How is Human Insulin Made?

Time Line

In 1973, biotechnology was initiated with the development of the first recombinant DNA microorganism. In 1978, Genentech and the City of National Medical Center successfully produced human insulin through recombinant DNA technology. In 1982, the FDA approved the first recombinant DNA drug, Humulin from Eli Lilly & Co. Human insulin pioneered the biotech industry, and its value among the worldwide community of insulin-dependent diabetics paved the path of the industry to increase quality control standards, improve purification methods and establish more efficient production. The acceptance and clinical benefit of human insulin also cleared the path for development of other biologic medications such as human growth hormone and drugs to treat cancer.

Cadavers

Human insulin has been isolated and purified from the pancreas of human cadavers. The hormone is extracted and crystallized before it is processed in solution for purification, Most human pancreas are reserved for transplantation and this method does not produce a significant yield to be of therapeutic value to the diabetic community. In history, porcine- and bovine-derived insulin from slaughtered pigs and cattle were extracted and purified using the same process because the hormones were similar in structure as human insulin.

Recombinant Human Insulin

DNA segments coding for human insulin were identified, along with the genetic sequence that triggers control within the human body. The DNA of bacteria or yeast are altered with this sequence through recombinant DNA technology. The cells are cultured to produce a pro-insulin which is identical in structure to human insulin. These cells reliably produce insulin in mass quantities which are purified for use in diabetes treatments.

Research

Islet (or beta) cells in the pancreas are responsible for producing insulin. Clinical research is currently underway to promote islet cell production using stem cells. Animal studies were conducted at the University of Pittsburgh using human beta cells which replicated in vivo to produce more insulin-producing cells. These studies signify the breakthroughs in medicine and technology to more fully understand disease and identify solutions.

References

• Genentech: How is Human Insulin Made?
• National Health Museum Resource Center: Transfer and Cloning of the Insulin Gene
• University of Pittsburgh Chronicle: Human Insulin-Producing Cells