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The breast cancer drug tamoxifen can help at least slow down the hereditary and incurable muscle disease. Researchers from the University of Geneva report with colleagues that the drug has expanded the lives of mice with the disease.
Myotobular myopathy is a serious hereditary disease that affects one of the 50,000 newborns. Genetic malformation causes the muscles to degenerate. In particular, due to respiratory muscle weakness, this rare disease usually leads to death in the first two years of life.
Healing still does not exist, but at least it can slow the progression of the disease: researchers from the universities of Geneva and Strasbourg report promising results in animal experiments with tamoxifen.
Tamoxifen has been used for years in the treatment of breast cancer and has some interesting features in terms of protecting muscle fibers, as announced by the University of Geneva. In a previous study, researchers have successfully tested the drug for its effect on more common muscular dystrophy, Duchenne muscular dystrophy. This concerns one of 3500 boys; Life expectancy is 30 years. Now clinical trials are underway.
Based on these promising early results, the scientists around Leonardo Scopoza also tested the efficacy of tamoxifen in mouse models of myotropic myopathy. The results are reported in Nature Communications.
However, both diseases lead to muscle weakness in different ways: in myopubular myopathy lacks an enzyme called myotubularin. Without it, a protein called 2-D accumulates, causing the muscles to degenerate. Tamoxifen starts with Dynamin 2.
Mice with the same symptoms as infants with myopubular myopathy lived twice the time with the lowest dose tested, with the highest dose even seven times more on average than untreated mice. The highest dose was the equivalent of the mouse organism, which was used for breast cancer.
In addition, the drug slowed the progressive muscle paralysis or even resulted in it stagnation. Muscle strength was also significantly increased by treatment.
Early approach prevents paralysis
The researchers began tamoxifen therapy when the first symptoms appeared in three-week mice. A Canadian research group from Toronto had begun earlier, and mice had not developed signs of paralysis, he wrote at the University of Geneva.
Meanwhile, there are also research efforts to treat serious hereditary disease through genetic therapy. Its effectiveness and safety, however, should take years, doubt the author's hypothesis Olivier Dorchies from the University of Geneva.
Since tamoxifen has been approved for human use, and as clinical trials for Duchenne and muscular dystrophy are already in progress, researchers hope that treatment with tamoxifen will be approved much faster than myotubular myopathy.