Folate receptor alpha (FR-alpha) (FR-alpha)

Folate receptor alpha (FR-alpha), encoded by the FOLR1 gene, is a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein that binds folic acid and its reduced derivatives with high affinity (UniProt P15328). It facilitates the unidirectional transport of folates into cells via receptor-mediated endocytosis, which is essential for DNA synthesis, repair, and cellular methylation. While its expression in healthy tissues is highly restricted and localized to the apical surfaces of certain epithelia (making it largely inaccessible to the bloodstream), it is significantly overexpressed in various solid tumors, particularly ovarian, lung, and endometrial cancers (PubMed: 24563397). This differential expression makes FR-alpha an ideal target for therapeutic interventions, including antibody-drug conjugates (ADCs) like Mirvetuximab soravtansine and targeted imaging agents (FDA, 2022). The KB cell line, originally identified as an oral epidermal carcinoma but later confirmed as a HeLa contaminant, is a standard laboratory model used extensively in research due to its constitutive high expression of FR-alpha (PubMed: 15501977). Note: The input 'FR-positive KB tumor cells' refers to a specific cell line model rather than a canonical molecular target name.

Other names

FOLR1Folate receptor 1Folate-binding proteinAdult folate-binding proteinFBPKB cell folate receptor

Drugs targeting Folate receptor alpha typically utilize receptor-mediated endocytosis to deliver cytotoxic payloads (e.g., antibody-drug conjugates or small molecule-drug conjugates) or induce antibody-dependent cellular cytotoxicity (ADCC) to eliminate malignant cells (PubMed: 24563397).