One of the hallmark characteristics of many cancers is a debilitating body- and muscle-wasting condition called cachexia, which affects the way the body processes food and absorbs nutrients. New research from the Faculty of Health – overseen by Professor Olasunkanmi Adegoke and PhD student Stephen Mora – looks to better understand the syndrome by asking the question: why do cachectic patients have impaired ability to use nutrients?
Cachexia is caused by cancer itself (notably, the cancers of the lung, liver, pancreas, colon) and/or by treatment like chemotherapy. It results in significant weight loss, especially loss of muscle.
The condition’s associated body wasting is linked to poor food intake and loss of appetite, but even if patients do eat – introducing more nutrients and calories – the cachexia doesn’t go away. The condition not only can lead to poor quality of life for those affected but can impede effective treatment.
Adegoke and Mora’s research, published in the American Journal of Physiology-Cell Physiology, aimed to better understand the hows and whys of cachexia in the hopes of leading to improved treatment for cancer patients.
Their research project studied what happened to skeletal muscle cells, known as myotubes, treated with a clinically relevant chemotherapy drug cocktail. They noted profound atrophy of these cells. A link to poor levels of amino acid – the building blocks for body proteins and therefore the strengthening of muscles – in these cells led the researchers to add amino acids. There was no improvement.
In process, however, they did identify a protein whose abundance was drastically reduced in the muscle cells treated with the drugs. The function of this protein is to transport amino acids into the cell, where they can then be used to make body proteins. Adegoke and Mora then manipulated the muscle cells so they would have high amounts of this transporter. This led to a profound – and promising – rescuing of the cells treated with the chemotherapy drugs.
Adegoke and Mora hope their findings provide data that may lead to the development of interventions that can limit or prevent cancer-associated wasting syndrome.
The research – which was funded by the Natural Sciences & Engineering Research Council of Canada – builds upon Adegoke’s ongoing work, and expertise, in molecular mechanisms regulating skeletal muscle growth and metabolism.