The Role Of PAIP2 Nanoparticles In The Proliferation And Metastasis Of Breast Cancer Cells

PART 1 The expression and biological function of PAIP2 in breast cancerObjective Lymph is a liquid that can better reflect the pathological state of cancer cells compared with blood,The differential expression of PAIP2 was found in the lymphatic fluid of breast cancer metastasis,but the mechanism of PAIP2 is still unclear.Therefore,it is of great significance to explore the mechanism of PAIP2 in lymph node metastasis of breast cancer.Methods Real-time quantitative PCR(RT-q PCR)and Western Blot were used to verify the expression of PAIP2 in breast cancer cells.Breast cancer tissue data were obtained from TCGA database and HPA database to analyze the expression of PAIP2 in breast cancer.Kaplan-Meier plotter database was used to analyze the prognostic value of PAIP2 in breast cancer patients.Using bioinformatics technology to explore the prognostic value of PAIP2 and its possible biological function,and its effect on tumor immunity and immunotherapy.The biological function of PAIP2 in breast cancer cells was verified by cell migration assay(Transwell),cell scratch assay and cell proliferation assay(CCK8).Results The m RNA and protein expression levels of PAIP2 in breast cancer cells(MCF-7,MDA-MB-231 cell lines)were higher than those in normal breast epithelial cells(MCF-10a),and the same results were obtained in tissues.The expression of PAIP2 is associated with the prognosis of patients and is negatively correlated with most chemotherapeutic drug sensitivity and IPS in cancer immunotherapy.The cancer cells with high expression of PAIP2 have stronger metastasis and proliferation ability than normal cells.After the expression of PAIP2 in cancer cells decreased,the proliferation and metastasis ability decreased significantly.Conclusion PAIP2 is highly expressed in breast cancer and is involved in the proliferation and metastasis of cancer cells.PAIP2 can be used as a potential therapeutic target for breast cancer and provide a new direction for clinical treatment.PART II The basic properties of PAIP2 siRNA nanoparticlesObjective To develop a suitable carrier of carrying PAIP2 siRNA into the targeted cells and achieve long-term therapeutic effect of the drug.Methods Nanoparticles were prepared by double emulsion method.The physical properties of nanoparticles were detected by inverted microscope,TEM,fluorescence microscope and Malvern.The optimal N / P ratio of nanoparticles was obtained by agarose gel experiment.The toxicity and cell viability of nanoparticles were verified by CCK8.Results The nanoparticles were spherical with uniform size,and fluorescent siRNA could be seen around them.The size was 361.6 ± 253.6 nm,the zeta potential was + 0.248 m V.After7 days of nanoparticles size detection,the stability was good,and the optimal N / P ratio was 2 :1.Conclusion The nanoparticles successfully prepared by the double emulsion method have stable physicochemical properties and good safety,which can lay the foundation for the next in vivo experiments.PART III The effects of PAIP2 siRNA nanoparticles on growth and lymph node metastasis ofbreast cancer cells in vivoObjective Through the first part,it was found that PAIP2 plays a role in the development and progression of breast cancer and promotes proliferation and migration of MCF-7 breast cancer cells in vitro.PDP siRNA nanoparticles were successfully prepared with good physicochemical properties and safety,so the role of PDP siRNA nanoparticles on breast cancer growth and lymph node metastasis in vivo was investigated.Methods The BALB / c mouse breast cancer model was established by injecting MCF-7breast cancer cells into the tail vein of mice.The mice were divided into three groups: siRNA group,PD blank siRNA NPs group and PDP siRNA NPs group,and four mice in each group were injected into the tail vein every two days at a dose of 200 ul per mouse,and the tumor size was measured for 16 consecutive days and the volume curves were plotted.The tumor in situ tissues and lymph nodes were analyzed by Ki67 and LYVE-1 immunohistochemistry,respectively.Results Compared with siRNA and PD blank siRNA NPs group,the volume of PDP siRNA NPs group decreased most significantly.The results of Ki67 and LYVE-1immunohistochemical experiments showed that the expression of Ki67 in PDP siRNA NPs group was the lowest and the degree of malignancy was the lowest.The expression of Ki67 in PD blank siRNA NPs group was the highest and the degree of malignancy was the highest.The expression of LYVE-1 in PDP siRNA NPs group was the lowest,and lymph node metastasis was significantly inhibited,followed by siRNA group.Conclusion PAIP2 inhibits breast cancer cell growth and lymphatic metastasis in vivo,and the inhibition effect in vivo is more significant after treatment with nanoparticles carrying PAIP2 siRNA,which may provide new directions for clinical development of new drugs to improve individual benefits.