Fibronectin synthesized by a human hepatoma cell line
Fibronectin is a family of immunologically similar glycoproteins which mediate a variety of cell-cell and cell-substratum interactions. It is a constituent of the extracellular matrix of connective tissue and circulates in plasma. When suspension and adherent cultures of a human hepatoma cell line (SK-HEP-1) were incubated in serum-free medium, the resulting conditioned medium contained material which was specifically immunoprecipitated by antisera to human plasma fibronectin. By double immunodiffusion, a component in the conditioned culture medium was shown to form a line of identity with fibronectin in human plasma and to migrate as an alpha 2- to beta-globulin during immunoelectrophoresis. Human fibronectin was quantified in conditioned medium by electroimmunodiffusion, and was found to increase for at least three days at about 0.1 micrograms/10(6) cells/day. Adherent cultures of SK-HEP-1 cells were incubated with L-(/sup 35/S)methionine to label newly synthesized proteins. Labeled fibronectin in conditioned medium or in cell extracts comigrated with fibronectin in human plasma as shown by autoradiography following crossed-immunoelectrophoresis. Fibronectin was demonstrated in the extra-cellular matrix of adherent SK-HEP-1 cultures by immunofluorescence. It was shown previously that SK-HEP-1 cells synthesize alpha 1-protease inhibitor, one of the products of normal hepatocytes. The finding that these hepatoma cells also synthesize fibronectin supports the concept that the hepatocyte may be one source of circulating fibronectin, a possibility consistent with the established role of this cell type in blood plasma protein synthesis.
- Research Organization:
- Thrombosis Research Center, Philadelphia, PA
- OSTI ID:
- 6541845
- Journal Information:
- Cancer Res.; (United States), Vol. 44:7
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GLUCOPROTEINS
BIOSYNTHESIS
LABELLING
TUMOR CELLS
BIOCHEMICAL REACTION KINETICS
AUTORADIOGRAPHY
CELL CULTURES
HEPATOMAS
METHIONINE
SULFUR 35
SULFUR COMPOUNDS
TRACER TECHNIQUES
AMINO ACIDS
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOHYDRATES
CARBOXYLIC ACIDS
DAYS LIVING RADIOISOTOPES
DISEASES
DRUGS
EVEN-ODD NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
LIPOTROPIC FACTORS
NEOPLASMS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SACCHARIDES
SULFUR ISOTOPES
SYNTHESIS
550201* - Biochemistry- Tracer Techniques