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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1992-6-30
pubmed:abstractText
B3 is a tumor-reactive monoclonal antibody (mAb) that binds to a limited number of normal tissues. Immunotoxins made with B3 coupled to either Pseudomonas exotoxin (PE) or recombinant forms of PE with a deletion of the cell-binding domain (LysPE40) have been shown to cause complete tumor regression in nude mice bearing a rapidly growing A431 (L. H. Pai et al., Proc. Natl. Acad. Sci. USA, 88: 3358-3362, 1991) human epidermoid carcinoma. In this study we show that an immunotoxin composed of mAb B3 when chemically coupled to LysPE40 (B3-LysPE40) led to complete regression of a slowly growing breast cancer, MCF-7, in nude mice when given i.v. every other day for five doses. mAb B3 coupled to native PE also produced significant regression of the MCF-7 tumor. The reactivity of mAb B3 was evaluated using an immunohistochemical method on the two responsive tumors, MCF-7 and A431, and compared with a typical human colon carcinoma specimen that has B3 antigen on its surface. The results showed that both A431 and MCF-7 xenograft tumors have similar reactivity to B3 when compared with the human colon carcinoma specimen. To evaluate the toxicity of B3-PE in primates, Cynomolgus monkeys received escalating doses of B3-PE i.v. on Days 1, 3, and 5. Based on antibody localization studies using frozen sections of normal human and monkey tissue, gastric, trachea, and bladder mucosal injury could have occurred. However, no clinical signs of injury or histological damage to these organs were seen at the doses administered. Chemical hepatitis due to PE was transient and well tolerated at doses up to 50 micrograms/kg for three doses. The lethal dose was about 100 micrograms/kg, and the cause of death was liver necrosis, as shown by necropsy. We conclude that mAb B3, when coupled to PE40 or PE, can produce strong antitumor activity in vivo. The similar level of reactivity of the B3 antibody in our tumor models with a surgical specimen of a human colon carcinoma and the toxicity study in monkeys indicate that therapeutic doses of B3-PE and B3-LysPE40 can be delivered without causing toxicity to normal organs that express B3 antigen. Although both B3-PE and B3-LysPE40 have antitumor activity in nude mice bearing a human xenograft, B3-LysPE40 is better tolerated and should be further evaluated as a therapeutic agent for cancer patients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3189-93
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed-meshheading:1591729-ADP Ribose Transferases, pubmed-meshheading:1591729-Amino Acid Sequence, pubmed-meshheading:1591729-Animals, pubmed-meshheading:1591729-Antibodies, Monoclonal, pubmed-meshheading:1591729-Antigens, Neoplasm, pubmed-meshheading:1591729-Bacterial Toxins, pubmed-meshheading:1591729-Base Sequence, pubmed-meshheading:1591729-Breast Neoplasms, pubmed-meshheading:1591729-Cell Line, pubmed-meshheading:1591729-Chromosome Deletion, pubmed-meshheading:1591729-Exotoxins, pubmed-meshheading:1591729-Female, pubmed-meshheading:1591729-Humans, pubmed-meshheading:1591729-Immunotoxins, pubmed-meshheading:1591729-Macaca fascicularis, pubmed-meshheading:1591729-Mice, pubmed-meshheading:1591729-Mice, Nude, pubmed-meshheading:1591729-Molecular Sequence Data, pubmed-meshheading:1591729-Neoplasm Transplantation, pubmed-meshheading:1591729-Pseudomonas aeruginosa, pubmed-meshheading:1591729-Recombinant Proteins, pubmed-meshheading:1591729-Transplantation, Heterologous, pubmed-meshheading:1591729-Tumor Cells, Cultured, pubmed-meshheading:1591729-Virulence Factors
pubmed:year
1992
pubmed:articleTitle
Antitumor effects of B3-PE and B3-LysPE40 in a nude mouse model of human breast cancer and the evaluation of B3-PE toxicity in monkeys.
pubmed:affiliation
Laboratory of Molecular Biology, DCBDC, National Cancer Institute, NIH, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article