Figure 1.

Sorafenib induces autophagy in HCC cells. (a) Sorafenib induces the conversion of LC3 in a dose-dependent manner. PLC5, Hep3B, SK-Hep1 and HepG2 were exposed to sorafenib at the indicated doses for 16 h and the expression levels of LC3-II were analyzed by western blot. (b) Time-dependent effect of sorafenib on autophagy-related proteins. PLC5 cells were exposed to 20 μM sorafenib for various periods of time (left). Sorafenib activates autophagic flux in PLC5 cells (middle). Western blot showing P62 degradation and LC3 lipidation in PLC5 cells treated with sorafenib and/or lysosomal inhibitor. The cells were treated with or without 20 μM sorafenib in the presence or absence of 10 μM chloroquine (CQ) for 16 h. PLC5 or SK-Hep1 cells were treated with or without 20 μM sorafenib in the presence or absence of 20 nM bafilomycin A1 (A1) for 16 h (right). The effect of CQ or A1 on cell viability was performed in MTT assay. (c) Transmission electron microscopy (TEM) images showing autophagosome (arrow) formation in PLC5 cells treated with 20 μM sorafenib for 16 h. (d) Images of acridine orange (AO) staining of HCC cells after 16 h treatment with 20 μM sorafenib as detected by fluorescence microscopy. AO-R indicates acidic vesicular organelle formation