Expression Of FSIP1 In Different Molecular Types Of Breast Cancer And Its Effect On Biological Behavior Of BT474 Cell Line

Background: Breast cancer is the most frequently diagnosed malignant tumor among women,and in recent years,the incidence and mortality of breast cancer in China located in worldwide front row and increased gradually.With the improvement of medical level,the detection rate and the treatment methods of breast cancer have been increasing,but there are still many patients died of breast cancer owing to detecting not be in time and poor treatment.Therefore,we need to find more sensitive detection methods,more accurate predictive indicators and new treatment methods to help us solve the difficulties encountered in the diagnosis and treatment of breast cancer.FSIP1(fibrous sheath interacting protein 1)is a newly discovered cancer-testis antigen in recent years.FSIP1 expression is usually restricted to germ cells and many cancer cells.It has been proved to be highly expressed in bladder cancer,lung cancer and breast cancer.It is related to the occurrence and development of malignant tumor.Cancer-testis antigens are expressed differently in different tumors,and the same type of tumor may express many different CTA.The expression of FSIP1 in breast cancer has been testified to related to the status of hormone receptor and the expression of her2.However,there are few studies on the expression of FSIP1 in different molecular types of breast cancer.Objective: The goal of this research is to investigate the expression of FSIP1 protein in different molecular subtypes of breast cancer.To analyze the relationship between the expression level of FSIP1 and clinicopathological characteristics of breast cancer patients.To determine the impact of high expression of FSIP1 on survival and prognosis of breast cancer patients,and investigate the effects of FSIP1 level on the migration,proliferation and invasion of breast cancer BT474 cell line.Methods:(1)The expression of FSIP1 in 140 breast cancertissue microarray those were purchased from Shanghai Xinchao was detected by immunohistochemical method.The relationship between the expression of FSIP1 and the clinicopathological characteristics of breast cancer and the expression of FSIP1 in different molecular typing of breast cancer were analyzed by SPSS statistical software and Graph Pad prism mapping software.(2)Western blot analysis of FSIP1 expression in various breast cancer cell lines.The BT47 cells(ER+ 、 PR+ 、 Her2+)those express high FSIP1 were then infected with si-FSIP1 or si-NC by transient transfer technique.(3)Scratch assay was used to detect the migration of breast cancer BT474 cells.(4)MTT assay was used to detect cell proliferation.(5)The invasion of BT474 cells was verified by Transwell assay.Rresults:1.FSIP1 is mainly expressed in tumor cells and stroma cells in breast cancer.2.The high expression rate of FSIP1 protein in breast cancer was 48.84%.3.In breast cancer patients,the expression of FSIP1 in tumor cells was bound up with ER status(p=0.011),PR(p=0.022)and disease recurrence(p=0.01),not related to age(p=0.44),tumor size(p=0.796),Her2 status(p=0.120),stage of disease(p=0.122),lymph node metastasis(p=0.255).The expression of FSIP1 in stroma cells was only related to the disease recurrence(p=0.015).4.Positive FSIP1 expression was independently associated with an unfavorable overall and disease-free survival by univariate and multivariate Cox regression.The survival rate of patients with high expression of FSIP1 was worse than that of patients with low expression of FSIP1.5.The expression of FSIP1 in patients with hormone receptor positive breast cancer were significantly higher than triple negative breast cancer(P < 0.05).6.The BT474 cell lines(ER+、PR+、Her2+)express higher levels of FSIP1 protein compare with other cell lines of our choice.7.The ability of cell proliferation,invasion and migration in si-RNA group was lower than that in siNC group.Conclusion:1.The expression of FSIP 1in breast cancer patients is related to hormone receptor status,but not to Her-2 status,lymph node metastasis,stage,age and tumor size.2.Patients with highly expression of FSIP1 are more prone to recurrence,FSIP1-positive status is an independent adverse prognostic factor in breast cancer patients.3.FSIP1 is expressed differently in different molecular types of breast cancer,and that is highly expressed in Hormone-Receptor positive breast cancer,lowly in triple-negative breast cancer.4.Silencing the FSIP1 gene can inhibit the proliferation,invasion and migration of BT474 cells,suggesting that FSIP1 may effect the biological behavior of BT474 cells through some mechanism.