Bombesin GPCR Assays
Background of Bombesin Receptors
The bombesin receptors are G protein-coupled receptors. They are activated when bind to endogenous ligands, including gastrin-releasing peptide (GRP), neuromedin B (NMB), and GRP18-27 (neuromedin C). The corresponding receptors are divided into three subtypes, including the NMB receptor (BB1 receptor), GRP receptor (BB2 receptor), and an orphan receptor (BB3 receptor).
Fig.1. Proposed molecular mechanisms mediating GRPR regulation of brain function. (Roesler, 2012)
Distribution and Function of Bombesin Receptors
The bombesin receptors are broadly expressed throughout the central nervous system (CNS), gastrointestinal tract, and other organs, which are responsible for many physiological and pathologic processes, such as the modulation of sensory transmission, thermoregulation, feeding and pituitary, gastric, and pancreatic secretion, tissue development, as well as the regulation of lung cancer, eating disorder and obesity, CNS diseases, memory loss and behavior disorders, and inflammatory diseases.
Subtypes and Mechanisms of Bombesin Receptors
The family of bombesin receptors contains three subtypes of receptors, BB1 receptor, BB2 receptor, and BB3 receptor. They all promote signal transduction through the family of Gq/G11 proteins.
| Receptor | Gene | Mechanism | Agonists | Antagonists |
| BB1 receptor | NMBR |
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| BB2 receptor | GRPR |
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| BB3 receptor | BRS3 |
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Assay List of Bombesin Receptors
Creative Biolabs can provide a range of assays of bombesin receptors. You can choose the assay in the list or contact us for more information:
Published Data
| Paper Title | ML-18 is a non-peptide bombesin receptor subtype-3 antagonist which inhibits lung cancer growth |
| Journal | Peptides |
| Published | 2015 |
| Abstract | BB3 receptor is a G protein-coupled receptor (GPCR). The study aimed to find out specific agonists and antagonists of the BB3 receptor. PD168368 is a nonpeptide antagonist for the BB1 receptor whereas PD176252 is a nonpeptide antagonist for the BB2 receptor (GRPR) and BB1 receptor (NMBR). ML-18 is the S-enantiomer of the nonpeptide analogs of PD176252. The study used ML-18 to investigate the effect of this antagonist on BRS-3 in lung cancer cells. |
| Result |
ML-18 inhibited specific (125)I-BA1 (DTyr-Gln-Trp-Ala-Val-βAla-His-Phe-Nle-NH2)BB(6-14) binding to NCI-H1299 lung cancer cells stably transfected with BRS-3 with IC50 values of 4.8. However, ML-18 has a lower affinity to the BB1 receptor and BB2 receptor with IC50 values of 16 and >100μM, respectively. The result also showed that ML-18 inhibited the ability of BA1 to elevate cytosolic Ca(2+) in a reversible manner using lung cancer cells loaded with FURA2-AM. In addition, the study has demonstrated that ML-18 inhibited the proliferation of lung cancer cells. As a nonpeptide BRS-3 antagonist, ML-18 is used as a model to increase potency and selectivity, according to the results.
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Fig.2. The ability of ML-18 and EMY-98 to inhibit specific I-BA1 binding to BRS-3. (Moody, 2015)
References
- Roesler, R.; Schwartsmann, G. Gastrin-releasing peptide receptors in the central nervous system: role in brain function and as a drug target. Frontiers in endocrinology. 2012, 3, 159.
- Moody, T. W.; et al. ML-18 is a non-peptide bombesin receptor subtype-3 antagonist which inhibits lung cancer growth. Peptides. 2015, 64: 55-61.
