Differential regulation of folate receptor isoforms in normal and malignant tissues in vivo and in established cell lines. Physiologic and clinical implications

Abstract

Although FR-beta is the more common isoform, FR-alpha and FR-beta are differentially regulated in normal tissues, carcinomas, nonepithelial malignancies, and immortalized cells or in response to changes in extracellular folate concentrations. The tissue specificity of FR isoforms and their elevation in malignant tissues may be a significant factor in FR-mediated folate uptake, in tissue responsiveness to promising novel antifolates, and in FR-related immunodiagnosis/immunotherapy.