Radiolabeled bombesin derivatives for preclinical oncological imaging

Abstract

Despite efforts, cancer is still one of the leading causes of morbidity and mortality worldwide, with approximately 14 million new cases and 8.2 million cancer-related deaths each year, according to the World Health Organization. Among the strategies to reduce cancer progression and improving its management, implementing early detection technologies is crucial. Based on the fact that several types of cancer cells overexpress surface receptors, small molecule ligands, such as peptides, have been developed to allow tumor identification at earlier stages. Allied with imaging techniques such as PET and SPECT, radiolabeled peptides play a pivotal role in nuclear medicine. Bombesin, a peptide of 14 amino acids, is an amphibian homolog to the mammalian gastrin-releasing peptide (GRP), that has been extensively studied as a targeting ligand for diagnosis and therapy of GRP positive tumors, such as breast, pancreas, lungs and prostate cancers. In this context, herein we provide a review of reported bombesin derivatives radiolabeled with a multitude of radioactive isotopes for diagnostic purposes in the preclinical setting. Moreover, since animal models are highly relevant for assessing the potential of clinical translation of this radiopeptides, a brief report of the currently used GRP-positive tumor-bearing animal models is described.

Synthesis of 2,5‐Disubstituted‐1,3,4‐oxadiazole Derivatives and Their Evaluation as Anticancer and Antimycobacterial Agents

“…Neoplaisa (abnormal growth of cells) usually leads to malignant tumours there by causing the complex disease cancer and spreads to distant sites, various tissues/organs of the body parts thus leading to morbidity and mortality across the globe . According to the world organisation of health estimates, approximately 14.1 million new cases and 8.2 million cancer related deaths were registered in 2012 and is likely to increase by 2030 thus posing a negative impact on the society ,. Conversely, the existing chemotherapy regimens are unsuccessful to deliver the expectations and resistance developed to them, ambiguity about the origin of cancer, process of cell division, metastatic scenery of cancer cells, efficient dispersion of drug to cancer tissues are some of the major hurdles for winning this challenging disorder ,.…”

The role of radionuclide probes for monitoring anti-tumor drugs efficacy: A brief review

“…However, the most important advantages of PET imaging over SPECT is the capacity for greater spatial resolution and sensitivity (by approximately two to three orders of magnitude), the ability to detect and record a higher percentage of the emitted events, which leads to improved image quality, improved temporal resolution and the possibility of performing shorter scans. In the recent years, the molecular imaging field has tended toward the use of PET imaging not only because of its sensitive advantage but also due to the increasing availability of PET imaging isotopes and its radiolabeling methods optimization [47]. A great number of PET isotopes have been increasingly used in the last years, ranging from short-lived types such as 15 0, 11 C, 13 N, 82 Rb to radioisotopes with longer half-lives, such as 76 Br, 86 Y, 89 Zr, and 124 I [48–50].…”

Synthesis, radiolabeling, and evaluation of gastrin releasing peptide receptor antagonist 68Ga‐HBED‐CC‐RM26

“…The elevated expression of gastrin releasing peptide receptors (GRPrs) in prostate cancer, breast cancer, and small‐cell and non‐small‐cell lung carcinomas has explicitly favored designing of radiolabeled peptides as GRPr‐specific probes . The enormous presentation of GRP receptors, especially in prostate and breast cancer specimens, has ensured GRPr to be a prospective target for imaging and therapy of these cancers.…”