OLR1 is a prognostic factor and correlated with immune infiltration in breast cancer.

• OLR1 was highly upregulated in the breast cancer compared with nontumor tissues. • High expression of OLR1 was significantly correlated with poor prognosis in breast cancer. • OLR1 markedly affected the immune infiltration level of breast cancer. Oxidized low-density lipoprotein receptor 1 (OLR1), a key receptor for oxidized low-density lipoprotein (ox-LDL), plays a crucial role in cancer and inflammatory disease. However, the correlation between OLR1 expression and immune infiltration in breast cancer (BC) remain unclear. In this study, we comprehensively analyzed the expression level of OLR1 in BC tissues and explore the prognostic importance of OLR1 using quantitative real-time PCR, immunohistochemical analysis and different databases. The significantly enriched KEGG and GO pathways were used to identify the potential biological function of OLR1 via LinkedOmics analysis. Furthermore, we detected the correlation between OLR1 expression and a variety of immune infiltrating cells via Tumor Immune Estimation Resource database and GEPIA database. Our study revealed that OLR1 upregulation was observed in BC tissues and correlated with worse clinical outcomes and advanced clinicopathological factors. Meanwhile, OLR1 regulated various immunity-related pathways, especially the polarization of macrophages. Immunohistochemical analysis further confirmed the significant correlation between OLR1 expression and tumor infiltration of M2 macrophages as well as tumor-associated macrophages. OLR1 upregulation indicated poor prognosis in BC, possibly through inducing macrophage polarization and triggering immune evasion. Collectively, OLR1 may represent a potential therapeutic target for BC tailored therapy. [ABSTRACT FROM AUTHOR]