Gene therapy for spine fusion

Gene therapy is a novel therapeutic modality for repair and regeneration of musculoskeletal tissues, including the spine. Various methods for therapeutic gene transfer are presented in this article. Several studies in which gene transfer has been used specifically to enhance spine fusion in animal models are reviewed.     

肝癌基因治疗的靶向性研究进展

目的　介绍目前关于肝癌基因治疗靶向性研究的进展。方法　采用文献回顾的方式对肝癌基因治疗研究中采用的组织特异性载体系统以及细胞特异性基因表达调控系统等相关文献进行了综述。结果　合成的DNA转运系统和经修饰的病毒载体体外转染靶细胞后 ,可获得显著表达。目的基因细胞特异性表达主要是以甲胎蛋白或白蛋白基因的转录调控元件为基础 ,体外实验显示出较强的作用靶向性。其它基因治疗策略也显示了很好的应用前景。结论　寻找更具特异性和普遍性的肝癌抗原是解决基因治疗靶向性的关键。根据疾病和患者的具体情况选择合适的基因转运系统和调控元件是未来基因治疗的方向。     

Gene Therapy for Cancer

The basic strategies for gene therapy that have been explored include immunogene therapy such as cytokine gene transfer, selective prodrug activation, so-called suicide genes, transfer of a tumor suppressor gene, and inhibition of activated oncogenes by antisense mechanisms. Many therapeutic protocols have so far been registered in the office of the Recombinant DNA Advisory Committee, NIH, as of June 1999. Regarding the basic research in gene therapy, we planned a clinical application of gene therapy for an esophageal cancer patient at our institution. We review herein the present status of gene therapy for cancer overseas, and describe a protocol of clinical trials for gene therapy for esophageal cancer at our institution. Received: January 18, 2000 / Accepted: July 25, 2000     

肢体缺血性疾病的血管基因治疗

目的 评价基因治疗在肢体缺血性疾病治疗中的作用。方法 复习相关文献,并作综述性报道。结果 基因治疗作为一种新的治疗方法,已在动物实验方面作了大量探索,在多方面取得重要成果,并开始在临床应用,其中血管内皮细胞生长因子（ＶＥＧＦ）,ｐ５３基因相关治疗方法疗效显著。结论 基因疗法在肢体缺血性疾病的治疗中前景广阔,但仍有诸多技术问题亟待进一步研究解决。     

Amplification of engrafted hepatocytes by preparative manipulation of the host liver

Scarcity of donor livers is a major obstacle to the general application of hepatocytes for the development of bioartificial liver assist devices as well as intracorporeal engraftment of hepatocytes for the treatment of inherited metabolic diseases. The number of hepatocytes that can be transplanted into the liver safely in a single sitting also limits the utility of this procedure. These limitations could be addressed by providing preferential proliferative advantage to the transplanted cells. Studies using transgenic mouse recipients or donors have indicated that massive repopulation of the host liver by engrafted hepatocytes requires that the transplanted cells are subjected to a proliferative stimulus to which the host hepatocytes cannot respond. Prevention of host hepatocyte proliferation has been achieved by treatment with a plant alkaloid, retrorsine. Because retrorsine is carcinogenic, we have evaluated preparative irradiation for this purpose. The proliferative stimulus may consist of the loss of hepatic mass (e.g., partial hepatectomy, reperfusion injury or induction of Fas-mediated apoptosis by gene transfer) or administration of stimulants of hepatocellular mitosis (e.g., growth factors or thyroid hormone). Potential applications of these preparative manipulations of the host liver include the treatment of inherited metabolic disorders by transplantation of allogeneic hepatocytes, hepatocyte-mediated ex vivo gene therapy, rescuing liver cancer patients from radiation-induced liver damage, and expansion of human hepatocytes in animal livers.     

In Vivo Gene Transfer of Hepatocyte Growth Factor to Skeletal Muscle Prevents Changes in Rat Kidneys After 5/6 Nephrectomy

Hepatocyte growth factor (HGF) has been reported to be a renal regeneration factor. We previously reported that HGF acts as a renotropic factor, inducing cell recovery from ischemic injury or drug toxicity. Gene transfer by electroporation, which uses plasmid DNA as the vector, has several advantages over the conventional gene transfer method using viral vectors, inducing the ability to perform repeated transfers without apparent immunologic responses to the DNA vector. We recently demonstrated that electroporation of the HGF gene into skeletal muscle was an effective treatment for liver injury in an animal model. We presently investigated prevention of development of chronic renal disease by repetitive HGF gene transfer in rats with 5/6 nephrectomy. Hepatocyte growth factor gene transfer-treated rats showed better growth in body weight than untreated rats. Histologic changes such as glomerulosclerosis and interstitial fibrosis were significantly ameliorated by HGF gene transfer compared with untreated rats. Hepatocyte growth factor gene transfer by electroporation into skeletal muscle is feasible and effective against morphologic injury in subtotally nephrectomized rats.     

肝癌基因治疗的机遇和挑战

Gene therapy has emerged as an efficient modality to treat human diseases.This method is based on the transfer of genetic material to tissues to induce a curative effect.Gene therapy vectors are molecular constructs used to facilitate the penetration of genomic sequences inside the cells.Viral vectots have however several limitations when administered directly to the patient.They may cause significant toxicity by activating innate immunity or by eliciting an adaptive immune response against viral proteins.In addition,targeting the vector to the desired site is an issue when given systemically.The use of cells as vehicles for gene therapy vectors has many advantages.The combination of cell-viro-gene therapy has been thought as a new and promising strategy for therapy of cancer.The targeting vector to cancer stem cells will become a new direction in the field of gene therapy.In this article,we will introduce progressions,limitations and future directions of gene therapy of liver cancer.     

Genetic Heterogeneity and Efficiency of Two Different Methods of Adenovirus-Mediated Gene Transfer in a Rat Liver Transplantation Model

PURPOSE: We used recombinant adenoviral vectors for gene therapy in liver transplantation, and investigated the efficacy of gene transfer and expression on the grafts and genetic heterogeneity, with two exogenous gene transfer methods in three different syngeneic rat strains. METHODS: We transferred adenoviral vector encoding Escherichia coli beta-galactosidase via a donor tail vein 3 days before transplantation; via a recipient tail vein immediately after grafting; and ex vivo by perfusion and clamping during transplantation. RESULTS: The high efficacy of beta-galactosidase gene transfer and expression was seen in both delivery systems, with 70% positivity for hepatocytes on day 3, which persisted for at least 3 weeks after transplantation. The efficacy of gene transfer and expression was similar in the three strains (DA, Lewis, and PVG). CONCLUSIONS: These data suggest that adenovirus-mediated gene transfer delivers effective gene therapy by tail vein injection of a donor or a recipient, or by ex vivo graft perfusion in rat liver transplantation. It is not necessary to consider the differences in the strains. Furthermore, ex vivo graft perfusion is probably more suitable not only for rat liver transplantation but also possibly for future clinical application.     

Getting arthritis gene therapy into the clinic

Gene transfer technologies enable the controlled, targeted and sustained expression of gene products at precise anatomical locations, such as the joint. In this way, they offer the potential for more-effective, less-expensive treatments of joint diseases with fewer extra-articular adverse effects. A large body of preclinical data confirms the utility of intra-articular gene therapy in animal models of rheumatoid arthritis and osteoarthritis. However, relatively few clinical trials have been conducted, only one of which has completed phase II. This article summarizes the status in 2010 of the clinical development of gene therapy for arthritis, identifies certain constraints to progress and suggests possible solutions.     

Therapeutisches Potenzial der Stickstoffmonoxid-Synthase-Isoformen in Restenose, Transplantat- und Bypassarteriosklerose

The diverse biological effects of nitric oxide (NO) have led to intense research into its roles in vascular physiology and pathophysiology. Using recombinant DNA and gene transfer the effects of endogenous NO production by the family of NO synthase (NOS) enzymes can be elegantly studied in a variety of tissues. In addition, the feasibility of vascular NOS gene therapy has been demonstrated in animal models. However, technical and safety limitations have to be addressed before NOS gene therapy for cardiovascular disease is available for humans. Since NO exerts critical functions in vascular pathology, including atherosclerosis, post-angioplasty restenosis, vein graft atherosclerosis, transplant atherosclerosis and cardiac allograft vasculopathy, this article reviews recent progress in the field with a focus on potential future applications of NOS-modulating therapies.     

The efficacy and safety of gene transfer into the porcine liver in vivo by HVJ (Sendai virus) liposome

BACKGROUND: Gene transfer systems using viral vectors are efficient; however, most viral vectors also tend to evoke immunologic reactions, thereby clinically causing serial side effects. HVJ-liposome vector is a hybrid vector consisting of liposome and an inactivated Sendai virus (Hemmagglutinating Virus of Japan [HVJ]), which has been reported to be less immunogenic and can also be repeatedly administered. We examined the usefulness of this vector for hepatic gene therapy in a pig model. METHODS: Genes encoding beta-galactosidase and luciferase were used as reporter genes. The pigs were injected with the reporter gene loaded-HVJ-liposome into the portal vein under total vascular exclusion of the liver. The transfection efficiencies were then assessed by beta-galactosidase staining, a luciferase assay, and RT-PCR for LacZ mRNA. Biochemical and histologic analyses were performed to evaluate tissue toxicity after gene transfer. RESULTS: The luciferase gene expression in the liver reached its highest level at 7 days after transfection. It continued to be detected up to 28 days after transfection, while all pigs remained healthy throughout the observation period. The transfection efficiency was 15% in the hepatocytes according to beta-galactosidase staining. Extrahepatic transgene expression was slightly observed in the lung and kidney, but not in the spleen or ovary. CONCLUSIONS: These data suggest for the first time that the use of the HVJ-liposome vector is a safe and feasible modality for liver-directed gene transfer in pigs, and it might therefore be suitable for clinical gene therapy trials.     

First report of liver transplantation in Blau syndrome: The challenges faced in this rare granulomatous liver disease

Blau syndrome is a rare autoinflammatory granulomatous disease caused by variants in the NOD2 gene, classically presenting in childhood. Hepatic manifestations are recognized including cholestasis and granulomatous liver disease. We describe a novel NOD2 gene variant c.1471A > C, p.(Met491Leu) in an adult who developed cirrhotic complications despite selective immunotherapy, including recurrent esophageal bleeding and spontaneous bacterial peritonitis which resulted in liver transplantation. He required a second liver transplant as his first graft failed due to ischemic cholangiopathy. Disease recurrence has been observed (hitherto unreported). Of 84 patients with Blau syndrome treated with antibody therapy, five hepatic cases responded to anti-TNF therapy, with promising results if instigated before decompensation occurs. We report the first case of liver transplantation for Blau syndrome in an adult with a novel NOD2 variant. Blau related liver disease can reoccur post transplantation and is an important consideration for any future graft.Lay summaryBlau syndrome is a rare immune disease which presents in childhood. We describe the first liver transplant for this condition following development of progressive liver disease in adulthood. The patient had a newly described variant in the Blau gene (NOD2). We discuss the effectiveness of antibody therapy currently being used to control the disease, and the role of liver transplantation in Blau syndrome.     

Total vascular exclusion of the liver enhances the efficacy of retroviral-mediated associated thymidine kinase and interleukin-2 genes transfer against multiple hepatic tumors in rats

BACKGROUND: Recent advances in gene transfer technology render gene therapy an attractive treatment of disseminated liver metastases for which other treatments remain disappointing. In this setting, total vascular exclusion of the liver could improve gene transfer to cancer cells and prevent extrahepatic vector spreading during portal infusion of therapeutic genes. We evaluate the efficiency of combined herpes simplex virus type-1 thymidine kinase (HSV1-TK) and interleukin-2 retrovirus-mediated gene transfer through the portal vein, under total vascular exclusion of the liver, in a model of macroscopic multiple liver metastases in rats. METHODS: Multifocal liver metastases were established in BDIX rats with intraportal injection of DHDK12 colon cancer cells. On randomization, rats received either vector-producing cells or saline solution under total vascular exclusion of the liver. Vector-producing cells released retroviral vectors encoding Lac-Z in marking studies or HSV1-TK or interleukin-2 in therapeutic studies. Rats were either killed for pathologic studies, or followed for survival. RESULTS: Total vascular exclusion of the liver markedly improved gene transfer efficacy in marking studies. In therapeutic studies we observed a significant reduction in tumor volume of treated rats compared with untreated controls (2170 +/- 310 mm(3)). Although singular HSV1-TK or interleukin-2 gene transfer showed significant efficacy, the greatest tumor volume regression was observed in rats treated with combined HSV1-TK + interleukin-2 gene therapy (145 +/- 60 mm(3); P =.0001 vs control). This translated into an increased median survival rate compared with either control rats (P =.006) or rats treated with single gene therapy. CONCLUSION: In a rat model, a significant antitumoral effect against macroscopic multifocal liver metastases can be observed after retrovirus-mediated HSV1-TK and interleukin-2 gene transfer through the portal vein under total vascular exclusion of the liver, followed by ganciclovir administration. We believe that this well-tolerated and efficient therapeutic approach deserves clinical evaluation in patients with disseminated colorectal liver metastases.     

Gene therapy for gastrointestinal tract cancer: Prospects for combination treatment consisting of surgery and molecular surgery

Progress in understanding carcinogenesis has shown cancer to be a disease caused by gene abnormalities, and a variety of oncogenes and tumor suppressor genes have thus been identified. Advances in molecular biology have given us new tools for diagnosing, staging and predicting the outcome for cancer patients and gene therapy could therefore potentially revolutionize the treatment of gastrointestinal (GI) tract cancer. Progress has been made in several approaches related to genetic modification: (1) antisense oncogene and the restoration of tumor suppresor gene therapy; (2) suicide gene therapy; and (3) cancer immunotherapy. In situ in vivo gene transfer is a practical method of gene therapy for GI tract cancer. Although many hurdles need to be overcome to achieve effective gene transfer and targeting, our early results of in situ in vivo suicide gene therapy for canine gastric cancer are promising. The era of combined treatment consisting of surgery and molecular surgery for GI tract cancer is thus considered to soon be possible.     

Current concepts in gene therapy of the musculoskeletal system

The purpose of this article is to review the remarkable progress in the field of musculoskeletal system gene therapy. Since the introduction of this concept 15 years much of the preclinical and clinical data have emerged. The original target, rheumatoid arthritis, has been subjected to clinical phase II efficacy protocol, and osteoarthritis gene therapy efficacy is being thoroughly investigated in various animal models. The most promising area of research in this field however, is the tissue repair, because it doesn't require prolonged period of gene expression, local delivery is reasonably simple and it avoids substantial risk associated with systemic delivery, and levels of gene expression don't need to be so finely regulated. Gene transfer is successfully being used to aid the repair and regeneration of bone, cartilage, ligament tendon, meniscus and intervertebral disc. Other potential applications of gene therapy in musculoskeletal system include osteoporosis, aseptic loosening, genetic diseases and tumors. Highly encouraging data gained from these studies have confirmed that gene therapy is a promising therapeutic solution to treat various musculoskeletal system disorders.     

Suicide gene therapy for urogenital cancer: current outcome and prospects

Viral-mediated transfer of the herpes simplex virus thymidine kinase (HSV-tk) gene has been demonstrated by several investigators to confer sensitivity to nucleoside analogs such as ganciclovir (GCV) in a variety of tumor cells including brain, prostate, bladder, kidney, ovary, head and neck, lung, pancreas, and liver cancers. Fourteen suicide gene clinical protocols using adenovirus vectors have been conducted, including four in prostate cancer. Two additional protocols for prostate cancer are in preparation in Japan and the Netherlands. A study conducted at Baylor College of Medicine was the first to demonstrate the safety of HSV-tk plus GCV therapy for human prostate cancer and the anticancer activity of gene therapy in this disease. However, it is still in the early stage of its development, with a number of problems to be overcome. Systemic delivery, specific introduction, and specific expression of the target gene are the major issues to be managed in order to establish a clinically relevant treatment strategy.     

Gene therapy as an alternative to liver transplantation

Liver transplantation has become a well-recognized therapy for hepatic failure resulting from acute or chronic liver disease. It also plays a role in the treatment of certain inborn errors of metabolism that do not directly injure the liver. In fact, the liver maintains a central role in many inherited and acquired genetic disorders. There has been a considerable effort to develop new and more effective gene therapy approaches, in part, to overcome the need for transplantation as well as the shortage of donor livers. Traditional gene therapy involves the delivery of a piece of DNA to replace the faulty gene. More recently, there has been a growing interest in the use of gene repair to correct certain genetic defects. In fact, targeted gene repair has many advantages over conventional replacement strategies. In this review, we will describe a variety of viral and nonviral strategies that are now available to the liver. The ever-growing list includes viral vectors, antisense and ribozyme technology, and the Sleeping Beauty transposon system. In addition, targeted gene repair with RNA/DNA oligonucleotides, small-fragment homologous replacement, and triplex-forming and single-stranded oligonucleotides is a long-awaited and potentially exciting approach. Although each method uses different mechanisms for gene repair and therapy, they all share a basic requirement for the efficient delivery of DNA. (Liver Transpl 2002;8:1089-1108.)