Correlation Between Mars Gene Expression Level And Breast Cancer Progression And Establishment Of Breast Cancer Culture Model In Vitro

Methionyl tRNA synthetase(MARS)is one of the 8 aminoacyl-trna synthetases(ARSs)which catalyze the binding and transport of amino acids to the corresponding tRNA in mammalian cells.The expression level of MARS is not only closely related to the imbalance of redox in cells,but also involves in the regulation of cancer occurrence and progression.MARS gene expression level in cancer tissues,such as lung cancer,malignant fibrous cell tumor and glioma cancer,is significantly higher than that of paracancerous tissues.More and more research results show that there is significant correlation between the abnormal rise of MARS gene expression level and cancer progress,but the research of the correlation between MARS gene expression level and progress of breast cancer has not been reported.First,three different methods was used to analyze the correlation between MARS gene expression level and breast cancer progression in this study.1.The expression level of MARS gene in different cancers was analyzed by bioinformatics method in network database.2.The expression levels of MARS gene in fresh breast cancer and paracancer tissues which were collected from 40 breast cancer patients were analyzed using quantitative real-time chain polymerase reaction and protein immunoblotting.3.Immunohistochemical staining and statistical methods were used to analyze the correlation between MARS protein expression level and clinicopathological factors in cancer and paracancerous tissues of 142 breast cancer patients,and further evaluated the effect of MARS protein expression level on the prognosis of patients.Epithelial-mesenchymal transition(EMT)is closely associated with the progress of cancer and is an important indicator of cancer progression such as invasion and metastasis.Therefore,in subsequent study,the expression of MARS protein in MCF-7 cells of breast cancer was down-regulated by RNA interference,and the effect of reducing the expression of MARS protein on the EMT process of breast cancer cells was detected,so as to determine the effect of reducing the expression level of MARS protein on the progression of breast cancer.Cancer progression is also closely related to Extracellular matrix(ECM),which not only maintains the three-dimensional structure of tissues,but also constitutes an important component of the cell microenvironment,and is involved in the regulation of cell differentiation,proliferation,communication,adhesion and other processes.To further research the corelation between MARS gene expression level and breast cancer progression,sodium lauryl sulfate(SLES)solution was used to prepare breast cancer tissue ECM scaffolds for the first time in this study.Observed the proliferation and migration of MCF-7 cells in breast cancer tissue ECM,combined with 5-Fu drug treatment,detected the change of drug resistance of MCF-7 cells to determine the feasibility of simulating the environment in vivo of breast cancer ECM.Finally,the changes of EMT-related genes and MARS gene expression levels of MCF-7 cells in ECM were analyzed to further verify the correlation between MARS gene expression level and breast cancer progression.Wish to provide theoretical basis for the diagnosis and treatment of breast cancer through the research above.The results are as following:1.Network database analysis results showed that MARS gene expression levels were associated with breast cancer progression and other cancers(p<0.05),such as Adrenocortical carcinoma(ACC),Kidney renal clear cell carcinoma(KIRC),Kidney renal papillary cell carcinoma(KIRP),Brain lower grade glioma(LGG),Liver hepatocellular carcinoma(LIHC),Mesothelioma(MESO),Sarcoma(SARC)and Uveal melanoma(UVM).In clinical samples,mRNA and protein levels of MARS gene in breast cancer tissues were significantly higher than those in paracancer tissues(p<0.05).The relative expression of MARS gene was 0.8938±0.1672 in breast cancer tissues and 0.6689±0.1607 in paracancer tissues.The transcription level of MARS gene in breast cancer tissues was 1.34 times higher than that in paracancer tissues.The analysis of the correlation between the protein level of MARS gene and clinical prognostic factors showed that the expression of MARS protein at high level was significantly correlated with the progression of breast cancer.2.Down-regulated the expression of MARS gene by RNA interference in breast cancer MCF-7 cells significantly inhibited its EMT process and migration efficiency.3.Treatment of breast cancer tissues with 0.5% SLES solution for 6 hours was conducive to the retention of key components in the ECM scaffolds,which supported the proliferation and migration of MCF-7 cells in vitro.Compared with conventional cultured single-layer MCF-7 cells,recellular ECM scaffolds improved its stem cell characteristics and 5-Fluorouracil(5-Fu)drug resistance.The ECM of breast cancer not only promoted the EMT process of breast cancer MCF-7 cells,but also significantly increased the expression level of MARS gene with the occurrenced of EMT.