TLR7 Controls Hair Follicle Stem Cell Differentiation And Relevant Regulated Signaling

Objective: To study the effect of deguelin on inhibiting proliferation and inducing apoptosis of breast cancer cells MDA-MB-231. On this basis, To explore the relation between induction of apoptosis of deguelin and mitochondrial signaling pathway , and the effect of deguelin on mitochondrial permeability transition pore.Methods: Breast cancer cells MDA-MB-231 were investigated in the study. The inhibitory effect of deguelin with different concentrations on MDA-MB-231 cells proliferation was detected by MTT method, and cell apoptosis rate was analyzed by flow cytometry (FCM) using Annexin V/propidium iodide(PI) double staining; MDA-MB-231 cells were stained by Rhodamine123 to detect changes in mitochondrial transmembrane potential by FCM; Alteration of protein of Cyt c,Caspase-3,Bcl-2 and Bax was detected by Western Blot; MDA-MB-231 cells were stained by Fluo-3/AM to detect changes in intracellular Ca2+ concentration by FCM. The mRNA expression of Bcl-2 and Bax was examined by RT-PCR. Caspase-3 activity was assessed by colorimetric assay.Results: Deguelin inhibited the proliferation of MDA-MB-231 cells on a time- and dose-depending manner(P﹤0.05). FCM analysis showed that the apoptotic rate of MDA-MB-231 cells and intracellular Ca2+ concentration increased gradually with the increase of deguelin concentration. After treatment with deguelin, mitochondrial transmembrane potential was deceased, the protein expressions of Cyt c outside of mitochondria and caspase-3 were increased, caspase-3 activity was significantly increased compared with negative control group(P﹤0.01). RT-PCR and Western bloting analysis showed that the expression of Bcl-2 mRNA and protein were down-regulated and those of Bax were up-regulated after deguelin treatment.Conclusions: Deguelin inhibited proliferation and induced apoptosis of MDA-MB-231 cells, its mechanism is closely related to mitochondrial signaling pathway; Deguelin could regulate the the change of mitochondrial permeability transition pore induced by increased intracellular Ca2+ concentration and altered Bcl-2,Bax expression.