Ruxolitinib alleviated muscle atrophy in cancer cachexia by inhibiting IL-6/JAK/STAT3 signaling pathway in mice

OBJECTIVES: Ruxolitinib (Rux), an oral Janus tyrosine Kinase (JAK) tyrosine kinase inhibitor, has demonstrated anti-inflammatory properties and the ability to mitigate denervation-induced skeletal muscle atrophy. Here, we checked the potential efficacy of Rux on cancer cachexia and tried to clarified its mechanisms. METHODS: The in vitro cell models of C26 or LLC CM-induced C2C12 myotubes were used to check the influence of Rux on myotube atrophy. C26 tumour-bearing mice (male BALB/c mice) were applied as the animal model to examine the effects of Rux in attenuating cachexia symptoms. Western blot analysis was utilized to investigate the potential mechanisms of Rux. KEY FINDINGS: Rux significantly attenuated C2C12 myotube atrophy in vitro. Rux suppressed the interleukin-6 secretion by inhibiting STAT3 activation in tumour cells and macrophages. The administration of Rux prevented body weight loss and muscle wasting in C26 tumour-bearing mice without affecting tumour growth. At the end of the experiment, mice in the Rux treatment group exhibited a 6.7% increase in body weight compared to the C26 model group. Furthermore, Rux enhanced in gastrocnemius myofibres cross-sectional area and grip strength. CONCLUSIONS: Rux ameliorates cancer cachexia muscle atrophy by inhibiting STAT3/Atrogin-1 signaling. Rux may represent a promising therapeutic candidate for the treatment of cancer cachexia.