Intra-individual comparison of therapeutic responses to vascular disrupting agent CA4P between rodent primary and secondary liver cancers

AIM To compare therapeutic responses of a vascular-disrupting-agent, combretastatin-A4-phosphate(CA4 P), among hepatocellular carcinomas(HCCs) and implanted rhabdomyosarcoma(R1) in the same rats by magneticresonance-imaging(MRI), microangiography and histopathology.METHODS Thirty-six HCCs were created by diethylnitrosamine gavage in 14 rats that were also intrahepatically implanted with one R1 per rat as monitored by T2-/T1-weighted images(T2wI/T1wI) on a 3.0 T clinical MRIscanner. Vascular response and tumoral necrosis were detected by dynamic contrast-enhanced(DCE-) and CE-MRI before, 1 h after and 12 h after CA4P iv at 10 mg/kg(treatment group n = 7) or phosphate-buffered saline at 1.0 mL/kg(control group n = 7). Tumor blood supply was calculated by a semiquantitative DCE parameter of area under the time signal intensity curve(AUC30). In vivo MRI findings were verified by postmortem techniques.RESULTS On CE-T1wIs, unlike the negative response in all tumors of control animals, in treatment group CA4P caused rapid extensive vascular shutdown in all R1-tumors, but mildly or spottily in HCCs at 1 h. Consequently, tumor necrosis occurred massively in R1-tumors but patchily in HCCs at 12 h. AUC30 revealed vascular closure(66%) in R1-tumors at 1 h(P < 0.05), followed by further perfusion decrease at 12 h(P < 0.01), while less significant vascular clogging occurred in HCCs. Histomorphologically, CA4P induced more extensive necrosis in R1-tumors(92.6%) than in HCCs(50.2%)(P < 0.01); tumor vascularity heterogeneously scored +^+++ in HCCs but homogeneously scored ++ in R1-tumors.CONCLUSION This study suggests superior performance of CA4P in metastatic over primary liver cancers, which could guide future clinical applications of vascular-disruptingagents.

Transcatheter Arterial Embolization Combined with Anti-vascular Agent Combretastatin A4 Phosphate Inhibits Growth and Vascularization of Liver Tumor in an Animal Model

Objective This study aimed to investigate the effect of combretastatin A4 phosphate(CA4P)on proliferation,migration,and capillary tube formation of human umbilical vein endothelial cells(HUVECs)and the efficacy of transcatheter arterial embolization combined with CA4P in the treatment of rabbit VX2 liver tumor.Methods The effects of different concentrations of CA4P on proliferation,migration and capillary tube formation of HUVECs were investigated by cell proliferation assay,wound healing assay and capillary tube formation assay,respectively.Thirty-two rabbits implanted with liver VX2 tumors were randomly divided into 4 groups.After catheterization of the left hepatic artery,the infusion was performed using normal saline(group A),CA4P aqueous solution(group B),lipiodol and polyvinyl alcohol particles(group C),and CA4P lipiodol emulsion and polyvinyl alcohol particles(group D),respectively.Half of the animals in each group were euthanized for immunohistochemical analysis to evaluate microvessel density(MVD)at 3 days post-treatment.The other half were examined by MRI and histology to evaluate tumor growth and necrosis at 7 days post-treatment.Results CA4P could inhibit the proliferation,migration,and tube formation of HUVECs in cell experiments.After interventional treatment,the level of MVD in group D was lower than that in group C(P<0.01).The tumor volume in group C or D was lower than that in group A or B(P<0.01).The tumor necrosis rate was higher in group D than in the other groups.Conclusion The study suggests that CA4P could inhibit the proliferation,migration,and capillary tube formation of HUVECs,and transcatheter arterial embolization combined with CA4P could inhibit the growth of VX2 tumor and obviously induce tumor necrosis.

Multiparametric MRI biomarkers for measuring vascular disrupting effect on cancer

Solid malignancies have to develop their own blood supply for their aggressive growth and metastasis;a process known as tumor angiogenesis.Angiogenesis is largely involved in tumor survival,progression and spread,which are known to be significantly attributed to treatment failures.Over the past decades,efforts have been made to understand the difference between nor-mal and tumor vessels.It has been demonstrated that tumor vasculature is structurally immature with chaotic and leaky phenotypes,which provides opportunities for developing novel anticancer strategies.Targeting tumor vasculature is not only a unique therapeutic interven-tion to starve neoplastic cells,but also enhances the efficacy of conventional cancer treatments.Vascular dis-rupting agents(VDAs) have been developed to disrupt the already existing neovasculature in actively growing tumors,cause catastrophic vascular shutdown within short time,and induce secondary tumor necrosis.VDAs are cytostatic;they can only inhibit tumor growth,but not eradicate the tumor.This novel drug mechanism has urged us to develop multiparametric imaging biomark-ers to monitor early hemodynamic alterations,cellular dysfunctions and metabolic impairments before tumor dimensional changes can be detected.In this article,we review the characteristics of tumor vessels,tubulin-destabilizing mechanisms of VDAs,and in vivo effects of the VDAs that have been mostly studied in preclinical studies and clinical trials.We also compare the differ-ent tumor models adopted in the preclinical studies on VDAs.Multiparametric imaging biomarkers,mainly diffu-sion-weighted imaging and dynamic contrast-enhanced imaging from magnetic resonance imaging,are evalu-ated for their potential as morphological and functional imaging biomarkers for monitoring therapeutic effects of VDAs.

肿瘤血管破坏剂5,6-二甲基黄嘌呤-4-乙酸对小鼠Lewis肺癌转移的抑制作用及机制

目的探讨肿瘤血管破坏剂5,6-二甲基黄嘌呤-4-乙酸(DMXAA)对小鼠Lewis肺癌(LLC)转移的抑制作用及其机制。方法制备2种小鼠肿瘤模型(LLC异位移植瘤小鼠模型和转移型LLC小鼠模型),评价DMXAA对LLC转移的抑制作用。LLC异位移植瘤小鼠模型制备成功后,随机分为3组:模型组(含1%DMSO的生理盐水,ip,2天1次)、模型+苏尼替尼组(30 mg·kg^(-1),ip,2天1次)和模型+DMXAA组(25 mg·kg^(-1),ip,给药1次)。首次给药后每隔1天测量小鼠移植瘤体积,并绘制移植瘤体积生长曲线和小鼠体重变化曲线;给药后2和5 d剥瘤称取瘤重,并将瘤组织进行免疫荧光染色,测定血小板内皮细胞黏附分子1(CD31)和α平滑肌肌动蛋白(α-SMA)阳性表达,计算α-SMA/CD31荧光强度比值,表示移植瘤组织血管表面周细胞覆盖率;哌莫硝唑(pimonidazole)染色检测瘤组织低氧程度。转移型LLC小鼠模型制备成功后,随机分为3组:模型组(含1%DMSO的生理盐水,ip,1周2次)、模型+苏尼替尼组(60 mg·kg^(-1),ip,1周2次)和模型+DMXAA组(25 mg·kg^(-1),ip,给药1次)。首次给药后2和5周用小动物活体成像系统观察小鼠体内肿瘤转移,并进行荧光定量分析。结果与模型组相比,模型+苏尼替尼组和模型+DMXAA组移植瘤体积和重量均显著减小(P<0.05,P<0.01);模型+苏尼替尼组小鼠体重明显下降(P<0.05),而模型+DMXAA组则无显著差异。与模型组相比,苏尼替尼对LLC转移无影响,而给药后2周DMXAA明显抑制LLC转移(P<0.01)。给药后5 d,模型+苏尼替尼组和模型+DMXAA组移植瘤组织中周细胞覆盖率均显著升高(P<0.05);模型+苏尼替尼组瘤组织低氧面积无明显变化,模型+DMXAA组瘤组织低氧面积显著降低(P<0.01)。结论肿瘤血管破坏剂DMXAA显著抑制小鼠LLC生长和转移,其机制可能与其诱导肿瘤血管正常化和改善瘤组织低氧微环境有关。

A Novel Vascular Disrupting Agents Noncovalent Polymeric Nanomedicine:Significantly Increased Antitumor Therapeutic Efficiency

This work was supported by the National Natural Science Foundation of China(Nos.52025035,52103195).The comprehensive graphic content and graphic abstract were created with BioRender.com by coauthors.

Vascular disrupting agent-induced amplification of tumor targeting and prodrug activation boosts anti-tumor efficacy

Vadimezan,one of the typical vascular disrupting agents(VDAs) currently in clinical trials,has been extensively implemented for cancer research,whereas its clinical efficacy is adversely affected by the inevitable side effects.Inspired by Vadimezaninduced intratumoral coagulation activation and hypoxia aggravation,we report a strategy by utilizing these biological effects to achieve targeted delivery and activation of hypoxia-activated prodrug(HAP) thus to maximize the therapeutic effect of Vadimezan.By encapsulating HAP tirapazamine into poly(lactic-co-glycolic acid)(PLGA) nanocarriers along with the modification of clot-binding peptide,the obtained nanoplatform could target tumors under the coagulation activation effect of Vadimezan.Meanwhile,the aggravated hypoxia tumor microenvironment induced by Vadimezan can also boost hypoxia-activated chemotherapy.In the murine tumor model,this strategy showed 80.0% suppression of tumor growth,indicating its great potential in tumor treatment.This study offers an ingenious tactic for the combination of vascular disrupting therapy and hypoxia-activated chemotherapy,which may open up a window of the VDAs-based combination therapy.

1-苯基-1-苯并呋喃/噻吩甲烯基环烷烃衍生物的合成及抗肿瘤活性研究

目的设计合成1-苯基-1-苯并呋喃/噻吩甲烯基环烷烃衍生物,测定其体外抗肿瘤活性。方法以甲氧基取代的2-羟基苯甲醛或苯乙酮(4a^4c)为起始原料,经缩合、Mcmurry偶联反应得到目标化合物2a^2c;以2-羟基-4-甲氧基苯甲醛或苯乙酮(6a^6b)为起始原料,经酯化、重排、水解、缩合、Mcmurry偶联反应得到目标化合物3a^3b;采用四氮唑盐(MTT)法测定对人白血病细胞活性。结果共合成5个衍生物,其结构均经核磁共振氢谱、碳谱和高分辨质谱确证;其中衍生物3a^3b的体外抗人白血病CEM细胞活性与先导物1相当,但低于考布他汀A-4(CA-4)。结论采用苯并噻吩环取代先导物的B环能保持化合物的体外抗肿瘤活性。

血管阻断剂(Z)-2-甲氧基-5-[2-(3,4,5-三甲氧基苯基)乙烯基]-苯胺的合成

对(Z)-2-甲氧基-5-[2-(3,4,5-三甲氧基苯基)乙烯基]-苯胺(AVE-8063)的合成进行了研究。采用两条路线得到AVE-8063,均以对甲氧基苯乙酸为起始原料,经硝化、Perk in缩合、还原得到(E)-2-(3-氨基-4-甲氧基苯基)-3-(3,4,5-三甲氧基苯基)-丙烯酸(Ⅳ),直接脱羧得到目标化合物(路线1);为改善后处理操作条件,还将化合物Ⅳ的氨基保护、再经脱羧及去保护得到目标化合物(路线2)。路线1和路线2的总收率分别为20.4%和17.1%,均高于文献报道的W ittig反应路线,各中间体及产物结构经MS、IR以及1HNMR确证。

血管阻断剂活性化合物AVE-8063的合成

对血管阻断剂活性分子(Z)-3'-氨基-3,4,4',5-四甲氧基二苯乙烯(AVE-8063)的合成进行了研究。以对甲氧基苯乙酸(Ⅰ)为原料,经溴代及Perkin反应得到(E)-2-(3-溴-4-甲氧基苯基)-3-(3,4,5-三甲氧基苯基)丙烯酸(Ⅲ),再经芳环上溴的氨基取代得到(E)-2-(3-氨基-4-甲氧基苯基)-3-(3,4,5-三甲氧基苯基)丙烯酸(Ⅳ),最后在Cu/1,10-Phen/PEG-400体系微波辅助下反应6 min即脱羧得到目标化合物(Ⅴ),总收率为60.1%。产物结构经IR、MS和1HNMR确证。

An overview of translational(radio)pharmaceutical research related to certain oncological and non-oncological applications

Translational medicine pursues the conversion of scientific discovery into human health improvement.It aims to establish strategies for diagnosis and treatment of diseases.Cancer treatment is difficult.Radiopharmaceutical research has played an importantrole in multiple disciplines,particularly in translational oncology.Based on the natural phenomenon of necrosis avidity,Onco Ci Dia has emerged as a novel generic approach for treating solid malignancies.Under this systemic dual targeting strategy,a vascular disrupting agent first selectively causes massive tumor necrosis that is followed by iodine-131 labeled-hypericin(123IHyp),a necrosis-avid compound that kills the residual cancer cells by crossfire effect of beta radiation.In this review,by emphasizing the potential clinical applicability of Onco Ci Dia,we summarize our research activities including optimization of radioiodinated hypericin Hyp preparations and recent studies on the biodistribution,dosimetry,pharmacokinetic and,chemical and radiochemical toxicities of the preparations.Myocardial infarction is a global health problem.Although cardiac scintigraphy using radioactive perfusion tracers is used in the assessment of myocardial viability,searching for diagnostic imaging agents with authentic necrosis avidity is pursued.Therefore,a comparative study on the biological profiles of the necrosis avid 123I-Hyp and the commercially available 99mTc-Sestamibi was conducted and the results are demonstrated.Cholelithiasis or gallstone disease may cause gallbladder inflammation,infection and other severe complications.While studying the mechanisms underlying the necrosis avidity of Hyp and derivatives,their naturally occurring fluorophore property was exploited for targeting cholesterol as a main component of gallstones.The usefulness of Hyp as an optical imaging agent for cholelithiasis was studied and the results are presented.Multiple uses of automatic contrast injectors may reduce costs and save resources.However,cross-contaminations with bloodborne pathogens of infectious diseases may occur.We developed a radioactive method for safety evaluation of a new replaceable patient-delivery system.By mimicking pathogens with a radiotracer,we assessed the feasibility of using the system repeatedly without septic risks.This overview is deemed to be interesting to those involvedin the related fields for translational research.

Separate calculation of DW-MRI in assessing therapeutic effect in liver tumors in rats

AIM:To explore whether the antitumor effect of a vascular disrupting agent(VDA)would be enhanced by combining with an antiangiogenic agent,and whether such synergistic effects can be effectively evaluated with separate calculation of diffusion weighted magnetic resonance imaging(DW-MRI).METHODS:Thirty-seven rats with implanted liver tumors were randomized into the following three groups:(1)ZD6126,a kind of VDA;(2)ZDTHA,ZD6126 in combination with an antiangiogenic,thalidomide;and(3)control.Morphological DW-MRI were performed and quantified before,4 h and 2 d after treatment.The apparent diffusion coefficient(ADC)values were calculated separately for low b values(ADC low),high b values(ADC high)and all b values(ADC all).The tissue perfusion contribution,ADC perf,was calculated as ADC low-ADC high.Imaging findings were finally verified by histopathology.RESULTS:The combination therapy with ZDTHA significantly delayed tumor growth due to synergistic effects by inducing cumulative tumor necrosis.In addition to delaying tumor growth,ZDTHA caused tumor necrosis in an additive manner,which was verified by HE staining.Although both ADC high and ADC all in the ZD6126and ZDTHA groups were significantly higher compared to those in the control group on day 2,the entire tumor ADC high of ZDTHA was even higher than that of ZD6126,but the significant difference was not observed for ADCall between ZDTHA and ZD6126.This indicated that the perfusion insensitive ADC high values calculated from high b value images performed significantly better than ADC all for the monitoring of tumor necrosis on day 2.The perfusion sensitive ADC perf derived from ADC low by excluding high b value effects could better reflect the reduction of blood flow due to the vessel shutdown induced by ZD6126,compared to the ADC low at 4 h.The ADC perf could provide valuable perfusion information from DW-MRI data.CONCLUSION:The separate calculation of ADC is more useful than conventional averaged ADC in evaluating the efficacy of combination therapy with ZD6126and thalidomide for solid tumors.

肿瘤血管靶向治疗的研究进展

肿瘤血管在实体瘤的发生发展中具有重要的作用,靶向肿瘤血管的抑制在抗肿瘤治疗已得到广泛的认同,并生产出大批抗血管制剂,有的已应用于临床治疗。这些新研发的抗血管制剂与传统的针对实体瘤的细胞毒性药物作用机理截然不同。根据作用机理及对血管抑制的阶段不同,肿瘤血管靶向治疗分为抗血管新生制剂和肿瘤血管阻断制剂。抗血管新生制剂旨在抑制肿瘤新生血管新生过程,而肿瘤血管阻断制剂则通过快速而有选择性地损坏或阻塞已构建完成的肿瘤血管,使肿瘤血供受阻引起肿瘤坏死。两者区别主要在作用靶点、肿瘤类型及治疗时机不同。本文对近年来抗血管新生制剂和血管阻断剂的研究进展进行综述。

抗血管生成药物作用机制研究进展

血管生成是成人体内血管形成的一种主要方式。血管生成异常可影响多种疾病的进程,如恶性肿瘤、糖尿病视网膜病变和年龄相关性黄斑变性等;而抗血管生成药物对于上述疾病的治疗具有重要意义。抗血管生成药物可分为内源性血管生成抑制剂和间接血管生成抑制剂。前者通过降低某些血管活性因子(如血管内皮生长因子)的活性抑制内皮细胞增殖和(或)迁移,后者可通过间接降低某些血管活性因子的水平、减少原癌基因的表达、干预微环境、抑制炎症反应等多种方式影响血管生成。本综述主要阐述抗血管生成药物的分类及作用机制,对恶性肿瘤及多种眼科疾病的治疗具有重要意义。

Combretastatin A4的抗肿瘤作用研究进展

肿瘤细胞的生存和发展需要完整的血管系统提供氧气、养料并输送废物,同时提供转移的主要路线,因此肿瘤血管成为肿瘤治疗中一个很有吸引力的靶点。以往大量的研究集中在抗新生血管生成方面,近年来对于肿瘤血管靶向药物(Vascular targeting agents)的研究逐渐增多,此类药物针对肿瘤既存血管产生迅速且有选择性的破坏作用,使肿瘤细胞由于氧气和养料缺乏而死亡。Combretastatin A4作为其中的一个候选化合物,吸引众多的研究人员对其体内外药理作用进行研究,该候选化合物的水溶性前药已经被OxiGen公司开发,目前在美国和欧洲进行II期临床试验,且已获准进入美国FDA快速通道审批。现就其体内外药效学、作用机制以及临床研究进展作一综述。

作用于微管蛋白的小分子肿瘤血管阻断剂研究进展

肿瘤血管阻断剂(VDA)直接作用于已形成的肿瘤血管内皮细胞,引起肿瘤血管的坍塌,导致肿瘤细胞从内部向外部坏死,但对肿瘤的边缘部往往作用不佳。因此,VDA与互补性的传统化疗或放射疗法合用,为肿瘤细胞的彻底清除提供了可能。目前处于临床研究的作用于微管蛋白的VDA共有13个,本文对其研究进展进行综述,同时简单介绍VDA的临床前研究技术、联合用药及心血管副作用。

磁共振DWI动态监测新型血管阻断剂对兔VX2种植性肝癌的疗效

目的评价DWI动态监测新型血管阻断剂M410治疗兔VX2种植性肝癌的效果。方法建立28只兔VX2种植性肝癌模型,随机等分为2组,分别静脉注射M410（实验组）和生理盐水（对照组）。两组于给药前、给药后4h、1天、4天、7天、14天分别行MR平扫及DWI检查,并于各时间点取肿瘤组织行HE染色和CD34免疫组化检查,观察肿瘤体积、肿瘤整体及实质平均ADC值及病理变化。结果实验组肿瘤体积较对照组增长缓慢,给药后4～14天各时间点两组肿瘤体积差异均有统计学意义（P均〈0.05）。肿瘤整体及实质平均ADC值：给药后1天实验组低于对照组,4天实验组高于对照组,差异均有统计学意义（P〈0.05）。ADC值改变与肿瘤组织病理学结果相符。结论 DWI可动态反映新型血管阻断剂M410治疗兔VX2种植性肝癌后肿瘤分子水平的变化,通过测量肿瘤ADC值可早期监测M410的疗效。

ADC_(high)评价考布他汀抗人结肠癌移植瘤疗效的实验研究

目的:探讨磁共振扩散加权成像高b值拟合ADCh ig h评价考布他汀A4(CA4P)血管靶向治疗人结肠癌裸鼠移植瘤早期效果的可行性。方法:人结肠癌裸鼠皮下移植瘤实验组(18只)和对照组(12只),分别腹腔注射CA4P 100mg/kg及等剂量的生理盐水建立疾病模型。治疗前、治疗(1h、24h、48h)进行10个b值的DWI扫描,测量瘤体中心及边缘的ADCh ig h值;治疗后分批处死实验动物,计算瘤体不同区域PCNA计分。组内及组间ADChigh分别行方差分析和t检验。ADChigh与PCNA间行Pearson相关性分析。结果:治疗后实验组瘤体中心ADChigh逐渐升高,治疗24h与1h,48h与治疗前及治疗1h差异比较有统计学意义;瘤体边缘ADChigh治疗24h升高,治疗1h及48h均低于治疗前。治疗24h实验组ADChigh较对照组高,差异有统计学意义(中心t=2.978,P=0.0 08;边缘t=2.111,P=0.0 49);治疗48h瘤体中心A DCh ig h较对照组高,差异有统计学意义(t=5.008,P=0.001)。治疗48h边缘ADChigh与PCNA计分负相关(r=-0.568,P=0.000)。结论:多个高b值拟合的ADChigh能反映CA4P抗人结肠癌裸鼠移植瘤的早期坏死及存活,是动态监测和评价抗肿瘤血管靶向药物疗效的可行手段。

磁共振弥散加权成像评估血管阻滞剂对兔肝VX2瘤疗效的最优b值研究

目的探讨DWI监测血管阻断剂M410治疗兔肝VX2瘤疗效的最优成像b值。方法成功建立28只肝VX2瘤模型,随机等分成2组,分别静注M410(实验组)和生理盐水(对照组)。两组于给药前、给药后14d分别进行MR平扫及DWI检查,b值分别取100、200、300、400、500、600、700、800、900 s/mm^(2)。观察肿瘤大小,T1WI、T2WI及DWI表现,测量并分析两组动物各b值下DWI图像的CNR。结果给药前实验组与对照组肿瘤平均直径分别为12.3、13.6mm,差异无统计学意义(P>0.05);给药后14d,实验组与对照组肿瘤平均直径分别为23.8、31.7mm,差异有统计学意义(P<0.05)。肿瘤TiWI表现为低信号,T2WI主要为高信号,部分内部见低信号凝固性坏死区;b值小于600s/mm^(2)时,DWI图片上肿瘤与胆囊均表现为高信号影,其中胆囊呈明亮高信号,高于肿瘤信号;当b值大于等于600s/mm^(2)时,胆囊信号明显减低,但肿瘤仍为高信号,信号改变不明显;当b值等于700s/mm^(2)时,治疗前后CNR的差别最大,差异有统计学意义(P<0.05)。结论采用DWI检测新型血管阻断剂M410对兔肝VX2瘤的疗效时,b值选取700s/mm^(2)为较为合适。

抗肿瘤药物Vadimezan的合成及其临床研究近况

Vadimezan是一种小分子肿瘤血管生长抑制剂,它具有抑制多种实体瘤的生物活性。本文综述了Vadimezan的最新合成研究进展,并简要介绍了其临床研究近况。

考布他汀A_4类肿瘤血管破坏剂的研究进展

肿瘤血管破坏剂(VDA)是一类靶向肿瘤血管的抗肿瘤药物,能够快速、有选择地引发肿瘤组织内部既成血管的塌陷,阻断血液供应,从而引发肿瘤组织缺血性坏死。因此,VDA在治疗实体瘤方面具有很大的应用前景。其中,考布他汀A4(CA4)疗效较好,但同时毒性较大。在寻找更特异性的VDA过程中,研究者合成了一系列CA4的类似物。本文分析了这些CA4类似物的结构,指出二芳基桥链的顺式构型为其特点,而且这些化合物与微管蛋白上的秋水仙碱作用位点结合,抑制微管蛋白的聚合。与传统抗肿瘤药物不同的是,CA4类VDA的抗肿瘤作用主要是通过选择性破坏肿瘤组织的血管系统实现的。同时,本文介绍了CA4类VDA的典型药物、影响CA4类VDA药效的肿瘤因素和宿主因素,以及为增强疗效和降低毒性作用而进行的联合用药情况。虽然CA4类VDA具有很大的应用前景,但目前还存在一些缺点,因而有必要继续寻找高效低毒的VDA,同时寻找可靠的生物标志物来指导VDA的临床用药也很有必要。