The relationships between the expression of SPP1 and IL33 during the dedifferentiation of breast cancer associated adipocytes and the prognosis of breast cancer

Abstract Purpose We aimed to determine the biomarkers for breast cancer by studying the relationship between breast cancer and the dedifferentiation process of adipose tissue. Methods The public databases Gene Expression Omnibus (GEO) database, the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) databases, the Gene Expression Profiling Interactive Analysis 2 (GEPIA2) database, the Kaplan-Meier Plotter database, the Human Protein Atlas (HPA) database and the TIMER 2.0 database were used to analyze. Immunohistochemical experiment was carried out to verify the expression of Secreted phosphoprotein 1 (SPP1) gene and the interleukin 33 (IL-33) gene in adipose tissue and breast cancer tissue respectively. Results Totally, 19 differentially expressed genes (DEGs) were identified and mainly enriched in the three signaling pathways. Compared with normal controls, SPP1 microRNA and IL33 microRNA were differently expressed (P < 0.05). And SPP1 and IL33 gene were related to the prognosis of estrogen receptor (ER) positive/human epidermal growth factor receptor 2 (HER-2) negative breast cancer patients (P < 0.05). Immunohistochemical results showed that the positive expression rate of SPP1 and IL33 in breast cancer were higher than that in normal tissues; both associated with macrophages in breast cancer. Conclusion SPP1 and IL33 affect the prognosis of breast cancer during the dedifferentiation of breast cancer related adipocytes. The SPP1 and IL33 perhaps are potential biomarkers for breast cancer.