RESUMEN
Objective@#To explore effect of AMP-activated protein kinase (AMPK) /mammalian target of rapamycin (mTOR) /ribosomal protein S6 kinase-1 (S6K1) signaling pathways and the insulin-sensitizing effect by adiponectin in endometrial cancer HEC-1B cells.@*Methods@#The experiments were divided into 4 groups, adiponectin (Ad) group (HEC-1B cells treated with 20 μg/ml adiponectin for 30 minutes) , inhibitor group (HEC-1B cells treated with 10 μmol/L compound C for 30 minutes) , inhibitor+ Ad group (HEC-1B cells treated with 10 μmol/L compound C for 30 minutes following incubation with 20 μg/ml adiponectin for 30 minutes) , control group (only added the culture medium without serum DMEM) . (1) Real-time quantitative PCR and western blot analysis were used to detect the level of mRNA and protein of adiponectin receptor (AdipoR) 1 and AdipoR2. (2) Western blot analysis were used to detect phosphorylation of AMPK, mTOR, S6K1 or insulin receptor substrate 1 (IRS1) protein expression with stimulation in different concentrations of adiponectin (2.5, 5, 10, and 20 μg/ml) , or following incubation with insulin 50 nmol/L for 5 minutes; or treated with 20 μg/ml adiponectin for different times (15, 30, 45, and 60 minutes) , or following incubation with insulin 50 nmol/L for 5 minutes. (3) Cell counting kit-8 (CCK-8) assay was performed to investigate the cell proliferation, and transwell chamber assay was used to detect the cell migration in different groups.@*Results@#(1) The relative expression level of AdipoR1 mRNA and protein were higher than AdipoR2 in HEC-1B cell (8.50±0.09 to 1.00±0.00, and 0.91±0.03 to 0.69±0.03; P<0.05) . (2) The phosphorylation level of p-AMPK was significantly induced, and the phosphorylation level of p-mTOR and p-S6K1 proteins, and 20 μg/ml adiponectin at 30 minutes, AMPK protein had the highest level of activation. (3) Adiponectin induces increased tyrosine phosphorylation of IRS1 in a time-and concentration-dependent manner. (4) The proliferation inhibition ratio in Ad group (0.68±0.34) % was much more than that in inhibitor+Ad group (0.24±0.04) % (t=17.88, P<0.05) . The number of cell migration in Ad group (77±8) was much more than that in inhibitor+Ad group (132±13; t=-7.34, P<0.05) .@*Conclusions@#Adiponectin maybe inhibit proliferation and migration of endometrial cancer cells through AMPK/mTOR/S6K1 signal pathway. Adiponectin insensitizes insulin signaling may by regulating by the AMPK/S6K1/IRS1 pathway.