Experimental approach:
The expression of HSP90 and the activation of STAT3 were detected in
muscle from the patients with cancer cachexia or the tumour-bearing
cachectic mice. HSP90 inhibitors, including 17DMAG and PU-H71, were
administered to cachexic mice, and cachexia parameters, such as weight
loss, food intake, survival rate, body mass composition, serum
metabolites, muscle wasting pathology and catabolic activation, were
measured and analysed. The in vitro coculture of C2C12 myotube cells
with C26 conditioned media (CM) was performed to address the
pathological mechanism of catabolic muscle wasting. The roles of HSP90,
STAT3 and FOXO1 in myotube atrophy were explored via overexpression or
knockdown.