Linked Life Data

12852770

Source:http://linkedlifedata.com/resource/pubmed/id/12852770

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2003-7-10
pubmed:abstractText
The prevalence of neurotensin receptor (NTR) in several human tumors makes it an attractive target for the delivery of cytotoxic drugs and imaging agents. Native neurotensin (NT) is a tridecapeptide that binds to NTR and induces tumor growth. Unfortunately, NT has a short plasma half-life, which hinders its use for in vivo biomedical applications. Numerous reports suggest that Arg(8)-Arg(9) and Tyr(11)-Ile(12) amide bonds are particularly susceptible to degradation by proteolytic enzymes. Predicated on this observation, we substituted Arg(8), Arg(9), and Ile(12) amino acids with the corresponding commercially available mimics. These surrogate amino acids are amenable to standard Fmoc peptide synthesis strategy, and the resulting compounds are stable in biological media for >4 h and bind to NTR with high affinity. Furthermore, conjugating DTPA to the new peptides and subsequent labeling with (111)In-DTPA for nuclear imaging or fluorescein for optical imaging did not diminish the NTR binding affinities of the peptides. In vivo biodistribution of a representative (111)In-DTPA-NT peptide analogue in SCID mice bearing NTR-positive human adenocarcinoma (HT29) xenograft shows that the compound was primarily retained in tumor tissue (2.2% ID/g) and the kidneys (4.8% ID/g) at 4 h postinjection. Coinjection of cold NT and the radiolabeled NT peptide analogue inhibited the tumor but not the kidney uptake, demonstrating that retention of the radiolabeled compound in tumor tissue was mediated by NTR specific uptake while it accumulates in the kidneys by a nonspecific mechanism. These findings show that the new NT peptide analogues are robust and can deliver imaging agents to NTR-positive tumors such as pancreatic cancer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3403-11
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed-meshheading:12852770-Adenocarcinoma, pubmed-meshheading:12852770-Animals, pubmed-meshheading:12852770-Antineoplastic Agents, pubmed-meshheading:12852770-Binding, Competitive, pubmed-meshheading:12852770-Chelating Agents, pubmed-meshheading:12852770-Drug Stability, pubmed-meshheading:12852770-Fluorescent Dyes, pubmed-meshheading:12852770-Humans, pubmed-meshheading:12852770-Indium Radioisotopes, pubmed-meshheading:12852770-Mice, pubmed-meshheading:12852770-Mice, SCID, pubmed-meshheading:12852770-Molecular Mimicry, pubmed-meshheading:12852770-Neoplasm Transplantation, pubmed-meshheading:12852770-Neoplasms, Experimental, pubmed-meshheading:12852770-Neurotensin, pubmed-meshheading:12852770-Oligopeptides, pubmed-meshheading:12852770-Pentetic Acid, pubmed-meshheading:12852770-Radiopharmaceuticals, pubmed-meshheading:12852770-Rats, pubmed-meshheading:12852770-Receptors, Neurotensin, pubmed-meshheading:12852770-Structure-Activity Relationship, pubmed-meshheading:12852770-Tissue Distribution, pubmed-meshheading:12852770-Transplantation, Heterologous
pubmed:year
2003
pubmed:articleTitle
Novel bioactive and stable neurotensin peptide analogues capable of delivering radiopharmaceuticals and molecular beacons to tumors.
pubmed:affiliation
Mallinckrodt Institute of Radiology, Washington University School of Medicine, 4525 Scott Avenue, St. Louis, Missouri 63110, USA. achilefus@mir.wustl.edu
pubmed:publicationType
Journal Article