RESUMO
@#Objective: To explore the expression of AGR2 gene in breast cancer as well as to predict its relevant biological functions and molecular signaling pathways with bioinformatics tool. Methods: The expression of AGR2 in breast cancer tissues and normal tissues was analyzed in Oncomine and GEPIA databases, and the expression of AGR2 in breast cancer cell lines was evaluated in CCLE database. Meanwhile, HPA database was used to analyze the expression of AGR2 protein in normal and breast cancer tissues. Besides, the gene expression microarray data download from CCLE database was analyzed by using R software to obtain genes co-expressed withAGR2. Functional annotation ofAGR2 co-expressed genes was performed by using GO Enrichment and KEGG pathway analyses. Results: Oncomine and GEPIA databases showed that AGR2 gene was highly expressed in breast cancer tissues, and CCLE database analysis showed that AGR2 was highly expressed in all breast cancer cell lines. Immunohistochemistry results from the HPA database showed that the expression of AGR2 protein was significantly higher in breast cancer tissues compared with normal tissues. A total of 946 genes co-expressed with AGR2 in breast cancer were screened out with the R software. With the GO function Enrichment analysis, the co-expressed genes were demonstrated to be mainly involved in biological functions, such as protein localization to cell periphery, protein localization to plasma membrane, cell junction assembly, cell-substrate adhesion, and cell junction organization etc. In addition, the KEGG analysis results showed that co-expressed genes were mainly involved in the progression of gastric cancer and breast cancer, and were associated with proteoglycans in cancer, as well as proline, leucine and isoleucine degradation pathways. Conclusions:AGR2 is highly expressed in breast cancer tissues, which may be a potential oncogenic gene and a new therapeutic target of breast cancer.