Article

Synthesis, radiolabelling and biological characteristics of a bombesin peptide analog as a tumor imaging agent.

Cyclotron and Radiopharmaceuticals Department, King Faisal Specialist Hospital and Research Centre, MBC-03, PO Box 3354, Riyadh 11211, KSA.
Anticancer research (Impact Factor: 1.87). 01/2003; 23(3B):2745-50.
Source: PubMed

ABSTRACT Several human cancers, including small cell lung, prostate, breast, gastric, colon and pancreatic cancers, express receptors for bombesin-like peptides. Bombesin (BN) peptides that bind specifically to these receptors are useful for detection of bombesin receptor-expressing cancers in vivo. A new 99mTc-labelled-BN peptide for targeting bombesin receptor-expressing cancers was prepared and characterized.
MAG3-coupled BN peptide (MAG3-BN) was prepared by solid-phase synthesis and radiolabelled with 99mTc by an exchange method. In vitro cell binding assays were conducted on human breast cancer cell lines, MDA-MB-231 and MCF-7. In vivo biodistribution studies were performed in normal and nude mice bearing bombesin receptor-positive tumors.
Radiolabelling of MAG3-BN with 99mTc produces a single radioactive species (> 95%). In vitro cell-binding indicated the affinity and specificity of 99mTc-MAG3-BN towards bombesin receptors. In vivo biodistribution in mice demonstrated that 99mTc-MAG3-BN cleared rapidly from the blood and most non-targeted tissues and was excreted mainly via the kidneys. Uptake in bombesin receptor-positive tissues and in the tumor was low to moderate.
99mTc-MAG3-BN displays good radiolabelling together with certain favorable biological characteristics and might be a useful peptide radiopharmaceutical in the detection of bombesin receptor-expressing cancers in vivo.

Download full-text

Full-text

Available from: S. M. Okarvi, Jun 26, 2015
0 Followers
 · 
153 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The fact that a number of common human tumours, including those of breast and prostate, express increased levels of the gastrin-releasing peptide receptor (GRP-R) means that this receptor is a potential target for peptide receptor mediated scintigraphy and targeted radionuclide therapy. Although clinical application is yet in its infancy, there is a considerable literature on preclinical studies aimed at developing suitable radioligands for potential clinical application. This brief review provides an overview of this research and also describes some of the limited clinical studies that have been published.
    Cancer Imaging 02/2006; 6(1):153-7. DOI:10.1102/1470-7330.2006.0025 · 1.29 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Radiolabelled peptides are used for specific targeting of receptors (over-)expressed by tumour cells. Dependent on the kind of labelling and the radionuclide used, these compounds may be utilised for imaging or for therapy. A concise overview is provided on basic principles of designing and developing radiopeptides for these applications. Furthermore, clinical application of these compounds for imaging and therapy is described. Advantages of the method compared to other techniques (such as the use of radiolabelled antibodies or antibody fragments) are discussed as well as pitfalls and limitations.
    Cancer Imaging 02/2006; 6(Spec No A):S178-84. DOI:10.1102/1470-7330.2006.9038 · 1.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Accurate and rapid detection of tumors is of great importance for interrogating the molecular basis of cancer pathogenesis, preventing the onset of complications, and implementing a tailored therapeutic regimen. In this era of molecular medicine, molecular probes that respond to, or target molecular processes are indispensable. Although numerous imaging modalities have been developed for visualizing pathologic conditions, the high sensitivity and relatively innocuous low energy radiation of optical imaging method makes it attractive for molecular imaging. While many human diseases have been studied successfully by using intrinsic optical properties of normal and pathologic tissues, molecular imaging of the expression of aberrant genes, proteins, and other pathophysiologic processes would be enhanced by the use of highly specific exogenous molecular beacons. This review focuses on the development of receptor-specific molecular probes for optical imaging of tumors. Particularly, bioconjugates of probes that absorb and fluoresce in the near infrared wavelengths between 750 and 900 nm will be reviewed.
    Technology in cancer research & treatment 09/2004; 3(4):393-409. DOI:10.1177/153303460400300410 · 1.89 Impact Factor