Fig. 3

Overexpression of circRNA CDR1as increased DDP chemoresistance in DDP-sensitive NSCLC cells. The a circRNA CDR1as overexpression vectors, b miR-641 mimic and c vectors for HOXA9 ablation were pre-transfected into NSCLC cells, examined by Real-Time qPCR. Subsequently, the NSCLC cells (A549, H1299 and Calu6) were subjected to high-dose DDP for 48 h. d CCK-8 assay and e trypan blue assay results indicated that upregulated circRNA CDR1as increased DDP chemoresistance in DDP-sensitive NSCLC cells by regulating miR-641/HOXA9 axis. f, g Colony formation assay results showed that circRNA CDR1as rescued colony formation abilities in DDP-treated NSCLC cells by regulating miR-641/HOXA9 axis. (Note: “D” represented “DDP”, “C” and “OE-C” represented “circRNA CDR1as overexpression”, “Mic” represented “miR-641 mimic” and “KD-H” meant “Knock-down of HOXA9″). *P < 0.05, **P < 0.01. “NS” represented no statistical significance