The well-known drug aspirin has, in recent years, attracted considerable research interest, in light of its promising cancer-preventive effects. Widely used to treat inflammatory pain (such as headaches) and prevent post-operative thrombosis in patients recovering from heart disease (due to its blood-thinning properties), aspirin has also been shown to lower the incidence of common bowel cancers by at least a third, if prescribed in small daily doses over the span of at least five years.
Aspirin can lower cancer incidence partly by reducing inflammation and also by causing early-stage cancer cells to destroy themselves via programmed cell death, prior to tumour formation. The mechanisms by which aspirin selectively kills early-stage cancer cells, but not healthy cells, are not fully understood. Indeed, unearthing these elusive mechanisms has long been the scope of research carried out in our Yeast Molecular Biology and Biotechnology Laboratory, headed by Professor Rena Balzan, through the use of tiny, single-celled organisms known as yeast.
Baker’s yeast has long been recognised as an important experimental model for studies of disease and potential drug therapies, since it boasts several advantages for research and exhibits the same basic structural and functional features of human cells. In fact, in our lab, yeast cells have proved themselves very useful to study cell death mechanisms triggered by aspirin, so as to acquire better understanding of its cancer-preventive effects.
Our past work has already shown that, in mutant yeast cells with low tolerance to oxygen-associated stress (much like early-stage cancer cells), aspirin causes numerous forms of critical damage to the cellular power-generators known as mitochondria, resulting in cell death. Our ongoing research, currently financed by the Malta Council for Science & Technology, through the R&I Technology Development Programme (Project R&I2015001), has underlined even further mechanisms of how aspirin causes the lethal operational shutdown of mitochondria in stressed yeast cells. Essentially, in these cells, aspirin halts production of a metabolic compound that is critical for energy production, and its transport to the mitochondria. Starved of this fuel compound, mitochondria can no longer operate to produce energy needed for cell survival, consequently shutting down and causing cell death.
These findings reinforce the role of mitochondria as critical targets of aspirin in stressed yeast cells, but not in normal healthy cells, and suggest that aspirin may behave similarly in early-stage cancer cells. This should provide further insight into aspirin’s cancer-preventive mechanisms and contribute to the design of more effective cancer chemotherapies in the future.
Gianluca Farrugia is a post-doctoral researcher at both the Centre for Molecular Medicine and Biobanking, and the Department of Physiology and Biochemistry, University of Malta.
Did you know?
• At least half of Earth’s Oxygen comes from the ocean, not trees. Tiny aquatic plants called phytoplankton live near the surface of the water, drift with the currents, and generally do what plants do – make oxygen as a byproduct of taking in sunlight and carbon dioxide.
• Hot and cold water sound different when being poured. It’s actually noticeable to the human ear if you pay attention. Water changes viscosity (aka its thickness or stickiness) depending on temperature. Long story short, the colder the water, the higher the pitch, whereas pouring something hot like, oh, say..coffee...is going to have a lower, more comforting pitch.
• There are animals and plants considered to be ‘Biologically Immortal.’ While they can and do die, this is due to injury or disease. They don’t really age (at least not in the sense of breaking down) and won’t die from old age. Jellyfish and Lobsters are two examples of this.
For more trivia see: www.um.edu.mt/think
• Sixty-six million years ago, the world burned. An asteroid crashed to Earth with a force one million times larger than the largest atomic bomb, causing the extinction of the dinosaurs. But dinosaurs were not the only ones that got hit hard — in a new study, scientists learned that the planet’s forests were decimated, leading to the extinction of tree-dwelling birds. “Looking at the fossil record, at plants and birds, there are multiple lines of evidence suggesting that the forest canopies collapsed,” says Regan Dunn, a paleontologist at the Field Museum in Chicago and a co-author on the study in Current Biology. “Perching birds went extinct because there were no more perches.”
• The hotter our body temperature, the more our bodies speed up a key defence system that fights against tumours, wounds or infections, new research by a multidisciplinary team of mathematicians and biologists from the Universities of Warwick and Manchester has found. The researchers have demonstrated that small rises in temperature (such as during a fever) speed up the speed of a cellular ‘clock’ that controls the response to infections – and this new understanding could lead to more effective and fast-working drugs which target a key protein involved in this process.
• To find out some more interesting science news, tune in Radju Malta on Saturday Mornings at 11.05 am and listen to “Radio Mocha”.
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