Fig. 3.

OXA and PPC synergy activates the Nrf2/HMOX1 signalling pathway, amplifying HMOX1 gene expression. A RNA-sequencing was conducted to investigate expression differences in HGC-27 cells treated with and without PPC. Significantly altered genes following PPC treatment (log2FC > 2) are presented in the volcano plot. B-D RNA-sequencing data (B) highlighted a significant upregulation in HMOX1 expression upon combined OXA and PPC treatment. This observation was further supported by qRT-PCR (C) and western blotting (D) results. E The impact of OXA treatment on KEAP1 and Nrf2 expression, with or without PPC, evaluated through western blotting in AGS and HGC-27 cells using whole-cell lysates. F Influence of the combined treatment on AGS and HGC-27 cells analysed via western blotting, distinguishing between cytoplasmic and nuclear protein fractions. G Effect of the combined treatment on Nrf2 localization (green) and DAPI (blue) in AGS and HGC-27 cells visualized through immunofluorescence staining. Scale bar = 100 μm. H The impact of treatment, with or without PPC, on Nrf2 and HMOX1 expression examined using immunohistochemistry (IHC) on mouse tumour samples. Scale bar = 10 μm. I The combined treatment's modulation of the antioxidant response element (ARE) luciferase activity, with or without PPC, in AGS and HGC-27 cells.