Quercetin induces MCF-7 cell apoptosis via Fas/FasL pathway / 中国病理生理杂志

ABSTRACT

[ABSTRACT]AIM:ToinvestigatetheroleofquercetinintheapoptosisofhumanbreastcancercelllineMCF-7 and the association with Fas/Fas ligand (FasL) pathway.METHODS: The apoptosis model of MCF-7 cells was estab-lished by the induction with quercetin .The morphological characteristics of apoptotic MCF-7 cells were observed under transmission electron microscope .The apoptotic rates and alternation of mitochondrial membrane potential (Δψm ) in the MCF-7 cells were measured by flow cytometry using fluorescein labeled Annexin V-FITC/PI and JC-1, respectively.FasL neutralizing antibody was applied to block the apoptosis .The expression of Fas/FasL on the cells was detected by immuno-fluorescence technique and flow cytometry , respectively.The influence of SB203580 (an inhibitor of p38 MAPK) on the expression of Fas/FasL was also examined by flow cytometry .The protein levels of p 38 MAPK and p-p38 MAPK were de-termined by Western blot .RESULTS: The phenomenon of nuclear condensation and marginalization in the MCF -7 cells treated with quercetin at 80.0 μmol/L for 48 h was observed under transmission electron microscope .Compared with the control cells , theΔψm was decreased by 17.4%, 44.3% and 68.9% in the MCF-7 cells treated with quercetin at 80.0μmol/L for 24 h, 48 h and 72 h, respectively .The apoptotic rates of MCF-7 cells treated with quercetin at 80.0 μmol/L for 24 h, 48 h and 72 h were (10.2 ±3.3)%, (28.9 ±7.5)%and (39.2 ±8.9)%, respectively.However, the apop-totic rates were decreased to (8.2 ±2.8)%, (19.2 ±5.3)% and (22.5 ±6.9)% after the cells were pretreated with FasL neutralizing antibody , respectively .When MCF-7 cells were treated with quercetin for 24 h, 48 h and 72 h, Fas/FasL expression rates were increased in a time-dependent manner , which were largely inhibited by SB203580.The protein level of p38 MAPK was not changed obviously , but the protein level of p-p38 MAPK was significantly increased at 48 h and 72 h.CONCLUSION: Quercetin up-regulates the expression of Fas/FasL on MCF-7 cells, and induces apoptosis via Fas/FasL pathway .Meanwhile , p-p38 MAPK is potentially critical signaling molecule for up-regulating the expression of Fas/FasL.