Study On The Inhibiton Of Andrographolide On Metastatic Luminal-like Breast Cancer By Targeting NF-κB Signaling Pathway

Objective: The incidence rate of luminal-like breast cancer is the dominant type of breast cancer in women.The prognosis of luminal-like breast cancer is improved due to the hormone therapy in recently.However,the survival rate is decreased while tumor metastasis in luminal-like breast cancer.Moreover,there is no effective target drug in clinic to treatment of metastatic luminal-like breast cancer.Andrographolide(Andro),a commonly used anti-inflammatory drug in China and some South Asian countries,possesses the function of antipyretic,immune regulation,liver protection and anti-diabetic.Recently,it has been confirmed that Andro can inhibit tumor growth and metastasis in various types of cancers,including the inhibition of cell proliferation,migration and metastasis of three-negative breast cancer cells.However,whether Andro can inhibit the growth and metastasis of luminal-like breast cancer has not been reported.Andro has been considered as a nuclear factor kappa-B(NF-κB)inhibitor,because of Andro can inactivating of NF-κB by covalently modifying of the cysteine residues of p50 in endothelial cells.In this study,we try to confimed the expression of NF-κB in luminal-like breast cancer and evaluated whether NF-κB possess the potential of as a therapeutic target for metastatic luminal-like breast cancer.Furthermore,we try to investigate the potential of Andro that used to treatment of metastatic luminal-like breast cancer in clinic.Methods: In this study,the Immunohistochemistry and Western blotting assays were used to detect the expression of NF-κB in tumor tissues of human luminal-like breast cancer and MMTV-Py MT spontaneous luminal-like breast cancer mouse model.Furthermore,the in vivo and in vitro effects of Andro on the inhibition of NF-κB expression,tumor growth and metastasis,and histopathological changes of tumor were detected in MMTV-Py MT mice and MCF-7 cells.In addition,q RT-PCR array of miRNAs that transcriptional regulated by NF-κB was used to investigate the target miRNA of Andro in luminal-like breast cancer and futher investigate the expression of miRNA target gene in tumor tissues and cells that treated with Andro or DMSO.In this study,we try to explore the potential mechanism of Andro in the inhibition of tumor growth and metastasis of luminal-like breast cancer.Results: The expression of NF-κB was significantly upregulated in tumor tissues of human luminal-like breast cancers and MMTV-Py MT mice compared with adjacent tissues of human luminal-like breast cancers and normal breast tissues of mice.Andro significantly inhibited the tumor growth and metastasis and the expression of p65 and pp65(Ser536)in MMTV-Py MT mice and MCF-7 cells.In addition,both of inhibition of NF-κB and Andro treatment can significantly decrease the expression of miR-21-5p,and upregulate the expression of Programmed cell death 4(PDCD4),a miR-21-5p target gene,in tumor tissues of MMTV-Py MT mice and MCF-7 cells.Conclusion: In this study,it was confirmed that the high expression of NF-κB could be seemed as a potential therapeutic target in luminal-like breast cancer.We found that Andro can inhibit the expression of NF-κB and futher suppress miR-21-5p,and then promote the expression of PDCD4,which can further result in the inhibition of tumor growth and metastasis of luminal-like breast cancer.Andro has been widely used in clinic and has few side effects.Therefore,Andro as a potential NF-κB-targeted drug can be used in clinic to treatment of metastatic luminal-like breast cancer.