Up to 80 percent of people with cancer lose a lot of fat and muscle mass. This is also called cachexia. A research group at Hannover Medical School has discovered how inflammatory cancer messengers first disrupt the function of muscle cells and ultimately cause them to die completely.
Messenger substances change muscle cells
The researchers were able to show that the messenger substances intervene directly in the metabolism of the muscle cells and actively change the muscle cells. They also ensure that muscle cells release less calcium. However, calcium is essential for the contraction of muscle cells and thus for muscle function and strength. This also often affects the heart muscle, which further weakens those affected.
Why muscles lose their strength
In experiments with muscle cells from mice and rats, it was found that the internal structure of the muscle cells was disrupted by the messenger substances. This particularly affects the smallest functional units of the muscle, called sarcomeres. “We observed a dramatic loss of striated muscle cell contraction in cancer-induced cachexia, which was primarily due to acutely disorganized sarcomere structures and impaired calcium transport,” said scientist Dr. Arnab Nayak in a statement for publication. In addition, proteins that were actually needed are broken down in the muscle cells. This caused the muscle cells to slowly be destroyed.
A possible new therapeutic approach
So far, attempts have been made to slow down muscle loss with nutritional supplements, training and medication. The research group specifically modified a signaling pathway so that two important proteins remained active in the cells. “In our study, we upregulated SENP3 and SENP7 and observed a decrease in muscle loss,” reported Nayak. This meant that the muscle cells remained functional. Whether this method also works in the body will now be tested in animal experiments.
Those: DOI 10.1002/jcsm.13776
