Fig. 3
Suppression of shisa3 induces EGFR-TKI resistance and promotes a CSC phenotype. a. QRT-PCR and Western blot analysis of shisa3 expression in PC9 and HCC827 cells stably infected with shRNAs containing PC9-shControl or shisa3-targeting sequences (PC9-ShShisa3#1 and #2). b. IC50 values for gefitinib and osimertinib are shown in the bar graph in PC9-ShControl and PC9-ShShisa3#1 cells. c. HCC827 cells with or without shisa3 inhibition were treated with gefitinib (0.01 μM, 0.1 μM) or osimertinib (0.001 μM, 0.005 μM), and relative cell viability was determined by CCK-8 assay. d. Representative the primary and secondary sphere images in the transfected PC9 cells. Scale bars, 100 μm. e. The histogram shows the primary and secondary sphere formation efficiencies in PC9-shControl and PC9-shShisa3#1 cells. f. Higher expression levels of CSC-related markers were observed by qRT-PCR in shisa3-downregulated PC9 cells than in control cells. g. Transwell assays demonstrated the number of migrated and invasive PC9 cells transfected with the indicated shRNA. Scale bars, 100 μm. h, i. The graphs show the number of migrated and invasive PC9 (h) and HCC827 (i) cells transfected with the indicated shRNA, respectively. a, b, c, e, f, h and i: *p < 0.05; **p < 0.001; ***p < 0.0001