title: Targeting phosphodiesterases as a strategy for killing tumor cells.
abstract: Ribonucleases (RNases) are being employed as alternative cytotoxic proteins to the conventionally used ones such as ricin and Pseudomonas exotoxin. Mammalian RNases are attractive enzymes because of their comparable cytotoxicity when suitably directed and the likelihood of lower immunogenicity compared to plant and bacterial toxins. Bovine seminal RNase (BSRNase) is a member of the RNase superfamily, but differs in many interesting ways. Unlike the rest of the family it is dimeric, and possesses antitumor and immunosuppressive properties. These features make it a choice candidate for a single-chain antibody (scFv) based immunotoxin. This work describes preliminary data on the construction, expression in Escherichia coli and characterization of a tumor-specific scFv (directed against human placental alkaline phosphatase)-BSRNase chimeric molecule. It is shown that the created molecule has RNA degrading activity and antigen-binding activity when refolded from bacterial inclusion bodies.
authors.affiliation: Tumour Targeting Laboratory, Imperial Cancer Research Fund, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
authors.forename: M P
authors.initials: MP
authors.lastname: Deonarain
authors.forename: A A
authors.initials: AA
authors.lastname: Epenetos
mesh_terms: D000818:Animals; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D004926:Escherichia coli; D005822:Genetic Vectors; D006801:Humans; D000922:Immunotoxins / Q000627:therapeutic use*; D009369:Neoplasms / Q000628:therapy*; D010727:Phosphoric Diester Hydrolases / Q000096:biosynthesis / Q000235:genetics / Q000627:therapeutic use*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012260:Ribonucleases / Q000096:biosynthesis / Q000235:genetics / Q000627:therapeutic use*
chemical_list: D000922:Immunotoxins; D011993:Recombinant Fusion Proteins; D012260:Ribonucleases; D010727:Phosphoric Diester Hydrolases