, and can result from the induction of DNA double-strand breaks (DSBs). Experiments were performed with the use of normal human mammary epithelial cells (HMEC); HMEC transfected with HPV16 E6 protein which inactivates p53 (HE6), or p53-mutant MDA-MB-231 tumor cells. CPT, UCN-01, or a 1:1 combination of both, in either HMEC or HE6 cells did not induce DSBs. In contrast, simultaneous treatment of MDA-MB-231 cells with both UCN-01 and CPT induced significant levels of DSBs while treatment with either drug alone did not. While UCN-01 was surprisingly potent against HMEC, the growth inhibition was only additive between UCN-01 and CPT against these cells. HE6 cells were much less sensitive than HMEC to UCN-01 and slightly less sensitive to the combined treatment with UCN-01 and CPT. The drug combination was synergistic against HE6 cells, due to their lower sensitivity to UCN-01. Unlike what was observed previously in MDA-MB-231 cells, UCN-01 did not abrogate CPT-induced inhibition of DNA synthesis in either HMEC or HE6 cells. These data indicate that synergistic growth inhibition by UCN-01 and CPT against p53 mutant MDA-MB-231 tumor cells may be due to induction of DSBs however the loss of p53 function alone does not sensitize normal cells to the combination of both drugs.
    背景与目标: :先前的研究表明,在具有突变型p53的肿瘤细胞与具有野生型p53的肿瘤细胞中,UCN-01和喜树碱(CPT)之间具有协同生长抑制作用。为了确定p53在这种药物组合中的可能作用,我们测试了以下假设:协同生长抑制是由于p53的缺失,并且可能是由DNA双链断裂(DSBs)引起的。使用正常人乳腺上皮细胞(HMEC)进行实验;用HPV16 E6蛋白转染的HMEC,该蛋白可灭活p53(HE6)或p53突变的MDA-MB-231肿瘤细胞。 HMEC或HE6细胞中的CPT,UCN-01或两者的1:1组合均不会诱导DSB。相反,用UCN-01和CPT同时处理MDA-MB-231细胞可诱导显着水平的DSB,而单独使用任何一种药物均不能。尽管UCN-01令人惊讶地对HMEC有效,但其生长抑制作用仅是UCN-01和CPT之间对这些细胞的加和作用。 HE6细胞对UCN-01的敏感性比HMEC低得多,而对UCN-01和CPT的联合治疗敏感性稍低。该药物组合对HE6细胞具有协同作用,因为它们对UCN-01的敏感性较低。与以前在MDA-MB-231细胞中观察到的不同,UCN-01在HMEC或HE6细胞中都没有消除CPT诱导的DNA合成抑制作用。这些数据表明,UCN-01和CPT对p53突变MDA-MB-231肿瘤细胞产生的协同生长抑制作用可能是由于DSB的诱导所致,但是仅p53功能的丧失并不能使正常细胞对两种药物的组合敏感。
  • 【喜树碱诱导凋亡的HEp-2细胞中FasL三聚体向细胞表面的转移。】 复制标题 收藏 收藏
    DOI:10.2478/s11658-006-0025-3 复制DOI
    作者列表:Meza-Lamas E,Bollain-y-Goytia JJ,Ramírez-Sandoval R,Sánchez-Rodríguez SH,López-Robles E,Avalos-Díaz E,Herrera-Esparza R
    BACKGROUND & AIMS: :Fas ligand (L) is a membrane protein from the tumor necrosis factor (TNF) family. It induces apoptosis upon contact with its Fas/CD95/APO1 receptor. Trimerization of FasL on the surface of effector cells is essential in the binding of the Fas trimer of the target cells. The receptor then recruits an adaptor and caspase-like proteins which lead apoptosis. This paper reports on the fate of FasL in HEp-2 cells committed to apoptosis by induction with campthotecin. Our main results demonstrated that in non-apoptotic cells, FasL aggregates in the cytoplasm forming trimers of 120 kDa. Apoptosis increases the trimeric FasL species, but also induces its dissociation into monomers of 35 kDa. In conclusion, camptothecin appears to perturb the Fas and FasL segregation in the cytoplasm by promoting the transit of FasL to the cell surface, thus fostering a process of autocrine or paracrine apoptosis. FasL is trimerized prior to Fas/FasL complex formation, and after apoptosis, FasL undergoes an intense turnover.
    背景与目标: :Fas配体(L)是一种来自肿瘤坏死因子(TNF)家族的膜蛋白。与Fas / CD95 / APO1受体接触后,它会诱导凋亡。 FasL在效应细胞表面的三聚化对于靶细胞Fas三聚体的结合至关重要。然后,受体募集衔接子和胱天蛋白酶样蛋白,从而导致细胞凋亡。这篇论文报道了通过喜树碱诱导的凋亡导致Hep-2细胞中FasL的命运。我们的主要结果表明,在非凋亡细胞中,FasL在细胞质中聚集,形成120 kDa的三聚体。凋亡增加了三聚体FasL种类,但也诱导其解离成35kDa的单体。总之,喜树碱通过促进FasL向细胞表面的转移,似乎干扰了Fas和FasL在细胞质中的分离,从而促进了自分泌或旁分泌细胞凋亡的过程。 FasL在Fas / FasL复合物形成之前被三聚,并且在细胞凋亡后,FasL经历强烈的更新。
  • 【叶酸靶向的单分散PEG喜树碱偶联物的合成和活性。】 复制标题 收藏 收藏
    DOI:10.1016/j.bmcl.2013.08.113 复制DOI
    作者列表:Henne WA,Kularatne SA,Hakenjos J,Carron JD,Henne KL
    BACKGROUND & AIMS: :A folate targeted camptothecin small molecule drug conjugate (SMDC) was synthesized using a monodisperse PEG spacer linked to folate via a releasable disulfide carbonate linker. Cell cytotoxicity in human KB cells exhibited an IC50 of 6nM. Importantly, activity of the prodrug was blocked by excess folate, demonstrating receptor-mediated celluar uptake of the PEG conjugate.
    背景与目标: 叶酸靶向喜树碱小分子药物偶联物(SMDC)的合成是通过可释放的二硫化碳碳酸酯连接子与叶酸连接的单分散PEG间隔基进行的。人KB细胞中的细胞毒性显示出6nM的IC50。重要的是,前药的活性被过量的叶酸所阻断,表明受体介导的细胞对PEG缀合物的摄取。
  • 【喜树碱和鬼臼毒素衍生物:拓扑异构酶I和II的抑制剂-作用机理,药代动力学和毒性特征。】 复制标题 收藏 收藏
    DOI:10.2165/00002018-200629030-00005 复制DOI
    作者列表:Hartmann JT,Lipp HP
    BACKGROUND & AIMS: :Camptothecins represent an established class of effective agents that selectively target topoisomerase I by trapping the catalytic intermediate of the topoisomerase I-DNA reaction, the cleavage complex. The water-soluble salt camptothecin-sodium - introduced in early trials in the 1960s - was highly toxic in animals, whereas the semisynthetic derivatives irinotecan and topotecan did not cause haemorrhagic cystitis because of their higher physicochemical stability and solubility at lower pH values. Myelosuppression, neutropenia and, to a lesser extent, thrombocytopenia are dose-limiting toxic effects of topotecan. In contrast to the structurally-related topotecan, irinotecan is a prodrug which has to be converted to SN-38, its active form. SN-38 is inactivated by conjugation, thus patients with Gilbert's syndrome and other forms of genetic glucuronidation deficiency are at an increased risk of irinotecan-induced adverse effects, such as neutropenia and diarrhoea. The cytotoxic mechanism of podophyllotoxin is the inhibition of topoisomerase II. Common adverse effects of etoposide include dose-limiting myelosuppression. Hypersensitivity reactions are more common with etoposide and teniposide than with etoposide phosphate because the formulations of the former contain sensitising solubilisers. Leukopenia and thrombocytopenia occur in 65% and 80%, respectively, of patients after administration of conventional doses of teniposide. Anorexia, vomiting and diarrhoea are generally of mild severity after administration of conventional doses of topoisomerase II inhibitors. Clinical pharmacokinetic studies have revealed substantial interindividual variabilities regarding the area under the concentration-time curve values and steady-state concentrations for all drugs reviewed in this article. Irinotecan, etoposide and teniposide are degraded via complex metabolic pathways. In contrast, topotecan primarily undergoes renal excretion. Regarding etoposide and teniposide, the extent of catechol formation over time during drug metabolism may be associated with a higher risk for secondary malignancies.
    背景与目标: 喜树碱代表一类已建立的有效药物,通过捕获拓扑异构酶I-DNA反应的催化中间体,裂解复合物,选择性地靶向拓扑异构酶I。 1960年代早期试验中引入的水溶性喜树碱钠盐对动物具有高毒性,而半合成衍生物伊立替康和托泊替康因其较高的理化稳定性和在较低pH值下的溶解度而不会引起出血性膀胱炎。骨髓抑制,中性粒细胞减少和血小板减少是托泊替​​康的剂量限制性毒性作用。与结构相关的拓扑替康相反,伊立替康是一种前药,必须将其转变为其活性形式SN-38。 SN-38会因结合而失活,因此患有吉尔伯特综合症和其他形式的遗传性葡萄糖醛酸缺乏症的患者罹患伊立替康引起的不良反应(如中性粒细胞减少和腹泻)的风险增加。鬼臼毒素的细胞毒性机制是对拓扑异构酶II的抑制。依托泊苷的常见不良反应包括限制剂量的骨髓抑制。依托泊苷和替尼泊苷的过敏反应比依托泊苷磷酸酯的过敏反应更为常见,因为前者的配方中含有增敏剂。常规剂量的替尼泊苷给药后,白细胞减少症和血小板减少症分别发生在65%和80%的患者中。常规剂量的拓扑异构酶II抑制剂给药后,厌食,呕吐和腹泻的严重程度通常较轻。临床药代动力学研究表明,本文中综述的所有药物的浓度-时间曲线值和稳态浓度下的面积之间存在很大的个体差异。伊立替康,依托泊苷和替尼泊苷通过复杂的代谢途径降解。相反,拓扑替康主要经历肾脏排泄。关于依托泊苷和替尼泊苷,药物代谢期间儿茶酚形成的程度可能与继发性恶性肿瘤的较高风险有关。
  • 【转录因子OpWRKY3参与喜树碱及其毛状根喜树碱及其前体的发育和生物合成。】 复制标题 收藏 收藏
    DOI:10.3390/ijms20163996 复制DOI
    作者列表:Wang C,Wu C,Wang Y,Xie C,Shi M,Nile S,Zhou Z,Kai G
    BACKGROUND & AIMS: :The plant Ophiorrhiza pumila produces camptothecin (CPT), a kind of terpene indole alkaloid (TIAs) that has been widely used in treatment of cancer. Tryptophan-arginine-lysine-tyrosine (WRKY) transcription factors have been reported to play important roles in plant metabolism and development. In this study, a novel WRKY transcription factor named OpWRKY3 was isolated from O. pumila, with full-length open reading frame (ORF) of 1128 bp, encoding 375 amino acids. Phylogenetic tree analysis revealed that OpWRKY3 shared the highest homology with VvWRKY30, and it is a significant feature belonging to group III. OpWRKY3 was responsive to various treatments, including gibberellin (GA3), methyl jasmonate (MJ), acetylsalicylic acid (ASA), salicylic acid (SA), and abscisic acid (ABA). Besides, OpWRKY3 is expressed predominantly in stems. Subcellular localization analysis showed that OpWRKY3 localized in the nucleus. The biomass of OpWRKY3-SRDX transgenic hairy roots (S line) was visibly suppressed, while there were slight changes between overexpression of the OpWRKY3 line (OE line) and the control. In addition, the concentration and total production of camptothecin precursors including loganin and secologanin were significantly changed in both OE and S lines while total production of CPT was significantly changed in most transgenic lines. Thus, the present work revealed that OpWRKY3 may act as a regulator in the growth and development of O. pumila, and in production of camptothecin and its precursors.
    背景与目标: :Ophiorrhiza pumila植物产生喜树碱(CPT),这是一种被广泛用于治疗癌症的萜烯吲哚生物碱(TIA)。色氨酸-精氨酸-赖氨酸-酪氨酸(WRKY)转录因子据报道在植物代谢和发育中起重要作用。在这项研究中,从O. pumila中分离出了一种名为OpWRKY3的新型WRKY转录因子,其全长开放阅读框(ORF)为1128 bp,编码375个氨基酸。系统进化树分析表明,OpWRKY3与VvWRKY30具有最高的同源性,这是第三类的重要特征。 OpWRKY3对多种处理有响应,包括赤霉素(GA3),茉莉酸甲酯(MJ),乙酰水杨酸(ASA),水杨酸(SA)和脱落酸(ABA)。此外,OpWRKY3主要在茎中表达。亚细胞定位分析表明OpWRKY3定位在细胞核中。 OpWRKY3-SRDX转基因毛状根(S系)的生物量受到明显抑制,而OpWRKY3系(OE系)的过表达与对照之间略有变化。另外,喜树碱前体包括loganin和secologanin的浓度和总产量在OE和S系中均发生了显着变化,而CPT的总产量在大多数转基因系中均发生了显着变化。因此,目前的工作表明,OpWRKY3可能在O. pumila的生长和发育以及喜树碱及其前体的生产中起调节作用。
  • 【喜树碱通过诱导DNA损伤并激活同源重组来提高哺乳动物细胞中寡核苷酸定向基因修复的频率。】 复制标题 收藏 收藏
    DOI:10.1093/nar/gkh822 复制DOI
    作者列表:Ferrara L,Kmiec EB
    BACKGROUND & AIMS: :Camptothecin (CPT) is an anticancer drug that promotes DNA breakage at replication forks and the formation of lesions that activate the processes of homologous recombination (HR) and nonhomologous end joining. We have taken advantage of the CPT-induced damage response by coupling it to gene repair directed by synthetic oligonucleotides, a process in which a mutant base pair is converted into a wild-type one. Here, we show that pretreating DLD-1 cells with CPT leads to a significant stimulation in the frequency of correction of an integrated mutant enhanced green fluorescent protein gene. The stimulation is dose-dependent and coincident with the formation of double-strand DNA breaks. Caffeine, but not vanillin, blocks the enhancement of gene repair suggesting that, in this system, HR is the pathway most responsible for elevating the frequency of correction. The involvement of HR is further proven by studies in which wortmannin was seen to inhibit gene repair at high concentrations but not at lower levels that are known to inhibit DNA-PK activity. Taken together, our results suggest that DNA damage induced by CPT activates a cellular response that stimulates gene repair in mammalian cells.
    背景与目标: 喜树碱(CPT)是一种抗癌药,可促进复制叉处的DNA断裂和损伤的形成,从而激活同源重组(HR)和非同源末端连接的过程。我们通过将CPT诱导的损伤反应与合成寡核苷酸指导的基因修复相结合来利用CPT诱导的损伤反应,在该过程中,突变碱基对被转化为野生型。在这里,我们显示用CPT对DLD-1细胞进行预处理可显着刺激整合突变增强型绿色荧光蛋白基因的校正频率。刺激是剂量依赖性的,并且与双链DNA断裂的形成同时发生。咖啡因而不是香草醛阻止了基因修复的增强,这表明在该系统中,HR是最主要的途径来提高校正频率。研究表明,渥曼青霉素在抑制DNA-PK活性的高浓度下抑制基因修复,但在较低水平上却不抑制基因修复,这进一步证实了HR的参与。综上所述,我们的结果表明,CPT诱导的DNA损伤会激活细胞反应,从而刺激哺乳动物细胞中的基因修复。
  • 【喜树碱通过激活FOXO1诱导人视网膜母细胞瘤细胞凋亡。】 复制标题 收藏 收藏
    DOI:10.3109/02713683.2010.510943 复制DOI
    作者列表:Han S,Wei W
    BACKGROUND & AIMS: PURPOSE:The purpose of this study was to investigate the pro-apoptotic effect of camptothecin (CPT) on Y79 retinoblastoma cells and the role of Forkhead box, class O (FOXO1) in CPT-induced apoptosis. METHODS:CPT-induced apoptosis was determined by flow cytometry with annexin V-FITC positive cells and Western blot of PARP expression, respectively. The expressions of FOXO1 were detected by Western blot. The transcriptional activity of FOXO1 was determined by luciferase reporter assay. siRNAs specifically inhibiting FOXO1 were used, and flow cytometry and Western blot were executed to test the role of FOXO1 in CPT-induced apoptosis. RESULTS:CPT was extremely effective in inducing apoptosis of Y79 retinoblastoma cells. FOXO1 was highly expressed in Y79 cells. CPT not only elevated the FOXO1 dephosphorylation level but also promoted its transcriptional activity, suggesting that the activation of FOXO1 was, at least in part, triggered by CPT. The decreased annexin V positive cells and less PARP cleavage demonstrated that siRNAs-mediated inhibition of FOXO1 significantly abrogated CPT-induced apoptosis, indicating that FOXO1 plays an important role in CPT-induced apoptosis. Moreover, the expression of Bim was also elevated with the treatment of CPT, which is in accordance with the activation of FOXO1. CONCLUSIONS:Our study provides the evidence that a high level of endogenous FOXO1 expression in retinoblastoma cells contributes, at least in part, to CPT-induced apoptosis, which may help broad application of CPT in retinoblastoma therapy in the future.
    背景与目标: 目的:本研究旨在探讨喜树碱(CPT)对Y79视网膜母细胞瘤细胞的促凋亡作用以及O型叉头盒(FOXO1)在CPT诱导的细胞凋亡中的作用。
    方法:用膜联蛋白V-FITC阳性细胞通过流式细胞术和PARP表达的Western印迹分别测定CPT诱导的细胞凋亡。 Western blot检测FOXO1的表达。 FOXO1的转录活性通过荧光素酶报告基因测定。使用特异性抑制FOXO1的siRNA,并进行流式细胞仪和Western印迹法测试FOXO1在CPT诱导的细胞凋亡中的作用。
    结果:CPT在诱导Y79视网膜母细胞瘤细胞凋亡中非常有效。 FOXO1在Y79细胞中高表达。 CPT不仅提高了FOXO1的去磷酸化水平,而且还促进了其转录活性,这表明FOXO1的激活至少部分是由CPT触发的。膜联蛋白V阳性细胞的减少和PARP裂解的减少表明siRNA介导的FOXO1抑制显着废除了CPT诱导的凋亡,表明FOXO1在CPT诱导的凋亡中起重要作用。此外,随着CPT的处理,Bim的表达也升高,这与FOXO1的激活有关。
    结论:我们的研究提供了证据,视网膜母细胞瘤细胞中高水平的内源性FOXO1表达至少部分地促进了CPT诱导的细胞凋亡,这可能有助于CPT在将来的视网膜母细胞瘤治疗中广泛应用。
  • 【大分子偶联物DE-310的长效抗肿瘤作用的可能机制:通过细胞摄取和药物释放来调节其活性喜树碱类似物DX-8951。】 复制标题 收藏 收藏
    DOI:10.1007/s00280-004-0911-1 复制DOI
    作者列表:Ochi Y,Shiose Y,Kuga H,Kumazawa E
    BACKGROUND & AIMS: :DE-310, a new macromolecular prodrug, was designed to enhance the pharmacological profiles of a novel camptothecin analog (DX-8951f), and a single treatment with DE-310 exhibits a similar or greater therapeutic effect than do optimally scheduled multiple administrations of DX-8951f in several types of tumors. In this study, the drug-release mechanism by which DE-310 excites antitumor activity was investigated in Meth A cells, a malignant ascites model of murine fibrosarcoma. A single i.v. injection of DE-310 at the maximum tolerated dose (MTD) prolonged survival of Meth A-bearing mice by 300%. DX-8951 and glycyl-8951 (G-DX-8951), enzymatic cleavage products of DE-310, were detected in serum and ascites fluid, and also in the culture medium of Meth A ascites cells incubated in vitro with DE-310. The total amounts of DX-8951, G-DX-8951, and conjugated DX-8951 in Meth A tumor cells were three times higher than that in macrophages. Furthermore, DX-8951-related fluorescence was observed in Meth A ascites cells obtained from Meth A-bearing mice that had received DE-310 or CM-Dex-PA-DX-8951 that does not release free DX-8951. DX-8951-related fluorescence was also observed at the site of lysosomes in cells incubated in vitro with DE-310 at 37 degrees C, but not in those incubated at 4 degrees C. Drugs were released from DE-310 by cysteine proteinase prepared from Meth A tumor tissue. These results suggest that the mechanism by which DX-8951 is released from DE-310 in vivo is involved in the process of uptake of DE-310 into tumor or macrophages, digestion by intracellular lysosomal cysteine proteinase, and subsequent secretion of the drugs.
    背景与目标: :DE-310是一种新的大分子前药,旨在增强新型喜树碱类似物(DX-8951f)的药理作用,并且与最佳预定多次给药相比,DE-310的单次治疗具有相似或更高的治疗效果。 DX-8951f在几种类型的肿瘤中。在这项研究中,研究了在小鼠纤维肉瘤的恶性腹水模型Meth A细胞中DE-310激发抗肿瘤活性的药物释放机制。单个i.v.以最大耐受剂量(MTD)注射DE-310可将含Meth A的小鼠的生存期延长300%。在血清和腹水液中以及在与DE-310体外孵育的Meth A腹水细胞的培养基中检测到DX-8951和glycyl-8951(G-DX-8951)(DE-310的酶促裂解产物)。 Meth A肿瘤细胞中DX-8951,G-DX-8951和结合DX-8951的总量是巨噬细胞的三倍。此外,在得自接受DE-310或未释放游离DX-8951的CM-Dex-PA-DX-8951的携带Meth A的小鼠的Meth A腹水细胞中,观察到了DX-8951相关的荧光。在与DE-310于37°C体外温育的细胞中,在溶酶体的位点也观察到了DX-8951相关的荧光,而在4°C的温育细胞中则未观察到。方法:肿瘤组织。这些结果表明DX-8951在体内从DE-310释放的机制涉及DE-310被摄取到肿瘤或巨噬细胞中,被细胞内溶酶体半胱氨酸蛋白酶消化以及随后的药物分泌过程。
  • 【监测拓扑异构酶(I)抑制剂喜树碱从内源性氧化还原刺激的GO-聚合物杂合载体中的释放。】 复制标题 收藏 收藏
    DOI:10.1016/j.jphotobiol.2018.09.019 复制DOI
    作者列表:Rashmi R,Nedungadi D,Podder A,Mishra N,Bhuniya S
    BACKGROUND & AIMS: :We have developed endogenous redox-responsive polymer conjugated GO-based hybrid nanomaterials (GO-PEGssFol-CPT) for delivery of anticancer drug camptothecin (CPT) to the cancer cells. The synthesized intermediate (PEGSSFol) and CPT loaded GO- PEGSSFol were characterized using Fourier transform infrared spectroscopy (FTIR) and 1H NMR. The morphological feature changes of TEM and AFM images have confirmed the loading of CPT on the nanocarrier and its release from the nanocarrier. The amount of CPT was loaded was found to be 14.2%. The extent of camptothecin (CPT) release from GO-BiotinPVA-CPT in the presence of different concentrations of glutathione (GSH) was monitored with the increase in the fluorescence intensity at λmax 438 nm and UV-Vis absorbance at 366 nm. The time-dependent camptothecin (CPT) release was monitored in the presence of GSH. It was noticed that CPT was completely released from GO-PEGssFol-CPT within 45 min. This release process is free from interference by other ubiquitous analytes in the living system. The constant fluorescence intensity of GO-PEGssFol-CPT against acidic pH indicated that CPT would not be released in the extracellular region of cancer cells. Therefore, such delivery system could be used to prevent unwanted cytotoxicity to the healthy cells. The GO-PEGssFol-CPT showed higher antiproliferative activity against cervical cancer cells compared to the CPT. Thus, GO-PEGssFol-CPT can be a new material to deliver the anticancer drug to the target tumor region.
    背景与目标: :我们已经开发了内源性氧化还原反应性聚合物共轭的基于GO的杂化纳米材料(GO-PEGssFol-CPT),用于将抗癌药物喜树碱(CPT)递送至癌细胞。使用傅立叶变换红外光谱(FTIR)和1H NMR对合成的中间体(PEGSSFol)和CPT负载的GO-PEGSSFol进行表征。 TEM和AFM图像的形态特征变化已经证实了CPT在纳米载体上的负载及其从纳米载体上的释放。发现CPT的负载量为14.2%。在存在不同浓度的谷胱甘肽(GSH)的情况下,通过λmax438nm处的荧光强度增加和366nm处的UV-Vis吸光度来监测喜树碱(CPT)从GO-BiotinPVA-CPT释放的程度。在GSH存在下监测时间依赖性喜树碱(CPT)的释放。注意到CPT在45分钟内从GO-PEGssFol-CPT完全释放。该释放过程不受生物系统中其他普遍存在的分析物的干扰。 GO-PEGssFol-CPT对酸性pH的恒定荧光强度表明CPT不会在癌细胞的细胞外区域释放。因此,这种递送系统可用于预防对健康细胞的有害细胞毒性。与CPT相比,GO-PEGssFol-CPT对宫颈癌细胞显示出更高的抗增殖活性。因此,GO-PEGssFol-CPT可能是一种将抗癌药物递送至靶肿瘤区域的新材料。
  • 【如定量结构-活性关系和分子对接研究所预测,喜树碱前药被特定的羧酸酯酶活化。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Yoon KJ,Krull EJ,Morton CL,Bornmann WG,Lee RE,Potter PM,Danks MK
    BACKGROUND & AIMS: :7-Ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (irinotecan, CPT-11) is a camptothecin prodrug that is metabolized by carboxylesterases (CE) to the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38), a topoisomerase I inhibitor. CPT-11 has shown encouraging antitumor activity against a broad spectrum of tumor types in early clinical trials, but hematopoietic and gastrointestinal toxicity limit its administration. To increase the therapeutic index of CPT-11 and to develop other prodrug analogues for enzyme/prodrug gene therapy applications, our laboratories propose to develop camptothecin prodrugs that will be activated by specific CEs. Specific analogues might then be predicted to be activated, for example, predominantly by human liver CE(hCE1), by human intestinal CE (hiCE), or in gene therapy approaches using a rabbit liver CE (rCE). This study describes a molecular modeling approach to relate the structure of rCE-activated camptothecin prodrugs with their biological activation. Comparative molecular field analysis, comparative molecular similarity index analysis, and docking studies were used to predict the biological activity of a 4-benzylpiperazine derivative of CPT-11 [7-ethyl-10-[4-(1-benzyl)-1-piperazino]carbonyloxycamptothecin (BP-CPT)] in U373MG glioma cell lines transfected with plasmids encoding rCE or hiCE. BP-CPT has been reported to be activated more efficiently than CPT-11 by a rat serum esterase activity; however, three-dimensional quantitative structure-activity relationship studies predicted that rCE would activate BP-CPT less efficiently than CPT-11. This was confirmed by both growth inhibition experiments and kinetic studies. The method is being used to design camptothecin prodrugs predicted to be activated by specific CEs.
    背景与目标: :7-乙基-10- [4-(1-哌啶子基)-1-哌啶子基]羰基氧基喜树碱(irinotecan,CPT-11)是喜树碱前药,它通过羧酸酯酶(CE)代谢为活性代谢物7-乙基-10-羟喜树碱(SN-38),一种拓扑异构酶I抑制剂。 CPT-11在早期临床试验中已显示出令人鼓舞的针对多种肿瘤的抗肿瘤活性,但造血和胃肠道毒性限制了它的给药。为了提高CPT-11的治疗指数并开发用于酶/前药基因治疗应用的其他前药类似物,我们的实验室提议开发喜树碱前药,该药将被特定的CE激活。然后可以预测特定的类似物被激活,例如,主要被人肝CE(hCE1),人肠CE(hiCE)激活,或者被基因疗法使用兔肝CE(rCE)激活。这项研究描述了一种分子建模方法,该方法将rCE激活的喜树碱前药的结构与其生物激活联系起来。比较分子场分析,比较分子相似性指数分析和对接研究用于预测CPT-11 [7-乙基-10- [4-(1-苄基)-1-哌嗪子酮] 4-苄基哌嗪衍生物的生物活性。用编码rCE或hiCE的质粒转染的U373MG神经胶质瘤细胞系中的[羰基氧基喜树碱(BP-CPT)]。据报道,通过大鼠血清酯酶活性,BP-CPT比CPT-11更有效地被激活。然而,三维定量构效关系研究预测,rCE激活BP-CPT的效率低于CPT-11。生长抑制实验和动力学研究均证实了这一点。该方法正用于设计喜树碱前药,预计它们会被特定的CE激活。
  • 【低分子量聚合物-药物缀合物,用于喜树碱和阿霉素组合的协同抗癌活性。】 复制标题 收藏 收藏
    DOI:10.2217/nnm.16.33 复制DOI
    作者列表:Camacho KM,Menegatti S,Mitragotri S
    BACKGROUND & AIMS: BACKGROUND:High-molecular-weight (MW) polymers (>50,000 Da) can be conjugated to chemotherapy drugs in order to improve their tumor accumulation, while low MW polymers ≤10,000 Da are often overlooked due to faster plasma clearance. Small polymers, however, may facilitate deeper tumor penetration. MATERIALS & METHODS:Here, we investigate the anticancer efficacy of 10 kDa hyaluronic acid or poly(vinyl alcohol) conjugated to synergistic combinations of camptothecin and doxorubicin, with emphasis on chemical linker impacts. RESULTS:Our results emphasize drug hydrolyzability for synergy preservation, and also demonstrate superior cancer cell inhibition with low MW polymer-drug conjugates. CONCLUSION:This study shows the high therapeutic potential of low MW polymer-drug conjugates for polychemotherapy delivery, and provides further insight into the development of polymer-drug therapeutics.
    背景与目标: 背景:高分子量(MW)聚合物(> 50,000 Da)可以与化疗药物结合以改善其肿瘤蓄积,而≤10,000 Da的低MW聚合物由于更快的血浆清除率而经常被忽略。但是,小的聚合物可能会促进更深的肿瘤渗透。
    材料与方法:在这里,我们研究了喜树碱与阿霉素协同组合结合的10 kDa透明质酸或聚乙烯醇的抗癌作用,重点是化学接头的影响。
    结果:我们的结果强调了药物的水解性以保持协同作用,并且还证明了低分子量聚合物-药物结合物具有优异的癌细胞抑制作用。
    结论:这项研究表明低分子量聚合物-药物缀合物在多化学疗法治疗中具有很高的治疗潜力,并为聚合物-药物疗法的发展提供了进一步的见识。
  • 【基于结构的药物设计和H2O可溶性和低毒性六环喜树碱衍生物的鉴定,在癌症和致死性炎症模型体内具有更高的功效。】 复制标题 收藏 收藏
    DOI:10.1021/acs.jmedchem.8b00498 复制DOI
    作者列表:Pan P,Chen J,Li X,Li M,Yu H,Zhao JJ,Ni J,Wang X,Sun H,Tian S,Zhu F,Liu F,Huang Y,Hou T
    BACKGROUND & AIMS: :Camptothecin (CPT) has been shown to block disassembly of the topoisomerase I (Topo I)/DNA cleavable complex. However, the poor aqueous solubility, intrinsic instability, and severe toxicity of CPTs have limited their clinical applications. Herein, we report the design and synthesis of H2O-soluble and orally bioavailable hexacyclic CPT derivatives. By analysis of a virtual chemical library and cytotoxicity screening in vitro, 9 and 11 were identified as potential prodrugs and chosen for further characterization in vivo. Both compounds exhibited remarkable anticancer and anti-inflammation efficacies in animals and improved drug-like profiles.
    背景与目标: 已证明:喜树碱(CPT)可以阻断拓扑异构酶I(Topo I)/ DNA可裂解复合物的分解。然而,CPT的差的水溶性,固有的不稳定性和严重的毒性限制了它们的临床应用。在此,我们报告了H2O可溶性和口服生物可利用的六环CPT衍生物的设计和合成。通过对虚拟化学文库的分析和体外细胞毒性筛选,将9和11鉴定为潜在的前药,并选择用于体内进一步表征。两种化合物在动物中均表现出显着的抗癌和抗炎功效,并具有类似药物的特性。
  • 【使用喜树碱从热可逆水凝胶中从聚乳酸-乙醇酸微球中持续释放喜树碱来治疗大鼠脑部肿瘤。】 复制标题 收藏 收藏
    DOI:10.1248/cpb.58.1142 复制DOI
    作者列表:Ozeki T,Hashizawa K,Kaneko D,Imai Y,Okada H
    BACKGROUND & AIMS: :A thermoreversible gelation polymer consisting of an aqueous solution in the sol state at room temperature and in the gel state near body temperature was examined for its use in the retention of microspheres and sustained, long-term delivery of anti-cancer drugs using a rat model of malignant glioma. The poly(lactic-co-glycolic acid) (PLGA) microspheres containing camptothecin at ratios of 1 : 33 or 1 : 50 mediated sustained release, with approximate 80% of camptothecin released after 28 d. Rats were inoculated in the brain with C6 glioma cells, followed 7 d later by injection in the tumor site with 1 : 33 and 1 : 50 PLGA microspheres dispersed in a thermoreversible gelation polymer (TGP) solution. Kaplan-Meier analysis showed that the mean survival period of the untreated group was 16 d, with a slight increase in rats treated with TGP-only solution, empty or 1 : 50 microspheres in phosphate-buffered saline. The mean survival period of rats treated with the camptothecin powder in TGP was 21 d, while that of rats treated with 1 : 33 and 1 : 50 microspheres in TGP was significantly longer than the untreated group; long-term survival rats were observed. These results suggest that the anti-tumor effect of camptothecin can be enhanced by long-term sustained release from microspheres retained in the rat brain by TGP gel.
    背景与目标: :研究了一种由大鼠在室温下处于溶胶状态且在接近人体温度的凝胶状态下的水溶液组成的热可逆凝胶化聚合物在保留微球和持续,长期使用抗癌药物中的用途恶性神经胶质瘤模型。以1:33或1:50的比例含有喜树碱的聚乳酸-乙醇酸共聚物(PLGA)微球介导了持续释放,在28天后约有80%的喜树碱被释放。大鼠在脑中接种C6胶质瘤细胞,随后7天后在肿瘤部位注射1:33和1:50分散在热可逆凝胶聚合物(TGP)溶液中的PLGA微球。 Kaplan-Meier分析显示,未治疗组的平均存活期为16天,用仅TGP溶液,空的或1:50微球在磷酸盐缓冲液中处理的大鼠略有增加。用喜树碱粉末在​​TGP中治疗的大鼠的平均生存期为21天,而用1:33和1:50的微球治疗的大鼠的平均生存期明显大于未治疗组;观察长期存活大鼠。这些结果表明,喜树碱的抗肿瘤作用可以通过TGP凝胶从保留在大鼠脑中的微球中长期持续释放来增强。
  • 【Rottlerin通过不依赖PKCδ的途径增加拓扑异构酶I-DNA裂解复合物的形成和稳定性来增强喜树碱诱导的人激素难治性前列腺癌的细胞毒性。】 复制标题 收藏 收藏
    DOI:10.1016/j.bcp.2012.03.023 复制DOI
    作者列表:Hsu JL,Ho YF,Li TK,Chen CS,Hsu LC,Guh JH
    BACKGROUND & AIMS: :Combination therapy, which can optimize killing activity to cancers and minimize drug resistance, is a mainstream therapy against hormone-refractory prostate cancers (HRPCs). Rottlerin, a natural polyphenolic component, synergistically increased PC-3 (a HRPC cell line) apoptosis induced by camptothecin (a topoisomerase I inhibitor). Using siRNA technique to knockdown protein kinase C-δ (PKCδ), the data showed that rottlerin-mediated synergistic effect was PKCδ-independent, although rottlerin has been used as a PKCδ inhibitor. Rottlerin potentiated camptothecin-induced DNA fragmentation at S phase and ATM phosphorylation at Ser1981. The effect was correlated to apoptosis (r2 = 0.9). To detect upstream signals, the data showed that camptothecin acted on and stabilized topoisomerase I-DNA complex, leading to the formation of camptothecin-trapped cleavage complexes (TOP1cc). The effect was potentiated by rottlerin. To determine DNA repair capability, the time-related γH2A.X formation was examined after camptothecin removal. Consequently, rottlerin significantly inhibited camptothecin removal-mediated decline of γH2A.X formation at S phase, indicating the impairment of DNA repair activity in the presence of rottlerin. The combinatory treatment of camptothecin and rottlerin induced conformational change and activation of Bax and formation of truncated Bad, suggesting the contribution of mitochondria stress to apoptosis. In summary, the data suggest that rottlerin-mediated camptothecin sensitization is through the augmented stabilization of TOP1cc, leading to an increase of DNA damage stress and, possibly, an impairment of DNA repair capability. Subsequently, mitochondria-involved apoptosis is triggered through Bax activation and truncated Bad formation. The novel discovery may provide an anticancer approach of combinatory use between rottlerin and camptothecin for the treatment of HRPCs.
    背景与目标: :组合疗法可优化对癌症的杀伤活性,并最大程度降低耐药性,是抵抗激素难治性前列腺癌(HRPC)的主流疗法。天然多酚成分Rottlerin协同增加喜树碱(拓扑异构酶I抑制剂)诱导的PC-3(HRPC细胞系)凋亡。使用siRNA技术敲除蛋白激酶C-δ(PKCδ),数据显示,尽管已将rottlerin用作PKCδ抑制剂,但rottlerin介导的协同作用不依赖PKCδ。 Rottlerin增强了喜树碱诱导的S期DNA片段化和Ser1981的ATM磷酸化。该作用与细胞凋亡相关(r2 = 0.9)。为了检测上游信号,数据显示喜树碱作用于拓扑异构酶I-DNA复合物并使其稳定,从而导致喜树碱捕获的裂解复合物(TOP1cc)的形成。劳特林增强了该作用。为了确定DNA修复能力,在喜树碱去除后检查时间相关的γH2A.X的形成。因此,鲁特林显着抑制喜树碱去除介导的S期γH2A.X形成的下降,表明存在鲁特林时DNA修复活性受到损害。喜树碱和rottlerin的联合治疗诱导构象变化和Bax的活化以及截短的Bad的形成,表明线粒体应激对细胞凋亡的贡献。总而言之,数据表明,铁蛋白介导的喜树碱敏化作用是通过增强TOP1cc的稳定性来实现的,从而导致DNA损伤应力增加,并可能损害DNA修复能力。随后,通过Bax激活和截短的Bad形成触发线粒体参与的凋亡。这一新发现可能提供一种在rottlerin和喜树碱之间联合使用的抗癌方法,以治疗HRPC。
  • 15 Camptothecin and taxol: discovery to clinic. 复制标题 收藏 收藏

    【喜树碱和紫杉醇:发现于临床。】 复制标题 收藏 收藏
    DOI:10.1002/(sici)1098-1128(199809)18:5<299::aid-med2> 复制DOI
    作者列表:Wall ME
    BACKGROUND & AIMS: Camptothecin (CPT) is a pentacyclic alkaloid isolated from wood and bark of Camptotheca acuminata. Initially it was found to be highly active in a number of mouse in vivo cancer assays. Subsequently, CPT was found to uniquely inhibit an enzyme, topoisomerase I, which is involved in DNA replication. A number of CPT analogs are in advanced clinical trial, and two, Topotecan and CPT-11, have been approved for marketing by the FDA. taxol, a taxane alkaloid, was isolated from Taxus brevifolia. Taxol is a highly cytotoxic compound active in several mouse antitumor assays. It was subsequently found to uniquely inhibit tubulin, a protein involved in mitosis. After clinical evaluation, it has become the drug of choice for treatment of ovarian cancer.

    背景与目标: 喜树碱(CPT)是一种从喜树喜树的木材和树皮中分离出来的五环生物碱。最初发现它在许多小鼠体内癌症试验中具有很高的活性。随后,发现CPT独特地抑制了参与DNA复制的酶拓扑异构酶I。许多CPT类似物正在进行高级临床试验,而FDA已经批准了Topotecan和CPT-11这两种类似物。紫杉醇是一种紫杉烷生物碱,是从短叶红豆杉中分离得到的。紫杉酚是在几种小鼠抗肿瘤试验中有活性的高度细胞毒性化合物。随后发现它可以独特地抑制微管蛋白(一种参与有丝分裂的蛋白质)。经过临床评估,它已成为治疗卵巢癌的首选药物。

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