Fig. 6.

Individual and combined effect of GEM and Evr on PI3K/AKT/mTOR signaling in GEM_sen and GEM_res cells. Western blot and quantification of a proteins associated with the Warburg effect (GLUT1, LDHB, HK2, and PKM2), b the phosphorylation level of AKT and PI3K, and c the phosphorylation level of mTOR (at S2481 and S2448) and P70S6K in GEM_sen and GEM_res cells treated with GEM or/and Evr. All protein expression was normalized to that of GAPDH as an internal control. The numbers in the arrows represent the difference (increase or decrease) in protein expression between GEM and GEM + Evr. In GEM-treated GEM_res cells, the overall suppressive effect of Evr on the Warburg effect was weaker than that in GEM-treated GEM_sen cells. Similarly, in GEM-treated GEM_res cells, the suppressive effect of Evr on the phosphorylation of AKT, PI3K, and mTOR (S2481) was weaker than that in GEM-treated GEM_sen cells. Conversely, the suppressive effect of Evr on the phosphorylation of mTOR (S2448) and P70S6K was stronger in GEM-treated GEM_res cells than that in GEM-treated GEM_sen cells. The data are expressed as the mean ± standard deviation of three replicates (n = 3). *P < 0.05; ^#P < 0.05 compared with the same treatment in GEM_sen cells. GEM: gemcitabine, Evr: everolimus; GEM_sen: GEM-sensitive pancreatic cancer cells; GEM_res: GEM-resistant pancreatic cancer cells; au: arbitrary units