David Robert Grimes wears many hats. He has written (and published) on everything from nuclear power to climate change to anti-vaxxers to musical acoustics. “I have about 7 different research interests. I have been described as schizophrenic in my approach to work in that if I find something that interests me, I find the time to do something on it,” says David. He is currently studying oxygen distribution in cancer as a Postdoctoral Research Fellow at Queen’s University Belfast and a Visiting Research Associate at Oxford University. He wants to understand the importance of the oxygen microenvironment to improve cancer therapies, treatments, and outcomes.
The human body has a system to ensure that all tissues that need oxygen have access to an adequate supply, however the same isn’t true when it comes to cancer tissues. Because tumors grow in irregular, uncontrolled ways they have pockets of very low oxygen and very high oxygen. How cancer cells react to radiation therapy is directly proportional to how much oxygen is in their region, making it important to understand where the areas of high and low oxygen are in the tumor. Oxygen is a potent radiosensitizer meaning that areas with high oxygen are three times more sensitive to radiation than areas with low oxygen. “If we had a tumor and we knew that the corner of it had a lot of oxygen but the centre was seriously oxygen deficient, you could deliver three times the dose to get the same cell kill and obliterate the tumor since the centre is radioresistant,” explains David.
Using chemotherapy and radiation therapy it’s possible to aim treatments at very specific sites—as long as you know where those sites are. That’s where David comes in. Although his PhD is in a different area of physics (ultraviolet radiation), the mathematical modelling techniques he learned allow him to work out which areas of the tumor have high oxygen levels. He works with biologists and clinicians to model oxygen levels in tumor spheroids. “I remember when I first started in cancer research I lamented that the tumors weren’t perfect spheres because that would make the maths easier. And one of my colleagues went, ‘we could just grow spheroids,’” says David. A spheroid, like the name suggests, is a sphere of cancer that actually mimic the dynamics of real tumors down to the varying oxygen levels. The spheroids eventually grow so big that the oxygen can’t get into the centre and they become like hollow balls, making them the perfect experimental model.
“My argument is if you understand what’s actually happening, how that oxygen gets out, how it behaves once it’s in tissue, it actually doesn’t matter what shape it is,” David adds. “It’s the same physics that are happening. Once you understand those physics you can then apply them to different situations. I’m trying to minimize the guesswork.” His research can improve treatments, therapies, and also imaging techniques so doctors have a better picture of the underlying structure of tumors.
David also moonlights in public communication of science, working with Sense about Science and writing for the Guardian and the Irish Times. His articles investigate claims and help the public understand current scientific debates. There’s an assumption that the general public knows nothing about science, but David has found this to be untrue. The communications problem rests with the scientists, not the public. “If you can’t explain your idea to an intelligent six year old it’s you that has the communication problem not that your idea is too complicated,” says David. “I say this when I do talks for Sense About Science. You’ll often hear PhD students go, ‘Oh but my research is far too complicated to explain to the media.’ And I just look at them and go, ‘No, it’s not. There’s people in quantum mechanics who can roughly explain their work to the media. If they can, you certainly can!’” David is clearly good at explaining; in 2014, he was awarded the John Maddox Prize for his work to promote science and evidence to the public.
For David, science is a way to make the world a little more beautiful. “The more you understand something the more beauty you see in it, and different levels of beauty,” he says. “You go from just having the aesthetic the world is beautiful to, ‘My god it’s beautiful and look how intricate it is!’ I think that kind of wanting to know why has always driven me.”
David studies oxygen distribution in cancer as a Postdoctoral Research Fellow at Queen’s University Belfast and a Visiting Research Associate at Oxford University.