The Role of Early Growth Response 1 in the Prognostic Value and Cell Migration of Breast Cancer

Abstract Background: Early growth response family members (EGRs), EGR1-4, have increasingly attracted attention in multiple cancers. However, the exact expression patterns and prognostic values of EGRs in the progress of breast cancer (BRCA) remain largely unknown. Methods: The mRNA expression and prognostic characteristics of EGRs were examined by the Cancer Genome Atlas (TCGA), Oncomine and Kaplan-Meier plotter. Enrichment analyses were conducted based on protein-protein interaction (PPI) network. The Tumor Immune Estimation Resource (TIMER) database and MethSurv were further explored. The protein expression level of EGR1 and cell migration were measured by Western blotting, immunohistochemistry, wound-healing assay and Boyden chamber assay in BRCA. Results: The transcriptional levels of EGR1/2/3 displayed significantly low expression in BRCA compared to that in normal tissues, while EGR4 was shown adverse expression pattern. Survival analysis revealed up-regulated EGR1-4 were remarkably associated with favorable relapse-free survival (RFS). A close correlation with specific tumor-infiltrating immune cells (TIICs) and several CpG sites of EGRs were exhibited. Immunohistochemistry assays showed that the protein expression of EGR1 was remarkably downregulated in BRCA compared to that in paracancerous tissues. Cell migration of MCF10A cells was increased after the silence of EGR1 by siRNA transfection.Conclusions: This study provides a novel insight to the role of EGR1 in the prognostic value and cell migration of BRCA.