miR-21 Targets ASPP2 to Inhibit Apoptosis via CHOP-Mediated Signaling in Helicobacter pylori-Infected Gastric Cancer Cells

Figure 5

ASPP2 suppression promotes p300-mediated CHOP degradation and inhibits CHOP-mediated apoptotic signaling in the H. pylori-infected GC cells. (a) Cell lysates of shCtrl and shASPP2 AGS cells incubated with H. pylori at 30 MOI for 8 h were incubated with antibodies against ASPP2 (upper) or CHOP (middle) immobilized on protein G beads for 16 hours. (b) Cell lysates of shCtrl and shASPP2 AGS cells incubated with H. pylori at 30 MOI for 8 h followed by 10 μM MG132 for 3 h were immunoprecipitated with antibodies against p300 (upper) or CHOP (middle) immobilized on protein A beads for 16 hours. In panels (a) and (b), the Co-IP complex and 20% input (lower) sample were subjected to immunoblotting. (c) Chromatin of shCtrl and shASPP2 AGS cells incubated with H. pylori at 30 MOI for 8 h were immunoprecipitated with CHOP antibodies immobilized on protein G or A beads for 16 hours. ChIP complex was retrieved and analyzed for relative CHOP binding level to promoters of Noxa (upper), Bak (middle), and Bcl-2 (lower) using qPCR. (d) shCtrl and shASPP2 AGS cells were incubated with H. pylori at 30 MOI for 8 h. Cell lysates were analyzed by immunoblotting using the indicated antibodies. All the data were presented as mean ± SD of 3 replicates.  < 0.01 and  < 0.01.

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