Inhibition Menchanism Of Grape Skin Extracts On The Metastasis Of Breast Cancer

In recent years, the incidence of breast cancer has been increasing gradually, which is a great threaten to female health. Breast carcinomar in situ is not fatal, which can be cured by surgery combined with radiotherapy, chemotherapy or any other methods. However, once breast cancer cells metastasize to blood, lymphatic and distal organs such as bone, lung and liver, it will threat to life. Some natural botanicals have been shown to have anti-carcinogenic activities, and become a hot field of researches for dietary supplements and new cancer drugs.Grape skins extracts (GSKE) contain many active ingredients such as grape polyphenols, procyanidins, resveratrol, gallic acid and oleanolic acid.They can be applied as dietary supplement, and show great potential in the prevention and treatment of cancer with advantages of wide source, high biological activity and without any side effect.To present, it has been shown that GSKE inhibit the growth as well as induce apoptosis of cancer cells.However, their efficacy on metastasis and migration of cancer cells remains unknown.In this paper,GSKE provided by Tianjin Jianfeng Research and Development of Natural Products Co.,Ltd were adopted. The inhibition of GSKE on the migration of murine mammary carcinoma 4T1 cells in vitro was studied , and the molecular mechanism was explored. By establishing mouse breast cancer metastasis model, the effect of GSKE on lung metastasis of breast cancer in vivo was investigated. The study provides experimental basis for the application of GSKE in dietary supplements and new cancer drugs, and supplies possibility of reducing risk of metastasis of breast cancer by taking dietary supplements. The main results are as follows:1.Migration assay showed that GSKE significantly inhibit the migration of 4T1 cells in a dose-dependent manner.The migration of 4T1 cells was totally inhibited by GSKE at the concentration of 20μg/ml.2.MTT assay showed that GSKE inhibit proliferation of 4T1 cells in a dose- dependent manner. Half maximal inhibitory concentration of GSKE (IC50) was 72.408μg/ml.Apoptosis experiment showed that GSKE induced apoptosis of 4T1 cells.The migration of 4T1 cells was totally inhibited by GSKE at the concentration of 20μg/ml, at which 4T1 cell viability was inhibited by only 11.37%,and the total apoptotic cells increased by only 11.89%.These results indicated that inhibition of GSKE on the migration of 4T1 cells was not a result of cell viability inhibition or apoptosis induction.3.Results of western blot showed that the total protein levels of signal molecules Akt, PDK1, ERK1/2, p38 in 4T1 cells remained stable when treated with different concentration of 4T1 cells.However, the phosphorylation of Akt, PDK1, ERK1/2, p38 were inhibited by GSKE in a dose-dependent manner.These results indicated that GSKE blocked the PI3K/Akt and MAPK pathway and contributed to the inhibition of cellular migration.4.Breast cancer metastasis model of BALB/c mouse was established.It was shown that GSKE could inhibit the metastasis of 4T1 cells in vivo when added into drinking water at appropriate concentration.Lung metastasis rate and number of metastasis nodules in tumor-bearing BALB/c mouse were significantly reduced When treated with GSKE at the concentration of 0.5 mg/ml, followed by extended survival time. However, the inhibition of GSKE on the metastasis of 4T1 cells in vivo reduced with the increase of the concentration.