Figure 4.

Metformin modulates the expression/phosphorylation of UPR proteins and AKT in an AMPK-independent manner in endometrial cancer cells. Ishikawa (A), HEC1B (B), or AN3CA (C) cells were treated or not for 24 h with 5 mM metformin in the presence or absence of 1 h pretreatment with 10 µM CC. Total cellular proteins were extracted and Western blot experiments were performed with antibodies against GRP78, ATF6, ATF4, p-eIF2α, p-AKT, or β-actin (loading control), as described in the Section 2.3. Values shown represent the mean (± s.d.) of three independent experiments. * p < 0.1; ** p < 0.05; *** p < 0.01.