Abstract
In recent years chimeric proteins carrying bacterial toxins as their killing moiety, have been developed to selectively recognize and kill cell populations expressing speciific receptors. The involvement of Gonadotropin releasing hormone (GnRH) has been demonstrated in several adenocarcinomas and a GnRH-bacterial toxin chimeric protein (GnRH-PE66) was thus developed and found to specifically target and kill adenocarcinoma cells both in vitro and in vivo. Because of the immunogenicity and the non-specific toxicity of the bacterial toxins, we have developed new chimeric proteins, introducing apoptosis inducing proteins of the Bcl-2 family as novel killing components. Sequences encoding the human Bik, Bak or Bax proteins were fused to the GnRH coding sequence at the DNA level and were expressed in E. coli. GnRH-Bik, GnRH-Bak and GnRH-Bax new chimeric proteins efficiently and specifically inhibited the cell growth of adenocarcinoma cell lines and eventually led to cell death. All three Bcl2-proteins-based chimeric proteins seem to induce apoptosis within the target cells, without any additional cell death stimulus. Apoptosis-inducing-proteins of the Bcl-2 family targeted by the GnRH are novel potential therapeutic reagents for adenocarcinoma treatment in humans. This novel approach could be widely applied, using any molecule that binds a specific cell type, fused to an apoptosis-inducing protein.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenocarcinoma / drug therapy*
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Adenocarcinoma / metabolism
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Adenocarcinoma / physiopathology
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Animals
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Antineoplastic Agents / pharmacology*
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Apoptosis / drug effects*
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Apoptosis / physiology
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Apoptosis Regulatory Proteins
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Gonadotropin-Releasing Hormone / genetics
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Gonadotropin-Releasing Hormone / metabolism
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Gonadotropin-Releasing Hormone / pharmacology
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Humans
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Membrane Proteins / pharmacology
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Mice
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Mitochondrial Proteins
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Plasmids / chemical synthesis
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Plasmids / genetics
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Proteins / genetics
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Proteins / metabolism
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Proteins / pharmacology
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Proto-Oncogene Proteins / genetics
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Proto-Oncogene Proteins / metabolism
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Proto-Oncogene Proteins / pharmacology
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Proto-Oncogene Proteins c-bcl-2 / metabolism
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Proto-Oncogene Proteins c-bcl-2 / pharmacology*
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / pharmacology*
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Transfection / methods
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Tumor Cells, Cultured / drug effects*
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Tumor Cells, Cultured / metabolism
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bcl-2 Homologous Antagonist-Killer Protein
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bcl-2-Associated X Protein
Substances
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Antineoplastic Agents
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Apoptosis Regulatory Proteins
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BAK1 protein, human
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BAX protein, human
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BIK protein, human
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Bak1 protein, mouse
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Bax protein, mouse
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Membrane Proteins
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Mitochondrial Proteins
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Proteins
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Proto-Oncogene Proteins
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Proto-Oncogene Proteins c-bcl-2
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Recombinant Fusion Proteins
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bcl-2 Homologous Antagonist-Killer Protein
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bcl-2-Associated X Protein
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Gonadotropin-Releasing Hormone