Effects Of Silent Scinderin On The Epithelial-mesenchymal Transition Of Breast Cancer Cell MCF-7 And Its Molecular Mechanism

ObjectiveBreast cancer is currently the most common malignancy in women worldwide.Tumor progression and metastasis is one of the important issues affecting the prognosis and quality of life of breast cancer patients.Exploring the cytological basis and molecular mechanisms that affect breast cancer metastasis is a hot research direction in the field of breast cancer.Studies have shown that epithelial-mesenchymal transition(EMT)is closely related to tumor metastasis,and multiple signaling pathways such as TGF-?,Wnt / ?-catenin,Notch,Hedgehog,IL-6 / STAT3,and NF-?B It is involved in the regulation of EMT and is an important molecular mechanism of tumor metastasis.Therefore,revealing the molecular regulatory mechanism of EMT and its relationship with malignant tumors is of great significance for the prevention and treatment of cancer.Scinderin(hereinafter referred to as SCIN)is a Ca2 +-dependent filament actin(F-actin)cleavage protein,which regulates the polymerization and disaggregation of filament actin(F-actin),affects cytoskeletal remodeling,and secretes in cells.Plays an important role in the process.Recent studies have shown that SICN is involved in the occurrence and development of many malignant tumors and may be related to the EMT regulation of malignant tumor cells and tumor stem cells.However,there have been few reports in breast cancer.We found in previous studies that low SCIN expression is positively correlated with breast cancer proliferation,invasion,and poor patient prognosis;however,the specific mechanism is unknown.The Wnt / ?-catenin signaling pathway is currently the most popular pathway in research.It was first discovered in mouse breast cancer in 1982 and is believed to be related to tumorigenesis and development.Based on the previous work,this study will further explore whether SCIN regulates EMT through the Wnt / ?-catenin signaling pathway,thereby affecting the molecular mechanism of breast cancer progression and metastasis.Methods1.Construct a SCIN-shRNA lentiviral vector and infect human breast cancer cell line MCF-7,observe the infection efficiency under a fluorescent microscope,and verify the silencing effect of SCIN by Western Blot to establish a stable breast cancer cell line MCF-7 with low SCIN expression.2.Western Blot was used to analyze the effects of SCIN-knockdown on the expression of E-cadherin and N-cadherin and other EMT marker molecules in MCF-7 cells and the expression of Wnt / ?-catenin signaling proteins such as Wnt3 a,?-catenin and GSK-3? impact.3.Amplify the two groups of MCF-7 cells transfected with Lv-shSCIN lentiviral vector and negative control(Lv-shCON)transfected with nonsense sequence lentiviral vector.The expanded cells were prepared into cell suspensions and injected into the skin of nude mice to establish a subcutaneous xenograft model.The effects of SCIN-knockdown on the tumorigenicity of MCF-7 cells were observed.4.Take out subcutaneous tumors from nude mice,and use Western Blot to analyze the expression of SCIN and E-cadherin and N-cadherin and the effects of Wnt3 a,?-catenin and Effect of GSK-3? and Other Wnt / ?-catenin Signaling Pathway Related Protein Expression.Results1.Lentiviral vector was successfully transfected into breast cancer MCF-7 cells.Western bolt test results showed that the protein expression level of Scinderin in MCF-7 cells transfected with Lv-shSCIN lentiviral vector was significantly lower than that of the control group(P <0.05).This confirmed that the breast cancer cell line MCF-7 with stable and low expression of Scinderin was successfully constructed.2.The results of Western Blot showed that the expression level of E-cadherin in SCIN-knockdown MCF-7 cells was significantly reduced(P <0.05),while the expression level of N-cadherin was significantly increased(P <0.05).The expression levels of ?-catenin and Wnt3 a proteins in SCIN-knockdown MCF-7 cells were significantly increased(P <0.05),while the expression levels of GSK-3? were significantly decreased(P <0.05).3.The results of subcutaneous xenograft tumors in nude mice showed that,whether or not SCIN was knockdown,subcutaneous xenografts could grow after 4 weeks,but the tumor-forming volume of the SCIN-knockdown MCF-7 cell line increased significantly.4.Western Blot test results confirmed that tumor tissue protein expression levels were consistent with intracellular protein expression levels: SCIN and E-cadherin expression levels in tumors of SCIN-knockdown MCF-7 cell lines were significantly reduced(P <0.05),and N-cadherin expression level was significantly increased(P <0.05).The expression of ?-catenin and Wnt3 a proteins in SCIN-knockdown MCF-7 cell lines was significantly increased(P <0.05,while the expression level of GSK-3? was significantly decreased(P <0.05).Conclusions1.Knockdown of SCIN promotes the tumorigenic ability of breast cancer MCF-7 cells in nude mice2.SCIN-knockdown can enhance the EMT process of breast cancer cell line MCF-7,and promote the invasion,proliferation and migration ability of cancer cells;3.SCIN-knockdown may regulate the EMT process through the Wnt / ?-catenin signaling pathway,thereby promoting cancer cell invasion,proliferation and migration.4.This study suggests that SCIN is involved in regulating the EMT process of breast cancer cells and is closely related to the metastasis of breast cancer cells.This provides new ideas for elucidating the mechanism of breast cancer metastasis and has potential practical value for the diagnosis,treatment,and prevention of breast cancer metastasis and recurrence.