Fig. 9

AHR down-regulation decreases chemotherapeutic resistance of both ALDH^high and ALDH^low Hs578T cells. MTT assays were used to measure cell viability after Hs578T cells were sorted into ALDH^low (a and c) and ALDH^high (b and d) populations and treated with adriamycin (a and b) or paclitaxel (c and d) with and without 10 μM CH223191 for 24 hours. CH223191 treatment alone did not affect cell viability (≥95 % viability in the presence or absence of CH223191 only). Data from six independent experiments were normalized to vehicle-treated cells and presented as mean percent viable cells ± standard error. Asterisks indicate a significant increase in cell death, *P <0.05, **P <0.005, ***P <0.005