Figure 6. Cyclin D1 is degraded in the autophagic flux induced by lonafarnib and sorafenib co-treatment. (A) HepG2 cells were transfected with Flag-Cyclin D1 plasmid. Cell lysates were immunoprecipitated with anti-Flag agarose followed by immunoblotting to investigate the levels of LC3B, P62, and cyclin D1 proteins. (B) Cells were maintained in the presence of MG-132 or CQ for another 12 h after treatment with lonafarnib and/or sorafenib. Western blotting was used to detect changes in cyclin D1 protein expression. (C) HepG2 cells were treated as indicated, and western blot assay was used to detect cyclin D1 protein degradation. (D) The protein degradation rates of cyclin D1 were quantified in (C).