Figure 3. (A) Upregulation of DR4 and DR5 and reduction of decoy receptors (DcR1 and DcR2) by TS essential oil in dose (i)- and time (ii)-dependent manner in HCT116 and other cancer cells (iii). Tumor cells (1 × 106 per well) were treated with various concentrations (A, left) of TS for 24 h or treated with 0.5 μg/ml TS for the indicated time points. Whole-cell extracts were prepared and subjected to Western blotting for DRs and DcRs. (B) TS enhances TRAIL-induced cell death through induction of DRs and down-regulation of DcRs expression in dose- (i) dependent manner and upregulation of death receptors in various time- (ii) periods in HCT116 and other tumor cells (iii).