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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1992-11-13
pubmed:abstractText
We have analyzed the expression of the multidrug resistance (mdr-1) gene product, P-glycoprotein, by immunohistochemical staining of frozen tissue sections of human normal muscle fibers and 31 tissue specimens of cases of myogenic sarcomas. The objective of this study was to further characterize what appears to be a variety of responses to therapy in like-appearing but distinct tumors. We have used two mouse monoclonal antibodies that recognize two different epitopes of P-glycoprotein. Mouse monoclonal antibody HYB-241 detects an extracellular epitope of P-glycoprotein, whereas C219 detects a carboxy-terminal intracellular epitope and has recently been reported to cross-react with the mdr-3 gene product. Differential epitope expression was observed among normal muscle fibers with the two antibodies used. Smooth-muscle cells were unreactive for the two antibodies, whereas cardiac and a subgroup of skeletal muscle fibers were intensely stained by C219, but not by HYB-241. P-glycoprotein expression was observed in 23% of the 31 myogenic sarcomas analyzed. Our study was conducted mainly using adult myogenic sarcomas (28 out of 31 cases), with a few cases (three out of 31 cases) of childhood sarcomas. Nineteen tumors were leiomyosarcomas, seven cases were embryonal rhabdomyosarcomas, and five cases were rhabdomyosarcomas. We have considered expression of the mdr-1-coded P-glycoprotein when we observed either HYB-241 and C219 staining, or just HYB-241 immunoreactivities. Although P-glycoprotein expression can now be detected in human sarcomas, further studies are needed, mainly comparing tumor samples before, during, and after therapy, to establish the possible significance of the P-glycoprotein expression in clinical drug resistance.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0003-9985
pubmed:author
pubmed:issnType
Print
pubmed:volume
116
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1055-61
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Expression of P-glycoprotein in normal muscle cells and myogenic tumors.
pubmed:affiliation
Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't