Origin of tumor-promoter released fibronectin in fibroblasts

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6933210

Burrous, B A; Wolf, G

Previous work from the laboratory showed that the chemical tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulated release of the cell surface glycoprotein, fibronectin (FN) from human lung fibroblasts (HLF), leading to depletion of cell surface FN, while FN synthesis is not altered by TPA. To further investigate the mechanism(s) by which TPA stimulates FN release, two types of experiments were performed. In the first, HLF were pulsed with /sup 35/S-methionine-labeled medium with or without TPA. In the second, cell-surface proteins were labeled by iodination (/sup 125/I) and then incubated in unlabeled medium with or without TPA. In both cases, the fate of labeled FN was followed over 12 hr. The /sup 35/S-meth-labeled HLF showed a rapid loss of labeled FN, first into a small, highly-labeled pool of cell surface FN (1 hr), later into the medium (4 hr or longer). Specific activities showed that this small pool in the cell surface turned over rapidly. TPA treatment resulted in more rapid movement of /sup 35/S-meth pulse-labeled FN to the cell surface and into the medium than in control cells. TPA thus affected the fate of intracellular FN. TPA treatment of HLF also resulted in more rapid removal of /sup 125/I-cell surface-labeled FN into the medium than in control cells. Thus, TPA affects the fate of preexisting cell surface FN in HLF. From these results, they hypothesize that TPA has two separate effects: it stimulates depletion of preexisting intracellular FN during the first hr of treatment, and it stimulates release of preexisting cell surface FN over all treatment times.

• Research Organization: Massachusetts Institute of Technology, Cambridge
• OSTI ID: 6933210
• Report Number(s): CONF-8606151-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
GLUCOPROTEINS
BIOSYNTHESIS
PHORBOL ESTERS
BIOLOGICAL EFFECTS
FIBROBLASTS
IODINE 125
METHIONINE
SULFUR 35
TRACER TECHNIQUES
AMINO ACIDS
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOHYDRATES
CARBOXYLIC ACIDS
CARCINOGENS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ESTERS
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PROTEINS
RADIOISOTOPES
SACCHARIDES
SOMATIC CELLS
SULFUR ISOTOPES
SYNTHESIS
560300* - Chemicals Metabolism & Toxicology
550201 - Biochemistry- Tracer Techniques