Figure 1

Chemoresistance to MTA is associated with an enriched stem cell gene signature and augmented ALDH activity. (a–c) mRNA levels of stem cell genes in chemoresistant A549_R, H358_R, H460_R and their parental A549, H358 and H460 cells were analyzed by qPCR. Data are shown as mean±S.D. of three independent experiments (n=3). (d–f) Augmented ALDH activity hallmarks a stem cell-like population with enhanced chemoresistance to MTA. The FACS-sorted ALDHhigh subset and unsorted A549 cells were analyzed by qPCR (d), by clonogenic assay (e) and by XTT assay after treatment with MTA for 24 h (f). Results are presented as mean±S.D. of three independent experiments (n=3). For clonogenic assay (e), the ALDHhigh and A549 cells were seeded in six-well plates (250 cells/well) and cultured for 10 days. *P<0.05; **P<0.01; ***P<0.001