遗传病的基因治疗

基因工程或称重组DNA技术是70年代初发展起来的一门技术,由于它有广阔的理论和应用前景,进展极为迅速,现已广泛应用于药品、农业、工业各方面。在医学方面,基因治疗是人们极为关注的领域,因为人类的遗传疾病有2000种以上,但却没有有效的治疗方法。遗传疾病的根本原因是基因有了缺陷。基因治疗就是在机体中,将有缺陷的基因换上正常的基因,并使之适当表达,或者说,将正常基因插入机体中来纠正遗传缺陷。基因治疗可以分为两类,一是体细胞基因     

基因治疗的昨天、今天与明天

基因治疗是指基因直接导入人体用于治疗（甚至预防）疾病。它是一项高度集成、综合性和高难度的生物高技术。它集中了基因分离、基因导入人体、基因在人体内的高效表达及其调控,既要求有效而又须确保安全。因此,它的难度远远高于基因在体外（细菌、酵母、哺乳动物细胞）表达的基因工程技术。国外的基因治疗研究经历了两个历史性阶段,一是从１９８９年至１９９４年的盲目阶段;二是从１９９５年开始的理性阶段。以下就其现状和我国发展基因治疗的对策,作一分析。关于基因治疗的一般概念、通用技术、载体种类、导入系统不再在本文中赘述。     

基因治疗心肌缺血的载体应用新进展

近年来,随着基因治疗技术的不断进步,为心肌缺血的治疗开辟了一条全新的途径,并取得了一些令人鼓舞的进展。基因治疗主要包括治疗基因、基因转移载体以及基因导入途径三个方面。基因转移载体又在治疗基因和基因表达之间起着桥梁作用,因此,发展安全、高效的基因转移系统是基因治疗的关键之一。目前用于基因治疗心肌缺血基因转移的载体主要有病毒载体和非病毒载体。下面将就不同载体在心肌缺血的基因治疗中的应用进展进行简要的总结。     

基因治疗心肌缺血的载体应用新进展

近年来,随着基因治疗技术的不断进步,为心肌缺血的治疗开辟了一条全新的途径,并取得了一些令人鼓舞的进展。基因治疗主要包括治疗基因、基因转移载体以及基因导入途径三个方面。基因转移载体又在治疗基因和基因表达之间起着桥梁作用,因此,发展安全、高效的基因转移系统是基因治疗的关键之一。目前用于基因治疗心肌缺血基因转移的载体主要有病毒载体和非病毒载体。下面将就不同载体在心肌缺血的基因治疗中的应用进展进行简要的总结。     

CRISPR/Cas及其衍生编辑技术在基因治疗中的应用进展

基因治疗是指利用基因编辑技术对细胞基因进行“修饰”而达到治疗的目的。CRISPR/Cas的出现为基因编辑提供了简单、高效和多功能的平台,同时,为克服DNA双链断裂产生的不良影响,基于CRISPR/Cas的新型技术,如碱基编辑器（base editors,BE）、Prime Editors（PE）和Cas13效应器,被相继开发出来。目前,CRISPR/Cas及其衍生编辑技术已被广泛应用于动物细胞模型构建、药物靶点筛查和基因功能研究等领域,在基因治疗领域也展现出广阔的应用前景。基于此,简要介绍了CRISPR/Cas及其衍生编辑技术,综述了其在单基因遗传病、肿瘤和其他疾病的基因治疗中的应用进展,并分析了其当下面临的挑战,以期为基因编辑在单基因遗传病、肿瘤和其他疾病治疗领域提供理论参考。     

人类基因治疗研究的进展

人类基因治疗研究的进展陈诗书（上海第二医科大学生化教研室分子生物学实验室）人类基因治疗研究中心一、基因治疗的概念基因治疗能够在比较短的时间从理论设想变为现实,主要是对疾病分子生物学的研究已取得了重大的进展,同时发展了许多有关的新技术新方法。特别是７０年代对ＲＮＡ或ＤＮＡ肿瘤病毒转化细胞的研究中所发现的病毒的遗传物质可以转移至宿主细胞基因组中的证据,揭示这些病毒可以作为基因转移的媒介。重组DNA 技术的迅速发展使人们可以在实验室构建各种病毒载体。     

基因治疗离我们有多远?

重组人 p35腺病毒注射液 ,成为世界上第一个获得正式批准的基因治疗药物。p35是科技界广泛研究并已获公认的一种抑癌基因。研究表明 ,人类 5 0 %以上的肿瘤都与这种基因的变异有关。重组人 p35腺病毒注射液这种基因治疗药物由两部分组成 :p35基因和基因载体——基因工程改造的腺病毒 DNA。自从 1990年美国国立卫生研究院批准第一例临床基因治疗申请以来 ,基因治疗已从单基因遗传病扩展到多个病种范围 ,包括恶性肿瘤、心血管疾病等。基因治疗的策略 ,概括起来大致分为基因置换、基因修复、基因修饰、基因失活、免疫调节等 6种。迄今全世界…     

基因治疗的进展与临床应用

在过去的40多年间,基因治疗已从临床前试验研究过渡到了临床试验阶段,并应用于多种疾病治疗中,从单基因隐性遗传的血友病到与多因素相关的疾病如癌症、心血管疾病以及人类免疫缺陷病。迄今为止,在近30个国家范围内．包括已经完成或正在进行或已经获得批准在内的基因治疗临床试验超过了1650项。在这些临床试验中,绝大多数是用于肿瘤的治疗。从20世纪60年代初提出基因治疗的理论到90年代初第一例基因治疗临床试验的开展再到当前基因治疗的广泛应用,可以说基因治疗经历了一个曲折的过程。尽管这个领域至今为止还没有成熟．但是基因治疗仍然有潜力能够为肿瘤患者减轻病痛。本文主要从基因治疗的策略和载体系统的研究两大方面对该领域的进展简单综述。     

多基因共表达载体的构建策略

于同一载体上同时表达多个外源基因在生物学领域中有广泛的应用价值,尤其在针对疾病发生发展的各个环节设计的联合基因治疗方案中,构建合适的载体获得多个外源基因的高效转移与表达具有重要意义,目前可提供的载体难以满足这一要求,近年来在多顺反子表达载体的构建策略方面有许多新的进展,本文拟对多基因共表达载体的构建策略予以总结和阐述。     

2023年基因治疗发展态势分析

基因治疗是指通过在基因水平上操纵或修饰细胞内基因的表达来治疗疾病的一种生物医学手段。近年来,基因治疗技术逐渐成熟,产业化加速,不断有重磅产品获批,已成为生物医药领域继小分子、大分子之后的一条新热门赛道。本文从基础研究、临床研究和产品获批等方面对2023年基因治疗的态势进行了分析,结果发现治疗及递送新技术的不断涌现及疾病生物学研究的深入,推动基因治疗发展进入快车道,适应证范围不断拓展,临床潜力不断获得验证,产品加速上市。2023年,基因替代治疗、基因编辑治疗和RNA治疗等基因疗法先后迎来多款突破性新产品上市,递送技术的开发和优化取得重要进展,同时基因治疗领域潜在的安全风险和有效性仍需进一步的长期跟踪研究;基因治疗的可及性也有待多渠道来进一步提高。最后,本文也对基因治疗领域的未来发展进行了展望。     

MENT: Methylation and expression database of normal and tumor tissues

Integrated analysis of DNA methylation and gene expression can reveal specific epigenetic patterns that are important during carcinogenesis. We built an integrated database of DNA methylation and gene expression termed MENT (Methylation and Expression database of Normal and Tumor tissues) to provide researchers information on both DNA methylation and gene expression in diverse cancers. It contains integrated data of DNA methylation, gene expression, correlation of DNA methylation and gene expression in paired samples, and clinicopathological conditions gathered from the GEO (Gene Expression Omnibus) and TCGA (The Cancer Genome Atlas). A user-friendly interface allows users to search for differential DNA methylation by either ‘gene search’ or ‘dataset search’. The ‘gene search’ returns which conditions are differentially methylated in a gene of interest, while ‘dataset search’ returns which genes are differentially methylated in a condition of interest based on filtering options such as direction, DM (differential methylation value), and p-value. MENT is the first database which provides both DNA methylation and gene expression information in diverse normal and tumor tissues. Its user-friendly interface allows users to easily search and view both DNA methylation and gene expression patterns. MENT is freely available at http://mgrc.kribb.re.kr:8080/MENT/.     

Construction of a bicistronic proangiogenic expression vector and its application in experimental angiogenesis in vivo

Manipulation of angiogenesis in vivo is an example of successful gene therapy strategies. Overexpression of angiogenic genes like VEGF, FGF or PDGF causes new vessel formation and improves the clinical state of patients. Gene therapy is a very promising procedure but requires large amounts of pharmaceutical-grade plasmid DNA. In this regard we have constructed a bicistronic plasmid DNA vector encoding two proangiogenic factors, VEGF165 and FGF-2. The construct (pVIF) contains the internal ribosome entry site (IRES) of the encephalomyocarditis virus (ECMV) which permits both genes to be translated from a single bicistronic mRNA. The IRES sequence allows for a high efficiency of gene expression in vivo. The pVIF vector was characterized in vitro and in vivo. In vivo angiogenesis studies showed that the bicistronic vector encoding two proangiogenic factors induces the formation of new vessels significantly more than pVEGF165 or pFGF-2 alone. In our opinion the combined proangiogenic approach with VEGF165 and FGF-2 is more powerful and efficient than single gene therapy. We also postulate that IRES sequence can serve as a useful device improving efficiency of gene therapy.     

Successes and prospects for genetic engineering]

The review of literature (1970-1976) on problems of gene engineering is given. Gene engineering is pointed out to be a new method of modern biology and a new page of modern molecular genetics. Gene engineering detected a real possibility of artificial creating living hybrid organisms, i.e. constructing functional recombinant DNA molecules according to a project of investigator, but not to possibilities of crossing. The determination of gene engineering (in contrast with genetical engineering) is given in the first division of the article. Genetical engineering is a construction of hybrid organisms on the basis of recombination between non-homologous chromosomes cy crossing. Genetical engineering is based on sex crossing, thus the application of this method is restricted by crossability (i.e. experiments in vivo), which possibilities are determined by taxonomical limits. Gene engineering is a new method of operating directly with genes. It permits constructing in vitro any hybrid genomes desirable. There is no limits of combining ability for gene engineering. Three main stages of constructing hybrid genomes should be taken into account for the proper determination of gene engineering as a method of genome constructing: 1) the gene isolation; 2) their cross-linking in vitro; 3) the transfer of hybrid DNA into recipient cell or its genome. The cardinal stage of gene engineering is the construction of hybrid DNA, cross-linking any initial DNAs from any remote animals, plants and bacteria. All the methods known of gene isolation are described. The chemical method of gene isolation is based on that case, when DNA of some gene differs in its physico-chemical characteristics from total DNA, for example, DNAs of genes coding ribosomal RNAs or sea urchine histone DNA. Isolation of promotors and operators using DNA dependent RNA polymerase, which recognizes promotors, repressor and operator DNA, should also be considered as the chemical method of gene isolation. Restrictase method, which is also well known, is convenuent because the restricts have long enough sticky ends, which is important for the following gene cross-linking. The method of total restriction, reported by Lederberg et al. and Debabov et al., is described. The phage method (in particular, Shimada method) is given, permitting the direct integration of lambda phage into a number of sites of Escherichia coli chromosome. Gene engineering method of gene isolation is mentioned, in particular, the data of Kameron et al. on hybrid phages carrying DNA ligase gene, and Clark a. Carbon on hybrid plasmids carrying triptophane and arabinose operons genes. These methods are called "shot gun". Methods of gene isolation from higher organisms are less developed. A method of gene isolation using so called colony hybridization (according to Grünstein and Hognes) is also given...     

Gene delivery into hepatocytes with the preS/liposome/DNA system

Gene delivery into human hepatocytes remains a critical issue for the development of liver-directed gene therapy. Gene delivery based on non-viral vectors is an attractive approach relative to viral vectors. In this report, novel delivery system of preS/liposome/DNA virus-like particle (VLP) was developed for gene transfection into hepatocytes in vivo and in vitro. Plasmid pCMVbeta, expressing beta-galactosidase, was encapsulated with cationic liposome, and then the histidine-tagged preS domain of hepatitis B virus was coated on the surface of liposome/DNA to form preS/liposome/ DNA VLP. Transfection efficiencies of preS/liposome/DNA, liposome/DNA, naked DNA and preS were analyzed using several different human cell lines. The highest transfection efficiency was found using preS/liposome/DNA VLP as the transfection reagent in human hepatocyte (HH) cell line. Results show that preS domain of hepatitis B virus coated on liposome/DNA can be used for highly efficient gene transfection into human hepatocytes. Moreover, the target characteristic of preS/liposome/DNA was analyzed in vivo. After preS/liposome/DNA VLP was injected into immunocompromised (Nude) mice via the tail vein, most of beta-galactosidase was expressed in the liver; however, no significant target expression was found with the injection of liposome/ DNA or naked DNA. Our results show that preS/liposome/DNA VLP can be used as a novel liver-specific gene delivery system.     

Development of DNA delivery system using Pseudomonas exotoxin A and a DNA binding region of human DNA topoisomerase I

Gene therapy is defined as the delivery of a functional gene for expression in somatic tissues with the intent to cure a disease. Thus, highly efficient gene transfer is essential for gene therapy. Receptor-mediated gene delivery can offer high efficiency in gene transfer, but several technical difficulties need to be solved. In this study, we first examined the DNA binding regions of the human DNA topoisomerase I (Topo I), using agarose gel mobility shift assay, in order to identify sites of noncovalent binding of human DNA Topo I to plasmid DNA. We identified four DNA binding regions in human DNA Topo I. They resided in aa 51–200, 271–375, 422–596, and 651–696 of the human DNA Topo I. We then used one of the four regions as a DNA binding protein fragment in the construction of a DNA delivery vehicle. Based on the known functional property of each Pseudomonas exotoxin A (PE) domain and human DNA Topo I, we fused the receptor binding and membrane translocation domains of PE with a highly positively charged DNA binding region of the N-terminal 198 amino acid residues of human DNA Topo I. The resulting recombinant protein was examined for DNA binding in vitro and transfer efficiency in cultured cells. The results show that this DNA delivery protein is a general DNA delivery vehicle without DNA sequence, topology, and cell-type specificity. The DNA delivery protein could be used to target genes of interest into cells for genetic and biochemical studies. Therefore, this technique can potentially be applied to cancer gene therapy. Received: 19 July 1999 / Received revision: 10 September 1999 / Accepted: 24 September 1999     

Asialoglycoprotein receptor and liposome synergistically mediate the gene transfer into primary rat hepatocytes

Gene transfer into primary rat hepatocytes was performed by employing cationic liposome as DNA carrier and the specific ligand of hepatic asialoglycopmtein receptor (ASGPR), asialofetuin, as liver-targeting ligand. The results showed that asialofetuin, when added to the gene transfer complexes, could significantly increase the hepatocyte transfection efficiency, and alleviate the cellular toxicity of Lipofectin. Several synthetic ligands of ASGPR (galactosyl albumin) could also increase the transfection efficiency of hepatocyte like asialofetuin. It was proved that ASGPR and cationic liposome could synergistically mediate the gene transfer into primary rat hepatocytes. This novel gene delivery system provided a safer, more simple and efficient gene transfer method for primary hepatocytes, and showed prospecting application in hepatic gene therapy.     

Asialoglycoprotein receptor and liposome synergistically mediate the gene transfer into primary rat hepatocytes

Gene transfer into primary rat hepatocytes was performed by employing cationic liposome as DNA carrier and the specific ligand of hepatic asialoglycoprotein receptor (ASGPR), asialofetuin, as liver-targeting ligand. The resuits showed that asialofetuin, when added to the gene transfer complexes, could significantly increase the hepatocyte transfeetion efficiency, and alleviate the cellular toxicity of Lipofectin. Several synthetic ligands of ASGPR (galactosyl albumin) could also increase the transfection efficiency of hepatocyte like asialofetuin. It was proved that ASGPR and cationic liposome could synergistically mediate the gene transfer into primary rat hepatoeytes. This novel gene delivery system provided a safer, more simple and efficient gene transfer method for primary hepatocytes, and showed prospecting application in hepatic gene therapy.     

Protamine Sulfate Provides Enhanced and Reproducible Intravenous Gene Transfer by Cationic Liposome/DNA Complex

Abstract

A novel lipid/polycation/DNA (LPD) formulation has been developed for in vivo gene transfer. It involves the condensation of plasmid DNA with protamine sulfate, a cationic polypeptide, followed by the addition of DOTAP cationic liposomes. Compared with DOTAP/DNA complex, LPD offers greater protection of plasmid DNA against enzymatic digestion and gives consistently higher gene expression in mice via tail vein injection. The in vivo efficiency of LPD was dependent upon charge ratio and was also affected by the lipid used. Increasing the amount of DNA delivered induced an increase in gene expression. The optimal dose was approximately 50 μg per mouse, at which concentration approximately 10 ng luciferase protein per mg extracted tissue protein could be detected in the lung. Gene expression in the lung was detected as early as 1 h after injection, peaked at 6 h, and declined thereafter. Using LacZ as a reporter gene, it was shown that endothelial cells were the primary locus of transgene expression in both lung and spleen. No sign of inflammation in these organs was noticed. Since protamine sulfate has been proven to be non-toxic and only weakly immunogenic in humans, this novel vector may be useful for the clinical use of gene therapy.     

Recombinant mussel adhesive protein as a gene delivery material

Efficient target gene delivery into eukaryotic cells is important for biotechnological research and gene therapy. Gene delivery based on proteins, including histones, has recently emerged as a powerful non-viral DNA transfer technique. Here, we investigated the potential use of a recombinant mussel adhesive protein, hybrid fp-151, as a gene delivery material, in view of its similar basic amino acid composition to histone proteins, and cost-effective and high-level production in Escherichia coli. After confirming DNA binding affinity, we transfected mammalian cells (human 293T and mouse NIH/3T3) with foreign genes using hybrid fp-151 as the gene delivery carrier. Hybrid fp-151 displayed comparable transfection efficiency in both mammalian cell lines, compared to the widely used transfection agent, Lipofectamine 2000. Our results indicate that this mussel adhesive protein may be used as a potential protein-based gene-transfer mediator.     

Recombination induced by triple-helix-targeted DNA damage in mammalian cells.

Gene therapy has been hindered by the low frequency of homologous recombination in mammalian cells. To stimulate recombination, we investigated the use of triple-helix-forming oligonucleotides (TFOs) to target DNA damage to a selected site within cells. By treating cells with TFOs linked to psoralen, recombination was induced within a simian virus 40 vector carrying two mutant copies of the supF tRNA reporter gene. Gene conversion events, as well as mutations at the target site, were also observed. The variety of products suggests that multiple cellular pathways can act on the targeted damage, and data showing that the triple helix can influence these pathways are presented. The ability to specifically induce recombination or gene conversion within mammalian cells by using TFOs may provide a new research tool and may eventually lead to novel applications in gene therapy.