Western blot analyzed the levels of AMPK and LKB1 and PCNA in colorectal mucosal cells isolated from DSS- or AOM/DSS-treated mice. DSS or AOM/DSS decreased levels of AMPK and LKB1 and increased expression of PCNA in colorectal mucosal cells. Metformin increased the levels of AMPK and LKB1. Metformin reduced PCNA in colorectal mucosal cells. **P < 0.01 vs. model mice. (C) The comparison of LKB1 and AMPK levels in colorectal mucosa from WT mice and Igf1r± mice exposed to DSS and AOM/DSS. Both DSS and AOM/DSS induced high level of Akt. The levels of AMPK and LKB1 were consequently reduced. Metformin inhibited Akt and increased AMPK and LKB1 in colorectal mucosal cells. In Igf1r± mice, knockdown of IGF-1R prevented DSS- and AOM/DSS-induced high level of Akt and increased AMPK and LKB1 levels. *P < 0.05, **P < 0.01, ***P < 0.001, between colitis model and metformin-treated mice or Igf1r± mice; #P < 0.05, ##P < 0.01, ###P < 0.001, between CAC model and metformin-treated mice or Igf1r± mice. ^P < 0.05, ^^P < 0.01, ^^^P < 0.001, between Igf1r± mice and WT mice.