BHLHE40 triggered metastasis of pancreatic cancer cells. (A) The expression levels of BHLHE40, ENO1, SDC4, and TGM2 under normoxic or hypoxic conditions were evaluated in 9 PCA cell lines; (B) the protein expression level of BHLHE40 in PCA (https://www.proteinatlas.org/ENSG00000134107-BHLHE40/pathology/pancreatic+cancer#img) and normal pancreatic tissue (https://www.proteinatlas.org/ENSG00000134107-BHLHE40/tissue/pancreas#img); (C-F) the expression of BHLHE40 of PCA patients with different grades, stages, T stages, and M stages in the TCGA cohort; (G) the expression levels of BHLHE40 in MIA PaCa-2, SW1990, and PANC-1 cell lines were determined by qRT-PCR; (H) knockdown of BHLHE40 by using siRNAs targeting BHLHE40 (siBHLHE40) repressed the expression of BHLHE40 in PANC-1 cells; (I) Transwell assays were performed to assess the invasion ability of PANC-1 cells transfected with siRNAs targeting BHLHE40 (siBHLHE40) (×200), in which cells were stained with 0.1% crystal violet; (J) cell migration was assessed using a wound healing assay (×40). All data are presented as the mean ± SD of 3 independent experiments. *P<0.05; **, P<0.01; ***, P<0.001. PCA, pancreatic cancer; TCGA, The Cancer Genome Atlas; siRNA, small interfering RNA; qRT-PCR, quantitative real-time polymerase chain reaction; SD, standard deviation.