| Breast cancer is one of the most common malignancies in women.The incidence of breast cancer has increased steadily over the past few years,but breast cancer mortality appears to be declined,suggesting benefits from early detection and more effective treatment.The treatment of systemic disease with cytotoxic chemotherapy is one of the treatments of breast cancer.Anthracycline antineoplastic drugs,which include epirubicin and liposome doxorubicin,are the most important chemotherapy drug.Epirubicin is one of the first line chemotherapy drugs in the treatment of breast cancer.And liposome doxorubicin is a new antitumor drug,which through encapsulation of the drug in macromolecular,such as liposome,the volume of distribution is significantly reduced and the concentration of drug in the tumor is increased.The liposome protects the drug from metabolism and activation in the plasma and due to size limitations in the transport of large molecular or carriers across healthy endothelium,the drug accumulates to a reduced extent in healthy tissues. However,discontinuity in the endothelium of the tumor vasculature have been shown to result in increased extravasations of large carriers and,in combination with an impaired lymphatic,an increased accumulation of liposome drug at the tumor.Dentritic cells(DC)play important roles in tumor immunity.DCs phagocytose endogenous and exogenous antigens,and initiate the Ag-specific T cell proliferation with the capability of antigens presentation.It has been reported that in breast cancer,numbers of DCs are lower in sentinel lymph nodes(SLN).And the reason of this may be that tumor cells release a variety of cytokines and other biologically active materials.These various mediators must flow into the SLN,making it easy to imagine that they could influence the response to tumor cells within the SLN,for instance,via a reduction in DC number.CXCR4 is a G-protein coupled receptor,and it belongs to chemokines,a family of small pro-inflammatory cytokines.And chemokines and their eceptors regulate a variety of immune responses to infection,inflammation,and tissue repair.Recently,it has been established that cancer cells exploit signaling through chemokine receptors for several key steps in initiation and progression of primary and metastasis cancer.In particular,the chemokine CXCL12 and its receptor CXCR4 have prominent roles in primary and metastasis breast cancer, as well as a number of other important malignancies including lung,brain,and prostate.Signaling through CXCR4 activates a number of downstream effector molecules,including molecules that regulate key processes such as cell cycle control and apoptosis.Based on those above mentioned,our study carried out the research from the following two aspects: Experiment 1.Culture and identification of human dentritic cell.Successive adherence method was utilized to obtain mononuclear cells.The mature DC was induced in vitro by granulocyte-macrophage colony-stimulating factor(GM-CSF),interleukin-4(IL-4)and tumor necrosis factor-a(TNF-α). Identification of DC included observing the utrastructure with electron microscope.Then,human breast cancer cell lines,Bcap37 and MDA-MB-231, together with human dentritic cells,were cultured with epirubicin and liposome adriamycin,respectively,under different concentrations(0,0.25,0.5,1.0,2.0,4.0,10.0μg/ml).The inhibitory effects were detected by MTT method after 24,48,72 h.The result was that epirubicin and liposome adriamycin could inhibited the proliferation of Bcap37 cells,MDA-MB-231 cells,and human dentritic cells.Liposome adriamycin exhibited a lighter inhibition on dentritic cells than on human breast cancer cell lines(Bcap37 and MDA-MB-231) (F=22.208,P＜0.01;F=20.534,P＜0.01).And compared with MDA-MB-231 cells,the proliferation of Bcap37 cells was inhibited more effectively by liposome adriamycin.In conclusion,breast cancer cell lines with lower malignant degree appears to be more sensitive to chemotherapy,as compared to those with higher degree.The toxicity of liposome adriamycin on dentritic cells is lower than epirubicin.Experiment 2.The construction of plasmid interference vector of CXCR4 -Psilencer3.1-CXCR4 was utilized the method of molecular cloning.It was detected to be correct with DNA sequencing.Then detecting mRNA and protein express of CXCR4 gene in human breast cancer cell line SK-BR-3.Results indicated that the express level of CXCR4 in breast cancer cell line SK-BR-3 interferenced by Psilencer3.1-CXCR4 was significantly lower than the control, SK-BR-3 without transfection. |
