| Objective: Based on the most recent statistics from the International Agency for Research on Cancer,breast cancer is now the most common newly diagnosed cancer worldwide.Despite various clinical studies having shown the efficacy of targeted drugs,many patients with breast cancer have been found to be unresponsive to drug therapy alone when compared to those who have undergone combined surgery treatments.With the rapid development of genome sequencing technology and the cross-application of biological information and big data science,molecular biology has made great progress in the field of malignant tumor treatment.As a new model,precision medicine has become a new trend in breast cancer treatment to develop individualized molecular typing treatment strategies.Tumor cells are usually characterized by infinite proliferation,unlike normal cells,tumor cells acquire ATP mainly by aerobic glycolysis and abnormal glucose metabolism is the signature feature of tumor cells.Therefore,to explore the mechanism of abnormal glucose metabolism and identify the corresponding targets is the development direction of the next generation of antitumor drugs.In recent years,tumor microenvironment has attracted extensive attention in the exploration of antitumor therapy.Tumor microenvironment is the cell environment for tumor cells to survive,and macrophages are an important member of the tumor microenvironment,which can promote the occurrence and development of tumors by inducing the formation of tumor neovascularization and the formation of immunosuppressive tumor microenvironment.This study observed the influence of macrophages on the glucose metabolism of breast cancer cells from the perspective of tumor microenvironment,and explored the prognostic value of glycometabolism-related genes in breast cancer,providing a new target and basis for the influence of tumor microenvironment on the metabolism of breast cancer as well as the prevention and treatment of breast cancer metastasis.Methods: Firstly,we constructed a co-culture model of macrophages and breast cancer cells at the cellular level to investigate the effect of macrophages on sugar metabolism of breast cancer.Secondly,transcriptome and clinical data of breast cancer patients were obtained from public databases(TCGA and ICGC cohorts),and differential expression genes of glucose metabolism related to prognosis of breast cancer patients(namely glycometabolism-related candidate genes)were screened out.Based on the above candidate genes,a prognostic model of glycometabolism-related genes was constructed using LASSO and multivariate regression,and a risk score was performed for the breast cancer patients included in the analysis.Patients were divided into high and low risk groups according to the median risk score.The Estimate and Cibersort algorithms were used to evaluate the breast cancer microenvironment.IC50 and TMB values were used to further explore the relationship between risk score and therapeutic effect.Subsequently,the protein-protein interaction(PPI)network of differentially expressed genes between high and low risk groups was constructed using STRING database,and key metabolic genes regulating the immune microenvironment were obtained through Cytoscape screening.Finally,paraffin sections of 31 breast cancer patients with definite pathological diagnosis were collected,and the paraffin sections were stained with SDC1 and CD163 specific antibodies by immunohistochemistry.Target protein expression levels were independently assessed by two pathologists who were unaware of the clinical data,based on the proportion and intensity of positive cells measured in 5 random microscopic fields per section(200x magnification).Results: Firstly,it was observed at the cellular level that macrophages significantly increased glucose consumption,lactate production and the expression of key enzymes in glucose metabolism(GLUT1,HK2 and LDH)in breast cancer cells.Secondly,six differentially expressed genes(CACNA1H,SDC1,CHPF,IRS2,ATP6AP1 and NT5E)related to breast cancer prognosis were screened from public data sets.Prognostic models of genes associated with glucose metabolism showed that patients in the high-risk group had poorer overall survival(OS).Since glucose metabolism-related risk scores were associated with poor prognosis,further analysis showed that patients in the low-risk group were more sensitive to chemotherapy,while those in the high-risk group were more sensitive to targeted and immunotherapy.Immune infiltration analysis showed that the risk score related to glucose metabolism was significantly correlated with the immune microenvironment,and patients in the high-risk group had higher infiltration level of M0-type macrophages.Subsequently,we further analyzed and found that SDC1 is a key gene for differential expression of risk,suggesting that SDC1 is a key metabolic gene regulating immune microenvironment.The expression of SDC1 was different in different pathological types of breast cancer,and the expression of SDC1 was the highest in Her2 overexpression type.The OS of the low-SDC1 group was significantly better than that of the high-SDC1 group,and the high SDC1 group had higher infiltrating level of M2-type macrophages.Finally,the expression level of SDC1 in breast cancer tissue was significantly higher than that in normal breast tissue by specific antibody immunohistochemical staining.In addition,in the breast cancer immune microenvironment,we found that the expression of M2-type macrophage surface marker CD163 was positively correlated with the expression of cancer cell surface marker SDC1.Conclusions:1.The co-culture model of macrophages and breast cancer cells was constructed to simulate the tumor microenvironment,suggesting that macrophages can significantly promote the glucose metabolism of breast cancer.2.The glycometabolism-related genes(CACNA1H,SDC1,CHPF,IRS2,ATP6AP1 and NT5E)may be the key genes in the occurrence and prognosis of breast cancer.Glycometabolism-related genes not only complement the current understanding of breast cancer biomarkers,but also provide new insights into the individualized treatment of breast cancer patients.3.The key metabolic gene(SDC1)regulating immune microenvironment was obtained,and the OS of breast cancer patients with high expression of SDC1 was found to be poor,suggesting that SDC1 is associated with poor prognosis of breast cancer patients.In addition,we found that M2-type macrophages with higher infiltration levels were found in the high-SDC1 group.4.The high expression of SDC1 was confirmed in breast cancer tissue samples,and the expression of M2-type macrophage surface marker CD163 was positively correlated with the expression of SDC1 in the breast cancer immune microenvironment. |
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