On the 9th of May, we had the pleasure of attending Spotlight on Couples in Biomedical Science hosted by the Convergence Science Network with keynote speakers Associate Professor Sarah Jane Dawson and Professor Mark Dawson from the Peter MacCallum Cancer Centre. Both Sarah Jane and Mark are leading experts in the field of cancer research but with different research focuses. Associate Professor Sarah Jane Dawson is involved in the development of ‘liquid biopsy’, while her partner, Professor Mark Dawson's expertise is in the development of drugs for epigenetic therapy treatment.
There is a growing trend towards minimally invasive medical procedures to help treat cancer patients. One of these innovations is the development of a non-invasive biomarker known as a ‘liquid biopsy’. Unlike traditional tissues biopsy techniques the liquid biopsy uses the patient's blood sample reducing the complication, time and inconvenience for patients. Tumour cells are known to shed fragmented DNA as circulating tumour DNA (ctDNA) into the bloodstream. As shredded ctDNA differs from one tumour region to another using a liquid biopsy, it can better inform doctors about the profile of that particular tumour region and provide clues about which treatments are most likely to work for that patient. The process involves applying the biomarker to a sample of a patient's blood and then analysing the results.
Associate Professor Dawson noted the biggest benefit of liquid biopsies is their potential to detect disease progression or treatment resistance long before it would trigger clinical symptoms or appear on imaging scans. This can also eliminate the ‘one size fits all’ model of patient management and move towards a personalised treatment plan for each cancer patient.
Until recently, scientists thought genetic mutations played a bigger role in cancer risk than epigenetic changes to our DNA. However, it has become widely accepted that epigenetics potentially plays an equal if a not bigger role in cancer than genetic mutations. The difference between genetic mutations and epigenetic changes is simple and complex. In the simplest terms, genetic mutations involve actual changes in our genetic code, while epigenetic changes do not alter our DNA, but rather the expression of our DNA. Our DNA is the same throughout our bodies - but a skin cell expresses very different genes to a liver cell.
An epigenetic change is a normal and natural process, but it is affected by age, environment, lifestyle, disease state and toxic exposure. In our cells, DNA is bundled into a structure known as chromatin, which acts a little like bubble wrap, in which proteins called histones enclose, compact and protect it, exerting a significant influence on genes’ behaviour. Histones serve as a beacon for genes to be turned on or off. Professor Dawson explained that once a stem cell has chosen a pathway to becoming a particular cell in the body, it is not permanently set. The cell can be manipulated to reverse the process and encouraged to take a different pathway.
The power of epigenetics to tackle cancer-causing gene mutations is in using these processes to reverse a cell’s decision. This can be done by identifying genes have gone awry and targeting the epigenetic proteins with drugs to force that cell to take a different pathway. Professor Mark Dawson’s research adds to his partners and now sees epigenetic drugs as central to any cancer treatment - by themselves unlikely to overcome cancer - but powerful when used together with other therapies like chemotherapy and immunotherapy (where the body’s own immune system is turned on to attack cancer cells).
Both Associate Professor Sarah Jane Dawson and Professor Mark Dawsons research and findings give us great insight into the latest innovations in biomedical science. And it is hopeful that soon these two different processes can become advanced enough to be used in clinical trials before moving further into mainstream cancer treatment. With this, hopefully, the future will change for many cancer patients.
written by Philbert Lay