Bombesin receptor subtype-3(BRS-3) is an orphan receptor in the bombesin receptor family. Its signal transduction mechanism and biological function have attracted much attention. Seeking the ligand for BRS-3 is of great significance for exploring its function. Considering the fact that the activation of BRS-3 receptor can induce the change in intracellular Ca~(2+) concentration, the fluo-rometric imaging plate reader(FLIPR) was utilized for ligand screening at the cellular level. Among more than 400 monomeric compounds isolated from Chinese herbs, yuanhunine from Corydalis Rhizoma and sophoraisoflavanone A and licoriphenone from Glycyrrhizae Radix et Rhizoma antagonized BRS-3 to varying degrees. It was confirmed in HEK293 cells expressing BRS-3 that yuanhunine, sophoraisoflavanone A, and licoriphenone inhibited the calcium current response after the activation of BRS-3 by [D-Phe~6,β-Ala~(11),Phe~(13),Nle~(14)]bombesin-(6-14) in a dose-dependent manner with the IC_(50) values being 8.58, 4.10, and 2.04 μmol·L~(-1), respectively. Further study indicated that yuanhunine and sophoraisoflavanone A exhibited good selectivity for BRS-3. In this study, it was found for the first time that monomers derived from Chinese herbs had antagonistic activity against orphan receptor BRS-3, which has provided a tool for further study of BRS-3 and also the potential lead compounds for new drug discovery. At the same time, it provides reference for the research and development of innovative drugs based on the active ingredients of Chinese herbs.
Drugs, Chinese Herbal/chemistry* ; HEK293 Cells ; Humans ; Ligands ; Receptors, Bombesin

Previously, we have isolated authentic bombesin and another bombesin like peptide named bombesin like immunoreactivity (BLI)-K2 from the skin of Korean fire-bellied toad, Bombina orientalis. In the present study, we have newly purified three heterogeneous forms of BLI named BLI-K3, BLI-K4, and BLI-K5 from side fractions obtained in previous isolation of bombesin like peptide. The BLIs were separated into five peaks on a column of C18 preparative HPLC. Among them, three minor peaks containing BLI-K3, K4, and K5 were purified by means of sequential chromatography on the columns of SP cation exchange HPLC and C18 reverse phase HPLC. The purified BLI-K3 and K4 showed high binding affinity to an anti-bombesin serum (LBE 2G-2) with binding potency of 72 and 95%, respectively, relative to that of bombesin. However, they did not possess any distinctive biological activity of bombesin like peptide. On the contrary, the biological activity of BLI-K5 was similar to that of bombesin but its binding affinity to an anti-bombesin serum was low. The results indicate that three heterogeneous forms of BLI were coexpressed with bombesin and BLI-K2 in the skin of B. orientalis. All forms of the purified BLI in the present study were immunologically active but only BLI-K5 possessed the distinctive biological activity of bombesin like peptide.
Anura* ; Bombesin* ; Chromatography ; Chromatography, High Pressure Liquid ; Population Characteristics ; Skin*

Neuromedin B (NMB) acts as a growth factor or a morphogen and plays a role in cancer progression. Indeed, the NMB receptor (NMB-R) is overexpressed in different types of tumors. In our current study, we investigated the involvement of NMB-R in the proliferation of oral cancer cells. Human oral squamous cell carcinoma (SCC) and human oral cancer cells, SCC-25 cells were found to be NMB-R-positive. The NMB-R antagonist PD168368 inhibited the proliferation of SCC-25 cells and reduced their colony formation capacity. We also found that PD168368 induced the cell cycle arrest and apoptosis of SCC-25 cells in a dose-/time-dependent manner. Overall, this antitumor activity of PD168368 in human oral cancer cells suggests that NMB-R is a potential target for the future prevention and treatment of human cancers.
Apoptosis ; Carcinoma, Squamous Cell ; Cell Cycle Checkpoints ; Humans ; Mouth Neoplasms* ; Receptors, Bombesin*

PURPOSE: Bombesin-like peptides are known to be important in the autocrine growth of a number of small cell lung cancer cell lines. The aim of this study was to investigate the extent of bombesin family ligands/receptors expression in human gastric cancer tissues and cell lines, and to evaluate the relationship between the expression of bombesin family ligands/receptor and clinicopathologic parameters. METHODS: We measured the expression of gastrin releasing peptide (GRP), neuromedin B (NMB), and their receptors, in human gastric cancer tissues and cell lines. Ligand and receptor mRNA studies were carried out on; 20 tumor and matched normal samples, and 9 gastric cell lines. The expression of mRNA of GRP/NMB, and their receptors, was examined by the reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Expression of GRP, NMB and GRPR, NMBR mRNA was found in 55%, 100%, 40%, and 100% of gastric cancer tissue, respectively. GRP/GRPR co-expression was observed in 30% of gastric cancer tissues and expression of gastric cancer was higher than that of normal mucosa. GRP and GRPR were highly expressed in the differentiated type of gastric cancer. In gastric cancer cell lines, these peptides and receptors were expressed equally. CONCLUSION: The result demonstrate that GRP, NMB, GRPR, and NMBR were expressed in gastric cancer tissues and cell lines. This result suggests that these may have a role as growth factors in gastric cancer growth, and these peptides may act in an autocrine fashion as a morphogen in gastric cancer.
Bombesin* ; Cell Line* ; Gastrin-Releasing Peptide ; Humans ; Humans* ; Intercellular Signaling Peptides and Proteins ; Ligands* ; Mucous Membrane ; Peptides ; RNA, Messenger ; Small Cell Lung Carcinoma ; Stomach Neoplasms*

AIMTo determine whether bombesin prevents IFN-alpha-induced fever and it's possible mechanism.

METHODSEffects of BN on changes in body temperature and arginine vasopressin(AVP) content in the ventral septal area(VSA) and hypothalamus were measured in the rats following intracerebroventricular (ICV) injection of IFN-alpha.

RESULTS(1) IFN-alpha produced a dose-dependent rise in colonic temperature simultaneously with increase in AVP content in the VSA in the rats. (2) BN produced a dose-dependent hypothermia and significantly elevated AVP content in the VSA in rats. (3) BN injected intracerebroventricularly at 30 min after IFN-alpha prevented the increase in colonic temperature which recovered to the control level as well as AVP content in the VSA in rats at 150 min.

CONCLUSIONAVP in the VSA may play a role in IFN-alpha-induced fever. AVP in the VSA may play a partial role in the BN antipyretic action and hypothermic action.

Animals ; Arginine Vasopressin ; metabolism ; Body Temperature Regulation ; drug effects ; Bombesin ; pharmacology ; Brain ; drug effects ; metabolism ; Fever ; chemically induced ; physiopathology ; Interferon-alpha ; adverse effects ; Male ; Rats ; Rats, Wistar

BACKGROUNDTumor cells can reduce the number of dendritic cells (DCs) in the tumor environment and cause DC dysfunction through autocrine or paracrine pathways. We sought to measure cyclooxygenase-2 (COX-2) expression in bombesin-inhibited DCs treated with theanine in vitro and to explore the protection and activation effects of theanine on DCs.

METHODSEnzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and Western blotting were used to analyze the effects of theanine on COX-2 expression and interleukin (IL)-12/IL-10 secretion of bombesin-treated DCs.

RESULTSDCs acquired an impaired phenotype as a result of bombesin treatment. Theanine increased the expression of mature DC surface molecules. The number of cell apoptosis with the treatment of bombesin and theanine significantly decreased, accounting for 15.9%, compared with 26.1% of cell apoptosis with bombesin. COX-2 expression in bombesin-treated DCs was inhibited by theanine in a dose-dependent manner. Theanine promoted DC secretion of IL-12. IL-12 levels reached (137.4 ± 4.9) pg/ml with theanine at 200 µmol/L. However, theanine inhibited the secretion of IL-10 in a dose-dependent manner. IL-10 levels were only (58.4 ± 6.9) pg/ml with theanine at 200 µmol/L.

CONCLUSIONTheanine inhibits the transcription and translation of COX-2 and regulates the balance of IL-10/IL-12 secretion in bombesin-inhibited DCs, leading to the recovery of a state of activation in DCs.

Bombesin ; pharmacology ; Cells, Cultured ; Cyclooxygenase 2 ; metabolism ; Dendritic Cells ; drug effects ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Glutamates ; pharmacology ; Humans ; Interleukin-10 ; metabolism ; Interleukin-12 ; metabolism

OBJECTIVETo observe the effect of bombesin noncytoskeleton form and intracellular free calcium ([Ca2+]i) concentration in PC-3 prostate cancer cell line.

METHODSImmunofluorescent histochemistry (IH) combined with laser scanning confocal microscopy (LSCM) was used to examine the expression of cytokeratin (CK) in PC-3 cells treated with definite concentrations of BBS and observe its effect on cytoskeleton form. Fluo-3/AM fluorescence technique and LSCM were adopted to measure the [Ca2+]i concentration after different concentrations (10(-9), 10(-7) and 10(-5) mol/L) of BBS were added in PC-3 cells.

RESULTSBBS (10(-5) mol/L) stimulated the expression of CK in PC-3 cells and the formation of lamellipodium, and increased the [Ca2+]i concentration, with concentration dependence.

CONCLUSIONDefinite concentrations of BBS could obviously enhance the [Ca2+] i concentration, CK expression and cytoskeleton morphology of PC-3 cells. The results provide a basis for further studies on the role of BBS in tumour researches as well as in intracellular signal transmission.

Bombesin ; pharmacology ; Calcium ; analysis ; Cytoskeleton ; drug effects ; metabolism ; Fluoroimmunoassay ; Humans ; Keratins ; biosynthesis ; Male ; Microscopy, Confocal ; Prostatic Neoplasms ; metabolism ; Serum Albumin, Bovine ; Tumor Cells, Cultured

The effect of bombesin (BOM) on non-cholinergic excitatory synaptic transmission of the guinea pig inferior mesenteric ganglion (IMG) was investigated by intracellular recording. Repetitive stimulation of the colon nerves (1 ms, 25 Hz, 4 s) elicited a burst of action potentials, which was followed by a long-lasting depolarization in 74.3% (52/70) of the IMG neurons. The depolarization was not blocked by nicotinic (d-tubocurarine, 100 micromol/L) and muscarinic (atropine, 1 micromol/L) antagonists, but was eliminated in a low Ca(2+)/high Mg(2+) Krebs solution, indicating that the depolarization was due to the release of non-cholinergic transmitters. Superfusing the ganglia with BOM (10 micromol/L, 1 min) induced a slow depolarization in 66.5% (109/164) neurons tested. The BOM response was not appreciably changed in low Ca(2+)/high Mg(2+) Krebs solution (n=6, P>0.05), suggesting that BOM depolarized the neurons by acting directly on the postsynaptic membrane rather than via a release of other endogenous depolarizing substances. In a total of 102 cells that exhibited late slow excitatory postsynaptic potential (ls-EPSP), superfusion of the ganglia with BOM produced a membrane depolarization in 82 neurons (80%), while the remaining 20 cells (20%) exhibited no response to BOM. In 18 neurons with ls-EPSP, 4 (22%) neurons were sensitive to both BOM and SP; 6 (33%) and 5 (28%) neurons were only sensitive to BOM and SP, respectively. The remaining 3 (17%) neurons were insensitive to both BOM and SP. Membrane resistance (Rm) had no apparent change in 47.3%, 59.5 % of the neurons tested during the ls-EPSP (n=55) and BOM depolarization (n=84), respectively, but had a marked decrease in 38.2%, 27.4%, and a marked increase in the remaining 14.5%, 13.1% of the neurons. However, when the Rm change accompanying ls-EPSP was compared with that accompanying BOM depolarization (n=20) in the same neuron, the changes in Rm were always parallel. Moreover, ls-EPSP (n=6) and BOM depolarization (n=8) were all augmented by conditioning hyperpolarization. The extrapolated values of the reversal potentials of ls-EPSP and BOM depolarization were 46.0+/-8.0 and 50.0+/-7.0 mV (n=8, P>0.05), respectively. In 14 BOM-sensitive neurons, a ls-EPSP was elicited by repetitive colon nerve stimulation. Superfusion of BOM (10 micromol/L) in these cells initially caused a large depolarization and then membrane potential gradually subsided to resting level in the continuous presence of BOM. Stimulation of the presynaptic nerves at this time failed to elicit a detecable ls-EPSP in 2 neurons and induced a much smaller one in 10 cells, while the ls-EPSP in the remaining 2 neurons was not appreciably affected. On the other hand, prolonged superfusion of BOM had no effect on the amplitude and duration of ls-EPSP in 6 BOM-insensititive neurons studied (P>0.05). The amplitude and duration of SP-induced depolarization were not altered by prolonged superfusion of BOM (n=4, P>0.05) Superfusion of tyr(4) D-phe(12) bombesin (1 micromol/L, 10 15 min), a BOM receptor antagonist, did not cause any noticeable changes in passive membrane properties nor block nicotinic f-EPSPs, but markedly suppressed (n=5) or completely abolished (n=11) BOM depolarization in all 16 neurons tested Similarly, tyr(4) D-phe(12) bombesin partially or completely antagonized the ls-EPSP in 9 out of a total of BOM sensitive neurons (n=11). The ls-EPSP elicited in the remaining two neurons was insignificantly affected by this drug. However, following 10 20 min of wash with Krebs solution the ls-EPSP was reversed. In contrast, superfusion of the ganglia with tyr(4) D-phe(12) bombesin did not change the amplitude and duration (P>0.05) of ls-EPSP in 10 BOM-insensitive cells. Similarly, the amplitude and duration of SP-induced depolarization were not appreciably affected by tyr(4) D-phe(12) bombesin (n=6, P>0.05). In conclusion, our results indicate that BOM may be another transmitter mediating the ls-EPSP in the guinea pig IMG and that there is no cross-desensitization of BOM receptors and SP receptors.
Action Potentials ; drug effects ; physiology ; Animals ; Bombesin ; pharmacology ; Electric Stimulation ; Excitatory Postsynaptic Potentials ; drug effects ; physiology ; Female ; Ganglia, Sympathetic ; drug effects ; physiology ; Guinea Pigs ; In Vitro Techniques ; Male ; Synaptic Transmission ; drug effects

Recently various peptide receptors which displayed the highest binding affinity and specificity with their peptide ligands by ligand-receptor have been exploited to develop drug delivery system which can directionally deliver drug to targeted cell. It is significant to study and applicate, including targeted drug delivery system mediated by bombesin receptor, somatostatin receptor, SynB3 receptor, LH-RH receptor and other peptide receptor, et al. Several small peptide fragments were selected as carriers radicals combining doxorubicin, 2-pyrrolino-DOX, methotrexate, cis-platinum, and camptothecin to form hybrid cytotoxic analogs. These highly potent cytotoxic analogs have been designed as targeted anti-tumor agents for the treatment and study of various cancers that possess receptors for the carrier peptide.
Animals ; Antineoplastic Agents ; therapeutic use ; Doxorubicin ; analogs & derivatives ; therapeutic use ; Drug Delivery Systems ; Humans ; Neoplasms ; drug therapy ; metabolism ; Oligopeptides ; metabolism ; Pyrroles ; therapeutic use ; Receptors, Bombesin ; metabolism ; Receptors, LHRH ; metabolism ; Receptors, Somatostatin ; metabolism

OBJECTIVETo study the effect of Jiaweisinisan (JWSNS), a traditional Chinese herbal medicinal recipe, on gastric mucosal ultrastructure and brain-gut axis in rat models of chronic psychological stress and elucidate the mechanism of JWSNS for ameliorating stress-induced gastrointestinal dysfunction.

METHODSSixty rats were randomly assigned into normal control group, model group, 3 JWSNS groups (high, moderate, and small doses), and omeprazole group (n=10). Rat models of chronic psychological stress were established by random stressful stimulations, and following the corresponding interventions, plasma adrenocorticotropic hormone (ACTH) and cortisol (CORT) levels were detected using radioimmunoassay, and the mRNA expressions of gastrin receptor in the gastric tissue (GASR) and vasoactive intestinal peptide II receptor (VIPR2) in the jejunal tissue were examined using RT-PCR. Transmission electron microscopy was employed to examine the ultrastructural changes in the gastric mucosa tissue cells of the glandular stomach area and alterations in the intercellular junctions.

RESULTSElectron microscopy revealed obvious damages in gastric mucosal epithelial cell organelles and nuclei in the model rats. These damages were ameliorated after treatments with JWSNS and omeprazole. Compared with the model group, the 3 JWSNS groups and omeprazole group all showed significantly lowered plasma ACTH and CORT levels, increased gastrin receptor mRNA expression and decreased jejunal VIPR2 mRNA expression (P<0.05 or 0.01).

CONCLUSIONJWSNS can obviously ameliorate the pathologies of the gastric mucosa cells, regulate the state of brain-gut axis, and modulate the gastric gastrin receptor and jejunal VIPR2 mRNA expressions in rats with chronic psychological stress.

Adrenal Cortex Hormones ; blood ; Adrenocorticotropic Hormone ; blood ; Animals ; Drugs, Chinese Herbal ; pharmacology ; Gastric Mucosa ; metabolism ; pathology ; ultrastructure ; Hydrocortisone ; blood ; Jejunum ; metabolism ; Male ; Rats ; Rats, Wistar ; Receptors, Bombesin ; metabolism ; Receptors, Vasoactive Intestinal Peptide, Type II ; metabolism ; Stress, Psychological ; pathology