Journal: Cell death & disease

Article Title: ID1 confers cancer cell chemoresistance through STAT3/ATF6-mediated induction of autophagy.

doi: 10.1038/s41419-020-2327-1

Figure Lengend Snippet: Fig. 5 ATF6 mediates the ID1-induced autophagy and is transactivated by STAT3. a Effects of ATF6 and cell starvation on the expression of ID1 and ATF6. b Alteration of STAT3, pSTAT3, ATF6, Beclin1, 4E-BP1, p4E-BP1, and LC3B in ID1, and ATF6 overexpression or silencing cells treated with or without starvation for 4 h. β-actin is a loading control. c A schematic diagram showing the STAT3-binding sites in ATF6 promoter constructs for luciferase assays. Blue boxes and numbers indicate the binding sites and sequences. d Dual-luciferase reporter assay tested in SKOV3 ip1 cells transiently co-transfected with STAT3, Renilla luciferase, and various ATF6 promoter fragment constructs as indicated. Bars represent SD from three independent experiments. e STAT3 activates ATF6 promoter transcription. IL-6 (30 ng/ml) activated STAT3 and magnified the luciferase activity while S3I-201 (50 μM) inhibits STAT3 and reduces the luciferase activity of ATF6 transcription. Bars represent SD from three independent experiments. All error bars = 95% CIs. *P < 0.05, **P < 0.01, ***P < 0.001.

Article Snippet: Cell lines and cell culture Human ovarian epithelial cancer cell lines (HEY, HEY A8, SKOV3, SKOV3 ip1, OVCA420, OVCA429, OVCA433, and A2780), and lentiviral packaging cells (HEK293T cells) were purchased from American Type Culture Collection (ATCC, USA) or maintained in our laboratory.

Techniques: Expressing, Over Expression, Control, Binding Assay, Construct, Luciferase, Reporter Assay, Transfection, Activity Assay