Mechanism of Transfer in Gene Therapy
Abstract:
Gene therapy is the transfer of “normal” genes into the body to replace defective or undesired genes. The transfer may be in somatic or germline cells and may take place in vivo or in vitro. The DNA may be inserted in a retrovirus, adenovirus, adeno-associated virus, herpes simplex virus, or liposome, or it may be naked DNA. The vector travels to a target cell and inserts the gene, which goes to the host cell’s nucleus and may integrate into the genome. In cells with dominant negative genes, resulting protein must be prevented from translation or transcription using oligonucleotides or antisense technology. Though many obstacles delay the development of gene therapy, this new field will surely improve the future of medicine.
Mechanism of Transfer in Gene Therapy
Gene therapy is a method of replacing defective or undesired genes in the body with “normal” genes. A vector is re-engineered to deliver the gene to a target cell. Then the gene is transferred to the cell’s nucleus and must be activated in order to function. The gene must be integrated into the cell’s genome in order for it to continue to function and be replicated. Side effects are possible because the vector may be detected as a foreign substance by the body’s immune system. Gene therapy may take place either in vivo or in vitro, the transfer may be in either somatic or germline cells, and a variety of viral and non-viral vectors may be used.
In vivo gene therapy is done inside a living organism. This is accomplished by inhalation, oral administration, intramuscular injection, or intravenous administration (Brooks, 24). Currently, most in vivo experiments have taken place in animals other than humans. Most gen...
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...ocated, ensure that gene therapy will be a revolutionary aspect of medicine’s future.
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There have been four somewhat recent successful gene therapy treatments. The four deal with correcting hemophilia, bone marrow transplants, skin cancer, and vessel growth. In the success with the bone marrow transplants, French researchers collected bone marrow cells from patients, used gene therapy to correct the bone marrow, and then returned the bone marrow to the patient. This was 80% successful as reports 16 months after the transplants showed. Squamous cell carcinoma, skin cancer of the head and neck, was treated using gene therapy as well. The fourth trial was where DNA was used to carry a substance that stimulates blood vessel growth to damaged heart tissue and in this trial there was much success noted.
Gene therapy is an experimental technique that allows doctors to insert a gene into a patient’s cell rather than using drugs or surgery. Gene therapy is a process of which defective or undesired genes in the body with “normal” genes. A vector is re-engineered to deliver the gene to a target cell. Then the gene is transferred to the cell’s nucleus and must be activated in order to function. The main focus of gene therapy is to replace a lost or improper gene with a new functional copy into a vector that is inserted into the subject’s genome by way of penetrating its DNA. Gene therapy can be done outside of the body known as ex vivo by way of taking cells form patients bone marrow or blood and then growing them in a laboratory. Thus the corrected copy of the gene is inserted into the cells before being put back into the body. Gene therapy can also be done in vivo which can be done directly to the patient’s body. The word gene therapy really defines the management of genetic information that is encased in the cells, however, in most recent procedures the available technology is closely related in adding new genetic information, and many researchers favor the term gene transfer rather than gene therapy to mirror the reason that the purpose of gene work cannot always be therapeutic.
Gene therapy, a relatively new innovention, is becoming popular across the country. Gene therapy modifies a part of an organism, whereas cloning creates an entirely recreated organism. This technique can be conducted in vivo in either somatic or germ cells. The process is essentially aimed at fixing a genetic disorder or disease by inserting a functional gene to replace the faulty one (Houdebine 2003). Many methods to conduct a gene transfer have been tested. The two types are in vivo and in vitro. Transferring genes in vivo means placing the functional genes directly into the target tissue; while vitro transfers creates the genes outside of the body, in Petri dishes. Vitro is an expensive process that r...
Gene therapy works by introducing new and functioning genetic material to damaged genes to help it function and to produce beneficial proteins. If a gene is inserted directly into a cell, it usually will not function. So to complete this task, a vector, a modified virus is used to carry and deliver the new gene. There are two different categories of vectors than can be utilized in this process; recomb...
Gene therapy is a technique which has developed in the wake of recombinant DNA (rDNA) technology. It is a process which results in the correction of a genetic disorder by the addition of a piece or fragment of DNA into the genetic material of a living, functioning cell. A mere thirty years ago this concept belonged to the realm of the human imagination made manifest in the works of science fiction. Today it belongs to the realm of the human imagination made manifest in the works of science, period. It is mind boggling to try to comprehend the far reaching effects of gene therapy. How is it affecting society? Who will benefit from its use? Should it be used at all? Should research continue? How do we answer all of these questions? The answers are not readily available, nor are they black and white, but an attempt at finding some solutions must be made. Before exploring this line of thought further, a basic understanding of the technical aspects of gene therapy is essential.
Despite being magical of gene therapy, it is high-risk. Few people got benefits from it, and it has a low rate of success. Prior to the human trial, Batshaw and Wilson had done experiment on animals to ensure the safety. Over 20 experiments have been done on mice but only 12 of them survived at last (Sophia, M. and Kolehmainen, J.D., 2000). More seriously, complicating diseases, which can be more dangerous than genetic diseases, might set in during the treatment period. In December 200...
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Shi, Y., & Zou, M. (2008). Progress in gene therapy research. In J. L. Lewis (ED.), Gene therapy and cancer research progress (pp. 23-130). New York, NY: Nova Science Publishers, Inc.
Gene therapy is a method used by doctors that ‘uses genes as medicine’. It repairs faulty or damaged gene copies by transferring a therapeutic or working gene into specific parts of faulty gene copy. This means that gene therapy can be used to replace a faulty gene or to introduce a new gene whose function is to modify the clinical course of a condition or to cure a problem in the gene (Refer to image 2). Image 1 shows how gene therapy is completed using an adenovirus vector while image 2 explains the method of gene therapy and shows how cells are removed, altered and injected back into the patient. Gene therapy has potential to treat and cure many medical conditions such as various types of cancer, degenerative diseases and viral infections such as AIDS. Research into gene therapy still needs to be done before this approach to the treatment of certain conditions will realise its full potential. Trials are being conducted in the United States and Europe and a modest number initiated in other countries, including Australia. The majority of these trials are focussing on treating acquired conditions such as cancer (European Society of Gene & Cell therapy, 2011).
Since its inception, gene therapy has captured the attention of the public and ethics disciplines as a therapeutic application of human genetic engineering. The latter, in particular, has lead to concerns about germline modification and questions about the distinction between therapy and enhancement. The development of the gene therapy field and its progress to the clinic has not been without controversy. Although initially considered as a promising approach for treating the genetic of disease, the field has attracted disappointment for failing to fulfil its potential. With the resolution of many of the barriers that restricted the progress of gene therapy and increasing reports of clinical success, it is now generally recognised that earlier expectations may have been premature.
5. Leiden, Dr. Jeffrey M. "Gene therapy -- Promises, Pitfalls, and Prognosis." The New England Journal of Medicine 28 September 1995: 871-873.
Gene therapies necessity, stems from the fact that it can cure, life threatening gene based diseases, with minimal after effects. Although there are some ethical and physical issues that can occur through this technology, when comparing it to the other genetic technologies, it’s quite reliable. Although it is in its infancy, the technology has still been present for several years, with the first case of gene therapy being done in 1990. Sure, there have been some complications, but its still a growing technology with a strong future in front of
However, the safety of gene therapy should be carefully considered. First, it may cause angiogenesis, which may trigger nonfunctional vessels or stimulation of angiogenesis in ...
One of the biggest concerns involved in gene therapy in humans is the lack of knowledge and the possibility for consequences later on or i...