Learning cancer resistance from muscles

Physical activity extends the lifespan of cancer patients and correlates with lower incidence of many cancers, but the mechanism of such correlation is still unknown. The concept that a muscle releases bioactive molecules (myokines) is quite new and opens exciting possibilities. Secretion of myokines during physical activity could explain why exercise protects against cancer and halts its progression.

The EU-funded project MUSCLEANDCANCER, carried out in Italy, aims to understand a connection between muscle weight loss and cancer, and to search for novel anticancer molecules from exercised muscles.

Early results describe the elements of the cachexia signalling cascade. Cachexia is a severe body weight loss affecting many cancer patients. A pathway specific to cachectic muscles is being analysed to understand its role during cachexia. Researchers are testing agonists and antagonists for this pathway for their effects against cancer cachexia.

Out of two studies employing in vivo mice models of cachexia, one was very promising. Mice injected with colon adenocarcinoma cells showed cachexia in 9–12 days. The expression of the ligand of the receptor was downregulated, and the inverse agonist of the pathway caused myotube atrophy. The in vivo studies are continuing.

The search for anticancer myokines is ongoing. It aims to understand which kind of exercise (strength and/or endurance) retards tumour growth. Finding the correlation between decreased myokine secretion from atrophying muscles and cancer acceleration would be truly revolutionary. Isolation of anticancer myokines may greatly help cancer patients, especially those that cannot exercise. The project will continue until May 2016.