Combination of Fructose-1,6-Diphosphate and Proteasome Inhibitor Enhances Inhibition of Cell Proliferation in Human MCF-7 Breast Cancer Cells

ObjectiveTo investigate whether inhibition proteasome can induce autophagy,effects of fructose-1,6-diphosphate(FDP) on autophagy and effects of autophagy on the fate of human breast cancer MCF-7 cells. MethodsCell viability was measured by MTT assay. Apoptosis was detected by flow cytometry. The expression of autophagy related proteins was determined by Western blot. ResultsMCF-7 cells proliferation was inhibited by proteasome inhibitor Bortezomib in a dose dependent manner and autophagy was activated in the same manner.However,when MCF-7 cells were co-treated with Bortezomib and FDP,it could lead the most significant inhibition of cell proliferation. Moreover,FDP blocked the increase of LC3-II protein expression induced by Bortezomib. ConclusionThe inhibition of proteasome can induce autophagy in human breast cancer MCF-7 cells and FDP could inhibit autophagy induced by proteasome inhibitor. Combination of FDP and Bortezomib increases cell death.