24?h post transfection, cells were harvested for western blot analysis (f and g), RT-qPCR (h) and glucose consumption measurement (i)
24?h post transfection, cells were harvested for western blot analysis (f and g), RT-qPCR (h) and glucose consumption measurement (i). disrupting the interaction between FBP1 and TRIM28 in pancreatic cancer cells. Moreover, we demonstrated that FBP1 promoted c-Myc degradation through disrupting the ERK-c-Myc axis. Conclusions FBP1 modulates the sensitivity of pancreatic cancer cells to BET inhibitors by decreasing the expression of c-Myc. These findings highlight FBP1 could be used as a therapeutic niche for patient-tailored therapies. Electronic supplementary material The online version of this article (10.1186/s13046-018-0888-y) contains supplementary material, which is available to authorized users. value MSX-130 BET inhibitor sensitivity in PDAC. a, PANC-1 cells were infected with lentivirus expressing control, FBP1-specific shRNAs. After 48?h infection, shControl cells were transfected with pcDNA3.1 or Flag-FBP1 constructs. All cells were treated with different doses of indicated chemicals 24?h post-transfection. The cell Adipor2 viability was measured by MTS assay. Heat map showing the IC50 ratio (log2 (IC50 ratio)) between shControl versus shControl, knockdown FBP1 versus shcontrol or overexpression FBP1 versus control treated with indicated chemicals. b, PANC-1 cells were infected with lentivirus expressing control, FBP1-specific shRNAs. After 48?h infection, shControl cells were transfected with pcDNA3.1 MSX-130 or Flag-FBP1 constructs. Cells were treated with different doses of JQ1 24?h post-transfection. The cell viability was measured by MTS assay. Data shown are mean values SD from six replicates. c-f, PANC-1 cells were infected with lentivirus expressing control or FBP1-specific shRNAs. After 72?h infection, cells were harvested for MTS assay (c), western blotting (d), caspase 3 activity assay (e) and colony formation assay (f). All data are shown as mean values SD (values are also shown To investigate the clinical relevance of FBP1 in regulating c-Myc protein levels in MSX-130 pancreatic cancer patients, we assessed both c-Myc and FBP1 protein levels in 8 non-tumor and tumor-paired human pancreatic cancer specimens (Fig. ?(Fig.4e).4e). We found that c-Myc expression was up-regulated in pancreatic cancer tissues compared with adjacent normal pancreatic tissue (Fig. ?(Fig.4e4e and ?andf).f). In contrast, the protein level of FBP1 was lower in pancreatic cancer tissues compared to adjacent normal control tissues (Fig. ?(Fig.4e4e and ?andF).F). Intriguingly, there was no correlation between and at the mRNA level (Fig. ?(Fig.4g).4g). Meanwhile, we used a tissue microarray of human pancreatic cancer specimens obtained from a cohort of patients (mRNA level was not overtly correlated with that of (Fig. ?(Fig.4g).4g). Our data suggested that FBP1 regulated c-Myc expression by influencing its post-translational modifications. We systematically investigated whether FBP1 regulate the stability of c-Myc protein in PDAC cells. The overexpression of Flag-FBP1 decreased the protein level of c-Myc in PANC-1 cells, and this effect of FBP1 was completely blocked by the treatment of the proteasome inhibitor MG132 (Fig.?5a and ?andb).b). Moreover, the knockdown of endogenous FBP1 prolonged.
