Fig. 4: CREB1 stimulates SESN3 transcription.
From: Pifithrin-μ sensitizes mTOR-activated liver cancer to sorafenib treatment
A, B Immunoblotting of HCCLM3 or HepG2 cells (A) transfected with vector or mTOR plasmid, and SNU886 or SNU398 cells (B) transfected with control or mTOR shRNA. C, D mRNA (C) and protein (D) levels of SESN3 in HCCLM3 and HepG2 cells transfected with vector or CREB1 plasmid. E, F mRNA (E) and protein (F) levels of SESN3 in SNU886 and SNU398 cells transfected with control or CREB1 shRNA. G, H SNU886/shmTOR cells were transfected with vector or CREB1 plasmid. Immunoblotting of cells (G). Viability of cells treated with different concentrations of sorafenib for 24 h, n = 3 (H). I Sequence logo of CREB1 binding motif generated from JASPAR database. J Schematic representation of human SESN3 genomic structure. Shown are two potential CREB1 response elements (RE1 and RE2) and the corresponding mutant response elements (RE1 mut, RE2 mut). K Relative luciferase activity detected after transfection of luciferase reporter constructs containing RE1, RE2, RE1 mut, or RE2 mut into HCCLM3 cells. Renilla vector was used as a transfection internal control, n = 5. L Interaction between CREB1 and promoter region of SESN3 analyzed in SNU886 cells by CHIP assay. Three PCR probe sets were designed, namely RE1, RE2, and NC-RE, a negative control probe that is 5 kb upstream of the transcription start site of SESN3, n = 3. Data are displayed as mean ± SD (error bars). **p < 0.01, ***p < 0.001. Sora: sorafenib. TSS: transcription start site.
