Figure 7. The combination therapy activates the AMPK/mTOR/HMMR signaling axis. (A) Western blot analysis of key proteins in the AMPK/mTOR/HMMR pathway in DLD1 cells treated with 5-FU (30 µM), esketamine (1 mM), or their combination for 48 h. (B) Western blot analysis of the same pathway proteins in HCT15 cells under identical treatment conditions. GAPDH served as the loading control for both cell lines. (C,D) Densitometric quantification of p-AMPK and AMPK protein levels in (C) DLD1 and (D) HCT15 cells. (E,F) Densitometric quantification of p-mTOR and mTOR protein levels in (E) DLD1 and (F) HCT15 cells. (G,H) Densitometric quantification of HMMR protein levels in (G) DLD1 and (H) HCT15 cells. Data are presented as the mean ± SD (n = 3 independent experiments). *p < 0.05, ***p < 0.001, ****p < 0.0001. p-, phosphorylated.