Current Issue : April - June Volume : 2013 Issue Number : 2 Articles : 5 Articles
Integrating gene delivery systems allow for a more stable transgene expression in mammalian cells than the episomal ones.\r\nHowever, the integration of the shuttle vector within the cellular chromosomal DNA is associated with the risk of insertional\r\nmutagenesis, which, in turn, may cause malignant cell transformation. The use of a retroviral-derived vector system was\r\nresponsible for the development of leukemia in five children, who participated in various clinical trials for the treatment of severe\r\ncombined immunodeficiency (SCID-X1) in France and in the United Kingdom. Unfortunately, the hematological malignancy\r\nclaimed the life of one patient in 2004, who was enrolled in the French clinical trial. In addition, adeno-associated-viral-(AAV-)\r\nmediated gene transfer induced tumors in animal models, whereas the Sleeping Beauty (SB) DNA transposon system was\r\nassociated with insertional mutagenesis events in cell culture systems. On these grounds, it is necessary to develop safer gene\r\ndelivery systems for the genetic manipulation of mammalian cells. This paper discusses the latest achievements that have been\r\nreported in the field of vector design....
Current treatment of hemophilia A by intravenous infusion of factor VIII (fVIII) concentrates is very costly and has\r\na potential adverse effect of developing inhibitors. Gene therapy, on the other hand, can potentially overcome these\r\nlimitations associated with fVIII replacement therapy. Although hemophilia B gene therapy has achieved promising\r\noutcomes in human clinical trials, hemophilia A gene therapy lags far behind. Compared to factor IX, fVIII is a\r\nlarge protein which is difficult to express at sustaining therapeutic levels when delivered by either viral or non-viral\r\nvectors. To improve fVIII gene delivery, numerous strategies have been exploited to engineer the fVIII molecule\r\nand overcome the hurdles preventing long term and high level expression. Here we reviewed these strategies, and\r\ndiscussed their pros and cons in human gene therapy of hemophilia A....
Background. The heart consists of various kinds of cell components. However, it has not been feasible to separately analyze the\r\ngene expression of individual components. The laser microdissection (LMD) method, a new technology to collect target cells from\r\nthe microscopic regions, has been used for malignancies. We sought to establish a method to selectively collect the muscular and\r\nvascular regions fromthe heart sections and to compare the marker gene expressions with this method.Methods and Results. Frozen\r\nleft ventricle sections were obtained fromWistar-Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHR-SP) at\r\n24 weeks of age. Using the LMD method, themuscular and vascular regions were selectively collected under microscopic guidance.\r\nReal-time RT-PCR analysis showed that brain-type natriuretic peptide (BNP), a marker of cardiac myocytes, was expressed in the\r\nmuscular samples, but not in the vascular samples, whereas a-smooth muscle actin, a marker of smooth muscle cells, was detected\r\nonly in the vascular samples.Moreover, SHR-SP had significantly greater BNP upregulation than WKY (P < 0.05) in the muscular\r\nsamples. Conclusions. The LMD method enabled us to separately collect the muscular and vascular samples from myocardial\r\nsections and to selectively evaluate mRNA expressions of the individual tissue component....
Ocular gene therapy is rapidly becoming a reality. By November 2012, approximately 28 clinical trials were approved to assess\r\nnovel gene therapy agents. Viral infections such as herpetic keratitis caused by herpes simplex virus 1 (HSV-1) can cause serious\r\ncomplications that may lead to blindness. Recurrence of the disease is likely and cornea transplantation, therefore, might not\r\nbe the ideal therapeutic solution. This paper will focus on the current situation of ocular gene therapy research against herpetic\r\nkeratitis, including the use of viral and nonviral vectors, routes of delivery of therapeutic genes, new techniques, and key research\r\nstrategies. Whereas the correction of inherited diseases was the initial goal of the field of gene therapy, here we discuss transgene\r\nexpression, gene replacement, silencing, or clipping. Gene therapy of herpetic keratitis previously reported in the literature is\r\nscreened emphasizing candidate gene therapy targets. Commonly adopted strategies are discussed to assess the relative advantages\r\nof the protective therapy using antiviral drugs and the common gene therapy against long-term HSV-1 ocular infections signs,\r\ninflammation and neovascularization. Successful gene therapy can provide innovative physiological and pharmaceutical solutions\r\nagainst herpetic keratitis...
The liver is a target for gene therapy of inborn errors of metabolism, of\r\nhemophilia, and of acquired diseases such as liver cancer and hepatitis. The ideal gene\r\ntransfer strategy should deliver the transgene DNA to parenchymal liver cells with\r\naccuracy and precision in the absence of side effects. Liver sinusoids are highly specialized\r\ncapillaries with a particular endothelial lining: the endothelium contains open fenestrae,\r\nwhereas a basal lamina is lacking. Fenestrae provide a direct access of gene transfer\r\nvectors to the space of Disse, in which numerous microvilli from parenchymal liver cells\r\nprotrude. The small diameter of fenestrae in humans constitutes an anatomical barrier\r\nfor most gene transfer vectors with the exception of adeno-associated viral (AAV)\r\nvectors. Recent studies have demonstrated the superiority of novel AAV serotypes for\r\nhepatocyte-directed gene transfer applications based on enhanced transduction, reduced\r\nprevalence of neutralizing antibodies, and diminished capsid immune responses. In a\r\nlandmark clinical trial, hemophilia B was successfully treated with an AAV8 human factor\r\nIX expressing vector. Notwithstanding significant progress, clinical experience with these\r\ntechnologies remains very limited and many unanswered questions warrant further study.\r\nTherefore, the field should continue to progress as it has over the past decade, cautiously\r\nand diligently....
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