Olfactory receptor gene abundance in invasive breast carcinoma

Expression of olfactory receptors (ORs) has been reported in many human tissues outside the nasal epithelium. ORs have been validated as biomarkers in prostate cancer. In breast cancer, however, the expression and role of OR genes remain understudied. We examined the significance of OR transcript abundance in a large invasive breast carcinoma population and identified two OR genes, OR2W3 and OR2B6 to be potentially correlated to breast cancer progression. 960 breast invasive tumors and 56 human breast cancer cell lines were assessed for OR gene expression and 21 OR genes were highly abundant among 198 cases. Our transcriptome analysis discovered three significantly abundant OR genes among three sub-populations of invasive breast carcinoma patients. OR2W3 was correlated with invasion genes and basal-like subtype whereas OR2B6 was correlated with proliferation genes and luminal A subtype. Analyzing the OR gene upregulation among breast cancer cell lines showed that OR2B6 and OR2W3 were abundant similar to invasive breast tumors. Our study suggests that specific OR genes may be correlated with breast cancer characteristics, making ORs potential new diagnostic, and/or treatment markers. This study suggests future directions for the exploration of a role for ORs in the mechanisms of breast cancer proliferation and progression.