ABSTRACT
Phospholipase A2, group IIA, gene expression has been analyzed in primary heart tumors. High expression has been demonstrated through several ways: reverse-transcriptase chain polymerase chain, Northern blotting hybridization at the RNA level and immunoblotting, immunohistochemical assay at the protein level. Human cardiac myxoma exhibits highly positive phospholipase A2, group IIA, immunophenotype (100% positive cases). The immunophenotype is unique among human primary cardiac tumors. Phospholipase A2, group IIA, can be proposed as a tissue marker for pathological examination after heart tumor resection.
Subject(s)
Biomarkers, Tumor/metabolism , Group II Phospholipases A2/metabolism , Heart Neoplasms/enzymology , Heart Neoplasms/pathology , Myxoma/enzymology , Myxoma/pathology , Adolescent , Adult , Aged , Biomarkers, Tumor/immunology , Child , Female , Group II Phospholipases A2/immunology , Heart Neoplasms/immunology , Humans , Male , Middle Aged , Myxoma/immunologyABSTRACT
By gene-engineering technique a chimeric protein made up of fragments of Staphylococcus aureus protein A and . Pseudomonas aeruginosa exotoxin A has been constructed. The chimeric protein was shown to preserve features characteristic of its both constituents--it ADP-ribosylates elongation factor 2 and binds to Ig. Cytotoxic properties of the chimeric protein were studied in two model systems. Treatment of target cells in both systems was performed successively with antibodies against corresponding antigens and after washing--with recombinant chimeric toxin which bound to antibodies on the surface of target cells. In the first model system human B-lymphoma cells (Daudi line) carrying Ig molecules on their surface were treated with polyclonal antibodies against human Ig L-chains. In the other system, human T-lymphoma cells (Jurkat line) were treated successively with monoclonal antibodies against cell surface CD5 antigen and further on--with polyclonal antibodies against mouse Ig. In both systems, only a slight inhibition of the target cells' growth was registered. The probable reasons of low cytotoxic activity of the chimeric protein and prospects of increasing it are discussed.
Subject(s)
ADP Ribose Transferases , Bacterial Toxins , Cell Survival/drug effects , Exotoxins/genetics , Staphylococcal Protein A/toxicity , Virulence Factors , Adenosine Diphosphate Ribose/metabolism , Catalysis , Electrophoresis, Polyacrylamide Gel , Escherichia coli/genetics , Exotoxins/pharmacology , Genes, Bacterial , Immunoglobulin Light Chains/metabolism , Peptide Elongation Factor Tu/metabolism , Plasmids , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/toxicity , Staphylococcal Protein A/genetics , Tumor Cells, Cultured/drug effects , Pseudomonas aeruginosa Exotoxin AABSTRACT
Monoclonal antibodies to proteins of polyribosome-bound informosomes from rabbit reticulocytes were obtained. Using the immunoblotting technique, it was shown that antibodies produced by one of the clones react with several polypeptides of polyribosome-bound informosomes.