Fig. 7

LIF promotes cancer-induced muscle wasting through the JAK/STAT and MAP-kinase pathways. A LCM induces catabolic response in C2C12 myotubes. C2C12 myotubes were treated with a conditioned medium of LLC cells for 48 h. The protein involved in catabolic response were evaluated by western blotting. Data (n = 3) were analyzed by Student’s t-test, *P < 0.05; **P < 0.01; ***P < 0.001. B LIF is elevated in C2C12 myotubes. C2C12 myotubes were treated as described in A. The mRNA level of LIF in C2C12 myotubes was determined by using qRT-PCR analyses. Data (n = 3) were analyzed by Student's t-test, ****P < 0.0001. C LIF and its signaling pathway is activated in C2C12 myotubes. C2C12 myotubes were treated as described in A. The protein involved in LIF signaling pathways were evaluated by western blotting. Data (n = 3) were analyzed by Student’s t-test, *P < 0.05; ***P < 0.001. D LCM induces C2C12 myotube atrophy. C2C12 myotubes were treated as described in A. Representative immunofluorescence (MHC, red) images of C2C12 myotubes. E LCM induces C2C12 myotube atrophy. C2C12 myotubes were treated as described in A and analyzed for myotube diameter (at 48 h). Data (n = 3) were analyzed by Student’s t-test, ****P < 0.0001. F miR-29c directly targets LIF. C2C12 myotubes were transfected with LIF siRNA and treated with a conditioned medium of LLC cells for 48 h. The protein levels of LIF, atrogin1, and MuRF1 in C2C12 myotubes were evaluated by western blotting. Data (n = 3) were analyzed by Student's t-test, *P < 0.05; **P < 0.01; ***P < 0.001