Linked Life Data

9581824

Source:http://linkedlifedata.com/resource/pubmed/id/9581824

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1998-6-2
pubmed:abstractText
Recent data suggest that somatostatin receptors (SSTRs) are expressed on various tumor cells. High-level expression of SSTR on the tumor cell surface provides the basis for the successful clinical use of radiolabeled ligands for the in vivo localization of tumor sites. We have characterized the in vitro binding properties of the novel SSTR ligand 99mTc-P829 using primary human tumors (carcinoids, breast cancers, intestinal adenocarcinomas, pheochromocytomas, small cell and non-small cell lung cancer, and melanomas; n = 28), various tumor cell lines, and COS7 cells transfected with the human SSTR (hSSTR) subtypes 1, 2, 3, 4, and 5. 99mTc-P829 bound to primary tumor cells and tumor cell lines with high affinity and high capacity. The dissociation constants (Kd) ranged between 1 and 20 nM. 99mTc-P829 also bound with high affinity to the transfected hSSTR2 (Kd, 2.5 nM), hSSTR5 (Kd, 2 nM), and hSSTR3 (Kd, 1.5 nM). Binding of 99mTc-P829 to hSSTR3 was found to be displaceable by unlabeled P829/([ReO]-P829), SST-14, and vasoactive intestinal peptide (VIP; IC50, 2 nM) and, less effectively, by Tyr3-octreotide (IC50, 20 nM). In contrast, the binding of 99mTc-P829 to hSSTR2 and hSSTR5 could be displaced by P829/([ReO]-P829) and Tyr3-octreotide but not by VIP. 99mTc-P829 scintigraphy revealed in vivo binding to primary or metastatic tumor sites in seven of eight patients with breast cancer and six of six patients with melanoma. In summary, our data show that 99mTc-P829 binds with high affinity to many different types of primary and cloned tumor cells. Furthermore, our data identify hSSTR2, the VIP acceptor hSSTR3, and hSSTR5 as the respective target receptors. Because these receptors are frequently expressed at high levels on primary tumor cells, 99mTc-P829 appears to be a promising novel peptide tracer for tumor imaging.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
58
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1850-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Somatostatin receptor subtype specificity and in vivo binding of a novel tumor tracer, 99mTc-P829.
pubmed:affiliation
Department of Nuclear Medicine, University of Vienna, Austria. irene.virgolini@akh-wien.ac.at
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't