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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
9
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pubmed:dateCreated |
1996-1-4
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pubmed:databankReference | |
pubmed:abstractText |
ACTH secretion by tumors of nonpituitary origin is characteristically resistant to negative feedback regulation by glucocorticoids. One possible mechanism for the phenomenon could be a structural defect in the intracellular glucocorticoid receptor (GR). We studied the GR in DMS-79 cells derived from a human ACTH-secreting small cell lung cancer. Compared with control cells, DMS-79 cells were found to have greatly diminished GR ligand-binding activity and immunoreactive 94-kilodalton (kDa) GR content. Northern blot analysis revealed expression of GR transcripts that appeared to be slightly larger than those in control cells. A DMS-79 cell GR cDNA was cloned by reverse transcription/polymerase chain reaction amplification of mRNA using primers specific for full-length normal GR. The derived sequence of this full-length GR differed from the reported sequence by a single altered codon (G to A; Asn to Ser at codon 363) outside the steroid-binding domain. This N363S DMS-79 GR functioned normally to activate a target gene [mouse mammary tumor virus-chloramphenicol acetyl transferase (MMTV-CAT)] in transient transfection experiments in COS cells. Evidence for expression of a second type of GR mRNA was obtained by screening a DMS-79 cell cDNA library. This GR cDNA contained normal GR sequence up to nucleotide 2155, corresponding exactly to the end of exon 7 in the normal GR gene. The sequence appended to the GR sequences was not matched by any known sequence in DNA databases and included an in-frame termination codon after only 6 bases. The predicted truncated GR protein product (GR delta) has a mol wt of 73,740 and lacks most of the ligand-binding domain. Transient transfection of the GR delta form into COS cells did not reveal any dominant negative effect on the function of a cotransfected normal GR.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0888-8809
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
9
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1193-201
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:7491111-Adrenocorticotropic Hormone,
pubmed-meshheading:7491111-Animals,
pubmed-meshheading:7491111-Base Sequence,
pubmed-meshheading:7491111-Blotting, Northern,
pubmed-meshheading:7491111-Carcinoma, Small Cell,
pubmed-meshheading:7491111-DNA, Complementary,
pubmed-meshheading:7491111-Humans,
pubmed-meshheading:7491111-Lung Neoplasms,
pubmed-meshheading:7491111-Mice,
pubmed-meshheading:7491111-Molecular Sequence Data,
pubmed-meshheading:7491111-RNA, Messenger,
pubmed-meshheading:7491111-Receptors, Glucocorticoid,
pubmed-meshheading:7491111-Signal Transduction,
pubmed-meshheading:7491111-Transfection,
pubmed-meshheading:7491111-Tumor Cells, Cultured
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pubmed:year |
1995
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pubmed:articleTitle |
Glucocorticoid receptor structure and function in an adrenocorticotropin-secreting small cell lung cancer.
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pubmed:affiliation |
Division of Endocrinology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.
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