Arginine-glycine-aspartic acid (RGD) peptides preferentially bind to alphavbeta3 integrin, an integrin expressed on newly formed endothelial cells and on various tumor cells. When labeled with beta-emitting radionuclides, these peptides can be used for peptide-receptor radionuclide therapy of malignant tumors. These studies aimed to investigate whether tumor targeting and tumor therapy could be...

The identification of specific cell surface glycoprotein receptors for Arg-Gly-Asp-containing extracellular matrix proteins such as fibronectin has focused attention on the role of gangliosides in this process. Is their involvement dependent or independent of the protein receptors? In attachment assays with cells from a human melanoma cell line, titration experiments with an antibody (Mel 3) wi...

Maurocalcine (MCa) is the first natural cell penetrating peptide to be discovered in animal venom. In addition to the fact that it represents a potent vector for the cell penetration of structurally diverse therapeutic compounds, MCa also displays several distinguishing features that make it a potential peptide of choice for clinical and biotechnological applications. The aim of the present stu...

Relaxin-3, the most recently identified member of relaxin/insulin family, is an agonist for leucine-rich repeat-containing G protein-coupled receptor (LGR)7, GPCR135, and GPCR142. LGR7 can be pharmacologically differentiated from GPCR135 and GPCR142 by its high affinity for relaxin. Selective ligands that specifically activate GPCR135 or GPCR142 are highly desirable for studying their functiona...

UNLABELLED The glucagon-like peptide-1 (GLP-1) receptors are important biomarkers for imaging pancreatic β-cell mass and detection of benign insulinomas. Using GLP-1 receptor antagonists, we aimed to eliminate the insulin-related side effects reported for all GLP-1 receptor agonists. Additionally, using a nonresidualizing tracer, (125)I-Bolton-Hunter-Exendin(9-39)NH2 ((125)I-BH-Ex(9-39)NH2), we...

The potential of PACE4 as a pharmacological target in prostate cancer has been demonstrated as this proprotein convertase is strongly overexpressed in human prostate cancer tissues and its inhibition, using molecular or pharmacological approaches, results in reduced cell proliferation and tumor progression in mouse tumor xenograft models. We developed a PACE4 high-affinity peptide inhibitor, na...

We developed 211 At-radiolabeled 2,6-diisopropylphenyl azide (ADIPA) for targeted α-particle therapy. In the experiment using a mouse model, low-dose (70 kBq) administration of ADIPA effectively suppressed tumor growth without causing adverse effects.

UNLABELLED Imaging agents based on peptide probes have desirable pharmacokinetic properties provided that they have high affinities for their target in vivo. An approach to improve a peptide ligand's affinity for its target is to make this interaction covalent and irreversible. For this purpose, we evaluated a (64)Cu-labeled affinity peptide tag, (64)Cu-L19K-(5-fluoro-2,4-dinitrobenzene) ((64)C...