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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2000-9-7
pubmed:abstractText
Heregulin (Hrg) growth factors are natural ligands for ErbB3 and ErbB4. Because these receptors are involved in papillary thyroid carcinomas, we studied expression of Hrgs in fresh-frozen thyroid tissue and analyzed for possible coexpressions among the 4 members of the ErbB family of growth factor receptors and Hrgs in papillary carcinomas. Immunohistochemistry for the Hrg precursor isoform (134 biopsies from 101 patients) showed nuclear immunostaining in 83% of papillary carcinomas but not in normal thyroid tissue. Cytoplasmic immunopositivity for the Hrg precursor isoform was moderate or strong in 78% of papillary carcinoma specimens and weak in 13% of normal thyroid tissue samples. Western blot for the Hrg precursor isoform showed the expected protein band of approximately 70 kDa in papillary carcinomas, but not in non-neoplastic thyroid biopsies. Whereas weak cytoplasmic immunostaining for the mature Hrg alpha, beta1, and beta3, was present in 48, 38, and 51% of papillary carcinomas, respectively, normal thyroid tissue samples were negative. Hrg mRNA was present in both tumor and nontumor tissue, with evidence of increased mRNA expression in 5 of 12 papillary carcinomas. RT-PCR of hrg mRNA, with subsequent DNA sequencing, confirmed the presence of hrg alpha, beta1, beta2, and beta3 mRNA in papillary carcinomas. In 55 papillary carcinomas, increased cytoplasmic immunostaining of the ErbB2 and ErbB3 receptors was significantly associated with each other and with cytoplasmic epidermal growth factor receptor (EGFR) immunoreactivity, indicating a common regulatory mechanism. Cytoplasmic staining for Hrg beta3 was significantly associated with ErbB3 immunostaining, indicating this receptor as the cognate one. The overexpression and nuclear localization of the Hrg precursor isoform were not associated with the expression of ErbB-receptors. This may reflect an unknown mechanism of action, possibly independent of the ErbB receptor system.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0020-7136
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
87
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
763-70
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Expression of heregulins and associations with the ErbB family of tyrosine kinase receptors in papillary thyroid carcinomas.
pubmed:affiliation
Department of Molecular Biology, University of Bergen, Bergen, Norway. oystein.fluge@mbi.uib.no
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't