Fig. 1.

Altered expression of PKC isozymes in erlotinib-resistant NSCLC cells. (A) Parental (H1650) and erlotinib-resistant (H1650-M3) cells were treated with erlotinib at indicated concentrations and cell viability was determined 24 hours later using an MTS assay. (B) Expression of PKC isozymes in parental (H1650) and erlotinib-resistant (H1650-M3) cells was analyzed by Western blotting. Similar results were observed in three individual experiments. (C) PKCα and PKCδ mRNA levels in H1650 and H1650-M3 cells were measured by qPCR. Human 18S rRNA was used as an endogenous control for normalization. Results (relative to H1650 cells) are expressed as the mean ± S.D. of triplicate samples. Similar results were observed in three additional experiments. **P < 0.01; ***P < 0.001.