It has been claimed that “future medicine will only be based on synthetic DNA (XNA) technology”. Synthetic DNA are proteins that can duplicate synthetic genetic material. It could lead doctors to begin treating diseases by allowing the synthetic genetic material to interfere and prevent vital processes in the course of the disease. In theory, this method could function on all diseases (Sjorgen, 2012).
As a result of initial research, a broad research question “Can synthetic DNA treat diabetes?” was developed under the initial claim. The question was further improved to incorporate the specific treatment and the experimental models to treat diabetes.
Synthetic DNA comes under the broader aspect of synthetic biology. Synthetic biology refers to the construction and design of new standardised biological devices and parts which allows them to perform beneficial functions. Parts are encoded with the assistance of DNA and combined either in living cells or in a test tube. Synthetic DNA is then employed to provide a variety of unique outcomes. Synthetic biology allowed significant medical breakthroughs. For example, in 2017, an advanced immune cell engineering treatment resulted in complete remission rate of 50% in terminally ill blood cancer patients. Also, in 2016, a remission rate of 26% was achieved more. The same technique used for blood cancer patients was recently applied to cure complex breast cancer results (Vickers, 2018). Synthetic DNA chemistry is no longer an obscure discipline without clear practical applications.
On the contrary, synthetic DNA chemistry and its combination with recombinant DNA techniques and molecular cloning have already resulted in valuable products such as somatostatin and insulin (Riggs, 1979). Various studies have used rodents with humanised livers to see if gene therapy decreases blood glucose levels. Gene therapy refers to therapeutic genetic material being transferred to target cells to cure or prevent a certain disease. Thus, the following research question was proposed:
“Can gene therapy treat type 1 diabetes using humanised rodent models to reduce blood glucose levels?”
Background Information
Synthetic DNA can be used to create synthetic insulin, which can assist to better control blood glucose levels in diabetic patients. Type 1 diabetes mellitus (T1DM) is an autoimmune illness whereby the cells in the pancreas are destroyed, which causes an increase in blood sugar in the body. cells are responsible for the production, storage and the release of insulin (Diabetes.co.uk, n.d). cells under physiological conditions synthesise and secrete insulin as a reply to fluctuations in blood glucose levels to achieve homeostasis. Insulin is a requirement for the body as without adequate numbers of working cells, the production of insulin becomes unsatisfactory, and it will be unable to re-establish normal blood glucose levels. As time passes, chronically high blood glucose levels known as hyperglycaemia will have numerous secondary complications. For example, hyperglycaemia would eventually lead to widespread organ and tissue damage as well as an increased chance of death (Handorf, 2016).
For our society, diabetes causes a significant financial burden as the full economic cost of diabetes is approximately $245 billion per year. For T1DM specifically, the expenses are estimated to be $8-14 billion per year, and there is currently no cure available. However, there are several therapies that exist to control blood glucose levels better. For example, synthetic insulin is the most common therapy which typically requires numerous injections per day (Handorf, 2016). Synthetic insulin is the direct result of recombinant DNA technology and was the first golden molecule of the biotechnology industry. It is referred to as a golden molecule as synthetic DNA was created under the golden age of biotechnology. However, synthetic insulin requires multiple administrations and monitoring per day. Millions of diabetics currently around the world use synthetic insulin to control their blood sugar levels. Synthetic insulin is made from both bacteria and yeast. Synthetic insulin is made from bacteria by inserting a -galactosidase on a plasmid. Plasmids are circular, small pieces of DNA that can replicate independently, and it allows investigators to obtain numerous copies of human-made DNA molecules (Gelprin, 2005). The plasmids used also have the tetracycline resistance gene whereby, the plasmids are transformed into bacteria and tetracycline used to kill off any untransformed bacteria. Once the transformed bacteria are grown, the -galactosidase and insulin fusion protein is purified and harvested. Finally, the protein chains are bonded together, and under the correct circumstances, the disulphide bonds form and usable human insulin have been made from bacteria.It was in the mid-1950s when scientists decided to utilise the human insulin gene and create insulin from yeast. Once the proinsulin gene is inserted into a plasmid, the recombinant plasmid is transformed into yeast, and the yeast can now create insulin (DNA Learning Center, n.d.) However, this method is tedious, and it is unable to restore normal glucose control. The current method for treating diabetes is by using gene therapy, which is a promising alternative using synthetic DNA to induce insulin production. As diabetes is caused by insulin deficiency, gene therapy is a viable method to correct insulin deficiency. Efficient gene therapy should have an effective gene transfer system, a supervisory system that is responsible for the expression and release of insulin as a reply to glucose (Yoon, 2002)
Evaluation
There were various limitations with the evidence that conducted gene therapy experiments. For instance, both Tronko et al. and Hashimoto et al. used either mice and rats to conduct their testings meaning that actual human testings have not occurred, thus, suggesting that this method needs to be refined for it to be received by humans. Moreover, both methods use injections meaning that the gene therapy needs to be inserted continually, which will be tedious. In addition, in Table 1, data is not given for every day, and blood glucose levels were only recorded before and after the experiments. As a result, the data is hindered as it is unknown when the gene therapy activated the insulin in the mice.
Even though there were limitations to the conducted experiments, the data and information presented were credible. Table 1 was from a medical journal called the Diabetologia and is credible source as it is a peer-reviewed journal which focuses on the study of biology. The source was written by M. D. Tronko, who is a professor and is an expert in gene regulation, insulin resistance and diabetes drug development. Figure 1 was from Elsevier, which is a famous publishing company that is a major world provider of technical, medical and scientific information. The lead author was Haruo Hashimoto, who is a credible author as he specialises in genetics and biotechnology. Even though human testing has not been conducted, Hashimoto et al. used humanised liver mice to replicate a liver in a human.
Possible extensions for synthetic DNA could be used to treat and cure the Zika virus. Various studies have researched a potential vaccine from synthetic DNA, which was tested in non-primates and mice. Moreover, synthetic DNA can be used to treat HIV by creating an anti-HIV drug.
Conclusion
It can be deduced that diabetes treatment could be based on only synthetic DNA (gene therapy) in future medicine. However, more research and experiments are required to justify this statement as only mice, and rat testing has proved that gene therapy works. Even if diabetes could be treated using synthetic DNA (gene therapy), this does not prove that all future medicine will only be based on synthetic DNA. Not all diseases are associated with DNA, and there are more reliable and cheaper methods of treating these diseases, unlike synthetic DNA treatment.
List of references
Biotechnolgy Innovation Organisation n.d., 'Synthetic Biology Explained', Biotechnolgy Innovation Organisation, viewed 1 August 2019, .
Diabetes.co.uk n.d., 'Beta Cells - What They Do, Role in Insulin', Diabetes.co.uk, United Kingdom, viewed 5 August 2019, .
Gelperin, DM, White, MA & Wilkinson, ML 2005, Biochemical and genetic analysis of the, Capricorn Publishing, n.p., pp. 94-100, viewed 4 August 2019, .
Handorf, A & Sollinger, H 2016, 'Insulin Gene Therapy for Type 1 Diabetes', IntechOpen, viewed 1 August 2019, .
Hashimoto, H 2016, 'Study on AAV-mediated gene therapy for diabetes in humanized liver mouse to predict efficacy in humans', ELSEVIER, viewed 5 August 2019, .
'How insulin is made using bacteria' n.d., DNA Learning Center, viewed 1 August 2019, .
'How is insulin used made using yeast' n.d., DNA Learning Center, viewed 1 August 2019, .
Riggs, A & Itakura, K 1979, 'Synthetic DNA and Medicine', viewed 1 August 2019, .
Tronko, M 2012, 'Experimental gene therapy of type 1 diabetes mellitus: dose-dependent', Diabetologia,
Vickers, C & Small, I 2018, 'The synthetic biology revolution is now - here's what that means', COSMOS, viewed 1 August 2019, .
Yoon, J 2002, 'Trends in Molecular Medicine', ScienceDirect, vol. 8, viewed 6 August 2019, .