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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1995-6-29
pubmed:abstractText
A cephalosporin derivative of doxorubicin (C-Dox) was evaluated as a prodrug for activation by mAb conjugates of the beta-lactamase from Enterobacter cloacae P99 (beta L; EC 3.5.2.6). The conjugates consisted of beta L and the F(ab') fragments of either of the mAbs L6, P1.17, or 96.5. L6 binds to antigens on a variety of carcinomas, including the two lung adenocarcinoma cell lines H2981 and H2987 used in this study. 96.5 binds to the melanoma-associated antigen p97, and P1.17 was used for the control conjugate. C-Dox was found to be less cytotoxic to three different tumor cell lines in vitro compared to the parent drug doxorubicin (Dox). Immunospecific activation took place when the cells were pretreated with beta L conjugates that could bind to antigens on the tumor cells. In vivo toxicity and pharmacokinetics studies in athymic female nu/nu mice revealed that C-Dox was at least 7-fold less toxic than Dox (on a molar basis), despite the fact that a > or = 320-fold greater area-under-the-curve (blood concentration versus time) of C-Dox compared to Dox was obtained 0-2 h after administration of the two agents. Pharmacokinetic studies at maximum tolerated doses in mice bearing xenografts of either H2981 or H2987 revealed that the intratumoral levels of Dox after treatment with L6-beta L in combination with C-Dox were higher than were obtained by either systemic treatment with Dox or a combination of P1.17-beta L and C-Dox. This finding suggested that the conversion of C-Dox to Dox was tumor specific and dependent on the presence of the targeted antigen. Furthermore, the best antitumor activity against both H2981 and H2987 tumors was obtained by treatment with L6-beta L and C-Dox compared to P1.17-beta L and C-Dox or Dox alone. Thus, higher levels of Dox corresponded to greater therapeutic effects in both of the tumor models studied.
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
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2357-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7757987-Adenocarcinoma, pubmed-meshheading:7757987-Animals, pubmed-meshheading:7757987-Antibodies, Monoclonal, pubmed-meshheading:7757987-Biotransformation, pubmed-meshheading:7757987-Doxorubicin, pubmed-meshheading:7757987-Female, pubmed-meshheading:7757987-Humans, pubmed-meshheading:7757987-Hydrolysis, pubmed-meshheading:7757987-Immunoglobulin Fragments, pubmed-meshheading:7757987-Immunotoxins, pubmed-meshheading:7757987-Kinetics, pubmed-meshheading:7757987-Lung Neoplasms, pubmed-meshheading:7757987-Mice, pubmed-meshheading:7757987-Mice, Nude, pubmed-meshheading:7757987-Neoplasm Transplantation, pubmed-meshheading:7757987-Prodrugs, pubmed-meshheading:7757987-Sensitivity and Specificity, pubmed-meshheading:7757987-Tissue Distribution, pubmed-meshheading:7757987-Transplantation, Heterologous, pubmed-meshheading:7757987-beta-Lactamases
pubmed:year
1995
pubmed:articleTitle
In vitro and in vivo activities of a doxorubicin prodrug in combination with monoclonal antibody beta-lactamase conjugates.
pubmed:affiliation
Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121, USA.
pubmed:publicationType
Journal Article, Comparative Study