Fig. 4
IGF-1 activates AKT/S6 signaling in tumor cells, depletion of IGF-1 in mice inhibits bone metastasis. a The protein levels of AKT, pAKT (Ser473), S6, pS6 (Ser235/236), IGF-1R and pIGF-1R in 5-8F, 5-8F OE, BM3 sh and BM3 cells cultured in osteoclastic CM with/without IGF-1 neutralizing antibody (IGF-1 NA) and/or recombinant IGF-1 (rIGF-1). b Representative immunostaining images of IGF-1R and S6 phosphorylation and correlation between IGF-1R expression and S6 phosphorylation in the NPC cohort. c IGF-1 expression in bone marrow with/without IGF-1 neutralizing antibody. d Intracardiac injection of 5-8F IGF-1R OE or BM3 into mice with/without IGF-1 being neutralized for bone metastasis analysis. Representative BLIs and analysis of bone metastases. e Representative micro-CT images of femurs. f Micro-CT analyses for bone destruction of femurs. g Representative H&E images and analysis of bone metastases. h Osteoclastogenesis of primary bone marrow cells in mice with/without IGF-1 being neutralized. (Tumor tissue is noted in the red line, “IGF-1 NA” represents IGF-1 neutralizing antibody, “rIGF-1” represents recombinant IGF-1, “IGF-1 -” represents IGF-1 was neutralized, "IGF-1 + " represents IGF-1 was not neutralized. “ns” indicates P > 0.05, “*” represents P < 0.05, “**” represents P < 0.01,“***” represents P < 0.001 and “****” represents P < 0.0001, Scar bar = 50 μm.)