基因治疗的应用及研究进展

基因治疗是一种新的治疗手段,可用于癌症、遗传性疾病、感染性疾病、心血管疾病和自身免疫性疾病等的治疗。癌症基因治疗是基因治疗的主要应用领域。过去几年里,全球基因治疗临床试验取得了很大的进步,也遇到了很多困难。未来基因治疗的主要目标是发展安全和高效的基因导入系统,它们能将外源遗传物质靶向性地导入特异的细胞。简要综述了基因治疗研究和应用的进展、困难及其发展前景。     

基因治疗导入载体的研究进展

基因治疗在恶性肿瘤、癌症、遗传性疾病和心脑血管等疾病的治疗中开始应用,临床治疗效果明显。基因治疗中的关键技术是选用合适的载体将外源基因高效导入受体靶细胞,综述了基因治疗中病毒和非病毒载体的研究进展。     

碳纳米管作为siRNA转运载体的研究进展

随着人们对RNA干扰分子机理的研究愈加深入,siRNA作为一种新的基因治疗药物极有可能为人类攻克癌症等难以治愈的疾病带来希望。然而,目前在RNA干扰应用中遇到的最大挑战就是如何有效地将siRNA导入靶细胞且不致引起严重的细胞毒性。碳纳米管在药物传递和基因传递等生物医学领域的潜在应用受到广泛关注;但要实现碳纳米管在基因治疗领域的应用,碳纳米管的功能化是关键,也是近几年来研究的重点。综述近年来碳纳米管作为siRNA转运载体在基因治疗领域的研究进展。     

RNA干扰在疾病治疗上的应用

RNA干扰(RNA interference,RNAi)是一种双链RNA分子在mRNA水平上引发的特异性基因沉默现象。RNAi在基因治疗方面表现出了光明的前景,已成功地应用于多种疾病的临床治疗。本文主要介绍了RNAi在疾病治疗上的应用及研究进展。     

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。     

RNA干扰技术在基因治疗中的应用进展

RNA干扰(RNA interference,RNAi)是一种双链RNA分子在mRNA水平上关闭相应序列基因的表达或使其沉默的过程,在基因治疗方面有着无可比拟的优势,已成功的应用于肿瘤、病毒感染、遗传性疾病及神经系统疾病等重大疾病的治疗.本文将主要介绍siRNA基因治疗的导入方法与途径,以及在不同疾病中,RNAi技术进行基因治疗的应用.     

基因治疗中的受体介民反义RNA转移技术

在调节特定基因的表达上,反义ＲＮＡ是一种重要的手段。但由于存在降解、非特异性转移及安全性等问题,反义ＲＮＡ在个体基因治疗中无法得到充分利用。受体介导的内吞作用为定向转移反义ＲＮＡ提供一种运载工具,它可以将反义ＲＮＡ定向、高效、低毒、高安全性地转移到靶细胞中发挥作用,因而将大大加快反义ＲＮＡ基因治疗的临床应用。     

基因治疗的发展现状、问题和展望

基因治疗是一种新的治疗手段,可以治疗多种疾病,包括癌症、遗传性疾病、感染性疾病、心血管疾病和自身免疫性疾病。癌症基因治疗是基因治疗的主要应用领域。过去几年里,全球基因治疗临床试验取得了很大的进步。实际上,基因治疗也遇到了很多困难。未来,基因治疗的主要目标是发展安全和高效的基因导入系统,它们能将外源遗传物质靶向性地导入到特异的细胞。本文主要综述基因治疗所取得的突出进展、所遇到的困难和发展前景。     

RNA干扰用于基因治疗的研究进展

RNA干扰(RNAi)是20世纪末才被人们认识和重视的一种通过双链RNA抵御病毒入侵或抑制转座子活动的生物防御机制。随着RNA干扰分子机制研究的深入及其应用研究的发展,人们发现RNA干扰技术在基因功能研究及人类疾病的基因治疗上具有广阔的应用前景。本文在简述RNAi分子机制的基础上,综述了RNAi在抗病毒治疗及抗肿瘤治疗方面的研究和应用概况。     

RNA干涉的临床前实验研究进展

RNA干涉（RNA interference,RNAi）是一种非常保守的细胞现象,在基础研究和疾病治疗方面具有重大的应用前景。尤其引人注目的是,新的RNAi方法学与已建立的转基因策略相结合,有效地将组织特异性RNAi导入到患者体内,有望治疗人类疾病。本文综述了RNAi的机制与在其临床前的实验研究,简要介绍了RNAi的新用途,讨论了RNAi基因治疗存在的问题,展望了RNAi基因治疗的应用前景。     

Preclinical applications of imaging for cancer gene therapy

Gene therapy is a very attractive strategy in experimental cancer therapy. Ideally, the approach aims to deliver therapeutic genes selectively to cancer cells. However, progress in the improvement of gene therapy formulations has been hampered by difficulties in measuring transgene delivery and in quantifying transgene expression in vivo. In clinical trials, endpoints rely almost exclusively on the analysis of biopsies by molecular and histopathological methods, which provide limited information. Therefore, to ensure the rational development of gene therapy, a crucial issue is the utilisation of technologies for the non-invasive monitoring of spatial and temporal gene expression in vivo upon administration of a gene delivery vector. Such imaging technologies would allow the generation of quantitative information about gene expression and the assessment of cancer gene therapy efficacy. In the past decade, progress has been made in the field of in vivo molecular imaging. This review highlights the various methods currently being developed in preclinical models.     

Gene therapy. Therapeutic approaches and implications

The present article is an overview of gene therapy with an emphasis on different approaches and its implications in the clinic. Genetic interventions have been applied to the diagnosis of and therapy for an array of human diseases. The initial concept of gene therapy was focused on the treatment of genetic diseases. Subsequently, the field of gene therapy has been expanded, with a major focus on cancer. Although the results of early gene therapy-based clinical trials have been encouraging, there is a need for gene delivery vectors that feature reduced immunogenicity and improved targeting ability. The results of phases I/II clinical trials have suggested the important role of gene therapy as a versatile and powerful treatment tool, especially for human cancers. One reasonable expectation is that performing gene therapy at an earlier stage in the disease process or for minimal residual disease may be more advantageous.     

In pursuit of new developments for gene therapy of human diseases

Gene therapy aims at transferring a therapeutic gene into human somatic cells in order to treat a disease. Originally addressed to hereditary genetic disorders, gene therapy has found therapeutic applications in cancer, infectious diseases and degenerative disorders, particularly those of the nervous system. Although gene transfer into humans has been demonstrated in several clinical trials, with more than 300 currently underway worldwide, there is still no single outcome that undoubtedly showed a consistent benefit for the patient. Nevertheless, the expectations for gene therapy are still high, and the prospects of future clinical success are increasing together with the growing of the field. The development of better delivery systems specifically tailored to individual diseases, with sustained expression of the therapeutic gene in the appropriate cells, will in the end make possible true therapeutic applications of human gene transfer.     

Gene therapy techniques.

The most dramatic event of the past year in the field of gene therapy has been the initiation of clinical trials involving the introduction of genetically altered cells into human beings. Four studies, three involving new approaches to cancer therapy and one involving the treatment of adenosine deaminase deficiency, are presently under way. There has also been significant recent progress in the technology of gene transfer relevant to gene therapy. This progress, along with the recent clinical therapy trials, is the subject of this review.     

The role of therapeutic antibodies in drug discovery

The last 5 years have seen a major upturn in the fortune of therapeutic monoclonal antibodies (mAbs), with nine mAbs approved for clinical use during this period and more than 70 now in clinical trials beyond phase II. Sales are expected to reach $4 billion per annum worldwide in 2002 and $15 billion by 2010. This success can be related to the engineering of mouse mAbs into mouse/human chimaeric antibodies or humanized antibodies, which have had a major effect on immunogenicity, effector function and half-life. The issue of repeated antibody dosing at high levels with limited toxicity was essential for successful clinical applications. Emerging technologies (phage display, human antibody-engineered mice) have created a vast range of novel, antibody-based therapeutics, which specifically target clinical biomarkers of disease. Modified recombinant antibodies have been designed to be more cytotoxic (toxin delivery), to enhance effector functions (bivalent mAbs) and to be fused with enzymes for prodrug therapy and cancer treatment. Antibody fragments have also been engineered to retain specificity and have increased the penetrability of solid tumours (single-chain variable fragments). Radiolabelling of antibodies has now been shown to be effective for cancer imaging and targeting. This article focuses on developments in the design and clinical use of recombinant antibodies for cancer therapy.     

Gene therapy using anticancer drug-resistance genes

Myelosuppression is a major dose-limiting factor in cancer chemotherapy. Introduction of drug-resistance genes into bone marrow cells of cancer patients has been proposed to overcome this limitation. In theory, any gene whose expression protects cells against the toxic effects of chemotherapy should be useful in vivo for this purpose. Among such genes, human multidrug-resistance gene (MDR1) has been studied most extensively for this purpose, and clinical trials of drug-resistance gene therapy have been started in the US for cancer patients who undergo high-dose chemotherapy with autologous hematopoietic stem cell transplantation. In Japan, our clinical protocol of MDR1 gene therapy "A clinical study of drug-resistance gene therapy to improve the efficacy and safety of chemotherapy against breast cancer" has been submitted to the government. To improve the efficacy and safety of this drug-resistance gene therapy, we have constructed a series of MDR1-bicistronic retrovirus vectors using a retrovirus backbone of Harvey murine sarcoma virus and internal ribosome entry site (IRES) from picornavirus to co-express a second gene with the MDR1 gene. MDR1-MGMT bicistronic vectors can be used to protect bone marrow cells of cancer patients from combination chemotherapy with MDR1-related anticancer agents and nitrosoureas. In addition, MDR1-bicistronic retrovirus vectors can be designed to use the MDR1 gene as an in vivo selectable marker to enrich the transduced cells which express therapeutic genes, if disease is curable by the expression of a single-peptide gene in any types of bone marrow cells or peripheral blood cells.     

Clinical implication of p53 mutation in lung cancer

Lung cancer development involves multiple genetic abnormalities leading to malignant transformation of the bronchial epithelial cells, followed by invasion and metastasis. One of the most common changes is mutation of the p53 tumor suppressor gene. The frequency of p53 alterations in lung cancer is highest in small cell and squamous cell carcinomas. A genetic “signature” of the type of p53 mutations has been associated with carcinogens in cigarette smoke. The majority of clinical studies suggest that lung cancers with p53 alterations carry a worse prognosis, and may be relatively more resistant to chemotherapy and radiation. An understanding of the role of p53 in human lung cancer may lead to more rational targeted approaches for treating this disease. P53 gene replacement is currently under clinical investigation but clearly more effective means of gene deliver to the tumor cells are required. Novel approaches to lung cancer therapy are needed to improve the observed poor patient survival despite current therapies.     

Transfer and expression of the human multiple drug resistance gene as potential human gene therapy

The human multiple drug resistance (MDR) gene has been used as a model for human gene transfer which could lead to human gene therapy. MDR is a transmembrane protein which pumps a number of toxic substances out of cells including several drugs used in cancer chemotherapy. Normal bone marrow cells express low levels of MDR and are particularly sensitive to the toxic effects of these drugs. There are two general applications of MDR gene therapy: (1) to provide drug-resistance to the marrow of cancer patients receiving chemotherapy, and (2) as a selectable marker which when co-transferred with a non-selectable gene such as the human beta globin gene can be used to enrich the marrow for cells containing both genes. We demonstrate efficient transfer and expression of the human MDR gene in a retroviral vector into live mice and human marrow cells including CD34⁺ cells isolated from marrow and containing the bulk of human hematopoietic progenitors. MDR gene transduction corrects the sensitivity of CD34⁺ cells to taxol, an MDR drug substrate, and enriches the marrow for MDR-transduced cells. The MDR gene-containing retroviral supernatant used has been shown to be safe and free of replication-competent retrovirus. Because of the safety of the MDR retroviral supernatant, and efficient gene transfer into mouse and human marrow cells, a phase 1 clinical protocol for MDR gene transfer into cancer patients has been approved to evaluate MDR gene transfer and expression in human marrow.     

Localized hyperthermia and radiation in cancer therapy

Clinical researches in hyperthermia have recently expanded rapidly with the increase in our knowledge of the biological effects of heat on experimental systems. This article provides background information on the biological rationale and current status of technologies concerning thermometry and heating equipment for the application of hyperthermia to human cancer treatment. Much data has been accumulated recently in hyperthermia treatment with and without radiation to superficial tumours which are refractory to conventional treatments. In this paper the treatment results published recently have been surveyed. The complete responses of tumours treated by heat alone are in the range of 15 per cent as opposed to approximately 60 per cent for the combination of heat plus radiation. Clinical results so far published have demonstrated that local control is consistently better in the lesions treated with radiation plus heat than with radiation alone. The morbidity related to heat therapy is within tolerable limits. Several articles on the clinical results of deep-seated tumours treated by hyperthermia are reviewed. Problems to be solved in the application of heat to cancer therapy are discussed.     

Bioluminescence technology for imaging cell proliferation

As continuous cell proliferation caused by genetic alterations leads to cancer, monitoring abnormal cell proliferation in sporadic tumor models is important in the context of tumor generation, development and response to therapy. Bioluminescence imaging technology, which visualizes the conversion of chemical energy into visible light by luciferase enzymes, is an established method to measure cell numbers in grafted tumors in vivo, but has not been used to monitor cell proliferation per se. To measure cell proliferation noninvasively, transgenic mice have been developed that express the luciferase gene under the control of the E2F1 promoter. When these reporter mice are crossed with genetically defined mouse models of human cancer, the proliferative activity of the tumor cells can be monitored with proportional light production. These technologies support more detailed preclinical trials and could enable other biological pathways to be monitored in living cells.