5.15–5.18: Biotechnology has the potential for improving human health (and criminal justice).

In 1996, Dr. Ian Wilmut created a sheep named Dolly, the first mammal to be cloned from an adult somatic cell.

You can’t always get what you want. In the best of all worlds, biotechnology would prevent debilitating human diseases. Next best would be to cure diseases once and for all. But these noble goals are not always possible, so biotechnology often is directed at the more practical goal of treating diseases, usually by producing medicines more efficiently and more effectively than they can be produced with traditional methods. Biotechnology has had some notable successes in achieving this goal. The treatment of diabetes is one such success story.

Type 1 diabetes, often called juvenile diabetes, is a chronic disease in which the body cannot produce insulin, a chemical that allows cells to take up and break down sugar from the blood. Type 2 diabetes, which accounts for 90% of all cases of diabetes, is a metabolic disorder in which blood sugar levels rise higher than normal as a result of insulin resistance and insufficient insulin production. Complications from both types of diabetes can include vascular disease, kidney damage, and nerve damage. Approximately one-third of all people with diabetes (including the vast majority of those with type 1 diabetes) treat their condition with one or more daily injections of insulin. As recently as 1980, the insulin that most diabetics used was extracted from the pancreas of cattle or pigs that had been killed for meat. For most people, these insulin injections kept the disease under control. But the traditional process of collecting insulin this way was difficult and costly.

Everything changed in 1982, when a 29-year-old entrepreneur, Bob Swanson, joined scientist Herbert Boyer to transform the potential of recombinant DNA technology. In doing so, they started the biotech revolution. Working with the scientist Stanley Cohen, Swanson and Boyer used restriction enzymes to snip out the human DNA sequence that codes for the production of insulin. They then inserted this sequence into the bacterium E. coli, creating a transgenic organism. After cloning the new, transgenic bacteria, the team was able to grow vats and vats of the bacterial cells, all of which churned out human insulin (FIGURE 5-38). The drug could be produced efficiently in huge quantities and made available for patients with diabetes. This was the first genetically engineered drug approved by the U.S. Food and Drug Administration and it continues to help millions of people every day.

Figure 5.38: Lifesaving insulin. Human insulin is engineered through recombinant DNA technology.

Perhaps even more significant than providing a better source of insulin, Swanson, Boyer, and Cohen’s application of biotechnology revealed a generalized process for genetic engineering. It instantly opened the door to a more effective method of producing many different medicines to treat diseases. Today, more than 1,500 companies work in the recombinant DNA technology industry, and their products generate more than $40 billion in revenues each year.

Several important achievements followed the development of insulin-producing bacteria. Here are just two examples.

1. Human growth hormone (HGH). Produced by the pituitary gland, human growth hormone has dramatic effects throughout the body. It stimulates protein synthesis, increases the utilization of body fat for energy to fuel metabolism, and stimulates the growth of virtually every part of the body (FIGURE 5-39). Insufficient growth hormone production, usually due to pituitary malfunctioning, leads to dwarfism.

Figure 5.39: Bulking up with a little (illegal) help.

When treated with supplemental HGH, individuals with dwarfism experience additional growth. Until 1994, however, HGH treatment was prohibitively expensive because the growth hormone could be produced only by extracting and purifying it from the pituitary glands of human cadavers. Through the creation of transgenic bacteria, using a technique similar to that used in the creation of insulin-producing bacteria, HGH can now be produced in virtually unlimited supplies and made available to more people who need it.

The availability of HGH, which can increase strength and endurance, may be irresistibly tempting to some people (who don’t need it for medical reasons)—even at $7,500 for a month’s supply. Recent sporting scandals suggest that the illegal use of HGH occurs frequently among elite swimmers, cyclists, and other athletes.

2. Erythropoietin. Produced primarily by the kidneys, erythropoietin (also known as EPO) is a hormone that regulates the production of red blood cells. Numerous clinical conditions (nutritional deficiencies and lung disease, among others) and treatments (such as chemotherapy) can lead to anemia, a lower than normal number of red blood cells, which reduces an individual’s ability to transport oxygen to tissues and cells. This lack of sufficient oxygen, in turn, can cause a variety of symptoms, including weakness, fatigue, and shortness of breath.

First cloned in 1985, recombinant human erythropoietin (rhu-EPO) is now produced in large amounts in hamster ovaries. It is used to treat many forms of anemia. Worldwide sales of EPO are in the billions of dollars.

EPO has been at the center of several “blood doping” scandals in professional cycling. This hormone increases the oxygen-carrying capacity of the blood, so some otherwise healthy athletes have used EPO to improve their athletic performance. It can be very dangerous, though. By increasing the number of red blood cells, the blood can become much thicker, and this can increase the risk of heart attack.

Beyond these and other medicines currently produced by transgenic organisms, plans are under way to create a variety of other useful products for treating disease—including potatoes that produce antibodies enabling a more effective response to illness. In the next section we examine the strategies for preventing genetic diseases, and the much less successful attempts to cure diseases through biotechnology.