Gene Therapy Essay, Research Paper

Gene therapy offers a new treatment paradigm for curing human disease.

Rather than altering the disease phenotype by using agents who interact

with gene products, or are themselves gene products, gene therapy can

theoretically modify specific genes resulting in disease cure following

a single administration. Initially gene therapy was envisioned for the

treatment of genetic disorders, but is currently being studied in a

wide range of diseases, including cancer, peripheral vascular disease,

arthritis, neurodegenerative disorders and other acquired diseases.

Even though the range of gene therapy strategies is quite diverse,

certain key elements are required for a successful gene therapy

strategy (i.e. cloning). The most elementary of these is that the

relevant gene must be identified and cloned. Upon completion of the

Human Genome Project, gene availability will be unlimited, but until

then the starting point for any gene therapy strategy remains gene

identification and cloning for relevant genes related to the disease.

Once the gene has been identified and cloned, the next consideration

must be expression. Questions pertaining to the efficiency of gene

transfer and gene expression remain at the forefront of gene therapy

research. Currently many debates in the field of gene therapy revolves

around the transfer of desired genes to appropriate cells, and then

obtaining sufficient levels of expression for disease treatment.

Hopefully, future research on gene transfer and tissue-specific gene

expression will resolve these issues in the majority of gene therapy

protocols. Other important considerations for a gene therapy strategy

include a sufficient understanding of the pathogenesis of the targeted

disorder, potential side effects of the gene therapy treatment, and

understanding of the target cells to receive the gene therapy.

Gene transfer vector is the mechanism by which the gene is transferred

into a cell. Currently there are at least 150 clinical gene therapy

protocols worldwide. Since the approval process for these protocols is

not as public outside the U.S., it is difficult to obtain an exact

number of worldwide protocols. Of the publicized protocols, 125 are

approved in the United States, 48 in Europe and at least 1 each in

China and Japan. As of 31 December 1995, 1024 patients had been treated

in either a gene transfer or gene therapy protocol. Much controversy

exists regarding how many of these have benefited from their gene

therapy, and no one has yet been cured.

Public controversy in the field of human gene therapy is driven by

several factors. Ordinary citizens as well as scientists easily

understand the enormous potential of gene therapy, but the former may

not appreciate all the pitfalls and uncertainly that lies in the

immediate future. The financial interests of biotechnology firms and,

some have asserted, the career interests of some gene therapists have

encouraged extravagant, or at least overly optimistic, public

statements about contemporary gene therapy. In spite of the

proliferation of protocols, the actual number of patients treated

remains small, and only one genuinely controlled study of human gene

therapy has been published as of this date.

References:

Anderson WF. Human Gene Therapy. 1995; 6:1505-1506.

Lyon J and Gorner P. Altered fates: Gene therapy and the retooling of human life. (New York: W.W. Norton) 1995; 1-569.

Mulligan RC. The basic science of gene therapy. Science 1993; 260: 926-932.

Wolff J A and Lederberg J. A history of gene transfer and therapy. Chapter 1 in Wolff JA, editor, Gene therapeutics: Methods and applications of direct gene transfer. (Basel: Birkhaeuser) 1994; 3-25.

Report and Recommendations of the Panel to Assess the NIH Investment in

Research on Gene Therapy Available at:

http:/www.nih.gov/news/panelrep.html