Abstract: Objective To investigate the anti-tumor effect and preliminary mechanism of FTY720 on breast cancer cells MCF-7. Methods MCF-7 cells were incubated with different doses of FTY720 (1, 2.5, 5 µM·L^-1) in vitro for 24 hours to detect the effects of FTY720 on apoptosis of MCF-7 cells by DAPI and Annexin V-APC/ PI flow cytometry. Total RNA from cells was isolated and reverse transcribed to cDNA to test the mRNA expression levels of anti-apoptotic molecule Bcl-2 and Bax by real-time PCR, further signaling pathways molecules AKT, NFκB protein expression levels were detected by Western blotting. Results FTY720 could significantly inhibit cell proliferation and induce nuclear condensation and nuclear fragmentation at a concentration of 5 µM. FTY720 could induce apoptosis rate to 30.0% at a concentration of 5 µM, and the inhibition rate could be concentration-dependent (P<0.05). The mRNA expression level of anti-apoptotic related proteins Bcl-2 was significantly down-regulated and the mRNA expression of apoptosis protein Bax was significantly up-regulated (P<0.01). We confirmed that after the MCF-7 cell being dealed with FTY720, phosphorylated AKT protein expression level was significantly reduced (P<0.05), phosphorylation NFκB protein expression level was significantly increased (P<0.05). Conclusion FTY720 can induce apoptosis in breast cancer cells by regulating the expression levels of various proteins in cells.

Key words: FTY720, MCF-7, apoptosis, antitumor, breast cancer