The Experiment Study Of CXCR4 Knockdown By Sirna Inhibits The Breast Carcinoma Invasion And Metastasis In Vitro

PART ONE The Experimental Study on the Breast Cancer Cell Cxcr4 Gene Expression by Silencing Cxcr4 in VitroObjective: studied whether shRNA-CXCR4 could inhibit the CXCR4 gene expression in MCF-7, MDA-MB-231 and MDA-MB-435s breast cancer cells.Methods: through knockdown CXCR4 by shRNA , we examined the CXCR4 mRNA express by RT-PCR and the CXCR4 protein express by Western blot in breast cancer cells.Results: the CXCR4mRNA express and its protein express decreased significantly in MCF-7, MDA-MB-231 and MDA-MB-435s breast cancer cells by shRNA-CXCR4(P<0.05).Conclusion: Silencing CXCR4 could inhibit the breast cancer cell CXCR4 mRNA and its protein express. PART TWO Silencing CXCR4 on the Effect of Breast Cancer Cell Growth and Proliferation in VitroObjective: studied whether shRNA-CXCR4 could inhibit the CXCR4 gene express and the proliferation in MCF-7, MDA-MB-231 and MDA-MB-435s breast cancer cells.Methods: through knockdown CXCR4 by shRNA , The ability of breast cancer cell proliferation was evaluated by MTT and flow cytometry .Results: shRNACXCR4 could inhibit the cell proliferation(P<0.05) and induce the cell cycle arrest in G0/ G1 phase with a significant decrease of cells in S phase (P<0.05).Conclusion: Silencing CXCR4 could inhibit the breast cancer growth. It may be a potentially valuable therapeutic target in breast cancer treatment. PART THREE The Effects of shRNA-CXCR4 on Breast Cancer Cells Migration and InvasionObjective: To study the effect of shRNA-CXCR4 on human breast cancer cells migration and invasion .Methods: through knockdown CXCR4 by shRNA, the matrigel penetrating ability of human breast cancer cells was examined in vitro experiments.Result: the invasive ability of human breast cancer cells was significantly decreased (p<0.05).Conclusion: through knockdown CXCR4 by shRNA, the invasive ability of human breast cancer cells can be inhibited obviously. PART FOUR Experimental Study of the Effects of shRNA-CXCR4 on Tumor AngiogenesisObjective: To study the effects of shRNA-CXCR4 on angiogenesis of human breast cancer cells.Methods: A technique of co-culture of human breast cancer cells and endothelial cells of human umbilical vein cell(HUVEC) was applied. The morphology change of HUVEC , induced by human breast cancer cells ,was observed after RNA interfering CXCR4.Results: After shRNA–CXCR4, the ability of tube formation of HUVEC induced by human breast cancer cell lines such as MDA-MB-231, MDA-MB-435S and MCF-7 was inhibited obviously (p<0.05).Conclusion: By shRNA–CXCR4, the ability of angiogenesis induced by human breast cancer cells inhibited obviously. PART FIVE CXCR4 Expression and its Prognosis Value in Breast CancerObjective: To study the CXCR4 expression and its prognosis value in breast cancer.Methods: 44 samples of breast carcinoma were collected. CXCR4mRNA was examined by RT-PCR, CXCR4 protein was examined by Western-blot. ER,PR and C-erbB-2 were examined by immunohistological chemical method.Results: CXCR4mRNA and its protein did not correlate with ages,menstuel status, tumor size, hostological grade, ER and PR(P>0.05). CXCR4mRNA and its protein significantly increased in lymph node metastasis and C-erbB-2 extensive expression(P<0.05).Conclusion: CXCR4 was an important prognostic factor in metastasis , espassially coexpressed with C-erbB-2.