The protein level of GPT was measured using Western blotting as described previously[17 (link)]. The total protein was isolated from GC cells (AGS, MKN45, MKN28 and HGC27) and the normal immortalized cells (GES1) using RIPA lysis buffer containing protease phosphatase cocktail obtained from Beyotime (Shanghai, China). The extract was centrifuged at 10000 × g for 15 min to remove the cell debris. The protein concentration was quantified using a bicinchoninic acid (BCA) protein assay kit (Beyotime). Thereafter, the protein samples (20 μg per lane) were resolved using 10% Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and transferred onto a polyvinylidene difluoride (PVDF) membrane. After blocking with 5% skimmed milk for 1 h, the membrane was incubated overnight with the primary antibodies against GPT (PAS-29600, 1:1000; Thermo Fisher Scientific, Shanghai, China) and GAPDH (ab8245, 1:2000; Abcam) at 4 ℃. Subsequently the membranes were incubated with secondary antibodies for 2 h at the room temperature. The bands were visualized using an enhanced chemiluminescent reagent (Yeasen, Shanghai, China). The immunoblot images were quantified by ImageJ software.