Gene therapy is a procedure that applies genes to treat disorders, which have hereditary, viral or cancerous origin. Evidence of its humble beginnings can be found in the paper written by Stanfield Roger’s who in 1966 uncovered the ability of Shope rabbit papilloma virus to code for arginase. A mere 10 years later he was administering the virus to children suffering from argininemia “in the hope of replacing their genetically deficient enzymes” (Roger’s, 1976, p66).
As stated by the Lister Hill National Center for Biomedical Communications (2014, Para 1), the three gene therapy approaches currently under investigation are the removal of a mutated gene causing impairment, replacement of a ...view middle of the document...
The mechanism of gene therapy necessitates gene delivery to the correct target cells, with minimal side effects and enduring expression of the inserted gene. In essence the requirements entail secure non-viral vectors which to date, produce unreliable gene transfer. New approaches to gene therapy encompass the use of transposons and the implications of this technology in disease resolution could be immeasurable. Recent studies have been conducted into this very hypothesis.
Transposons, discovered by Barbara McClintock in 1983, can be described as distinct components of DNA, which are capable of movement between various chromosomal locations. They can be arranged in two categories, the first being retrotransposons, which experience transposition through intervening RNA and have the ability to replicate. That is to say, they undergo transcription to RNA, which then goes through the process of reverse transcription to DNA. Retrotransposons are not unlike retroviruses such as HIV, which have also come about via the mechanism of reverse transcription.
The second category is DNA transposons, which as the name precludes, can make their journey undeviatingly, as DNA. DNA transposons transpose via a cut and paste method that makes their participation in gene therapy particularly viable. Their two inverted repeats are bordered by a DNA sequence that encodes a protein. This protein encourages genetic recombination and is known as the transposase.
For many years transposons have been a component of the genetic manipulation of organisms such as plants and insects, whereby their introduction promoted the expression of a desired protein in a dysfunctional cell. Sleeping Beauty (SB) is a DNA transposon that was the first to be applied to vertebrate species inclusive of humans. It is an example of a transposon requiring two direct repeat binding sites. SB was created as a synthetic reconstruct of the Tcl/mariner family of fish, specifically salmonids (Richardson, 2002, p112), and devised by a concurrent sequence of elements derived from fossil transposons that had laid dormant for 10 million years.
In nature, the transposon would have easily moved around the chromosome causing many mutations. This undesirable property was negated by the development of the ‘SB transposon system’ in 1997, consisting of both the transposase and the transposon. The sequence of the SB transposon’s domain was also manipulated to allow hyperactive deviation to occur.
The transposition of Sleeping Beauty allows the duplication of the thymine-adenine (TA) dinucleotide upon cutting. This non-viral plasmid vector incorporates the transgene, which performs the role of the binding site for the transposase. Transposase binds, catalyzes, and then moderates its assimilation into the objective genome. As reported by Fernando et al. (2006, Para 4), it had transposed successfully in both cells and primary tissues during studies in murine somatic tissue, zebra fish, human...