Luteolin Inhibits Breast Cancer BT474 Cells Proliferation And Metastasis

[Background and Objection]:In recent years,the incidence of breast cancer is increasing,The mechanism still needs to be further perfect.Luteolin can inhibit the occurrence and development of a wide variety of tumor,less role in breast cancer research.The inactivation of anti-oncogene by methylation is the key mechanism for tumorigenesis.Therefore,reversing the inactivated status of anti-oncogene by drugs is the major strategy to prevent cancer.OPCML tumor-suppressor gene inactivation in breast cancer can cause tumor occurrence and progress.,to some extent curb the activity of DNA methyltransferases.The aim of this research is to discuss the impact of luteolin on brest cancer,on the OPCML expression in breast cancer cells,and explore its possible mechanism in cell proliferation and and invasion.[Methods and materials]:1.Culture in vitro breast cancer cell line BT474,and incubate it with luteolin of different concentrations.Do CCK-8 and Transwell cell experiment to observe the impact of luteolin on the proliferation,metastasis and invasion of BT474.Establish the nude mouse heterotransplanted tumor model and observe the impact of luteolin on the growth of the transplanted tumor.2.Use luteolin to process the BT474 cells or the nude mouse with transplanted tumor and do quantitative PCR and Western blot tests to check in a real time manner how luteolin of different concentrations affect the BT474 cells and the expression of OPCML mRNA and protein in the heterotransplanted tumor.Use OPCMLsiRNA to transfect BT474 cells.Observe whether the siRNA interference can affect the inhibiting effect of luteolin on BT474.Construct the OPCML expression vector and transfect BT474 cells to observe whether it can affect the growth and proliferation of cells.3.Use methylation-specific PCR to test the methylation level of the promoter regions of OPCML before and after applying luteolin.Meanwhile,test the activity of methylation factors and transcription factors Spl before and after applying luteolin.Use qPCR and Western blot to test the impact of luteolin on the expression of DNMT1 mRNA and protein.Lentiviral transfection causes BT474 cells to overexpress Spl.Observe the impact of luteolin on OPCML expression,promoter methylation and DNMT1 mRNA expression;at last,through flow cytometry,we check the apoptosis of BT474 cells and the changes of cell cycles,as well as the apoptosis-related factors,such as the phosphorylation of r-H2AX,Caspase-8 activation and PARP level.[Results]:(1)After being processed by luteolin of different concentrations,the proliferation,invasion and metastasis of breast cancer cells are distinctively inhibited;it depends on specific concentrations and time;in the meantime,luteolin can also curb the formation and growth of subcutaneous tumor of nude mouse.(2)Luteolin can raise the expression of OPCML mRNA and protein in breast cancer cells and breast cancer heterotransplanted tumors.After siRNA silencing OPCML,luteolin's inhibition effect on the proliferation,invasion and metastasis of BT474 cells is weakened;furthermore,the intracellular overexpression of OPCML can inhibit the proliferation,invasion and metastasis cells.(3)Luteolin can curb the DNA methylation of OPCML at promoter regions in the BT474 cells and the transplanted tumors;Luteolin can reduce the expression of DNMT1 mRNA and protein in the BT474 cells and the transplanted tumors;Luteolin can reduce the vitality of SP1;the overexpression of Spl in BT474 cells can weaken the effect of luteolin on inhibition effect on DNMT1 expression and DNA methylation and DNA methylation OPCML.Luteolin can also lead to the phosphorylation of r-H2AX in BT474 cells,accelerate the activation of caspase-8 and raise the PARP level in cells.It can cause the apoptosis of BT474 cells.[Conclusion]:Luteolin can curb the methylation of OPCML genes at the promoter regions and raise the corresponding expression level,so as to cause the retard of breast cancer cell cycles or apoptosis of breast cancer cells and finally inhibit the proliferation,invasion and metastasis of breast cancer cells.