β-elemene enhances the radiosensitivity of gastric cancer cells by inhibiting Pak1 activation

Figure 5 Protein expression in cells exposed to β-elemene, IR, and β-elemene plus IR examined by western blotting. A: Validation of PAK1IP1 expression and the examination of phospho-Pak1 in response to β-elemene treatment, using β-actin as a loading control. β-elemene upregulated PAK1IP1, and downregulates phospho-Pak1 (T423) and its downstream p-ERK1/2; B: Ionizing radiation upregulated phospho-Pak1 (T423), but not total Pak1; C: β-elemene pretreatment decreased IR-induced upregulation of phospho-Pak1 (T423) and phospho-ERK1/2. The level of cleaved caspase-3 was consistent with the level of apoptosis at the cytological level (Figure 3B). IR: Ionizing radiation.