Olfactory receptor family 5 subfamily B member 21 (OR5B21)

Olfactory receptor family 5 subfamily B member 21 (OR5B21) is a member of the large olfactory receptor family of G protein-coupled receptors (GPCRs) that are primarily responsible for the recognition and transduction of odorant signals in the olfactory epithelium[2][6][8]. OR5B21, like other olfactory receptors, has a 7-transmembrane domain typical of GPCRs and is encoded by a single exon gene[5][8]. While classically associated with odor detection, recent research has identified functional roles for OR5B21 beyond the olfactory system, including in cancer biology. Specifically, OR5B21 is upregulated in breast cancer metastases (notably to the brain, bone, and lung), where it promotes cell invasion and epithelial to mesenchymal transition via the STAT3/NF-κB/CEBPβ signaling pathway. Knockdown of OR5B21 in experimental systems reduces metastatic potential, suggesting a potential role as an oncogenic driver and candidate therapeutic target in metastatic breast cancer[1][3]. No approved drugs are known to target OR5B21 specifically, nor are there clinical drugs acting via this mechanism. OR5B21 levels may function as a biomarker for breast cancer metastasis risk, but this remains investigational.

Other names

Olfactory receptor 5B21OR5B21O5B21

G protein-mediated transduction of odorant signals