Using Modified Dna Inserted From An Organism With A...

Gene therapy is a rapidly developing technology first used in 1990.1 It involves the use of modified DNA inserted into an organism with a missing or mutated sequence. There are two methods of delivering this correction into the patient’s cells. In the viral method, a virus containing the vector with the corrected form of the gene, infects the cell naturally. Adenoviruses, adeno-associated viruses, lentiviruses, and retroviruses can all be used. They each utilize a different method of delivery and form of DNA. Adeno-associated viruses and lentiviruses are the easiest forms to construct.2 The corrected DNA faces many obstacles to gene expression and ultimately protein production. The viruses must target and enter the correct cell, avoid†¦show more content†¦Until the understanding of nucleases such as zinc finger nucleases was improved, gene therapy mainly focused upon single gene disorders that required a protein to be produced. With the discovery of nucleases, researc hers were then able to first target genes in order to disrupt the mutations and then correct them. The more successful delivery method utilizes a double stranded break in order to get the corrected sequence to be incorporated. This is called homologous recombination. Non-homologous recombination is when the double stranded break is made and then allowed to crash back together. It can be used to knock-out unwanted genes or for disease models and HIV therapy.2 Although there is a lot of potential for the field of gene therapy, there are some disadvantages that can make its use dangerous or ineffective. The disruption of a gene can be induced in an undesired location within the DNA sequence. Without more targeted techniques such as zinc finger nucleases or emerging technologies such as TALENs or CRISPR, it is difficult to foresee where the breaks will occur. For example, lentiviruses can randomly integrate into TSS or transcription start sites that code for oncogenes that cause cancer. Disrupting or activating unknown genes is a dangerous game. TALENs and CRISPR are emerging methods that are helping to appease these problems. With the development and improvement of gene therapy, further applications have been discovered and attempted. In particular, gene