Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among children with advanced neuroblastoma, serum concentrations of the iron storage protein ferritin correlate inversely with prognosis. To determine whether ferritin stimulates tumor cell growth, the effects of graded concentrations on cell number were studied for each of three neuroblastoma cell lines (CHP-126, CHP-100, IMR-32) plated in serum-free tissue culture medium. Ferritin extracted from human liver, spleen, or CHP-126 cells (150 ng/ml, final concentration) but not from human heart (150-300 ng/ml) resulted in 1.4-fold +/- 0.2-fold increases in cell numbers over 72 hours as measured spectrophotometrically after reduction of a tetrazolium dye. Higher concentrations of isoferritins (up to 1000 ng/ml) did not further increase cell number, but stimulation was abrogated by rabbit immunoglobulin G antiferritin. Although specific receptors for iodine 125-labeled ferritin could not be demonstrated on the two cell lines tested, deoxyribonucleic acid (DNA) synthesis, measured by incorporation of 3H-thymidine, also increased after addition of ferritin, by approximately 25%. We conclude that ferritin has mitogenic activity for human neuroblastoma cells in vitro which may explain the clinical correlation between levels of that protein and prognosis. Possible implications for therapy are discussed.
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PMID:Stimulation of growth of neuroblastoma cells by ferritin in vitro. 174 Jun 26

Ferritin is an iron-containing protein which is a normal component of serum. The levels of ferritin are increased in the sera of some children with neuroblastoma, and this increase appears to be a potent indicator of prognosis. To determine whether synthesis of ferritin by the tumor cells contributes to these increased serum levels, we examined incorporation of radiolabeled leucine by CHP 126, a neuroblastoma derived cell line, into ferritin. Using sequential immunoprecipitation and gel electrophoresis of sonicates from cells maintained in medium containing iron in amounts standard for tissue culture, incorporation of label into ferritin was 0.04% of that into total protein synthesized over the same time period. Addition of up to 40 micrograms of iron as ferric ammonium citrate increased ferritin synthesis to a maximum of 0.16% without altering synthesis of total protein. The pattern of iron-induced enhancement in the neuroblastoma cells was similar to that which was seen using Chang liver cells, a cell line well known to be capable of ferritin synthesis. These results confirm that neuroblastoma cells can synthesize ferritin and that synthesis is regulated by exogenous iron.
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PMID:Synthesis of ferritin by neuroblastoma. 238 59

That ferritin, an iron storage protein, can be produced by neuroblastoma cells raises the possibility that iron may have some role in promoting tumor cell growth. To explore this possibility, we studied the effects of desferoxamine, a compound which chelates iron, on viability of CHP 126 and CHP 100, two human neuroblastoma cell lines. Cells (5 X 10(4)) were incubated with graded amounts of desferoxamine or ferrioxamine, an iron-saturated analogue of desferoxamine. Within 5 days of exposure to 60 microM desferoxamine, approximately 90% of cells from each of these cell lines were dead. This effect was dose dependent, was not seen with ferrioxamine, and could be prevented by coincubation with greater than stoichiometric amounts of ferric citrate. As determined by binding of OK-T9, desferoxamine also resulted in increased expression of receptors for transferrin, an iron transport protein. Desferoxamine had only minimal effects on viability of several non-neuroblastoma cell lines. These results suggest that iron is required for growth of neuroblastoma and that desferoxamine has potent, specific, antineuroblastoma activity in vitro.
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PMID:Antineuroblastoma activity of desferoxamine in human cell lines. 381 70

Using oxidation of o-phenylenediamine (PDA) and tetramethylbenzidine (TMB) by hydrogen peroxide, cumene peroxide (CHP), tert-butyl hydroperoxide (TBHP), and Triton X-45 hydroperoxide (Triton X-45-HP), the peroxidase activity of horse spleen ferritin was investigated in reversed micelles of aerosol OT (AOT) in heptane with various hydration degrees. With hydrogen peroxide as oxidant the dependences of initial rate of oxidation of both substrates (v0) on hydration degree W0 are characterized by maxima at W0 = 9-11, 20, and 41. In the system containing TBHP--ferritin these maxima were not observed. The parameters kcat, Km, and their ratios kcat/Km as a criterion of ferritin efficiency in peroxidase reactions were determined for both substrates in micellar medium at various W0. Increase of W0 was accompanied by a decrease of kcat and Km. With hydrogen peroxide the peroxidase activity of ferritin in the AOT micelles was significantly lower than in 0.1 M acetate buffer, pH 4.2. However, the efficiency (expressed as kcat/Km) of a system ferritin--Triton X-45-HP in micellar TMB oxidation exceeded that in the aqueous medium. A method of purification of iron-containing crystallite from the ferritin molecule was developed using reversed AOT micelles in heptane and heating the mixture on a water bath.
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PMID:Peroxidase activity of ferritin in aerosol OT reversed micelles in heptane. 986 54