Genetic engineering has affected many fields over the last few decades
Genetic engineering has affected many fields over the last few decades, and the medical field and human health have been affected greatly. Recombinant DNA technology, genetic engineering, and other genetic techniques are complex processes which have led to a better understanding of gene expression or inheritance, treatment of various genetic disorders, and a more efficient production of medicines and biopharmaceuticals. Since the discovery of recombinant DNA (rDNA), there have been multiple vaccines, proteins, and other medicines manufactured impacting human health greatly. Advancements and research in these fields will continue to create medicines that can benefit all human health all over the world. According to the Center of Disease Control and Prevention more than 100 million people in the United States have either diabetes or prediabetes (CDC 2015). This one disease affects nearly a third of the population of Americans, and genetics created a method of effective production to help and impact these patients. Genetics impacts the production or discovery of many other synthetic hormones, vaccines, and genetic tests. The future of medicine and pharmaceuticals will continue to be impacted and advanced with the help of genetic engineering, but medicine was one of the first fields to be impacted by a genetic discovery.
The mass production of insulin through recombinant DNA has impacted millions of human lives around the world and is another important advancement in medicine. This breakthrough proved that the process can be used to create a functioning human protein more effectively and cheaper than previous methods. Patients with diabetes have an abnormally high blood glucose level either due to problems related to insulin production or resistance. There are two types of diabetes mellitus conveniently named diabetes type 1 (DMI) and diabetes type 2(DMII). Patients with type 1 diabetes do not produce insulin and type 2 the body does not make or use insulin well (medlineplus.gov/diabetes.html). Chronic Hyperglycemia can negatively affect many tissues and organs including but not limited to: retinopathy, neuropathy, nephropathy, macrovascular disease, hypertension, and bone and joint diseases (Kawahito, Kitahata, Oshita, 2009). The mechanism of this disease is hypothesized to be due to oxidative stress due to free radicals which is supported by many different researchers (P. Robertson 2003). This disease, particularly DMII, has become a major comorbidity especially in the United States where obesity has become more prevalent. Prior to recombinant insulin, insulin was extracted and purified from pigs and cows. This was a costly and ineffective technique to obtain insulin. The amount of insulin that could be extracted from these animals required the deaths of many animals for a small amount of insulin. According to Biologydiscussion.com, harvesting enough insulin for one diabetic patient for one year required the killing of about 70 pigs (2015). The insulin extracted from pigs and cows differed in structure by a few amino acids which didn’t affect the function, but the difference caused some patients to develop an allergy. The fact that it was largely ineffective and potentially harmful created a need for a more efficient method of creating insulin. With the discovery of recombinant DNA, bacterial gene transfer, lac operon structure, and restrictions enzymes; scientist began attempts to create recombinant insulin. Biologydiscussion.com describes the technique for production of recombinant DNA in a simplified, but concise manner (2015). The technique relied upon the insertion of the human insulin gene onto the lactose operon plasmids which were inserted into recombinant E. Coli bacteria. The technique used today has been changed slightly to increase efficiency, but largely remains the same. The older technique used the lac operon system with inducer, promoter, operator and lac-Z gene for beta-galactosidase (B-gal), and the insertion of two separate genes for an insulin A chain on one plasmid and B chain onto a plasmid that is inserted into an E coli. bacterium. The human insulin gene is isolated and sequenced as two different polypeptides by identifying the start and stop codons. The gene to produce human insulin is mapped and is chemically synthesized as A and B polypeptides. The anti-codon for methionine is placed at the beginning of each chain to allow the removal of the insulin protein from the bacterial cell’s amino acids. The A and B polypeptides are inserted onto two separate vectors (commonly plasmids) containing the lac operon. The insulin genes are inserted into the plasmid with the use of restriction enzymes to cut the plasmid at specific points, and then a ligase enzyme is used to rejoin the plasmid. These plasmids are inserted into two different E. Coli bacterium. Upon the insertion of the plasmid into the bacterium, the bacterium is then called recombinant E. Coli. The recombinant E. coli bacterium with the plasmid containing the human insulin gen and lac operon are transported onto two separate mediums. Both mediums are supplemented with lactose but no glucose. One medium contains the insulin A chain and the other medium the insulin B chain. The lactose in the medium is catalyzed by lac-Z gene (B-gal) creating monosaccharides including allolactose creating a positive feedback loop for the lac operon. The lac operon is activated further, and the protein formed consists partly of Beta galactosidase joined to either the A or B chain of insulin. The chains are separated from the B-gal fragment and purified. The two chains are mixed and reconnected by the disulfide cross bridges. The resulting protein is pure Humulin, or synthetic human insulin (biologydiscussion.com, 2014). These bacteria are produced on a large scale in a fermentation tank with lactose readily available. The recombinant bacteria which produce insulin are easy to handle, grow rapidly, and are easily amendable (N. Baeshen et al. 2014). There are other vectors and suitable hosts being explored to increase efficiency and production further. Diabetes has become a global problem due to dietary and lifestyle changes. The World Health Organizations estimates a dramatic increase from $12 billion to $54 billion dollars of insulin sales globally (N. Baeshen et al. 2014). This increase in demand has created the search for alternative methods of delivery and production. The current manufacturing supplies most likely will not be sufficient to meet the growing demand if the estimate is accurate. Genetic engineering of recombinant insulin production has saved millions of lives and remains one of the most significant pharmaceutical breakthroughs in medicine. The break throughs in production have driven down cost as well as created insulin production that can meet the current population demand. Genetic Engineering created a suitable method of production for these patients in the past and remains a viable solution to the problems of insulin production of the future.
Another breakthrough in medicine that has affected millions of lives is the creation and production of recombinant tissue plasminogen activator (tPA). The human body normally forms clot (coagulation) to prevent death from bleeding. There is a complex and dynamic system involving many steps termed the coagulation pathway. Usually the body forms a clot in response to an injury in a blood vessel, and when the vessel is healed the clot is absorbed by the body. When the coagulation cascade is initiated due to trauma to the vessel, a parallel system is also activated to limit the size of the clot (Palta, Saroa, & Palta, 2014). There can be several different reasons why the clot does not dissolve and propagates or accumulates inducing a life-threatening problem if not resolved. The CDC estimates about 2.5 million people in the United States are affected by clots in the brain, heart, or periphery (CDC.gov, 2018). These can lead to stroke, myocardial infarction (heart attack), deep vein thrombosis (DVT), or pulmonary emboli (PE). Stroke and ischemic heart disease are the two leading causes of deaths globally in 2016 according to the World Health Organization (WHO.int, 2018). Tissue plasminogen activator is an enzyme that activates plasmin. Plasmin acts on fibrin and degrades it to dissolve blood clots. This process is a natural protection to protect the heart and brain where clots will restrict flow causing ischemia and cell death. The process of thrombolysis can be inefficient at removing clots especially large amounts of clots. In the 1930’s Dr. William Tillett discovered a thrombolytic agent produced by streptococci bacteria which he named fibrinolysin, later named streptokinase (Sikri ; Bardia, 2007). Dr. Tillett isolated, purified, and tested streptokinase’s ability to dissolve human clot. The enzyme was very specific to the fibrin substrate and efficient at binding and removing the fibrin. This drug was studied and tested to treat a multitude of diseases involving clot formation. The research and testing showed some side effects as well as patients developing an allergy to the drug (Sikri & Bardia, 2007). Research for alternatives and the discovery of rDNA led to the discovery of recombinant tissue plasminogen activator. The production of recombinant tPA differs slightly from the production of recombinant insulin, but the major steps are very similar. Biotecharticles.com provides a simplified summary of the technique to produce recombinant tPA (Uppangala, 2010). The first step is to isolate and produce a complementary DNA (cDNA) molecule to the mRNA of the gene encoding tPA. Both PCR and Sanger sequencing are usually used to isolate the correct sequence and to amplify the cDNA needed to transfer to the plasmid. Once the full-length cDNA is outlined, it is inserted into the plasmid though a restriction enzyme. The transformed mammalian cells are cultured in a media conducive for viable mammalian cells. The mammalian cells that are active for tPA production are isolated and transferred into fermentation tanks for large quantity production. The recombinant tPA secreted in the tank is isolated and purified. Recombinant tPA was the first biotech pharmaceutical product to be produced using mammalian cell cultures (Uppangala, 2010). Recombinant tPA (marketed as Activase or alteplase) has emerged as the only FDA approved thrombolytic to treat acute ischemic stroke and is also indicated by the FDA to treat acute myocardial infarction and acute massive pulmonary embolism (Activase, Genentec, fda.gov, 2015). There is also a “consensus that t-PA was probably better” in younger, more acute, anterior infarctions, or patients who had received streptokinase in the past (Sikri and Bardia 2007). The discovery of a way to produce recombinant tPA has impacted medicine and saved many lives. There are now other thrombolytic agents being made and biosimilar chemical agents being genetically engineered. The production of biosimilar products could lead to an even more effective method of thrombolysis, and with more biosimilar chemicals on the market it will decrease the cost of alteplase.
Vaccines production and development have also impacted millions of lives, and genetic engineering is being used to create more efficient vaccines to a wider array of diseases on the large scale needed. Vaccines are administered to elicit specific antibodies which are either developed by the individual or directly administered. These antibodies create immunity from a specific disease which caused by pathogens. The administration of these vaccines which are either weakened or have been inactivated generate an immune response which then attacks the pathogens if infected after vaccine administration. Small pox was a virulent and deadly disease