Human Gene Therapy - The

Human Gene Therapy - the Molecular Band-Aid What is gene therapy? How does it work? Clinical Trials Recent Developments Concern for the Future. The key to Gene Therapy, according to Kay Crabtree, is in targeting the right cells. The areas that science has discovered gene therapy a possibility in science for are in the area of genetic disorders, cancer, peripheral vascular disease, arthritis and neurodegenerative disorders.

Genetic engineering began in 1932 at the 6th International Congress of Genetics focusing on plants and animals, according to Crabtree and the decade of the 1960's saw the establishment of Gene Transfer, a process of inserting cultured cells through aid of viral vectors. The decade of the 1970's transfection into cultured cells with recombinant DNA began and by the 1980's Retroviral vector transfer came into being which increased the efficiency in transfection. 1990 was the year that the first human trial was performed using Gene Therapy.

Not only is the targeting of the correct cells key in the process of Gene Therapy but also vital is the activation of the gene in order to gain a look into the gene itself as well as integration of the gene in order that the gene will replicate and stay put in the cell. Finally, the avoidance of harmful side effects of toxicity, cell death, tolerance by the cell or even organism death must be minimized as much as scientifically possible.

Crabtree also reviewed the vectors used in the transfer are those of the "Viral Vectors" which are the: "Retrovirus" "Adenovirus" "Adenoassociated" and the "Herpes Simplex" virus. Lipsomes as well as the Non-Viral Vectors. The question is asked by Crabtree, " What is a dominant negative mutation? The Answer: A mutated gene produces a mutated protein that blocks the function of a normal protein. Of this there are two types: Splicsome mediated - the delivery of RNA (a Repair Method) a.

Strand that pair specifically with the intron next to the mutated segment of mRNA and leaves the correct strand. b. Simultaneous delivery of a correct version of the segment to replace the mutated piece in the final RNA product. Translation of the repaired mRNA to produce the normal functional protein. Triple Helix-Forming Oligonucleotide: Oligonucleotides that bind the double strand of the mutated gene's DNA and actually forms a triple strand that blocks the mutation.

Antisense Technology is used to turn off a mutated gene in a cell by targeting the mRNA transcripts copied from the gene according to Crabtree. Further discussed in the role of Ribozymes (RNA enzymes). It is possible to have delivery of RNA strand that has been engineered to function as ribozymes to the cell, the RNA is encoded by a mutated gene preventing it from being translated into protein. Small interfering RNA (SIRNA).