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)

We examined the binding of soluble immune complexes in sera from patients with Hodgkin's disease to established tissue cultures derived from the tumor. Circulating immune complex levels were determined by the Raji cell assay, and the reaction of serum with cultured cells was examined with a radioimmune assay and by immunoferritin electron microscopy. Serum with elevated immune complexes was found to react with cells of Hodgkin's disease monolayers when tested with radioiodine-labeled antisera against human IgG heavy and light chains and the complement 3 (C3) component. When examined with the electron microscope, monolayers incubated with Hodgkin's disease serum containing immune complex and labeled with ferritin-conjugated antiserum to C3 contained surface-bound ferritin particles with a uniform but discontinuous pattern. Absorption of Hodgkin's disease serum with monolayer cells reduced immune complexes and decreased reactivity of the sample with cultured cells by radioimmune assay. Sera of patients with other disorders and aggregated gamma-globulin with complement, despite markedly elevated immune complex levels, did not react positively with monolayers derived from Hodgkin's disease tumors, and none of the sera reacted with normal cultured spleen. The approximate size of serum components reacting with Hodgkin's disease monolayers was estimated by sucrose density gradient centrifugation. Sedimentation fractions in the 19S region reacted with monolayer cells when tested with 125I-labeled antisera to both IgG and C3 and contained immunoglobulin-complement complexes by gel diffusion and immunoabsorption. A component sedimenting at 7-9S contained immunoglobulin not complexed with complement; this component reacted with monolayer cells when tested with anti-IgG antiserum but did not react when tested with antibody to C3. The reaction of Hodgkin's disease monolayers with serum containing immune complexes differed from that of two suspension culture lines composed of cells with surface complement and IgG Fc receptors. Inasmuch as cells of our long-term Hodgkin's disease monolayers do not contain these surface receptors, possibly the antibody component of the immune complex reacts with antigens on the surface of cultured cells.
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PMID:Reaction of immune complexes with Hodgkin's disease tissue cultures: radioimmune assay and immunoferritin electron microscopy. 37 54

Three monoclonal antibodies against human liver ferritin were selected to study antigenic determinants (epitopes) of human isoferritins. These monoclonal antibodies were found to form immunoprecipitin lines with ferritin in double diffusion tests (Ouchterlony), indicating multiple epitopes on a single ferritin molecule. The antibodies revealed high species specificity as well. Monoclonal antibodies MA301 and MA311 appeared to recognize different epitopes, since they did not inhibit each other in competitive enzyme-linked immunosorbent assay (ELISA). However, MA309 recognized both epitopes for MA301 and MA311 with similar competitive inhibition. These epitopes were not detectable when ferritin was treated with 8M urea (pH 2.5) and were detectable upon reconstruction by dialysis against 2 M urea (pH 7.2), suggesting that these monoclonals recognize epitopes in the tertiary structure of the ferritin molecule. As a matter of fact, these monoclonals react preferentially with intact ferritin molecule and only negligibly with subunits. Isoelectric focusing patterns of human ferritins demonstrated that liver, spleen, placenta, and hepatoma cells (Li-7) transplanted in nude mice contained basic isoferritins, whereas HeLa cells (carcinoma), Wa cells (EB virus-transformed B cells), and Raji cells (Burkitt's lymphoma) contained acidic isoferritins. Human heart ferritin displayed a somewhat intermediate pattern between liver and HeLa ferritins. In spite of the heterogeneous population of human isoferritins, the dissociation constants (Kd) of the three monoclonal antibodies to liver, HeLa, and heart isoferritins were quite similar.
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PMID:Common epitopes in human isoferritins characterized by murine monoclonal antibodies. 242 Jul 86

Iron is essential in cellular proliferation and survival based on its crucial roles in DNA and ATP synthesis. Tumor cells proliferate rapidly even in patients with low serum iron, although their actual mechanisms are not well known. To elucidate molecular mechanisms of efficient tumor progression under the hypoferric condition, we studied the roles of six-transmembrane epithelial antigen of the prostate family member 3 (STEAP3), which was reported to facilitate iron uptake. Using Raji cells with low STEAP3 mRNA expression, human STEAP3-overexpressing cells were established. The impact of STEAP3 expression was analyzed about the amount of iron storage, the survival under hypoferric conditions in vitro and the growth of tumor in vivo. STEAP3 overexpression increased ferritin, an indicator of iron storage, in STEAP3-overexpressing Raji cells. STEAP3 gave Raji cells the resistance to iron deprivation-induced apoptosis. These STEAP3-overexpressing Raji cells preserved efficient growth even in hypoferric mice, while parental Raji cells grew less rapidly. In addition, iron deficiency enhanced STEAP3 mRNA expression in tumor cells. Furthermore, human colorectal cancer tissues exhibited more STEAP3 mRNA expression and iron storage compared with normal colon mucosa. These findings indicate that STEAP3 maintains iron storage in human malignant cells and tumor proliferation under the hypoferric condition.
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PMID:Human STEAP3 maintains tumor growth under hypoferric condition. 2187 51