Bombesin is a 14-amino acid peptide. The bombesin (Bn) receptor family includes the gastrin-releasing peptide (GRPR) and neuromedin B (NMBR) receptors, Bn receptor subtype 3 (BRS-3) and Bn receptor subtype 4 (BB4). Among them, GRPR affects several systems in mammals, including neuroendocrine regulation and gastrointestinal secretion. Furthermore, it is involved in the development and regulation of the immune response. GRPR also as an autocrine or paracrine growth factor in the development and progression of pancreatic tumor. Many findings have strongly demonstrated that GRP receptor antagonists suppress the growth of many experimental tumors.
RC-3095 is a bombesin/gastrin releasing peptide receptor (GRPR) antagonist. This compound has potent anti-inflammatory properties. For example, in an experimental model of sepsis, RC-3095 could decrease the release of TNFα and IL-1β from activated macrophages. Moreover, RC-3095 exerts protective effects by reducing gastric oxidative injury in the arthritic mice. Furthermore, in 2 experimental models of arthritis, collagen-induced arthritis (CIA) and antigen-induced arthritis (AIA), RC-3095 shows a significant reduction in the concentrations of IL-17, IL-1β, and TNFα, and shows a diminished expression of GRPR. Besides, it has anticancer effects. For instance, in xenograft mice model, RC-3095 significantly reduces the volume and weight of tumors after 4 weeks of treatment. And RC-3095 also decreases the GRPR subtype-3 positive cells and protein expression in tumors.
To sum up, RC-3095 is a selective GRPR antagonist, with anti-inflammatory and anticancer properties.