| Breast cancer is the most common cancer in women wo rldwide,which can be divided into two categories according to pathological types: invasive ductal breas t cancer and non-invasive ductal breast cancer.Patients have a high risk of treatment failure or tumor recurrence,poor prognosis and high mortality.Protein arginine N-methyltransferase 4(PRMT4),also known as co-activator associated arginine methyltransferase 1(CARM1),belongs to the protein arginine methyltransferase family.As a type I protein arginine methyltransferase,CARM1 catalyzes the formation of asymmetric dimethylarginine from arginine on protein substrates.CARM1 activates transcription through a variety of mechanisms,including histone H3 methylation,coactivator CBP/P300 methylation,and the recruitment of chromatin remodesing proteins.CARM1 is an essential enzyme in mammals.Current studies have shown that CARM1 is overexpressed in lung cancer,colorectal cancer,breast cancer and other cancers,and is associated with tumorigenesis,development and poor prognosis.The tetracycline expression regμLation system is one of the most widely studied gene expression systems.It consists of transcriptional regμLatory factors,tetracycline reactive promoters and tetracycline antibiotics,including the Tet-on gene regμLation system and the Tet-off gene regμLation system,which has the characteristics of high mμLtiple induction genes and "on/off" of regμLated genes.It has been reported that,after continuous improvement,the application of tetracycline expression reg μLation system is not limited to cancer cell lines and transgenic animals,but also can be applied to primary cells.Tetracycline expression regμLation system provides an effective method for the study of gene expression and reg μLation and gene biological effects.This paper studied the biological effect of CARM1 in breast cancer cells.Through the online data analysis website of bioinformatics,it was found that there was a strong correlation between CARM1 and breast cancer.Using breast cancer MDA-MB-231 cells as the research object,tetracycline induced breast cancer MDA-MB-231 cell line with high CARM1 expression was constructed using lentivir al packaging system.Western blot and RT-PCR showed that the protein expression and m RNA levels of CARM1 were significantly increased after cell l ine induction.Cell proliferation assay,plate cloning,flow cytometry,microsphere c μLture and cell scratch assay showed that cell proliferation,clone formation and cell migration were significantly enhanced after the induction of CARM1 overexpression.By flow cytometry analysis,it was found that the cell ratio of S phase and G2/M phase of the cell line increased after the induction of CARM1 expression,and overexpression of CARM1 coμLd promote the process of cell cycle.Microsphere cμLture experiments showed that microsphere formation ability was weakened and dryness was down-regμLated.The above resμLts indicate that overexpression of CARM1 in breast cancer cells can promote cell proliferation,improve the ability of clone formation and migration,accelerate the cell cycle process,and inhibit cell dryness.Through RNA-seq analysis,it is found that overexpression of CARM1 participates in the regμLation of mμLtiple development-related genes and activates the signal pathways related to the mitotic spindle.These experimental resμLts provide a reference for future research on the mechanism of breast cancer occurrence and development. |
