Nicotine-treated cells show enhanced viability during doxorubicin exposure.

<p>(<b>A</b>) MTS proliferation assay testing the viability of control vs. nicotine-treated cells in the presence of doxorubicin. Absorbance (Y-axis) values were normalized by dividing over the absorbance of the 0 µM doxorubicin samples. (B) MTS viability assays demonstrating the reversal of CSC-induced doxorubicin resistance by the nAChR inhibitor mecamylamine. Taken together, these results indicate that nicotine is at least partially responsible for the protective effect of CSC against doxorubicin-induced cell death. Error bars represent SEM.