title: Assessment of folate receptor-β expression in human neoplastic tissues.
abstract: Over-expression of folate receptor alpha on cancer cells has been frequently exploited for delivery of folate-targeted imaging and therapeutic agents to tumors. Because limited information exists on expression of the beta isoform of the folate receptor in human cancers (FR-β), we have evaluated the immunohistochemical staining pattern of FR-β in 992 tumor sections from 20 different human cancer types using a new anti-human FR-β monoclonal antibody. FR-β expression was shown to be more pronounced in cells within the stroma, primarily macrophages and macrophage-like cells than cancer cells in every cancer type studied. Moreover, FR-β expression in both cancer and stromal cells was found to be statistically more prominent in females than males. A significant positive correlation was also observed between FR-β expression on stromal cells and both the stage of the cancer and the presence of lymph node metastases. Based on these data we conclude FR-β may constitute a good target for specific delivery of therapeutic agents to activated macrophages and that accumulation of FR-β positive macrophages in the stroma could serve as a useful indicator of a tumor's metastatic potential.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, IN, USA.
authors.forename: Jiayin
authors.initials: J
authors.lastname: Shen
authors.affiliation: Center for Drug Discovery, Purdue University, West Lafayette, IN, USA.
authors.forename: Karson S
authors.initials: KS
authors.lastname: Putt
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Visscher
authors.affiliation: Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Murphy
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University Hospital, Atlanta, GA, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Cohen
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Hospital of the University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Sunil
authors.initials: S
authors.lastname: Singhal
authors.affiliation: Department of Pathology, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: George
authors.initials: G
authors.lastname: Sandusky
authors.affiliation: Protein Interactions Section, Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer, National Cancer Institute-Frederick, National Institutes of Health, Frederick, MD, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Protein Interactions Section, Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer, National Cancer Institute-Frederick, National Institutes of Health, Frederick, MD, USA.
authors.forename: Dimiter S
authors.initials: DS
authors.lastname: Dimitrov
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, IN, USA.|Center for Drug Discovery, Purdue University, West Lafayette, IN, USA.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Low
mesh_terms: D005260:Female; D058976:Folate Receptor 2 / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D009369:Neoplasms / Q000378:metabolism*
chemical_list: D058976:Folate Receptor 2
keywords: activated macrophage; folate receptor; folate receptor beta; tumor associated macrophage