Experimental Study Of Resveratrol Suppress The Bone Metastasis Of Breast Cancer

Objective:To investigate the effects of resveratrol(res) on proliferation, invasion of breast cancer cell line MDA-MB-231BO in vitro and related mechanism. To elucidate the molecular mechanism of resveratrol against bone metastasis of human breast cancer in nude.Methods:①MDA-MB-231BO cells were treated with different concentrations of resveratrol for 48 hours, and the effect of resveratrol on cell growth was measured by CCK-8 assay. The invasion capability in vitro was detected by Transwell chamber assay. The mRNA and protein expressions of MMP-9 were tested by RT-PCR and Western blot, respectively. The distribution of NF-κB/p65 was tested by RT-PCR and the nuclear translocation of NF-κB/p65 was tested by immunofluorescence detection.②The animal model of bone metastasis of humam breast cancer was developed by injecting cell line MDA-MB-231BO subcutaneously into the canon born of the left hind limb of nude mice. All the nude mices were randomly into control group, pyrrolidine dithiocarbamate(PDTC) group and res groups at low, medium and high doses(50,100,200 mg/kg) and treated the day after tumor challenge. Observe the action of the nude mice,and record the repast and the weight every day. Measure the diameter of the tumors regularly and depict the growth curve. After having been treated for 21 days, the animals were executed and tumor-inhibition rate of each group was calculated. The expression of MMP-9 protein and the distrution of NF-κB/p65 protein was measured by Western blot and immunohisto chemical method.Results:①The growth of MDA-MB-231BO cells was significantly inhibited by resveratrol in a dose-dependent fashion, the half inhibition concentration (IC50) was 101.1μmol.Resveratrol significantly decreased invasion capability of cells in vitro compared with control group (P <0.01). Resveratrol down-regulated the mRNA and protein levels of MMP-9 and the inhibitory effect was dose-dependent(P<0.05). Western blot showed that reveratrol decreased amounts of nuclear NF-κB/p65 markedly (P<0.05).②res could not show markedly effeet on basic status and the weight of the mude mice .Inhibition rates of tumor growth were 25.74%,23.76%,37.62% and 26.73% in res groups at low, medium and high doses (50,100,200 mg/kg)and PDTC grouprespectively, but there were no significant differences among the treatment groups(P﹥0.05).Meanwhile,in the result of immunocytochemistry ,PDTC,res200,res100 group could decreast the content of MMP-9 in tumour tissues of bone metastasis of human breast cancer in mice,compared with the model group with statistical significance (P<0.01). PDTC,res50,100,200 group could decreast the nucleolus content of NF-κB/p65 in tumour tissues,compared with the model group with statisticl significance(P<0.01).PDTC,res200 group could decreast the the nucleolus content of NF-κB/p65 in tumour tissues copared with res50 group with statisticl significance(P<0.05).In the result of Western blot showed that resveratrol down-regulated the protein levels of MMP-9 and inhibited the nuclear translocalization function of NF-κB/p65 markedly and the inhibitory effect was dose-dependent.Conclusion:res showed markedly inhibiting action on the tumor growth of bone metastasis of human breast cancer of the nude mice,but showed no serious adverse reactions on basic status of nude mice .The anti-tumor mechanism of res through decreasing the content of MMP-9 in tumour tissues and influneting the distrubition of NF-κB/p65 in tumour tissues,which provides stable scientific basis for reasonable exploiture and use in clinical.