Expression changes of metabolic related proteins in tumor cells after being treated with inhibitor NAC or 3-MA by using western blot and immunofluorescence. (D) Expression of metabolism related proteins IDH2, PKM2, GAPDH in colorectal cancer cells co-cultured with CCD-18-co under treatment of NAC or 3-MA, respectively. *P < 0.05 vs. negative respectively, **P < 0.01 versus negative respectively. (A, B, and C) Immunofluorescence observation of metabolism related proteins GAPDH, PKM2, IDH2 in tumor cells cultured alone or co-cultured with CCD-18-co under treatment of NAC or 3-MA, respectively (63×).