Protein ubiquitination and fatigue induced by C26. RT-PCR (a) and WB (b) analyses show the upregulation of E3 ligase (Atrogin-1)-mediated protein ubiquitination in the TA of tumor-bearing mice (C26). GAPDH is shown as loading control. c) The functional analysis of the EDL from control (open bar) and C26-bearing (solid bar) mice shows unaltered specific force (i.e. tetanic force normalized by muscle mass) and reduced fatigue time (i.e. time required to halve titanic force upon repeated stimuli) in cachectic muscles. p > 0.05 by Student's t test. The mean ± SEM of two experiments performed in triplicate is shown.