Research Paper Volume 11, Issue 19 pp 8156—8168

Knockdown of CREB3 activates endoplasmic reticulum stress and induces apoptosis in glioblastoma

Figure 7. The downregulation of CREB3 inhibited growth of U251MG cells via activating ERS pathway. (A) PERK levels were detected by qRT-PCR in U251MG cells transfected with the NC, PERK-siRNA1 or PERK-siRNA2. (B) The levels of the ERS-related proteins p-PERK, p-eIF2α and ATF4 were detected in U251MG cells transfected with the CREB3-shRNA2, PERK-siRNA2 or co-transfected with CREB3-shRNA2 and PERK-siRNA2. (CE) The relative levels of p-PERK (C), p-eIF2α (D) and ATF4 (E) were quantified and normalized to PERK, eIF2α and β-actin levels respectively. (F) The viability of U251MG cells was detected with a CCK-8 assay. (G, H) Apoptosis was detected with Annexin V and PI double staining, and the percentage of apoptotic cells was calculated. **P<0.01 compared with the NC group, ##P<0.01 compared with the CREB3-shRNA2 group.