磷酸二脂酶(PDE2、PDE4)抑制剂抗肿瘤血管生成作用的实验研究

目的:研究确定磷酸二脂酶(phosphodiesterase,PDE)抑制剂对内皮细胞增殖、迁移以及在体内血管生成中的作用。方法:分别以人静脉内皮细胞(HUVEC)及C57BL/N6纯系小鼠为体外、体内研究对象,通过酶联免疫方法检测PDE2(ENHA)、PDE4(RP705)抑制剂对HUVEC中cAMP的含量的影响,及其与细胞增殖和迁移的关系。ENHA和RP705联合应用在C57BL/N6小鼠中的抑瘤作用。结果:PDE2选择性抑制剂EHNA(25μmol/L)和PDE4选择性抑制RP705(15μmol/L)均能够抑制由VEGF刺激的HUVEC增殖和迁移,并能增加HUVEC内cAMP含量,实验结果还显示PDE2和PDE4抑制剂的联合应用能够抑制体内血管生成,对C57BL/6N小鼠的抑瘤率达45.50%。结论:上述结果充分提示在病理性血管生成中PDE2和PDE4可能是新的潜在性的治疗靶点。     

重组人血管内皮抑素对血管新生的影响研究

目的 探讨重组人血管内皮抑素（Endostar,恩度）对血管内皮细胞趋化、迁移、粘附、增殖及小管形成等与血管新生相关生物学行为的影响。方法 以原代培养的人脐静脉内皮细胞（HUVEC）为细胞模型,通过Boyden小室荧光定量分析、划痕试验、HUVEC荧光定量粘附分析、CFSE染色流式细胞术、CCK-8定量检测、小管形成试验和Matrigel栓试验研究恩度对HUVEC与血管新生相关的生物学行为的影响。结果 恩度在5～50 000ng／ml范围内可抑制血管内皮生长因子诱导HUVEC的迁移运动,且浓度为50ng／ml和500ng／ml时效果最明显;恩度在5～50 000ng／ml间可呈剂量依赖的方式抑制HUVEC向损伤部位的迁移。与0ng／ml相比,50、500和5000ng／ml 恩度处理的HUVEC的粘附率、增殖率及HUVEC形成网状小管结构的数量、面积和长度均降低,差异均有统计学意义（P＜0.05）; Matrigel栓实验结果显示,恩度在50～5000ng／ml间对SCID小鼠体内血管新生有明显的抑制作用。结论 恩度在细胞水平能抑制HUVEC与血管新生相关的生物学行为,包括HUVEC的趋化、迁移、粘附、增殖和小管形成;在动物水平能抑制SCID小鼠体内的血管新生,据此推断恩度能抑制血管新生。     

和厚朴酚抗血管生成作用的实验研究

目的：本研究通过检测和厚朴酚在体内对鸡胚尿囊膜（chicken chorilallantoic membranes，CAM）血管生成的抑制作用及体外对肿瘤血管生成的影响，探讨和厚朴酚的抗血管生成作用及其初步机制。方法：（1）用四甲基偶氮唑盐（MTT）法检测和厚朴酚对人脐静脉内皮细胞（human umbilical vein endothelial cell，HUVEC）、人成纤维细胞及人结肠癌RKO细胞增殖的抑制作用；（2）采用鸡胚绒毛尿囊膜模型，观测和厚朴酚对CAM新生血管生成的抑制作用；（3）逆转录聚合酶链反应（RT-RCR）方法检测和厚朴酚对RKO细胞血管内皮生长因子A（VEGF-A）mRNA表达及细胞培养上清液VEGF蛋白分泌的影响。结果：和厚朴酚对血管内皮细胞具有优先抑制作用，对HUVEC的半数抑制剂量（inhibitory concentration 50％，IC50）为14．5μmol/L，而对原代培养的人成纤维细胞的IC50高达150μmol/L，对人结肠癌RKO细胞的IC50为42μmol/L；和厚朴酚0．1μg／只和0．2μg／只剂量时显著抑制CAM新生血管形成，抑制率分别为58％和86％；和厚朴酚在10μmol/L和20μmol/L剂量时显著抑制RKO细胞的VEGF-A mRNA表达及细胞培养上清液中VEGF蛋白的分泌，具有显著性差异。结论：和厚朴酚在非凋亡剂量时具有抗血管形成作用，其机制与抑制血管内皮细胞增殖以及抑制肿瘤细胞表达VEGF有关。     

高通量肿瘤血管新生研究技术平台的建立

目的：建立高通量肿瘤血管新生研究的体内外技术平台。方法：以VEGF,hFGF为血管新生因子,以Thalidomide血管新生抑制因子对体外培养的血管内皮细胞系（RF／6A,SVEC）应用MTT试验,迁移试验,浸润试验和管状形成试验检测内皮细胞的各种特性;体内实验以鸡胚C57BL／6小鼠为实验动物检测血管新生因子和抑制因子在体内对血管新生的影响。结果：VEGF和bFGF在体内和体外均有促进血管新生的作用,体外试验表明VEGF和bFGF对内皮细胞的增殖活性,迁移、浸润和管状结构形成均有明显的促进作用（P＜0．01）;小鼠体内栓子试验和鸡胚绒毛尿囊膜试验结果均表明,VEGF和b FGF对体内血管新生同样具有促进或刺激作用,和阴性对照组相比主要表现在新生血管密度高、管腔大、管壁完整等;而Thalidomide在体内外均有明显抑制血管新生的作用。结论：本技术平台是一个高通量、经济、简便易行、实用的血管新生研究技术平台。     

长春瑞滨及联合热疗抗血管生成作用的实验

目的探讨长春瑞滨及联合热疗对血管生成的抑制作用。方法以人肺癌A549细胞为对照,采用MTT法观察长春瑞滨及联合热疗对人脐静脉内皮细胞（HUVEC）增殖的影响;通过Transwell趋化实验、小管形成实验及流式细胞术观察长春瑞滨对HUVEC迁移、小管形成及细胞凋亡的影响;利用鸡胚绒毛尿囊膜（CAM）模型,观察长春瑞滨对体内CAM新生血管的影响。结果小剂量（0.1～1 ng/ml）长春瑞滨对HUVEC和A549增殖抑制具有差异细胞毒性（P=0.000）。0.1～1 ng/ml 长春瑞滨呈剂量依赖性抑制HUVEC增殖（r=0.993,P=0.000）,联合热疗具有抑制HUVEC增殖的叠加或协同效应。小剂量长春瑞滨能够抑制HUVEC迁移和小管形成,诱导HUVEC凋亡,遏制CAM新生血管形成。结论小剂量长春瑞滨具有抗血管生成作用,联合热疗具有协同或叠加效应。     

重楼醇提物体外抑制血管生成作用研究

目的：探讨重楼醇提物对体外血管生成的抑制作用及其可能的机制。方法：采用MTT法观察重楼醇提物对人脐静脉血管内皮细胞（HUVEC）、人肠癌LOVO细胞增殖的影响。利用transwell小室趋化实验、体外管腔形成实验观察重楼醇提物对HUVEC迁移、成血管能力的影响。结果：重楼醇提物在（15—60）μg／ml浓度范围内，内皮细胞抑制率在24．2％-82．1％之间，具有抑制血管内皮细胞增殖作用；体外管腔形成实验发现，（15—60）μg／ml的重楼醇提物管腔形成数目减少，且管腔不完整，与对照组相比有显著性差异（P分别为0．0000011、0．0000417、0．0008752）。经（15—60）μg／m1的重楼醇提物处理后内皮细胞迁移数明显少于对照组（P分别为0．0000005、0．0000033、0．009993）。而在该浓度范围内，对人肠癌LOVO细胞无明显细胞毒作用（细胞抑制率在12．1％-13．9％之间）。（15—60）μg／ml的重楼醇提物可诱导内皮细胞凋亡，抑制内皮细胞DNA的合成，且呈剂量依赖性（相关系数分别为0．929、-0．922，P为0．036、0．039）。结论：重楼醇提物在体外能有效抑制血管生成。其机制可能与抑制内皮细胞增生、迁移和管腔形成，诱导内皮细胞凋亡，抑制内皮细胞DNA的合成有关。     

参麦注射液联合羟基喜树碱抑制血管生成作用的实验研究

背景与目的：某些小剂量中药和小剂量化疗药物可选择性地抑制血管内皮细胞的功能。因此本文探讨参麦注射液联合应用羟基喜树碱对体内外血管生成的抑制作用。方法：以人肝癌细胞HepGⅡ作为对照，采用MTT法和三维血管模型观察参麦注射液联合羟基喜树碱对体外人微血管内皮细胞（HMVEC）增殖和迁移的影响；利用鸡胚尿囊膜（CAM）模型观察参麦注射液联合羟基喜树碱对体内鸡胚绒毛尿囊膜血管生成的影响。结果：40μl／ml参麦注射液和20ng／ml羟基喜树碱对血管内皮细胞增殖的抑制率分别为18％、31．7％，联合应用后的抑制率为43．6％；40μl／ml参麦注射液和20ng／ml羟基喜树碱对HepGⅡ细胞的抑制率分别为1．2％、0．9％，联合应用后的抑制率为19．4％；40μl／ml参麦注射液和20ng／ml羟基喜树碱对血管内皮细胞有抑制出芽的作用，联合应用具有显著的协同效应，且与作用时间呈正相关（r=0．988，P=0．007）；40μl／ml参麦注射液和20ng／ml羟基喜树碱对鸡胚尿囊膜新生血管抑制率分别为30％、40％，联合应用后的抑制率为60％。结论：①小剂量参麦注射液（40μl／m1）、羟基喜树碱（20ng／m1）在体内外具有抑制血管生成作用，而对肝癌细胞无明显抑制作用，显示出明显差异性细胞毒作用；②小剂量参麦注射液（40μl／m1）联合羟基喜树碱（20ng／m1）在体外具有抑制HMVEC增殖和迁移协同作用，体内具有抑制血管生成协同作用。     

白头翁醇提物抑制血管生成的体外实验研究

目的 探讨白头翁醇提物对体外血管生成的抑制作用及其可能机制。方法 采用MTT法观察白头翁醇提物对人脐静脉血管内皮细胞（HUVEC）和人肠癌LoVo细胞增殖的影响;通过Transwell小室趋化实验、体外小管形成实验观察白头翁醇提物对HUVEC迁移、形成血管能力的影响;采用流式细胞仪检测白头翁醇提物对HUVEC的凋亡率及细胞周期的影响。结果 2～8μg／ml的白头翁醇提物作用48h对HUVEC的增殖抑制率为21.6％～72.0％,对LoVo细胞的增殖抑制率为13.2％～22.9％;体外小管形成实验发现,2～8μg／ml白头翁醇提物作用24h,HUVEC小管形成数目减少,且管腔不完整,与对照组比较差异有统计学意义（P＜0001）。经2～8μg／ml白头翁醇提物处理12h,HUVEC迁移数明显少于对照组（P＜0001）。2、4、8μg／ml白头翁醇提物作用于HUVEC细胞48h后,其凋亡率分别为952％、1864％和2007％,对照组为6.25％。8μg／ml白头翁醇提物作用于HUVEC细胞24h后,细胞周期停滞在G2／M期。结论 白头翁醇提物在体外能有效抑制血管生成,其机制可能与抑制HUVEC增殖、迁移和小管形成,诱导HUVEC凋亡,抑制HUVEC有丝分裂有关。     

内皮抑素及其抗肿瘤作用的研究进展

新生血管的形成（Angiogenesis）是肿瘤生长转移过程中的必要条件之一,它是一个多因素、多步骤的发展过程。因此控制血管生成己成为抑制肿瘤生长的重要途径之一。内皮抑素（Endostatin）是一种新发现的特异性血管内皮细胞增殖抑制剂,在血管生成过程中起负性调节作用。体外实验表明内皮抑素能有效抑制血管内皮细胞增殖、迁移及新生血管形成,是一种特异性的血管形成抑制剂,     

雷公藤红素抑制血管生成的实验研究

目的：探讨雷公藤红素对血管生成的抑制作用。方法：采用MTT法测定雷公藤红素对血管内皮细胞株(ECV)增殖的影响,观察雷公藤红素对ECV迁移实验和小管形成实验的作用,以及对鸡胚尿囊膜血管生成的影响。体内实验采用Matrigel plug方法。结果：雷公藤红素可明显抑制ECV的体外增殖,IC50为1．33μg／ml;可抑制ECV的迁移和小管形成,并且呈明显的剂量依赖性;同时具有抑制鸡胚尿囊膜血管生成和Matrigel plug中的血管新生的作用。结论：雷公藤红素具有明显抑制血管生成的作用,有可能成为有效的血管生成抑制剂。     

Inhibition of PDE3B augments PDE4 inhibitor-induced apoptosis in a subset of patients with chronic lymphocytic leukemia.

PURPOSE: cAMP phosphodiesterase (PDE) 4 is a family of enzymes the inhibition of which induces chronic lymphocytic leukemia (CLL) apoptosis. However, leukemic cells from a subset of CLL patients are relatively resistant to treatment with the PDE4 inhibitor rolipram, particularly when this drug is used in the absence of an adenylate cyclase stimulus such as forskolin. Elevated cAMP levels induce compensatory up-regulation of several cyclic nucleotide PDE families in other model systems. We here examine the hypothesis that CLL cells that survive treatment with rolipram do so as a result of residual PDE activity that is not inhibited by this drug. EXPERIMENTAL DESIGN: We examined by Western analysis the effect of rolipram treatment on CLL expression of PDE3B, PDE4A, PDE4B, PDE4D, and PDE7A. We also examined the ability of rolipram (PDE4 inhibitor) or cilostamide (PDE3 inhibitor), alone or together, to induce apoptosis or elevate cyclic AMP in leukemic cells from patients with CLL. RESULTS: Rolipram increased levels of PDE4B and, to a variable extent, PDE4D. When combined with forskolin, rolipram also increased levels of a second family of PDEs, PDE3B. Addition of the specific PDE3 inhibitor, cilostamide, modestly augmented rolipram-induced apoptosis in five of seven "rolipram-resistant" CLL samples. CONCLUSIONS: Although this work confirms that PDE4 appears to be the most important PDE target for induction of apoptosis in CLL, combination therapy with PDE3 and PDE4 inhibitors or use of dual-selective drugs may be of benefit in a subset of relatively PDE4-inhibitor resistant CLL patients.     

Tehranolide inhibits cell proliferation via calmodulin inhibition,PDE, and PKA activation

Tehranolide, natural sesquiterpene lactone with an endoperoxide group, has been shown to inhibit cell growth in cancer cells. Tehranolide was purified from Artemisia diffusa. To detect cell viability and proliferation, MTT assay was performed. In order to determine the role of tehranolide on calmodulin (CaM) structure and activity, its effects were evaluated with fluorescence emission spectra and CaM-mediated activation of phosphodiesterase (PDE1), in comparison with artemisinin. In fact, PDE1 inhibition, cAMP accumulation, and cAMP-dependent protein kinase A (PKA) activation were examined. The inhibitory effect of tehranolide on CaM structure is more than artemisinin. The kinetic analysis of tehranolide–CaM interaction has shown that this agent competitively inhibited the activation of PDE1 without affecting Vmax. Tehranolide increased Km value in higher amounts compared with artemisinin. Moreover, tehranolide had a cytotoxic effect on K562 cell line but not on normal human lymphocytes. Additionally, PDE inhibition and consequent cAMP accumulation and PKA activity were required for inhibiting cancer cell growth by tehranolide. Our results show that tehranolide significantly reduces cell proliferation in a time and dose-dependent manner in K562 cells via CaM inhibition, following PDE inhibition, cAMP accumulation, and consequent PKA activity.     

Oncogenic BRAF induces melanoma cell invasion by downregulating the cGMP-specific phosphodiesterase PDE5A

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Highlights? Oncogenic BRAF downregulates PDE5A in melanoma cells ? PDE5A downregulation or inhibition induces invasion in BRAF mutant melanoma cells ? PDE5A regulates invasion by increasing cGMP, Ca²⁺, and contractility in melanoma cells ? PDE5A loss increases short and long-term colonization of the lungs by melanoma cells     

Validation of a small molecule inhibitor of PDE6D-RAS interaction with favorable anti-leukemic effects

RAS mutations prevalent in high-risk leukemia have been linked to relapse and chemotherapy resistance. Efforts to directly target RAS proteins have been largely unsuccessful. However, since RAS-mediated transformation is dependent on signaling through the RAS-related C3 botulinum toxin substrate (RAC) small GTPase, we hypothesized that targeting RAC may be an effective therapeutic approach in RAS mutated tumors. Here we describe multiple small molecules capable of inhibiting RAC activation in acute lymphoblastic leukemia cell lines. One of these, DW0254, also demonstrates promising anti-leukemic activity in RAS-mutated cells. Using chemical proteomics and biophysical methods, we identified the hydrophobic pocket of phosphodiester 6 subunit delta (PDE6D), a known RAS chaperone, as a target for this compound. Inhibition of RAS localization to the plasma membrane upon DW0254 treatment is associated with RAC inhibition through a phosphatidylinositol-3-kinase/AKT-dependent mechanism. Our findings provide new insights into the importance of PDE6D-mediated transport for RAS-dependent RAC activation and leukemic cell survival.Subject terms: Acute lymphocytic leukaemia, Acute myeloid leukaemia, Drug development, Targeted therapies     

Phosphodiesterase 11A (PDE11A) and genetic predisposition to adrenocortical tumors.

PURPOSE: We have reported previously nonsense inactivating mutations of the phosphodiesterase 11A (PDE11A) gene in patients with micronodular adrenocortical hyperplasia and Cushing syndrome. The aim of this study is to investigate the presence of somatic or germ-line PDE11A mutations in various types of adrenocortical tumors: ACTH-independent macronodular adrenocortical hyperplasia (AIMAH), adrenocortical adenoma (ACA), and adrenocortical cancer (ACC). EXPERIMENTAL DESIGN: PDE11A was sequenced in 117 adrenocortical tumors and 192 controls subjects; immunohistochemistry for PDE11A and tumor cyclic AMP levels were studied in a subgroup of adrenocortical tumors. RESULTS: One PDE11A inactivating mutation (R307X) was found in one ACA, 22 germ-line missense variants (18.8%) were found in adrenocortical tumors, and only 11 missense variants (5.7%) were found in controls. By comparing the common mutations, a higher frequency of mutations in adrenocortical tumors than in age/sex-matched controls were observed [16% versus 10% in ACC, 19% versus 10% in ACA, and 24% versus 9% in AIMAH; odds ratio (OR), 3.53; P = 0.05]. Somatic DNA from adrenocortical tumors with missense variants showed a wild-type allelic loss. A significant difference between ACC and controls was observed for a polymorphism in exon 6 (E421E; OR, 2.1; P = 0.03) and three associated polymorphisms located in intron 10-exon 11-intron 11 (OR, 0.5; P = 0.01). In AIMAH/ACA, cyclic AMP levels were higher than in normal adrenals and decreased PDE11A immunostaining was present in adrenocortical tumors with PDE11A variants. CONCLUSIONS: The present investigation of a large cohort of adrenocortical tumors suggests that PDE11A sequence defects predispose to a variety of lesions (beyond micronodular adrenocortical hyperplasia) and may contribute to the development of these tumors in the general population.     

PDE5 inhibitors enhance the lethality of standard of care chemotherapy in pediatric CNS tumor cells

We determined whether clinically relevant phosphodiesterase 5 (PDE5) inhibitors interacted with clinically relevant chemotherapies to kill medulloblastoma cells. In medulloblastoma cells PDE5 inhibitors interacted in a greater than additive fashion with vincristine/etoposide/cisplatin to cause cell death. Knockdown of PDE5 expression recapitulated the combination effects of PDE5 inhibitor drugs with chemotherapy drugs. Expression of dominant negative caspase 9 did not significantly inhibit chemotherapy lethality but did significantly reduce enhanced killing in combination with the PDE5 inhibitor sildenafil. Overexpression of BCL-XL and c-FLIP-s suppressed individual and combination drug toxicities. Knockdown of CD95 or FADD suppressed drug combination toxicity. Treatment with PDE5 inhibitors and chemotherapy drugs promoted autophagy which was maximal at ~12 h post-treatment, and in a cell type-dependent manner knockdown of Beclin1 or ATG5 either suppressed or enhanced drug combination lethality. PDE5 inhibitors enhanced the induction of chemotherapy-induced DNA damage in a nitric oxide synthase-dependent fashion. In conclusion, our data demonstrate that the combination of PDE5 inhibitors with standard of care chemotherapy agents for medulloblastoma represents a possible novel modality for future treatment of this disease.     

外周血白细胞PDE4C基因甲基化及环境因素交互作用与乳腺癌发病的关系

目的 探讨外周血白细胞中磷酸二酯酶4C(PDE4C)基因甲基化和环境因素的交互作用与乳腺癌发病的关系。方法 采用病例对照研究,选择2010年10月—2014年12月纳入的402例乳腺癌病例和470例对照作为研究对象,使用特异性DNA甲基化修饰的定量PCR方法检测PDE4C基因的甲基化水平。应用叉生分析、多因素Logistic回归,分析基因甲基化水平及其和环境因素的交互作用与乳腺癌发病的关系。结果 未发现PDE4C甲基化与乳腺癌的发病有显著关联。高频次/摄入量的粗粮、蔬菜、葱属性植物、禽肉、牛奶及经常运动可降低乳腺癌的发病风险;高频次/摄入量的猪肉,以及月经周期不规律、心理应激指数偏高可增加乳腺癌的发病风险。PDE4C高甲基化与食用葱属性植物大于3次/周有显著的联合作用(OR=0.373,95% CI:0.208~0.668,P=0.001)。结论 PDE4C基因高甲基化不是乳腺癌发病的独立危险因素,其与环境因素的联合作用影响乳腺癌的发病风险。     

miR-218-5p靶向PDE7A调节人非小细胞肺癌A549细胞的糖酵解

目的：探究miR-218-5p靶向磷酸二酯酶7A（PDE7A）调节人非小细胞肺癌（NSCLC）A549细胞糖酵解过程的机制。方法：常规培养A549细胞,用Lipo3000将miR-218-5p mimic、mimic-NC、PDE7A过表达质粒（PDE7A-oe）和PDE7A对照质粒（PDE7ANC）转染A549细胞,记为miR-218-5p mimic组、mimic-NC组、PDE7A-oe组和PDE7A-NC组。qPCR法验证转染效率,WB法检测糖酵解关键酶蛋白的表达,葡萄糖测定法和乳酸生成测定法检测各转染组A549细胞中2脱氧葡萄糖和乳酸含量,双萤光素酶报告基因实验验证miR-218-5p与PDE7A靶向结合关系,用TCGA数据库数据分析PDE7A mRNA在肺癌组织中的表达水平。结果：在A549细胞中成功地过表达了miR-218-5p（P<0.01）。过表达miR-218-5p均能显著抑制A549细胞中PDE7A、HK2、PKM2蛋白的表达（均P<0.01）、葡萄糖摄取量和乳酸生成量（均P<0.01）。过表达PDE7A均可显著促进A549细胞中PDE7A、HK2、PKM2蛋白的表达（均P<0.01）,以及葡萄糖摄取量和乳酸生成量（均P<0.01）。A549细胞中miR-218-5p可与PDE7A mRNA的3′-UTR直接结合。数据库数据分析结果显示,PDE7A mRNA在肺鳞状细胞癌组织中呈高表达（P<0.01）。结论： miR-218-5p靶向PDE7A调控A549细胞中HK2和PKM2的表达水平,进而抑制糖酵解过程,miR-218-5p/PDE7A可能是NSCLC临床诊断和治疗的潜在靶点。