ABSTRACT: The peptide ghrelin is the endogenous ligand for the growth-hormone secretagogue receptor (GHSR), also referred to as the ghrelin receptor. While the primary role of ghrelin relates to appetite regulation, there is increasing evidence for the cancer associated implications of the presence of the GHSR. We are developing a variety of fluorine-containing ghrelin analogues for the purpose of molecular imaging of the GHSR and as potential diagnostic-therapeutic pairs. In this seminar I will describe our efforts to create high affinity fluorine-containing ligands that target the GHSR. These truncated peptides and small molecules have been successfully radiolabelled with 18F for PET imaging, while also having the potential to be used as peptide therapeutics with natural 19F. Dimerization of the GHSR is believed to play an important role in signalling and we have discovered a bivalent ligand capable of inducing and stabilizing the receptor homodimer, with unique signalling characteristics.
BIO: Dr. Len Luyt received his Ph.D. from the University of Western Ontario in Chemistry and subsequently undertook a post-doctoral fellowship with Prof. John Katzenellenbogen at the University of Illinois, Urbana-Champaign. He then led a research team as a Senior Medicinal Chemist with the pharmaceutical company Bayer-Schering. Dr. Luyt joined Western University in 2005 as a faculty member with appointments in the departments of Chemistry, Oncology and Medical Imaging. He has published 57 journal articles, 5 book chapters and has 10 patents granted or applied for. He was awarded the Early Researcher Award (ERA) from the Ministry of Research and Innovation and has held peer-reviewed grant funding from NSERC, CIHR, OICR, Prostate Cancer Canada, Cancer Research Society and the Canadian Breast Cancer Foundation. The research program of Dr. Luyt spans from basic chemistry activities, looking at novel methods of incorporating metal complexes into peptide structures, through to applied research, investigating new peptide therapeutics and molecular imaging agents for novel cancer targets.