Aspects of Human Gene Therapy :: Science Biology Genetic Essays

Aspects of Human Gene Therapy Introduction The prospect of human gene therapy was first realized in 1971 when the first recombinant DNA experiments were planned. Gene therapy can be simply viewed as inserting bits of foreign DNA into a patient’s tissue in hopes of evoking a biologic response that will effectively eliminate the targeted disease. Major advances in recombinant DNA technology have occurred over the last 20 years so that now gene therapy is becoming a reality. Gene therapeutic techniques have recently been attempted to treat patients with the genetic diseases severe combined immune deficiency (SCID), cystic fibrosis, and Duchenne’s muscular dystrophy (Donegan, 1995). The optimist foresees a time when a patient will simply receive a snippet of DNA and go home cured. There are many ethical and scientific hurdles that must first be crossed for such a dream to become reality. The technology has advanced so rapidly that many ethical questions weren’t originally addressed and accordingly are now bec oming the center of attention regarding human genetic research. Furthermore, scientists must find a way to outwit the body’s immune system which is primed to fight any foreign material such as inserted genes. There are also difficulties in getting the targeted cells to open up their molecular locks to allow the foreign genes inside. Gene therapy, like other medical advances before it, will have numerous failures before reaching its full potential. It will be important for the public, press, and medical industry to be patient in waiting for the dream of gene therapy to become a reality. Technological Aspects of Gene Therapy The underlying principle of gene therapy is the transfer of genetic material to specific cells of a patient in an effort to initiate a biological response to fight or eliminate a disease. There are two possible types of target cells, somatic cells that are non-reproducing, or reproducing germ-line cells. If germ-line cells are permanently altered, all future generations would be effected. Most of the current human genetic research involves somatic cells since the ethical ramifications of germ-line cell modification is still being debated. Some scientists have expressed concerns that even altered somatic cell genes could find their way to reproducing, germ-line cells (Donegan, 1995). Accordingly, regulations are strict in regards to somatic cell gene modification techniques so that this gene migration will not occur. Transfer of genes to target cells is usually accomplished by some sort of vector such as retroviruses, adenoviruses, or liposomes (Mulligan, 1993; Crystal, 1995).