Biomaterial Database

Transthyretin receptors on human astrocytoma cells. 1990

C M Divino, and G C Schussler

Department of Medicine, State University of New York Health Science Center, Brooklyn 11203.

Transthyretin (TTR), a transport protein for T4 and retinol-binding protein, is the principal T4-binding protein of cerebrospinal fluid. Its function in regard to the delivery of its ligands and in other respects is unclear. The binding of [125I] TTR to cultured human astrocytoma cells was studied to determine whether these cells carry receptors for TTR. Scatchard analysis was consistent with a single class of binding sites with a Kd of 3 nM. No significant cross-reactivity with transferrin or serum albumin was observed. Internalization of TTR was temperature dependent and proportional to receptor occupancy. Dilutions of cerebrospinal fluid displaced [125I]TTR in proportion to their content of radioimmunoassayable TTR and in parallel with purified TTR. The uptake and internalization of TTR increased in the presence of high T4 or T3 concentrations. These results demonstrate that TTR binds to specific high affinity receptors on human astrocytoma cells. Receptor binding of TTR provides a potential mechanism for the delivery of its ligands within the central nervous system.

UI	MeSH Term	Description	Entries
D011228	Prealbumin	A tetrameric protein, molecular weight between 50,000 and 70,000, consisting of 4 equal chains, and migrating on electrophoresis in 3 fractions more mobile than serum albumin. Its concentration ranges from 7 to 33 per cent in the serum, but levels decrease in liver disease.	Proalbumin,Transthyretin
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001254	Astrocytoma	Neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors. Fibrillary astrocytomas are the most common type and may be classified in order of increasing malignancy (grades I through IV). In the first two decades of life, astrocytomas tend to originate in the cerebellar hemispheres; in adults, they most frequently arise in the cerebrum and frequently undergo malignant transformation. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2013-7; Holland et al., Cancer Medicine, 3d ed, p1082)	Astrocytoma, Subependymal Giant Cell,Glioma, Astrocytic,Oligoastrocytoma, Mixed,Pleomorphic Xanthoastrocytomas,Anaplastic Astrocytoma,Astrocytoma, Grade I,Astrocytoma, Grade II,Astrocytoma, Grade III,Astrocytoma, Protoplasmic,Astroglioma,Cerebral Astrocytoma,Childhood Cerebral Astrocytoma,Fibrillary Astrocytoma,Gemistocytic Astrocytoma,Intracranial Astrocytoma,Juvenile Pilocytic Astrocytoma,Pilocytic Astrocytoma,Subependymal Giant Cell Astrocytoma,Anaplastic Astrocytomas,Astrocytic Glioma,Astrocytic Gliomas,Astrocytoma, Anaplastic,Astrocytoma, Cerebral,Astrocytoma, Childhood Cerebral,Astrocytoma, Fibrillary,Astrocytoma, Gemistocytic,Astrocytoma, Intracranial,Astrocytoma, Juvenile Pilocytic,Astrocytoma, Pilocytic,Astrocytomas,Astrocytomas, Grade III,Astrogliomas,Cerebral Astrocytoma, Childhood,Cerebral Astrocytomas,Childhood Cerebral Astrocytomas,Fibrillary Astrocytomas,Gemistocytic Astrocytomas,Gliomas, Astrocytic,Grade I Astrocytoma,Grade I Astrocytomas,Grade II Astrocytoma,Grade II Astrocytomas,Grade III Astrocytoma,Grade III Astrocytomas,Intracranial Astrocytomas,Juvenile Pilocytic Astrocytomas,Mixed Oligoastrocytoma,Mixed Oligoastrocytomas,Pilocytic Astrocytoma, Juvenile,Pilocytic Astrocytomas,Pleomorphic Xanthoastrocytoma,Protoplasmic Astrocytoma,Protoplasmic Astrocytomas,Xanthoastrocytoma, Pleomorphic
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012709	Serum Albumin	A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.	Plasma Albumin,Albumin, Serum
D013963	Thyroid Hormones	Natural hormones secreted by the THYROID GLAND, such as THYROXINE, and their synthetic analogs.	Thyroid Hormone,Hormone, Thyroid,Hormones, Thyroid
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured