Figure 7. SAR1B expression determines drug resistance in liver cancer cells.

A) TICs infected with lentivirus expressing SAR1B shRNAs or scrambled shRNA were treated with CCI779 alone or with CQ for 2 hr and immunoblotted with anti-LC3 and anti-SAR1B antibodies. B) TICs infected with lentivirus expressing HA-SAR1B or HA-blank control were treated with CQ alone or together with BC for 2 hr and immunoblotted with indicated antibodies. C) TICs infected with lentivirus expressing SAR1B-, RAB1B- shRNAs or scrambled-shRNA were treated with an escalating concentration of CCI779 for 4 days and MTT assay was performed to measure viability. Two-way ANOVA analysis was performed with Bonferroni post-test to determine the statistical significance. Error bars indicate SEM of six replicate measurements. D) Quantification of drug resistant TICs transduced with lentiviruses expressing HASAR1B and control treated with BC, CCI779 or both at indicated concentrations as assessed by crystal violet staining and expressed as percent of control. TICs were treated in spheroid forming condition for 7 days and surviving cells were replated in normal tissue culture conditions for 5 days. Two-way ANOVA analysis was performed with Bonferroni post-test to determine the statistical significance. Error bars indicate SEM of three replicate measurements. *p<0.05 and **p<0.01.