Research On The Role And Mechanism Of CNDP1 In Regulating Invasion And Metastasis Of Breast Cancer

Background: Breast cancer is one of the most common malignant tumors in Chinese women,and its prevalence and mortality have been on the rise in recent years.Due to its highly heterogeneous nature,breast cancer patients have developed resistance to therapeutic drugs,resulting in conventional radiotherapy no longer being effective in reducing the risk of breast cancer metastasis,recurrence and death.Therefore,finding potential molecular targets in the development of breast cancer is of great significance to improve the prognosis and survival of breast cancer patients.In previous study,we discovered high expression levels of CNDP1(Carnosine dipeptidase 1)in breast cancer serum samples by proteomics analysis,and speculated that CNDP1 may be involved in the development and progression of breast cancer.However,the mechanism of CNDP1 in breast cancer remains elusive.Objective: To analyze the relationship between CNDP1 and the prognosis of breast cancer patients,and explore the role and potential mechanism of CNDP1 gene in the development of breast cancer to provide new molecular targets for breast cancer treatment.Methods: 1.In serum samples from sisters with the same familial breast cancer,CNDP1 was screened out for its high expression difference in proteomic profiles established by conducting quantitative proteomic analysis(isobaric tags for relative and absolute quantitation,i TRAQ)of three biological replicates of breast cancer samples.2.Immunohistochemistry(IHC)staining was used to stain breast cancer tissues of different molecular subtypes,and the samples were observed and analyzed under an orthomosaic microscope.WB and PCR were used to analyze the expression of CNDP1 in different breast cancer cell lines,and the appropriate cell lines were selected for later experiments.The expression of CNDP1 in breast cancer tissues collected from breast cancer patients via surgical operation and the paired paracancer tissues was analyzed by WB.3.Western blot,RT-q PCR,CCK8 analysis,cell invasion test and other experiments were proceeded to investigate the effects of CNDP1 on cell proliferation and invasion capacity of breast cancer cell lines stably and differentially expressing CNDP1 in vitro.4.Fluorescent probes were used to label the cells treated with PBS and erastin,and fluorescence microscope was used to detect ferric ions in the cells,and flow cytometry was used to monitor the change of reactive oxygen species(ROS)levels,GSH concentration in cells was detected by GSH(glutathione,GSH)assay kit.5.RNA-SEQ analysis was applied to study the potential molecular mechanism of CNDP1 downstream signaling on the proliferation capacity of breast cancer cells.Results: 1.CNDP1 expression was significantly elevated in breast cancer serum samples,breast cancer tissues and breast cancer cell lines.2.Knock-down CNDP1 expression can markedly inhibit the proliferation and invasion of breast cancer cells in vitro.3.Knock-down CNDP1 expression can induce breast cancer cell apoptosis and promote ferroptosis that is mediated by ferric ions and ROS.4.Knock-down CNDP1 expression can enhance the expression of transcription factor EGR1(Early Growth Response 1)that may suppress cancer development.Conclusion: This study demonstrated for the first time that the gene expression of CNDP1 is related to the development and progression of breast cancer,and the knock-down CNDP1 expression inhibited the proliferation of breast cancer cells and can promote ferroptosis of breast cancer cells.The mechanism involved in ferroptosis may be related to the transcription factor EGR1.Our study suggests that CNDP1 is a carcinogenic factor and a new prognostic and therapeutic target for breast cancer.