IL-24的生物学特性及其抗肿瘤作用机制

目前研究显示,IL-24是惟一既具有抑制肿瘤细胞生长和血管形成又具有免疫刺激作用的细胞因子.其抑制作用不依赖p53、Rb和p16等抑癌基因,对正常细胞没有影响,现已成为肿瘤治疗研究的新热点.     

Recent advanced studies on mitomycins, antitumor activity and mode of action

Mitomycin C (MMC) showed a wide antitumor spectrum with regression of various tumors and the optimal schedule of a single or intermittent administration against human tumor cells xenografted to nude mice, confirming the early reports obtained in rodent tumor system. The sensitivity of various human tumors xenografted to nude mice has been tested to antitumor agents to establish the system which could select the clinically active drugs. The effectiveness of MMC against human stomach cancers xenografted to nude mice clearly correlated to the clinical effect of MMC against gastric cancer. The covalent cross-link adducts between MMC and DNA were isolated in the bioreductive system of NADPH-cytochrome C reductase and NADPH, and the major monoadduct was determined as N2-(2' beta 7'-diaminomitosen-1'-alpha yl)-2'-deoxyguanine. Importantly, bisadduct was isolated, and the structure was determined by spectroscopic method. DNA-DNA cross-link formation was shown by alkaline elution in cells treated with MMC. The activation of MMC has been characterized by the two electron transfer process, however, the one electron transfer process was proposed by electrochemical analysis. MMC was effective against hypoxic cells. Several cell lines resistant to MMC were isolated, and some MMC derivatives showed in vivo and in vitro anti-tumor activity against these resistant cells.     

靶向EGFR隐蔽表位的免疫毒素的制备及其对肿瘤细胞的特异性杀伤

目的： 制备靶向表皮生长因子受体（epithelial growth factor receptor,EGFR）隐蔽表位（287-302）的免疫毒素,并鉴定其生物学功能。 方法： 通过基因工程方法将抗EGFR（287-302）的806单链抗体（806 single-chain antibody fragment, 806scFv ）基因经柔性肽与铜绿假单胞菌外毒素A（Pseudomonas exotoxin A, PEA）的截短形式PE38KDEL连接,构建原核表达载体pET-22b-806scFv-PE38KDEL并转化至大肠杆菌BL21（DE3）中,经纯化获得该免疫毒素融合蛋白806scFv-PE38KDEL,ELISA和流式细胞术检测其与EGFR的结合活性,间接免疫荧光检测重组免疫毒素的内化作用,CCK-8法检测806scFv-PE38KDEL对人脑胶质瘤细胞U87MG和U87MG-EGFRvⅢ、表皮癌细胞A431、乳腺癌细胞MDA-MB-468、舌癌细胞CAL-27的细胞毒性。 结果： 成功构建重组免疫毒素806scFv-PE38KDEL,诱导表达的蛋白806scFv-PE38KDEL以包涵体形式存在,经纯化后的纯度>95%,经SDS-PAGE和Western blotting 鉴定为目的蛋白。806scFv-PE38KDEL 能EGFRvⅢ胞外段蛋白结合,还能与外源性表达EGFRvⅢ的肿瘤细胞和高表达EGFR的肿瘤细胞相结合,而与表达低水平EGFR的肿瘤细胞不结合。806scFv介导了重组免疫毒素的内化。806scFv-PE38KDEL对靶细胞有明显的杀伤作用,对过表达EGFRvⅢ的U87MG-EGFRvⅢ细胞IC50值为（5.85±0.03） ng/ml,对EGFR高表达细胞MDA-MB-468、A431、CAL-27的IC50值分别为（162.80±0.06）、（75.72±0.04）、（123.70±0.03） ng/ml。在1 μg/ml的质量浓度下,相比PBS对照组,806scFv-PE38KDEL对U87MG-EGFRvⅢ 、MDA-MB-468、A431和CAL-27细胞增殖的抑制率均显著增高\[（98.67±0.07）% vs （2.45±2.85）%、（86.26±101）% vs （0.48±1.76）%、（96.72±016）% vs （1.33±1.31）%、（96.29±0.30）% vs （2.00±0.60）%,均P<0.01\],而对U87MG细胞几乎没有抑制作用\[（359±2.09）% vs （0.19±0.95）,P>0.05\]。 结论： 本研究所制备的靶向EGFR（287-302）表位的重组免疫毒素806scFv-PE38KDEL能特异地结合并杀伤EGFRvⅢ或EGFR高表达的肿瘤细胞。     

程序化细胞死亡分子5及其在抗肿瘤研究中的应用

程序化细胞死亡分子5(PDCD5)是一种新型促凋亡基因,参与细胞凋亡的调控.研究发现PDCD5在多种肿瘤组织中表达量下调,因而增加PDCD5的表达量呵明显提高化疗药物杀伤肿瘤的敏感性.PDCD5有望成为一种新的化疗增敏剂.     

Genistein靶向多肽偶联物的制备及体外抑瘤活性研究

目的:制备Genistein靶向多肽偶联物(GEN-P),增强Genistein的抑瘤活性。方法:采用固相法设计、合成能够与组织因子(TF)特异性结合的配体分子-FHS001,凝血酶原时间(PT)法测定其凝血活性,荧光显微镜直接检测其与高表达TF的人乳腺癌细胞株MCF-7的结合。通过异型双功能交联剂Sul-fo-SANPAH将FHS001与Genistein交联,制备偶联物GEN-P;MTT法检测其对MCF-7的杀伤作用。结果:合成的FHS001多肽能够与高表达TF的MCF-7细胞特异性结合且无明显的凝血活性。GEN-P偶联物在0.2～200.0μmol/L的浓度范围内对MCF-7细胞均有不同程度的增殖抑制作用,作用6h后抑制率为16.3%～83.1%,且呈一定的剂量依赖性。GEN-P和Genistein对MCF-7细胞的IC50分别为2.0和120μmol/L,GEN-P效果明显优于游离药物Genistein。结论:与FHS001偶联后Genistein的抑瘤活性明显增强,有希望进一步应用于癌症的治疗。     

光动力疗法与抗肿瘤免疫治疗在肿瘤治疗中的应用

恶性肿瘤是威胁着人类健康,且难以治愈的一种重大疾病。尽管近年来陆续出现了手术、化疗、放疗等多种治疗方式。但由于这些治疗方式普遍存在较强的不良反应及不良预后,人们不得不去探索更好的治疗方法以提高肿瘤的治疗效率和患者的适应性。光动力治疗（photodynamic therapy,PDT）是目前肿瘤治疗的重要辅助治疗手段之一。相较于传统的治疗方法,PDT侵袭性小,不易损伤正常组织;此外,它还能够有效诱导免疫原性细胞死亡（immunogenic cell death,ICD）和刺激免疫,是一种理想的肿瘤微创治疗方法。本文将针对PDT具有抗肿瘤免疫的特点,对目前PDT与抗肿瘤免疫治疗结合的一些肿瘤治疗策略进行综述。      

Selective suppression of t-cell activity in tumor-bearing mice and its improvement by lentinan,a potent anti-tumor polysaccharide

The cellular site of immunosuppression in Ehrlich tumor-bearing mice was analysed with particular reference to the T- and B-cell activities. The B-cell activity as measured by the anti-dinitrophenyl (DNP) antibody responses to DNP-thymus-independent carriers (TID) was not impaired in tumor-bearing mice as compared with normal mice, whereas the anti-DNP antibody responses to DNP-thymus-dependent carriers (TD) and the development of helper T-cell activity to TD were markedly suppressed in tumor-bearing animals or mice pretreated with cell-free cancerous ascitic fluid. The selective suppression of T-cell response was not mediated by the generation of suppressor cell activity toward TD, which may depress the manifestation of developed helper T-cell activity. A marked suppression of T-cell response was observed when the animals were inoculated with tumor cells or injected with cancerous ascitic fluid prior to antigenic stimulation, but not when the animals were rendered tumor-bearing by such treatments after the immunization. The suppression of T-cell activity in both sarcoma 180 tumor-bearing mice and cell-free Ehrlich cancerous ascitic fluid-treated mice was prevented by treatment with lentinan, a potent anti-tumor polysaccharide. The applicability of this experimental system to the search for immunopotentiators relevant to tumor immunotherapy is discussed in the light of the preventive effect of lentinan on the suppression of T-cell response in tumor-bearing animals.     

Cimetidine, an unexpected anti-tumor agent, and its potential for the treatment of glioblastoma (review)

Cimetidine (CIM), the prototypical histamine H2 receptor antagonist (H2RA), was brought to market based on its ability to accelerate healing of gastrointestinal ulcers through the inhibition of gastric acid secretion. Cimetidine, the most studied H2RA, has been demonstrated to possess anti-tumor activity against colon, gastric and kidney cancers, and melanomas. This activity involves a number of different mechanisms of action: a) CIM antagonizes tumor cell-mediated interleukin-1-induced activation of selectins in liver sinusoids, inhibiting tumor cell binding on liver sinusoids, thereby reducing the development of liver metastasis; b) histamine acts as a growth factor in various tumor cell types via the activation of H2 receptors; CIM therefore may antagonize this effect; c) CIM acts as an immunomodulator by enhancing the host's immune response to tumor cells. With respect to malignant gliomas, CIM added to temozolomide was superior in vivo when compared to temozolomide alone in extending survival of nude mice with human glioblastoma cells orthotopically xenografted into their brain. We review the various mechanisms of action potentially associated with the therapeutic effects of CIM in the case of experimental glioblastomas, observations we hope will encourage clinical investigation of CIM in the management of highly malignant gliomas.     

内皮抑素的作用机制以及在肿瘤治疗中的研究现状

内皮抑素是胶原ⅩⅧ的20kD水解片断，它是血管生成最有效的天然抑制剂之一，特异性抑制内皮细胞的增殖，通过抑制细胞周期素D1而诱导凋亡。在内皮细胞表面，内皮抑素与整合素α5β1结合从而激活Src激酶，此外也下调RhoAGTP酶的活性，抑制Ras和Raf激酶家族介导的信号传导。所有的事件均导致激动蛋白细胞骨架的解体，细胞-基质相互作用的紊乱，内皮细胞迁移活性的下降等，抑制血管生成。本文概述内皮抑素的生物学活性及作用机制。     

血清神经节苷脂快速测定法及其初步应用

 目的　建立GLS快速测定法并研究其临床价值。方法　从血清提取糖脂 ,间苯二酚 -HCl与GLS特异糖基反应 ,测定吸光度。结果　健康人血清GLS含量 5 81± 90mg/L(40 0～ 76 0mg/L)。头颈恶性肿瘤患者GLS(90 8± 2 2 6mg/L)显著增高 ;良性肿瘤和非肿瘤患者GLS(6 0 2± 12 8与 6 95± 16 1mg/L)则不增高。该法对头颈恶性肿瘤敏感度、特异度、准确度、诊断效率为 73.8%、88.6 %、81.4 %、6 5 .4 %。结论　GLS快速测定法简便、稳定、可靠 ;测定GLS对头颈恶性肿瘤诊断具有显著临床价值。     

亚叶酸钙对氟尿嘧啶抗癌及骨髓抑制作用的实验研究

目的 观察在给S-180小鼠5-FU腹腔注射同时灌胃采用不同剂量CF能否增强5-FU抗小鼠S-180作用和对5-FU引起白细胞、血小板下降的影响;以及两药联合应用时对人胃癌细胞MGC的体外抑制增效作用.方法 给S-180小鼠腹腔注射5-FU 25～15 mg/(kg·d),连续用5天、7天,并在用5-FU前半小时灌胃CF60、90或120 mg/(kg·d).结果 各5-FU单用组抑制率为42.3%～44.5%;若合用组CF剂量≥90 mg/(kg·d),抑瘤率可提高至59.4%～73.3%(差异有显著性);体外实验显示作用96小时后,各浓度CF/5-FU合用组抑瘤率均明显高于5-FU单用组;毒性试验显示CF/5-FU合用组对白细胞、血小板的影响与5-FU单用组差异无显著性.结论 若用5-FU前灌胃CF90或120 mg/(kg·d)则可明显增加5-FU的抑瘤效应;CF可明显增强5-FU对MGC的增殖抑制作用,但合用时两者剂量均不必过高,时间需96小时以上;CF对5-FU的骨髓抑制作用基本没有影响.     

共表达ENDO-VEGI_(151)和survivin-siRNA双功能质粒的构建及其抗瘤活性

目的:构建pCDNA3.1-ENDO-VEGI151/survivin-shRNA(pEV/si-survivin)双功能表达质粒,观察其对乳腺癌细胞MDA-MB-231和人脐静脉血管内皮细胞(human umbilical vein endothelial cell,HUEVC)增殖和凋亡的影响,探讨其治疗肿瘤的可行性。方法:利用MDA-MB-231细胞筛选获得survivin的高效siRNA序列,构建pEV/si-survivin表达质粒并分别转染MDA-MB-231和HUEVC,以real-time PCR和Western blotting检测转染细胞中ENDO-VEGI151和survivin的表达;MTT法检测细胞增殖抑制情况,流式细胞术检测细胞周期和细胞凋亡。结果:成功构建pEV/si-survivin双功能表达质粒,并能在MDA-MB-231和HUEVC中正确表达相应基因产物。该质粒可明显抑制MDA-MB-231细胞内survivin的表达,并抑制细胞增殖[48、72 h的抑制率为(39.36±4.16)%、(48.43±3.49)%],促进MDA-MB-231细胞凋亡[(18.33±1.48)...     

Irreversible dual inhibitory mode: the novel Btk inhibitor PLS-123 demonstrates promising anti-tumor activity in human B-cell lymphoma

The B-cell receptor (BCR) signaling pathway has gained significant attention as a therapeutic target in B-cell malignancies. Recently, several drugs that target the BCR signaling pathway, especially the Btk inhibitor ibrutinib, have demonstrated notable therapeutic effects in relapsed/refractory patients, which indicates that pharmacological inhibition of BCR pathway holds promise in B-cell lymphoma treatment. Here we present a novel covalent irreversible Btk inhibitor PLS-123 with more potent anti-proliferative activity compared with ibrutinib in multiple cellular and in vivo models through effective apoptosis induction and dual-action inhibitory mode of Btk activation. The phosphorylation of BCR downstream activating AKT/mTOR and MAPK signal pathways was also more significantly reduced after treatment with PLS-123 than ibrutinib. Gene expression profile analysis further suggested that the different selectivity profile of PLS-123 led to significant downregulation of oncogenic gene PTPN11 expression, which might also offer new opportunities beyond what ibrutinib has achieved. In addition, PLS-123 dose-dependently attenuated BCR- and chemokine-mediated lymphoma cell adhesion and migration. Taken together, Btk inhibitor PLS-123 suggested a new direction to pharmacologically modulate Btk function and develop novel therapeutic drug for B-cell lymphoma treatment.     

Metronomic scheduling of a cyclic hexapeptide Ra-VII for anti-angiogenesis, tumor vessel maturation and anti-tumor activity

RA-VII, a cyclic hexapeptide isolated from Rubiae radix, binds to actin, causing a conformational change in the actin molecule and inducing G2 arrest by inhibiting cytokinesis. Here we examined the effect of RA-VII, its water-soluble derivative, and related RA-III and RA-V on endothelial cells. Among the four compounds tested, RA-VII most potently inhibited angiogenesis-related properties of endothelial cells (i.e. migration and proliferation) in vitro. We confirmed the anti-angiogenic activity of RA-VII in vivo by using a mouse corneal model. We then applied RA-VII for the treatment of tumors in mice. Daily intraperitoneal injection of RA-VII (1.5 or 3 mg/kg/day) exhibited no toxic effect on the animals, but significantly and dose dependently inhibited the growth of Lewis lung carcinoma cells previously inoculated into the mice. Interestingly, although two doses of RA-VII decreased the tumor vascular area to a similar extent, a higher dose of RA-VII led to tumor vessel maturation together with a significant increase in tumor cell apoptosis. Also, RA-VII showed a cytotoxic effect on Lewis lung carcinoma cells. These results indicate that metronomic scheduling of RA-VII is efficient for cancer treatment. A careful dose setting of RA-VII is crucial to obtain therapeutic superiority, possibly through tumor vessel maturation and a better distribution of the compound in the tumor tissue.     

粪便标志物检测在大肠癌筛查中的应用

大肠癌早期发生中常伴随基因突变、蛋白质和酶等分子代谢异常,通过检测粪便中基因、蛋白质和酶等标志物有助于大肠癌早期诊断。其中粪便K—ras、APC、p53、长片段DNA、DNA甲基化、钙卫蛋白（CPT）、微型染色体维持蛋白一2、促衰变因子、癌胚抗原（CEA）、Adnab-9和端粒酶、环氧合酶2（COX-2）、肿瘤M2型丙酮酸激酶（TUM2-PK）等在筛选大肠癌中取得了较大进展。     

粪便标志物检测在大肠癌筛查中的应用

大肠癌早期发生中常伴随基因突变、蛋白质和酶等分子代谢异常,通过检测粪便中基因、蛋白质和酶等标志物有助于大肠癌早期诊断。其中粪便K-ras、APC、p53、长片段DNA、DNA甲基化、钙卫蛋白(CPT)、微型染色体维持蛋白-2、促衰变因子、癌胚抗原(CEA)、Adnab-9和端粒酶、环氧合酶2 (COX-2)、肿瘤M2型丙酮酸激酶(TU M2-PK)等在筛选大肠癌中取得了较大进展。     

SHP2作为抗肿瘤治疗靶点的价值及其在肿瘤免疫治疗中的应用

包含Src同源2结构域的蛋白酪氨酸磷酸酶2(Src homology region 2-containing protein tyrosine phosphatase 2,SHP2)是目前唯一被证实具有促癌作用的细胞质蛋白酪氨酸磷酸酶,在多种恶性肿瘤中高表达。SHP2可以通过介导受体酪氨酸激酶(Receptor tyrosine kinase,RTK)下游的RAS/ERK、PI3K/Akt和JAK/STAT等信号通路促进肿瘤发生发展,影响肿瘤预后。同时,SHP2参与调控PD-1/PD-L1、CTLA-4、BLTA和TIGIT等免疫检查点信号通路,对于肿瘤微环境中各种免疫细胞都有重要的调节作用。靶向SHP2不仅可以通过抑制RTK下游信号通路,还可以通过改善免疫微环境治疗恶性肿瘤。因此,SHP2具有免疫与靶向双重治疗肿瘤的功能,作为抗肿瘤治疗的靶点展现出极高的潜能与价值。