ErbB3结合蛋白1的上调抑制食管癌细胞生长

本研究旨在探讨Erb B3结合蛋白1(Erb B3-binding protein 1,Ebp1)在食管癌细胞生长中的作用及其机制。用携带Ebp1基因的慢病毒载体感染食管癌Eca109和KYSE150细胞,用real-time PCR检测食管癌组织中Ebp1 m RNA的表达情况,用MTT和结晶紫分别检测食管癌细胞生长和存活能力,用软琼脂细胞生长实验检测细胞克隆形成能力,用流式细胞术检测细胞凋亡率,用Western blot检测和凋亡有关的蛋白表达变化,用裸鼠皮下成瘤实验检测食管癌细胞的成瘤能力。结果显示,与配对的正常组织相比,食管癌组织中Ebp1 m RNA水平显著下降。过表达Ebp1不仅抑制食管癌细胞Eca109和KYSE150的体外生长和存活能力,而且能诱导这两种食管癌细胞发生凋亡,上调Rb和P53的蛋白表达,下调Cyclin D1的表达。Ebp1过表达还能抑制Eca109细胞的裸鼠皮下成瘤能力。以上结果提示,Ebp1通过诱导细胞凋亡抑制食管癌细胞体外生长能力和体内成瘤能力。     

过表达Beclin 1对食管癌Eca109细胞株裸鼠成瘤的影响

自噬是一个进化上保守的溶酶体降解途径,激活自噬可以降解有缺陷的细胞器而发挥抑制肿瘤的作用,Beclin 1是关键的自噬和肿瘤抑制基因。该研究检测了Beclin 1蛋白在食管癌组织中的表达情况,构建Beclin 1的重组质粒并转染人食管癌Eca109细胞株。分别以电子显微镜观察自噬体的形成和Eca109细胞的自噬性死亡情况,RT-PCR检测Beclin 1基因的mRNA表达,Westernblot法检测Beclin 1及Bcl-2、P53的表达水平,裸鼠成瘤实验检测Beclin 1基因对Eca109细胞体内增殖的影响。结果显示,Beclin 1蛋白在食管癌组织中相对于癌旁正常食管组织低表达(P<0.05);成功构建了Beclin 1重组质粒并将其转染到Eca109细胞中,电子显微镜观察到自噬体形成,RT-PCR和Western blot显示Beclin 1基因过表达。升高Beclin 1蛋白的表达水平能降低Bcl-2表达和上调P53蛋白,使Eca109细胞的体内致瘤性减弱。过表达Beclin 1基因对食管癌有很好的抑制作用,这将为食管癌的靶向治疗奠定基础。     

溶瘤病毒与肿瘤治疗

研究发现有些病毒具有特异性感染并杀伤肿瘤细胞的能力,这类病毒被称为“溶瘤病毒”。天然的溶瘤病毒有细小病毒、呼肠孤病毒、新城疫病毒、水疱性口炎病毒、麻疹病毒等。有些病毒缺失一些病毒基因的突变体,具有溶瘤病毒的特性,其中包括腺病毒、疱疹病毒和甲型流感病毒。通过病毒基因工程可以进一步提高溶瘤病毒的安全性和杀伤肿瘤细胞的效果。一系列体外、动物模型和临床的试验证实,不少溶瘤病毒具有良好的安全性和抑制肿瘤的能力。     

一株人乳头瘤病毒阳性的新的食管癌细胞系的建立及鉴定

为了探讨人乳头瘤病毒(Human papillomavirus,HPV)与上消化道肿瘤食管癌关系,从食管癌高发区安阳市取到一例76岁的中国女性食管鳞癌患者肿瘤组织。通过直接SCID小鼠致瘤实验,可长成移植瘤。取出组织做组织培养并多次纯化传代筛选后,成均一单层细胞。分别进行免疫荧光,细胞生长曲线,软琼脂鉴定,染色体分析,细胞致瘤实验及瘤体切片HE染色等确定是上皮细胞来源的癌细胞。利用细胞STR分型结果显示,基因座均未出现三等位基因现象,无人类细胞交叉污染。对细胞DNA分析发现存在HPV18型的DNA。利用蛋白检测实验发现有HPV病毒癌蛋白表达。结果表明,所建细胞株为有HPV核酸存在并能表达病毒癌蛋白的新的食管鳞癌细胞株。为我们进行食管癌的发生发展的病因学研究提供了新的细胞学材料。     

溶瘤病毒的免疫学机制及临床研究进展

溶瘤病毒（oncolytic virus,OVs）历经百年发展,应用于当前最具潜力的肿瘤免疫疗法。它主要是天然的或基因修饰的DNA病毒和RNA病毒。近年来随着基因工程技术的飞跃发展,经基因改造的溶瘤病毒在肿瘤治疗领域取得很大进展,很多不同类型的病毒（包括单纯疱疹病毒、腺病毒、痘病毒、麻疹病毒和呼肠孤病毒等）正处于临床前研究、临床试验阶段或已批准上市,显示了良好的安全性和临床疗效。普遍认为溶瘤病毒靶向杀伤肿瘤细胞是通过选择性在肿瘤细胞内自我复制,最终裂解肿瘤细胞,同时可激发机体的免疫应答反应,进而增强抗肿瘤免疫效果,靶向杀伤肿瘤细胞而对正常细胞无明显影响。运用基因重组技术将溶瘤病毒与免疫检查点相结合以及肿瘤免疫联合疗法的兴起和不断进步,使溶瘤病毒的应用更加广泛,但仍存在病毒靶向性、安全性、给药途径等瓶颈问题。本文综述了溶瘤病毒的发展史、病毒分类、不同类型溶瘤病毒产品的临床研究进展、溶瘤病毒靶向杀伤肿瘤的免疫学机制及未来发展面临的挑战与展望等。     

HSV-1溶瘤病毒在肿瘤治疗研究中的新进展

基因工程改造的Ⅰ型单纯疱疹病毒(HSV-1)对肿瘤具有特异的靶向性和显著的杀伤能力,已经成为肿瘤治疗研究的热点。HSV-1类溶瘤病毒在临床上对多种肿瘤表现出良好的治疗效果,也被证实能够刺激机体产生较强的抗肿瘤免疫应答。2015年,Amgen公司的T-VEC被美国FDA批准用于治疗恶性黑色素瘤。溶瘤病毒疗法联合放、化疗等治疗方式能进一步提高肿瘤治疗效果。更重要的是,靶向免疫检查点疗法在肿瘤免疫治疗中有着巨大的应用前景,有望与溶瘤病毒疗法联用,成为未来肿瘤治疗的新方向。     

携带TRAIL的溶瘤腺病毒联合LiCl对癌细胞的生长抑制效应

研究糖原合成激酶3的抑制剂LiCl联合携带TRA／L基因的溶瘤腺病毒Ad．sp—ElA—E1B（△55kDa）．TRAIL—Flag（Ad．sp—TRAIL—Flag）对癌细胞的体外杀伤作用。采用MTT法检测癌症特异性病毒Ad．sp—TRAIL—Flag联合药物LiCl对三种癌症细胞株的生长抑制作用;通过结晶紫实验进一步检测联合用药的杀伤效果：进而通过Western blot实验检测联合作用对癌细胞中TRAIL蛋白表达的影响,最后通过流式细胞仪检测其对癌细胞的凋亡作用。结果显示,LiCl联合Ad．sp—TRAIL．Flag的处理对癌细胞的增殖抑制作用明显优于两者单独使用。Western blot实验证明,LiCl可提高溶瘤腺病毒Ad．sp—TRAIL—FIag处理后TRAIL蛋白的表达水平,从而增强了溶瘤腺病毒Ad．sp—TRAIL—Flag通过乃己4儿的信号通路的杀伤效果。     

溶瘤I型单纯疱疹病毒的研究进展

溶瘤病毒(Oncolytic virus,OV)是可以靶向感染并杀伤肿瘤细胞的一类病毒,其中溶瘤I型单纯疱疹病毒(Oncolytic herpes simplex virus type 1,OHSV-1)是目前研究最多的溶瘤病毒之一,可通过多种策略进行构建,已有多种OHSV-1进入临床试验,大量结果显示其具有较好的安全性和有效性。本文主要介绍OHSV-1的分子生物学特性与优势、主要的开发及靶向性策略、各类OHSV-1的研究进展以及目前存在的问题等。     

增强型肿瘤特异性启动子介导CDTK治疗肝癌的体内外研究

目的:探讨运用增强子上调肿瘤特异性启动子h TERT转录活性后,调控自杀融合基因CDTK对人肝癌细胞系Bel-7402的体内外杀伤作用。方法:将CMV增强子、h TERT启动子及CDTK自杀融合基因克隆入核糖体基因区打靶载体p Hrn,构建p Hr-Ce Tp CDTK-GFP治疗载体并转染Bel-7402细胞,经RT-PCR、HPLC、MTT检测CDTK基因的表达和对肝癌细胞的体外杀伤效果。再将Bel-7402细胞接种到裸鼠皮下致瘤,以肿瘤杀伤载体p Hr-Ce Tp CDTK-GFP进行瘤内转染并检测其抑瘤效果,此外将转染后的细胞接种致瘤,检测其成瘤时间及肿瘤生长曲线等,从两方面检测其体内杀伤效果。结果:成功构建了肿瘤特异性治疗载体,体外转染肝癌细胞后,经RTPCR、HPLC证明CDTK基因能在肝癌中表达,且治疗载体在体外对肝癌细胞有明显毒性。动物实验结果发现裸鼠致瘤后治疗组血清中5-Fu浓度为7.694μg/ml,治疗组肿瘤体积与对照组相比减小6.5倍。而细胞转染治疗载体后致瘤,治疗组成瘤时间比对照组晚8天,且治疗组裸鼠的平均生存期较对照组延长16天。结论:p Hr-Ce Tp CDTK-GFP载体能在体内外高效靶向杀伤肝癌细胞,为肝癌基因治疗提供了一种新的途径。     

可复制性单纯疱疹病毒在抗肿瘤方面的应用

单纯疱疹病毒是肿瘤生物治疗中常用的病毒载体之一,可复制性单纯疱疹病毒以其溶瘤效率高、特异性好、可行性强成为近年来研究的热点。其中对溶瘤性单纯疱疹病毒突变株G207的研究开展得早,其溶瘤效果、靶向性及安全性都得到了确认,这也带动了可复制性单疱病毒应用的发展,目前已研究出多种溶瘤单纯疱疹病毒突变株。本文就近几年可复制性单纯疱疹病毒在抗肿瘤方面的研究现状加以综述,以探讨其临床治疗肿瘤的潜在价值及可行性。     

Gene therapy for malignant glioma using Sindbis vectors expressing a fusogenic membrane glycoprotein

BACKGROUND: Malignant glioma has a dismal prognosis. It was previously shown that glioma cells are efficiently killed when they express a gene coding for a hyperfusogenic mutant of the gibbon ape leukemia virus envelope glycoprotein (GALV.fus). However, production of viral vectors expressing GALV.fus has proven problematic because the transgene is toxic to vector-producing cells of human origin. We reasoned that Sindbis-virus-based vectors might be ideal for GALV.fus gene transfer because high-titer stocks can easily be generated in hamster cells and Sindbis virus efficiently infects human tumor cells through the high-affinity 67 kDa laminin receptor. In addition, Sindbis virus nonstructural proteins are potent inducers of apoptosis, and Sindbis vector RNAs expressing fusogenic viral proteins have been shown to spread from cell-to-cell in membrane-formed infectious particles. METHODS: Sindbis virus replicon-containing particles were generated by co-transfecting vector and helper RNAs into baby hamster kidney (BHK-21) cells. Packaged beta-galactosidase and GALV.fus expressing Sindbis vectors were used to infect glioma cell lines, which were then compared for syncytial cytopathic effect, cell killing, and release of infectious virus-like particles containing the vector genome. Finally, the efficacy of GALV.fus and beta-galactosidase Sindbis vectors was compared in an orthotopic intracerebral U87 glioma xenograft model in nude mice. RESULTS: High-titer stocks (>10(9) infectious units (iu)/ml) of the GALV.fus and beta-galactosidase vectors were obtained. Glioma cells infected with the GALV.fus vector formed large syncytia which died rapidly by apoptosis and released infectious membrane-formed particles that could transfer vector genomes to uninfected cells. The GALV.fus vector had significantly greater antitumor therapeutic potency than the beta-galactosidase vector in the U87 glioma xenograft model. CONCLUSIONS: Sindbis vectors expressing GALV.fus can be packaged into infectious viral particles to high titer, they exhibit potent bystander cytopathic potential and are active against U87 glioma xenografts. Sindbis-virus-based replicons appear to be efficient vector systems for delivery and expression of fusogenic membrane glycoproteins.     

Packaging,Amplification, and Appraisal of the Recombinant Tumor-Selective Type I Herpes Simplex Virus Carrying GALV.fus Gene

The aim of the study was to successfully construct three plasmids, which include the GALV.fus gene plasmid regulated by the herpes simplex virus type 1 (HSV-1) late expression gene-UL38 promoter and induced by HSV-1 (HSV-UL38P-GALV.fus), the cytomegalovirus promoter without tumor specificity (CMVP) GALV.fus plasmid (HSV-CMVP-GALV.fus), and the control plasmid in which the GALV.fus gene fragment was replaced by the enhanced green fluorescent protein (EGFP) gene fragment (HSV-CMVP-EGFP). The three constructed plasmids were all packaged and named as Synco-2, Synco-1, and Baco-1. The plasmids were amplified in coliform bacterium and transfected into Vero cells using lipofectamine. These recombinant HSV-1 were amplified in Vero cells and purified by conventional methods of cesium chloride, TCID50 method is used to measure virus titers. The total RNA was then extracted from the HepG2 cells transfected by Synco-1 and Synco-2, and the expression of GALV.fus mRNA was detected by RT-PCR. The three recombinant HSV-1 vectors were propagated in Vero cells and purified by cesium chloride density gradient centrifugation, titrated by TCID50 method, and packaged. The titers of Baco-1, Synco-1, and Synco-2 were 3 × 10¹⁰, 1 × 10¹¹, and 4 × 10¹⁰ pfu/ml. The GALV.fus gene was identified in the infected HepG2 cells by RT-PCR method.     

Gene Therapy of Lung Adenocarcinoma using Herpes Virus Expressing a Fusogenic Membrane Glycoprotein

The aim of this study is to observe the in vitro-targeted destruction of lung adenocarcinoma using recombinant Type I herpes simplex virus (HSV-I)-mediated gibbon ape leukemia virus envelope glycoprotein (GALV.fus), controlled by UL38 promoter and cytomegalovirus promoter (CMVP). A recombinant HSV-I plasmid encoding the GALV.fus was transfected into green monkey kidney cells, the lung adenocarcinoma line A549, and the human fetal fibroblast cell line HFL-I GNHu5 in various doses. The effects and expression of in vitro GALV.fus were observed using an inverted microscope. Enhanced green fluorescence protein expression served as the contro1 for GALV.fus. Recombinant HSV-I virus was produced. Fusogenic recombinant virus infection led to cell fusions in A549 in a dose-dependent manner. Nonfusogenic viruses only produced conventional cytotoxic effects. Recombinant HSV-I with the CMVP initiated cell fusions in HFL-1 GNHu5 cells with arrested cell cycles or as quiescence. HSV-I regulated by UL38p caused cell fusion only in growing cells. Protein expression of GALV.fus was confirmed by Western Blot in infected A549 and HFL-1 GNHu5. Delivery and tumor-specific expression of GALV.fus gene can selectively and safely target lung cancer in vitro, and may prove to be a novel gene therapy for lung cancer.     

Adenoviral vectors expressing fusogenic membrane glycoproteins activated via matrix metalloproteinase cleavable linkers have significant antitumor potential in the gene therapy of gliomas

BACKGROUND: Fusogenic membrane glycoproteins (FMG) such as the gibbon ape leukemia virus envelope (GALV) glycoprotein are potent therapeutic transgenes with potential utility in the gene therapy of gliomas. Transfection of glioma cell lines with FMG expression constructs results in fusion with massive syncytia formation followed by cytotoxic cell death. Nevertheless, ubiquitous expression of the GALV receptor, Pit-1, makes targeting desirable in order to increase the specificity of the observed cytopathic effect. Here we report on use of matrix metalloproteinase (MMP)-cleavable linkers to target the cytotoxicity of FMG-expressing adenoviral vectors against gliomas. METHODS: Replication-defective adenoviruses (Ad) were constructed expressing the hyperfusogenic version of the GALV glycoprotein linked to a blocking ligand (C-terminal extracellular domain of CD40 ligand) through either an MMP-cleavable linker (AdM40) or a non-cleavable linker (AdN40). Both viruses also co-expressed the green fluorescent protein (GFP) via an internal ribosomal entry site. RESULTS: The glioma cell lines U87, U118, and U251 characterized by zymography and MMP-2 activity assay as high, medium and low MMP expressors, respectively, the MMP-poor cell lines TE671 and normal human astrocytes were infected with AdM40 and AdN40 at different multiplicities of infection (MOIs) from 1-30. Fusion was quantitated by counting both number and size of syncytia. Infection of these cell lines with AdN40 did not result in fusion or cytotoxic cell death, despite the presence of infection, as demonstrated by GFP positivity, therefore indicating that the displayed CD40 ligand blocked GALV-induced fusion. Fusion was restored after infection of glioma cells with AdM40 at an MOI as low as 1 to an extent dependent on MMP expression and coxsackie adenovirus receptor (CAR) expression in the specific cell line. Western immunoblotting demonstrated the presence of the cleaved CD40 ligand in the supernatant of fused glioma cells. Use of the MMP inhibitors 1,10 phenanthroline and N-hydroxy-5,5-dimethylpiperazine-2-carboxamide completely abolished AdM40-induced fusion, while the non-specific serine protease inhibitor soybean trypsin inhibitor did not affect it, thus demonstrating specificity of the observed effect. Intratumoral treatment of BalbC/nude mice bearing subcutaneous U87 glioma xenografts with AdM40 at a total dose of 1.2 x 10(10) plaque-forming units (pfu) resulted in statistically significant tumor regression as compared with control animals either treated with AdN40 (p = 0.01) or untreated animals (p = 0.01). Treatment with AdM40 also resulted in survival improvement as compared with AdN40-treated animals (p = 0.006) or untreated animals (p = 0.001). Histopathologic examination of treated tumors demonstrated extensive syncytia formation. CONCLUSIONS: Our data indicate that AdM40, a replication-defective adenovirus expressing the GALV fusogenic glycoprotein, attached to a blocking ligand via an MMP-cleavable linker, can target the cytotoxicity of GALV in MMP-overexpressing glioma lines and xenografts, and maintain significant antitumor activity both in vitro and in vivo. Given the high frequency of MMP overexpression in gliomas, AdM40 represents a potentially promising agent in the gene therapy of these tumors.     

Matrine inhibits proliferation and induces apoptosis via BID-mediated mitochondrial pathway in esophageal cancer cells

Matrine, as a member of Sophora family, is an alkaloid found in plants, and produces plethora pharmacological effects, including anti-cancer effects. However, the mechanism involved remains largely unknown. This study is conducted to investigate the anti-cancer mechanisms of matrine in human esophageal cancer in vitro and in vivo. In human esophageal cancer cell Eca-109, matrine significantly decreased the cell viability in a dose-dependent manner, and induced apoptosis as well as cell cycle arrest in G0/G1 phase by up-regulation of P53 and P21. The expression of several apoptosis-related proteins in cells and tumor tissues were evaluated by Western blot analysis. We found that matrine induced cell apoptosis by down-regulation of the ratio of BCL-2/BID and increasing activation of caspase-9. Further studies indicated that matrine induced apoptosis of Eca-109 was through the mitochondria-mediated internal pathway, but not by death receptor-mediated extrinsic apoptotic pathway, which was confirmed by the fact that Bid translocated from the nucleus to mitochondria during the process of the apoptosis induced by matrine. In vivo study found that matrine effectively inhibited the tumor formation of Eca-109 cells in nude mice. Our study suggests that matrine could serve as a potential novel agent from natural products to treat esophageal cancer.     

The flavonoid component isorhamnetin in vitro inhibits proliferation and induces apoptosis in Eca-109 cells

Isorhamnetin is one member of flavonoid components which has been used in the treatment of heart disease. Recently the in vitro anti-cancer effect of isorhamnetin on human esophageal squamous carcinoma cell line Eca-109 was investigated in our lab. When Eca-109 cells were in vitro exposed to the graded doses of isorhamnetin (0-80 microg/ml) for 48 h, respectively, isorhamnetin exhibited cytostatic effect on the treated cells, with an IC(50) of 40+/-0.08 microg/ml as estimated by MTT assay. Inhibition on proliferation by isorhamnetin was detected by trypan blue exclusion assay, clone formation test, immunocytochemical assay of PCNA and (3)H-thymidine uptake analysis. Cell cycle distribution was measured by FCM. It was found that the viability of Eca-109 cells was significantly hampered by isorhamnetin. Compared with the negative control group, the treated group which was exposed to isorhamnetin had increased population in G(0)/G(1) phase from 74.6 to 84 while had a significant reduction in G(2)/M phase from 11.9 to 5.8. In addition to its cytostatic effect, isorhamnetin also showed stimulatory effect on apoptosis. Typical apoptotic morphology such as condensation and fragmentation of nuclei and blebbing membrane of the apoptotic cells could be observed through transmission electron microscope. Moreover, the sharp increase in apoptosis rate between the control and treated group were detected by FCM from 6.3 to 16.3. To explore the possible molecular mechanisms that underlie the growth inhibition and apoptosis stimulatory effects of isorhamnetin, the expressions of six proliferation- and death-related genes were detected by FCM. Expressions of bcl-2, c-myc and H-ras were downregulated whereas Bax, c-fos and p53 were upregulated. However, the in vivo experiments were required to further confirm the anti-cancer effects of isorhamnetin. In conclusion, isorhamnetin appears to be a potent drug against esophageal cancer due to its in vitro potential to not only inhibit proliferation but also induce apoptosis of Eca-109 cells.     

应用抗体探针对人食管癌组织，Eca－109细胞及其染色体的NHP免疫反应性研究

应用自制的癌非组蛋白（ＮＨＰ）抗体探针,探讨了人食管癌Ｅｃａ－１０９细胞及其染色体和人食管癌组织的ＮＨＰ免疫反应性。结果表明：①以０．４ｍｏｌ／Ｌ及０．３５ｍｏｌ／ＬＮａＣｌ提取的ＮＨＰ均含１．１４万－４万道尔顿分子量的高速泳动族蛋白（Ｈｉｇｈｍｏｂｉｌｉｔｙｇｒｏｕｐｐｒｏｔｅｉｎ,ＨＭＧＰ）。②在人食管癌切片标本上癌细胞核、胞质、胞核均呈免疫反应阳性,且胞膜、胞质反应强于胞核。并见到癌巢周缘细胞比癌巢中心的细胞反应较强。③人食管瘤Ｅｃａ－１０９细胞的胞膜、胞质、胞核均呈ＮＨＰ免疫反应阳性,多见胞膜、胞质强于胞核。④人食管癌Ｅｃａ－１０９细胞的分裂中期染色体上,免疫反应呈阳性。这提示０．４ｍｏｌ／ＬＮａＣｌ提取的ＮＨＰ含有ＤＮＡ特异结合的ＮＨＰ组分。     

Human mesenchymal stem cells play a dual role on tumor cell growth in vitro and in vivo

Nowadays, some evidences demonstrate that human mesenchymal stem cells (hMSCs) favor tumor growth; however, others show that hMSCs can suppress tumorigenesis and tumor growth. With the indeterminateness of the effect of hMSCs on tumors, we investigated the effect of hMSCs on lung cancer cell line A549 and esophageal cancer cell line Eca-109 in vitro and in vivo. Our results revealed that hMSCs inhibited the proliferation and invasion of A549 and Eca-109 cells, arrested tumor cells in the G1 phase of the cell cycle and induced the apoptosis of tumor cells in vitro by using a co-culture system and the hMSCs-conditioned medium. However, animal study showed that hMSCs enhanced tumor formation and growth in vivo. Western blotting and immunoprecipitation data showed that the expressions of proliferating cell nuclear antigen (PCNA), Cyclin E, phospho-retinoblastoma protein (pRb), B-cell lymphoma/leukemia-2 (Bcl-2), Bcl-xL, and matrix metalloproteinase 2 (MMP-2) were downregulated and the formation of Cyclin E-cyclin-dependent kinase 2 (CDK2) complexes was inhibited in the tumor cells treated with the hMSCs-conditioned medium. According to the observation of tumor mass and the result of microvessel density (MVD), we found that the promoting role of hMSCs on tumor growth was related with the increase of tumor vessel formation. Our present study suggests that hMSCs have a contradictory effect on tumor cell growth between in vitro and in vivo, and therefore, the exploitation of hMSCs in new therapeutic strategies should be cautious under the malignant conditions.     

“Armed” oncolytic herpes simplex viruses for brain tumor therapy

Genetically engineered, conditionally replicating herpes simplex viruses type 1 (HSV-1) are promising therapeutic agents for brain tumors and other solid cancers. They can replicate in situ, spread and exhibit oncolytic activity via a direct cytocidal effect. One of the advantages of HSV-1 is the capacity to incorporate large and/or multiple transgenes within the viral genome. Oncolytic HSV-1 can therefore be “armed” to add certain functions. Recently, the field of armed oncolytic HSV-1 has drastically advanced, due to development of recombinant HSV-1 generation systems that utilize bacterial artificial chromosome and multiple DNA recombinases. Because antitumor immunity is induced in the course of oncolytic activities of HSV-1, transgenes encoding immunomodulatory molecules have been most frequently used for arming. Other armed oncolytic HSV-1 include those that express antiangiogenic factors, fusogenic membrane glycoproteins, suicide gene products, and proapoptotic proteins. Provided that the transgene product does not interfere with viral replication, such arming of oncolytic HSV-1 results in augmentation of antitumor efficacy. Immediate-early viral promoters are often used to control the arming transgenes, but strict-late viral promoters have been shown useful to restrict the expression in the late stage of viral replication when desirable. Some armed oncolytic HSV-1 have been created for the purpose of noninvasive in vivo imaging of viral infection and replication. Development of a wide variety of armed oncolytic HSV-1 will lead to an establishment of a new genre of therapy for brain tumors as well as other cancers.Key words: oncolytic virus therapy, gene therapy, herpes simplex virus, viral vectors, G47Δ, G207, antitumor immunity