Stability of hemoglobin and albumin adducts of naphthalene oxide, 1,2-naphthoquinone, and 1,4-naphthoquinone.

Naphthalene is an important industrial chemical, which has recently been shown to cause tumors of the respiratory tract in rodents. It is thought that one or more reactive metabolites of naphthalene, namely, naphthalene-1,2-oxide (NPO), 1,2-naphthoquinone (1,2-NPQ), and 1,4-naphthoquinone (1,4-NPQ) contribute to the tumorigenicity of this chemical. These electrophiles are all capable of covalent binding to macromolecules including DNA and proteins. The stability of cysteinyl adducts of NPO, 1,2-NPQ, and 1,4-NPQ were investigated in both hemoglobin (Hb) and albumin (Alb) of male F344 rats following a single administration of 2 different doses (400 or 800 mg naphthalene per kg body weight). To assess the stability of Alb adducts, we compared the rates of NPO-Alb turnover (half-life of approximately 2 days) and 1,2-NPQ-Alb (half-life of approximately 1 day) to the normal turnover rate of Alb in the rat (half-life = 2.5-3 days). Based on the rapid turnover of these adducts relative to Alb itself, we concluded that they were unstable. However, the stability of Alb adducts was not affected by the dose of naphthalene administered (400 or 800 mg/kg). In contrast, NPO-Hb adducts were relatively stable (rate constant of adduct instability 相似文献   

Glutathione conjugates of 2- or 6-substituted 5,8-dimethoxy-1,4-naphthoquinone derivatives: Formation and structure

Thirty-four glutathione conjugates of 5,8-dimethoxy-1,4-naphthoquinones (DMNQ) were synthesized and their structure was determined. The yield of GSH conjugate was dependent on size of alkyl group; the longer the size of alkyl group was, the lower was the yield. It was also found that the length of alkyl side chain influenced the chemical shift of quinonoid protons; the quinonoid protons of 2-glutathionyl DMNQ derivatives with R=H to propyl, 6.51-6.59 ppm vs. other ones with R=butyl to heptyl, 6.64-6.68 ppm. This was explained to be due to a folding effect of longer alkyl group. Glutathione (GSH) reacted with DMNQ derivative first to form a 1,4-adduct (2- or 3-glutathionyl-1,4-dihydroxy-5,8-dimethoxynaphthalenes) and then, the adduct was autooxidized to 2- or 3-glutathionyl-DMNQ derivatives. Moreover, GSH reduced DMNQ derivatives to their hydrogenated products. It was suggested that such an organic reaction might play an important role for a study of metabolism or toxicity of DMNQ derivatives in the living cells.     

Inhibition of hind-paw edema and cutaneous vascular plasma extravasation by 2-chloro-3-methoxycarbonylpropionamido-1,4-naphthoquinone (PP1D1) in mice

2-Chloro-3-methoxycarbonylpropionamido-1,4-naphthoquinone (PP1D1) produced a dose-dependent inhibition of the polymyxin B-induced hind-paw edema in normal as well as in adrenalectomized mice. A comparable inhibitory profile was observed in mice to which PP1D1 was injected i.p. or applied orally. Unlike dexamethasone, PP1D1 had no effect on the liver glycogen content in fasting adrenalectomized mice. Ear edema caused by passive cutaneous anaphylactic reaction, or by subcutaneous injection of compound 48/80, histamine, serotonin, bradykinin or substance P was reduced by PP1D1 in a dose-dependent manner. In addition, topical application of PP1D1 suppressed the capsaicin- and arachidonic acid-induced ear edema. In compound 48/80-pretreated mice, the tissue histamine content was greatly reduced. Under these conditions, PP1D1 reduced the bradykinin- and substance P-induced ear edema to a significantly greater extent than diphenhydramine plus methysergide. These results suggest that the inhibitory effect of PP1D1 on the edematous response is due to the protection of the microvasculature from mediator challenge.     

肿瘤新生血管生成抑制剂的研究进展

肿瘤血管生成柳制剂一类能破坏或抑制血管生成,有效地阻止肿瘤生长和转移的药物。按作用机制可分为5大类：①抑制基底膜降解。②直接抑制内皮细胞增殖。③抑制血管生长因子活化。④抑制内皮细胞特异性整合素／生存信号。⑤其他非特异性作用机制的药物。本文主要简介正在进行临床试验的肿瘤血管生成抑制剂的最新研究进展。     

雌激素调节肿瘤血管生成研究进展

妇科肿瘤已成为全球妇女的头号恶性肿瘤疾病。尽管医学界迄今为止尚未完全清楚其明确的发病机制,但有一点可以肯定:妇科肿瘤的发生与雌激素有关。近年来关于妇科肿瘤与雌激素分泌表达异常之间的分子调控机制已成为国内外研究的重点。临床及实验研究均认为雌激素可通过雌激素受体调节机体的多种信号途径,引起内皮细胞增殖、凋亡、运动、芽生、粘附等特性改变,导致肿瘤血管生成的异常,从而最终影响到肿瘤发生、发展、转移过程。现对近年来国内外有关雌激素调节肿瘤血管生成信号转导通路的研究进行概述,并提出其在中药抗肿瘤研究中的可能影响,期望对肿瘤临床及实验研究者有所借鉴。     

靶向肿瘤代谢的药物研究进展及与血管生成的关系

肿瘤细胞的代谢重排是肿瘤发生发展过程中的一个重要特征,主要表现为糖酵解、谷氨酰胺代谢及生物合成活动的增强。鉴于肿瘤代谢重排在肿瘤发展中的关键作用,靶向肿瘤细胞代谢已成为国际上抗肿瘤药物研发的热点之一。肿瘤微血管新生是肿瘤进展的另一个重要特点,与肿瘤血管内皮细胞的代谢转变密切相关,其为肿瘤细胞的代谢活动提供物质支持。该文讨论了肿瘤细胞与内皮细胞代谢中异常的代谢变化及探讨了两者的关系,并综述了靶向前述代谢变化的药物研发进展。     

Neuropilin与肿瘤血管新生

Neuropilin作为轴突导向分子collapsin/semaphorin的受体在神经发育过程中引导轴突选择正确途径以成功到达靶区 ,与此同时又可作为血管内皮生长因子受体在血管新生中发挥作用。近年neuropilin在神经系统中的作用已基本得以阐明 ,而有关其在血管新生方面的研究亦有所进展 ,并且指出neuropilin参与调节肿瘤血管新生 ,在肿瘤生长转移中发挥作用。现就neuropilin的结构和功能特性及其在血管新生中的作用作一综述     

6-(1-Alkenoyloxyalkyl)-5,8-dimethoxy-1,4-naphthoquinone derivatives: Synthesis and evaluation of antitumor activity

Thirty six 5,8-dimethoxy-1,4-naphthoquinone derivatives, which bear unsaturated alkyl side chain with ester bond, were synthesized and tested cytotoxic activity on L1210 cells and antitumor activity against ICR mice bearing S-180 cells. It could be recognized that the cytotoxicities of naphthoquinones with R₁ being methyl and propyl (IV1∼24) were not enhanced by replacing the alkanoyls with alkenoyls. In contrast, the introduction of the alkenoyl moieties on the compounds with R₁=hexyl (IV25∼36) resulted in the enhancement of their cytotoxicities. Replacement of alkanoyl group with an alkenoyl group generally increased the T/C value of the mice bearing S-180 cells.     

在肿瘤研究中转基因小鼠模型的研究进展

随着基因工程技术的飞速发展,转基因小鼠模型对研究肿瘤基因特征、肿瘤抑制基因的表达和功能有着重要的作用。近年来,肿瘤血管生成理论成为肿瘤研究的新热点。与肿瘤血管生成相关的调控基因的研究也越来越受到重视。该文对转基因小鼠模型在肿瘤研究中的进展作了综述,并着重介绍了关于肿瘤血管生成调控基因转基因小鼠模型的研究情况。     

抑癌基因PTEN与肿瘤血管生成研究进展

PTEN是具有磷酸脂酶活性的抑癌基因,是双特异蛋白磷酸酶家族(DSPs)的成员,同时具有脂质磷酸酶和蛋白酪氨酸磷酸酶活性。而在肿瘤增殖,侵袭,迁移的过程中,肿瘤血管生成作为肿瘤发生发展中一个关键因素已越来越受到人们的关注。抑癌基因PTEN可以参与PI3K/Akt信号通路,调控缺氧诱导因子1,基质金属蛋白酶,血管内皮生长因子,钠氢交换调控因子1等血管生成相关信号以及一些机体氧化产物来影响肿瘤血管生成。根据近年来PTEN基因与肿瘤血管生成关系最新研究信息,该文综述了其目前的研究现状。     

参麦注射液联合羟基喜树碱抑制肿瘤血管生成的作用机制

目的:研究参麦注射液联合羟基喜树碱对肿瘤血管生成的作用机制。方法:将人结肠癌细胞株CW-2细胞分4组:对照组,参麦组,羟基喜树碱组,参麦联合羟基喜树碱组。分组后的CW-2细胞培养24h后,用ELISA检测上清液中VEGF和bFGF的浓度,RT-PCR法检测VEGF和bFGF mRNA的量,Western-blot检测VEGF和bFGF的表达。结果:与空白对照组比较,3个实验组均能明显降低CW-2细胞上清液中VEGF和bFGF的含量,显著减少CW-2细胞VEGF和bFGF的mRNA合成及蛋白质表达,而参麦注射液联合羟基喜树碱则具有协同效应。结论:参麦注射液联合羟基喜树碱抑制肿瘤细胞VEGF和bFGF合成和分泌,是其抑制肿瘤血管生成的可能机制之一。     

Effects of Cordyceps militaris extract on angiogenesis and tumor growth

INTRODUCTIONAngiogenesis is the process of new blood vesselformation from existing blood vessels and a natural re-sponse of tissues to ischemia[1]. The steps of angio-genesis involve proteolytic degradation of extracelluarmatrix, endothelial cell-matrix adhesion, migration,proliferation, and differentiation[2]. This biological re-action is often associated with some diseases, such assolid tumor[3], diabetic retinopathy[4], and rheumatoidarthritis[5].Tumor formation requires the developm…     

肿瘤血管生成机制及抗肿瘤血管新生的靶向药物研究进展

抗肿瘤血管新生治疗是以血管内皮细胞为靶点,通过降低血管活性因子的活性、抑制内皮细胞增殖和迁移、改变肿瘤生长微环境,从而抑制肿瘤生长过程中的血管新生,切断肿瘤的供养,最终达到遏制肿瘤生长和转移的目的,是一种全新的靶向肿瘤治疗方法.该方法具有高效特异性、不易产生耐药性、药物易于到达靶部位和毒副作用小等优点,可以有效地抑制肿瘤的转移和复发,现在已成为抗肿瘤血管生成药物研究的热点之一,该文综述了肿瘤血管生成的机制及抗血管新生治疗药物的最新研究进展.     

Inhibition of angiogenesis and tumor growth by beta and gamma-secretase inhibitors

The involvement of beta-secretase and gamma-secretase in producing the beta-amyloid component of senile plaques found in the brain of Alzheimer's patients has fueled a major research effort to design selective inhibitors of these proteases. Interestingly, gamma-secretase cleaves several proteins including Notch, E-cadherin, CD44 and ErbB-4 (erythroblastic leukemia viral oncogene homolog 4), which are important modulators of angiogenesis. The beta-amyloid precursor protein, which is cleaved by beta-secretase and gamma-secretase to produce beta-amyloid, is highly expressed in the endothelium of neoforming vessels suggesting that it might play a role during angiogenesis. These data prompted us to explore the effects of beta and gamma-secretase inhibitors of different structures on angiogenesis and tumor growth. Both the gamma and beta-secretase inhibitors tested reduce endothelial cell proliferation without inducing cellular toxicity, suppress the formation of capillary structures in vitro and oppose the sprouting of microvessel outgrowths in the rat aortic ring model of angiogenesis. Moreover, they potently inhibit the growth and vascularization of human glioblastoma and human lung adenocarcinoma tumors xenotransplanted into nude mice. Altogether these data suggest that the gamma and beta-secretases play an essential role during angiogenesis and that inhibitors of the beta and gamma-secretases may constitute new classes of anti-angiogenic and anti-tumoral compounds.     

姜黄素抑制子宫内膜异位症血管形成的实验研究

目的:观察姜黄素对大鼠子宫内膜异位症(endometriosis,EMs)局部血管形成的影响和抗血管形成作用。方法:制作Wistar大鼠EMs动物模型,4周后将大鼠分为正常组、假手术组、模型组、姜黄素低剂量组及姜黄素高剂量组5组,持续用药28d,SP免疫组化法测定在位内膜和异位组织灶中微血管密度(microvessel density,MVD)的表达,western blotting测定局部血管内皮生长因子(vascular endothelial growth factor,VEGF)蛋白量的表达。结果:姜黄素治疗模型大鼠EMs,4周后异位组织中MVD和VEGF蛋白量的表达明显低于模型组,差异有显著性(P<0.05),而在位内膜中MVD的表达与模型组相比,差异无显著性(P>0.05);姜黄素可剂量依赖性的抑制EMs异位组织的增生。结论:姜黄素对子宫内膜异位症大鼠异位组织中MVD的表达和VEGF蛋白的表达均有抑制作用,作用呈剂量依赖性。姜黄素有望成为子宫内膜异位症抗血管形成治疗的新药。     

中华眼镜蛇毒活性组分体外抑制三维血管生成的实验研究

目的研究中华眼镜蛇毒活性组分的抗血管生成作用。方法采用拟血管生成三维培养法,观察活性组分对体外血管生成的抑制效应。结果活性组分可抑制内皮细胞在培养基质中生成血管网状三维结构的反应,0.6、1.2、2.4μg·ml-1的不同浓度组分抑制程度不同。在0.6μg·ml-1浓度组,培养基质Matrigel中的内皮细胞团只形成局部的、不完整的空间网状结构;在1.2μg·ml-1浓度组,悬浮于凝胶中的细胞团所形成的管芽不能相互连接而形成空间网状结构;在2.4μg·ml-1浓度组,细胞散在悬浮于胶层中大部分不能粘聚,且随培养时间的延长无明显的结构变化。结论中华眼镜蛇毒活性组分具有体外抑制血管生成的生物活性。     

Charge–transfer reaction of 2,3-dichloro-1,4-naphthoquinone with crizotinib: Spectrophotometric study,computational molecular modeling and use in development of microwell assay for crizotinib

The reaction of 2,3-dichloro-1,4-naphthoquinone (DCNQ) with crizotinib (CZT; a novel drug used for treatment of non-small cell lung cancer) was investigated in different solvents of varying dielectric constants and polarity indexes. The reaction produced a red-colored product. Spectrophotometric investigations confirmed that the reaction proceeded through charge–transfer (CT) complex formation. The molar absorptivity of the complex was found to be linearly correlated with the dielectric constant and polarity index of the solvent; the correlation coefficients were 0.9567 and 0.9069, respectively. The stoichiometric ratio of DCNQ:CZT was found to be 2:1 and the association constant of the complex was found to be 1.07 × 10² l/mol. The kinetics of the reaction was studied; the order of the reaction, rate and rate constant were determined. Computational molecular modeling for the complex between DCNQ and CZT was conducted, the sites of interaction on CZT molecule were determined, and the mechanism of the reaction was postulated. The reaction was employed as a basis in the development of a novel 96-microwell assay for CZT in a linear range of 4–500 μg/ml. The assay limits of detection and quantitation were 2.06 and 6.23 μg/ml, respectively. The assay was validated as per the guidelines of the International Conference on Harmonization (ICH) and successfully applied to the analysis of CZT in its bulk and capsules with good accuracy and precision. The assay has high throughput and consumes a minimum volume of organic solvents thus it reduces the exposures of the analysts to the toxic effects of organic solvents, and significantly reduces the analysis cost.     

热疗与阿霉素碘油化疗栓塞对兔VX2肝种植瘤生长及血管生成的影响

目的观察热疗联合阿霉素碘油化疗栓塞对兔VX2肝种植瘤生长及血管生成的影响。方法用日本大耳白兔建立VX2肝种植瘤模型,随机分为5组,每组8只,分别为生理盐水组(A组)、碘油组(B组)、热疗组(C组)、阿霉素加碘油组(D组)、热疗联合阿霉素加碘油组(E组)。治疗后1周CT扫描观察各组肿瘤体积;血清生化检测AST、ALT水平;免疫组化检测残存肿瘤区微血管密度(MVD)、血管内皮生长因子(VEGF)表达情况。结果治疗后1周,各治疗组肿瘤生长均受到限制,E组肿瘤体积及生长率与其他组相比有显著差异(P<0.05)。E组血清AST、ALT水平与B、D组相比无显著差异(P>0.05),与A、C组比较有显著差异(P<0.05)。E组残存肿瘤区MVD、VEGF表达最低,明显低于其他组各组(P<0.05)。结论热疗联合阿霉素碘油栓塞兔VX2肝种植瘤可明显抑制肿瘤生长并抑制残存肿瘤区血管生成。     

Antiplatelet and antithrombotic activities of CP201, a newly synthesized 1,4-naphthoquinone derivative

The antiplatelet and antithrombotic activities of a newly synthesized CP201, 2-(3,5-di-tert-butyl-4-hydroxyl)-3-chloro-1,4-naphthoquinone on human platelet aggregation in vitro and murine pulmonary thrombosis in vivo were examined. In addition, the antiplatelet activity of CP201 involved in calcium-signaling cascade was also investigated. CP201 showed concentration-dependent inhibitory effects on platelet aggregation induced by collagen and thrombin, with IC50 values of 4.1+/-0.3 and 4.6+/-0.4 microM, respectively. Orally administered CP201 protected mice against the collagen plus epinephrine-induced thromboembolic death in a dose-dependent manner. On the other hand, CP201 did not alter such coagulation parameters as activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) in human plasma in vitro. These results suggest that the antithrombotic activity of CP201 may be due to antiplatelet rather than anticoagulation activity. CP201 potently inhibited platelet aggregation challenged by calcium ionophore A23187 and thapsigargin, which is a selective inhibitor of the Ca(2+)-ATPase pump, in a concentration-dependent manner, indicating that CP201 may have an inhibitory effect on calcium-signaling cascade. This was supported by measuring [Ca2+]i in platelets loaded with fura-3AM, where CP201 inhibited the rise in cytosolic Ca2+ mediated by thrombin. Taken together, these results suggest that CP201 may be a promising antithrombotic agent, and the antithrombotic effect of CP201 may be due to antiplatelet activity, which was mediated, at least partly, by the inhibition of cytosolic calcium mobilization.     

Inhibition of angiogenesis by propolis

Propolis, obtained from honeybee hives, has been used in Oriental folk medicine as an anti-inflammatory, anti-carcinogenic, and immunomodulatory agent. There is considerable evidence suggesting that angiogenesis and chronic inflammation are codependent. Blockage of angiogenesis results in an anti-inflammatory effect. Ethanol (EEP) and ether extracts of propolis (REP), and caffeic acid phenethyl ester (CAPE), an active component of propolis, were examined for their anti-angiogenic activities using the chick embryo chorioallantoic membrane (CAM), and the calf pulmonary arterial endothelial (CPAE) cell proliferation, assays. The presence of EEP, REP and CAPE inhibited angiogenesis in the CAM assay and the proliferation of CPAE cells. The results suggest that anti-angiogenic activities of EEP, REP and CAPE are also responsible for their anti-inflammatory effect.