Recombinant DNA comprises DNA molecules from one or more sources that are combined to produce a new protein. This new recombinant protein may function as a substitute for human proteins that are difficult to isolate in large quantities, explains the Department of Life Sciences and Institute of Genome Sciences at Taiwan's National Yang-Ming University. Recombinant proteins, produced in sufficient quantities, offer therapeutic benefits for several health disorders and are less likely to cause an adverse reaction than similar proteins isolated from other species.
Insulin
Diabetes is a disease marked by your body's inability to produce enough insulin, a protein necessary for glucose metabolism. Treatment for diabetes historically included daily injections of cow or pig insulin, which sometimes resulted in an immune response in diabetic patients against these foreign proteins, according to Indiana University-Purdue University at Indianapolis. In 1978, scientists at Genentech cloned the human insulin gene using recombinant DNA technology, and in 1982, the Food and Drug Administration approved human recombinant insulin as the first-ever recombinant protein drug therapy. Today, diabetics commonly manage their disease with the use of human recombinant insulin.
Erythropoietin
Erythropoietin, also known as EPO, is a protein produced by your kidneys that increases the generation of red blood cells in your bone marrow. Kidney failure may result in decreased manufacture of EPO, leading to anemia, and recombinant EPO treats this type of anemia. Additionally, some athletes illicitly use recombinant EPO in "blood doping," states Mark Jenkins of Rice University. This type of performance enhancement increases red blood cell volume, allowing greater oxygen capacity in the blood, which may lead to improved performance. Besides being illegal, however, use of EPO as a performance enhancer increases an athlete's risk of stroke and dehydration due to greater viscosity, or thickening, of the blood.
Human Growth Hormone
Adults may suffer from a human growth hormone deficiency when pituitary or hypothalamus tissue is destroyed either by cancer or by cancer treatments such as radiation or surgery. Symptoms of growth hormone deficiency in adults include a shift in body composition with a loss of lean muscle mass and an increase in body fat, cardiovascular and lipid metabolism problems, changes in bone density and psychological issues. Recombinant human growth hormone therapy in these patients reverses these symptoms when administered in low doses, explains Dr. Steven Grinspoon of the Neuroendocrine Clinical Center at Massachusetts General Hospital. While the long-term effect of recombinant human growth hormone replacement requires further study, this therapy shows promise for adults with compromised pituitary or hypothalamus tissue.
References
- National Yang-Ming University Department of Life Sciences and Institute of Genome Sciences: Recombinant DNA and Gene Cloning
- Indiana University-Purdue University at Indianapolis Department of Biology: Controlling Diabetes: Recombinant Human Insulin
- Rice University SportsMedWeb: Erythropoietin
- "The New England Journal of Medicine"; Tainted Glory--Doping and Athletic Performance; Timothy D. Noakes, M.D., D.Sc.; August 2004
- Massachusetts General Hospital Neuroendocrine Clinical Center: Advances in Recombinant Human Growth Hormone Replacement Therapy in Adults
