title: Preclinical development of a recombinant toxin containing circularly permuted interleukin 4 and truncated Pseudomonas exotoxin for therapy of malignant astrocytoma.
abstract: Effective treatment is lacking for malignant glioblastoma/astrocytoma. We have identified interleukin-4 receptors (IL-4R) on human malignant astrocytoma. We demonstrate that 16 of 21 surgical samples of high-grade astrocytoma and glioblastoma but not normal brain tissues expressed IL-4R as assessed by reverse transcriptase PCR. We further demonstrate that human malignant astrocytoma cell lines express high-affinity IL-4R. Using a chimeric protein composed of circularly permuted IL-4 and a truncated form of Pseudomonas exotoxin A, we observed that this toxin IL4(38-37)-PE38KDEL) is highly cytotoxic to IL-4R-bearing glioblastoma cells. Compared with a previously reported IL4-PE chimeric protein (IL-PE4E), IL4(38-37)-PE38KDEL bound with higher affinity and was 3-30-fold more cytotoxic to glioblastoma cell lines. Upon intrathecal administration in monkeys, high cerebrospinal fluid IL4(38-37)-PE38KDEL levels were achieved using 2- and 6-microg/kg doses without any central nervous system or other abnormalities. IL4(38-37)-PE38KDEL levels were not detectable in the serum of any monkey studied. When IL4(38-37)-PE38KDEL was injected into the right frontal cortex of rats, localized necrosis was observed at 1000-ng/ml doses but not at < or = 100-ng/ml doses. We conclude that by localized administration, nontoxic levels of IL4(38-37)-PE38KDEL can be achieved, which may have significant cytotoxic activity against malignant astrocytoma.
authors.affiliation: Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, NIH, Bethesda, Maryland 20892, USA. puri@a1.cber.fda.gov
authors.forename: R K
authors.initials: RK
authors.lastname: Puri
authors.forename: D S
authors.initials: DS
authors.lastname: Hoon
authors.forename: P
authors.initials: P
authors.lastname: Leland
authors.forename: P
authors.initials: P
authors.lastname: Snoy
authors.forename: R W
authors.initials: RW
authors.lastname: Rand
authors.forename: I
authors.initials: I
authors.lastname: Pastan
authors.forename: R J
authors.initials: RJ
authors.lastname: Kreitman
mesh_terms: D036002:ADP Ribose Transferases; D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D001254:Astrocytoma / Q000188:drug therapy* / Q000378:metabolism; D001427:Bacterial Toxins / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D004354:Drug Screening Assays, Antitumor; D005098:Exotoxins / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D000922:Immunotoxins / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D007278:Injections, Spinal; D015847:Interleukin-4 / Q000009:adverse effects / Q000378:metabolism / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008252:Macaca fascicularis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D000970:Antineoplastic Agents; D001427:Bacterial Toxins; D005098:Exotoxins; D000922:Immunotoxins; D015847:Interleukin-4; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A