The enzymatic synthesis of a tetrapeptide Phac-Met-Gly-Trp-Met-OEt, a fragment of the cholecystokinin C-terminal octapeptide CCK-8, was reported. This fragment was synthesized by coupling Phac-Met-OEt with Gly-OMe, Trp-OMe and Met-OEt successively. These three steps were catalyzed by alpha-chymotrpsin, Papain and alpha-chymotrpsin respectively. The results of FAB-MS showed that all the products had the correct molecular mass.
Catalysis ; Chymotrypsin ; Oligopeptides ; Papain ; Peptide Fragments ; Sincalide ; chemical synthesis

BACKGROUND/AIMS: At present, the gallbladder dysfunction implies a disorder of decreased gallbladder contractility. Other motor disorder such as overactive gallbladder which shows excessive contraction cannot be excluded in the motility disorder of gallbladder. Thus, this study was done to define the diagnostic criteria and to develop the techniques to induce the excessive contraction of gallbladder. METHODS: CCK-op at 20 ng/kg by slow continuous infusion for 30minutes, that is known as most physiologic method for gallbladder contraction, was given for assessment of gallbladder emptying in 12 normal volunteers. Also, rapid bolus injection of cholecystokinin octapeptide (CCK-op) at 20 ng/kg or 40 ng/kg was performed to induce the excessive contraction of gallbladder. Gallbladder contractility was represented as the ejection fraction (GBEF) measured by cholecystokinin-cholescintigraphy. RESULTS: 1. With a slow continuous infusion of CCK-op, the mean GBEF was 78.2+/-5.6% (mean+/-SD). 2. With a rapid bolus injection of CCK-op, GBEF showed variable results (10-86%) among subjects who had normal gallbladder. 3. Based on the results obtained by slow continuous infusion of CCK-op in normal volunteers, overactive gallbladder was defined when GBEF approached more than 70% within 15minutes after bolus injection of CCK-op. The overactive gallbladder was noted in 6 (50%) subjects who received rapid bolus injection of CCK-op (40 ng/kg). 4. Abdominal pain developed only in high-dose (40 ng/kg) bolus injection group (6/12, 50%), concomitantly with increased bowel movements, irrespective of excessive gallbladder contractility. CONCLUSION: Excessive gallbladder contraction had no clinical significance in the experimentally induced clinical model.
Abdominal Pain ; Cholecystokinin ; Gallbladder Emptying ; Gallbladder* ; Healthy Volunteers ; Sincalide

The enzymatic synthesis of a tetrapeptide Phac-Met-Gly-Trp-Met-OEt, a fragment of the cholecystokinin C-terminal octapeptide CCK-8, was reported. This fragment was synthesized by coupling Phac-Met-OEt with Gly-OMe, Trp-OMe and Met-OEt successively. These three steps were catalyzed by alpha-chymotrpsin, Papain and alpha-chymotrpsin respectively. The results of FAB-MS showed that all the products had the correct molecular mass.
Catalysis ; Chymotrypsin ; *Oligopeptides ; Papain ; Peptide Fragments ; Sincalide/*chemical synthesis

OBJECTIVES: To explore the cytotoxicity of four wild mushrooms involved in a case of Yunnan sudden unexplained death (YNSUD), to provide the experimental basis for prevention and treatment of YNSUD. METHODS: Four kinds of wild mushrooms that were eaten by family members in this YNSUD incident were collected and identified by expert identification and gene sequencing. Raw extracts from four wild mushrooms were extracted by ultrasonic extraction to intervene HEK293 cells, and the mushrooms with obvious cytotoxicity were screened by Cell Counting Kit-8 (CCK-8). The selected wild mushrooms were prepared into three kinds of extracts, which were raw, boiled, and boiled followed by enzymolysis. HEK293 cells were intervened with these three extracts at different concentrations. The cytotoxicity was detected by CCK-8 combined with lactate dehydrogenase (LDH) Assay Kit, and the morphological changes of HEK293 cells were observed under an inverted phase contrast microscope. RESULTS: Species identification indicated that the four wild mushrooms were Butyriboletus roseoflavus, Boletus edulis, Russula virescens and Amanita manginiana. Cytotoxicity was found only in Amanita manginiana. The raw extracts showed cytotoxicity at the mass concentration of 0.1 mg/mL, while the boiled extracts and the boiled followed by enzymolysis extracts showed obvious cytotoxicity at the mass concentration of 0.4 mg/mL and 0.7 mg/mL, respectively. In addition to the obvious decrease in the number of HEK293 cells, the number of synapses increased and the refraction of HEK293 cells was poor after the intervention of Amanita manginiana extracts. CONCLUSIONS The extracts of Amanita manginiana involved in this YNSUD case has obvious cytotoxicity, and some of its toxicity can be reduced by boiled and enzymolysis, but cannot be completely detoxicated. Therefore, the consumption of Amanita manginiana is potentially dangerous, and it may be one of the causes of the YNSUD.
Humans ; HEK293 Cells ; Sincalide ; China ; Amanita ; Death, Sudden

OBJECTIVE: To investigate the inhibitory effect of aumolertinib on proliferation of human choroidal melanoma MUM-2B cells and explore the possible molecular mechanism. METHODS: CCK-8 assay and colony formation assay were used to evaluate the inhibitory effect of different concentrations of aumolertinib on viability and proliferation of MUM-2B cells. Flow cytometry was performed to analyze the apoptosis, necrosis, cellular ROS production and cell cycle changes in aumolertinib- treated MUM-2B cells. The antitumor effect of aumolertinib against human choroidal melanoma was observed in nude mouse models bearing MUM-2B tumor cell xenografts. RESULTS: The results of CCK-8 and colony formation assay showed that aumolertinib strongly inhibited the proliferation MUM-2B cells in a dose-dependent manner. Flow cytometry showed that aumolertinib dose-dependently increased the total apoptosis rate of MUM-2B cells to as high as 76.65% at the concentration of 8 μmol/L and induced obvious cell cycle arrest at G1 phase. Aumolertinib treatment also caused a dose-dependent increase of ROS production and reduction of mitochondrial membrane potential in MUM-2B cells. In the tumor-bearing nude mice, treatment with aumolertinib significantly inhibited tumor growth without causing obvious body weight loss. CONCLUSION Aumolertinib can effectively inhibit the growth of human choroidal melanoma MUM-2B cells both in vivo and in vitro, suggesting its potential clinical value in the therapy of choroidal melanomas.
Animals ; Mice ; Humans ; Mice, Nude ; Sincalide ; Indoles ; Melanoma/drug therapy*

OBJECTIVE: To investigate the physicochemical characterization of cuprous oxide (Cu₂O) nanoparticles and assess its antitumor effect against gastric cancer cells in vitro. METHODS: The morphology, particle size and Fenton-like properties of Cu₂O nanoparticles were analyzed using transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential analysis and ultraviolet absorption spectroscopy. CCK-8 assay and Transwell experiments were used for evaluating the in vitro anti-tumor effect of the nanometers in gastric cancer cells. RESULTS: The prepared Cu₂O nanoparticles had a quasi-circular structure with a diameter of about 100 nm. The temperature of the nanoparticles increased from 25 to 50 ℃ after irradiation with near-infrared light (NIR, 0.5W/cm²) for 5 min. At a nearly neutral pH (pH=6.5), the nanoparticles catalyzed the generation of a large amount of reactive oxygen species (ROS). CCK-8 assay and Transwell experiment showed that Cu₂O nanoparticles concentration-dependently inhibited the proliferation, invasion and migration of gastric cancer cells. CONCLUSION Cu₂O nanoparticles have good photothermal and chemokinetic properties with a strong anti-tumor effect, and can potentially serve as a new therapeutic agent for gastric cancer treatment.
Humans ; Stomach Neoplasms/therapy* ; Sincalide ; Nanoparticles ; Cell Proliferation

BACKGROUND/AIMS: It is generally believed that cholecystokinin (CCK) stimulates colonic motility, although there are controversial reports. It has also been suggested that postprandial peptide YY (PYY) release is CCK-dependent. Using a totally isolated, vascularly perfused rat colon, we investigated: (1) the roles of CCK and PYY on colonic motility, (2) to determine if CCK modulates PYY release from the colon to influence the motility and (3) to clarify whether the action of CCK and PYY on colonic motility is mediated via the influence of cholinergic input. METHODS: An isolated whole rat colon was used. Luminal pressure was monitored via microtip catheter pressure transducers from proximal and distal colon. After a control period, CCK-8 or PYY was administerd intraarterially with or without an anti-PYY serum, loxiglumide or atropine at 12, 60 and 240 pM. Each dose was given for a period of 15-minute and the contractile response was expressed as % changes over basal. PYY concentration in the portal effluent was determined by radioimmunoassay. RESULTS: Exogenous CCK-8 increased colonic motility which paralleled the increase in PYY release in the portal effluent. Exogenous PYY also significantly increased colonic motility although it was less potent than CCK. The stimulating effect of CCK-8 was significantly inhibited by an anti-PYY serum, and was completely abolished by loxiglumide, and almost completely abolished by atropine. CONCLUSIONS: CCK increases colonic motility via CCK1 receptor and it is mediated partly by PYY. Cholinergic input is required for the increased motility by either PYY or CCK.
Animals ; Atropine ; Catheters ; Cholecystokinin ; Colon ; Peptide YY ; Phenobarbital ; Proglumide ; Rats ; Sincalide ; Transducers, Pressure

This study analyzes the impact of echinacoside(ECH) in the proliferation, metastasis and adriamycin(ADR) resistance of breast cancer(BC) MCF-7 cells via the modulation of aldo-keto reductase family 1 member 10(AKR1B10)/extracellular signal-regulated kinase(ERK) pathway. The chemical structure of ECH was firstly confirmed. MCF-7 cells were treated with different concentration(0, 10, 20, 40 μg·mL~(-1)) of ECH for 48 h. Western blot was used to analyze expression of AKR1B10/ERK pathway-associated proteins and cell counting kit-8(CCK-8) assay to determine cell viability. MCF-7 cells were collected and classified into control group, ECH group, ECH + Ov-NC group, and ECH + Ov-AKR1B10 group. Then Western blot was employed to analyze the expression of AKR1B10/ERK pathway-associated proteins. CCK-8 and 5-ethynyl-2'-deoxyuridine(EdU) assay were used to examine cell proliferation. Cell migration was appraised with scratch assay, Transwell assay, and Western blot. Eventually, MCF-7 cells were treated with ADR for 48 h to induce ADR resistance. Cell viability was tested by CCK-8 assay and cell apoptosis was estimated based on terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL) assay and Western blot. Based on Protein Data Bank(PDB) and molecular docking, the binding affinity of ECH to AKR1B10 was assessed. Various doses of ECH decreased the expression of AKR1B10/ERK pathway-associated proteins in a dose-dependent manner and declined cell viability compared with the control group. Compared with the control group, 40 μg·mL~(-1) ECH blocked the AKR1B10/ERK pathway in MCF-7 cells and inhibited the proliferation, metastasis and ADR resistance of the cells. Compared with the ECH + Ov-NC group, ECH + Ov-AKR1B10 group showed the recovery of some biological behaviors of MCF-7 cells. ECH also targeted AKR1B10. ECH can inhibit the proliferation, metastasis, and ADR resistance of BC cells by blocking AKR1B10/ERK pathway.
Humans ; MCF-7 Cells ; Molecular Docking Simulation ; Sincalide ; Signal Transduction ; Neoplasms ; Aldo-Keto Reductases

OBJECTIVES: To investigate the inhibitory effect of cholecystokinin octapeptide (CCK-8) binding to cholecystokinin 2 receptor (CCK2R) on methamphetamine (METH)-induced neuronal apoptosis, and to explore the signal transduction mechanism of β-arrestin 2 in CCK-8 inhibiting METH-induced neuronal apoptosis. METHODS: SH-SY5Y cell line was cultured, and HEK293-CCK1R and HEK293-CCK2R cell line were constructed by lentivirus transfection. Small interfering RNA (siRNA) was used to knockdown the expression of β-arrestin 2. Annexin Ⅴ-FITC/PI staining and flow cytometry were used to detect the apoptotic rate of cells, and Western blotting was used to detect the expression of apoptosis-related proteins. RESULTS: The apoptosis of SH-SY5Y cells was induced by 1 mmol/L and 2 mmol/L METH treatment, the number of nuclear fragmentation and pyknotic cells was significantly increased, and the expression of apoptosis-related proteins Bax and cleaved caspase-3 were increased. CCK-8 pre-treatment at the dose of 0.1 mmol/L and 1 mmol/L significantly reversed METH-induced apoptosis in SH-SY5Y cells, and inhibited cell nuclear fragmentation, pyknosis and the changes of apoptosis-related proteins induced by METH. In lentivirus transfected HEK293-CCK1R and HEK293-CCK2R cells, the results revealed that CCK-8 had no significant effect on METH-induced changes of apoptosis-related proteins in HEK293-CCK1R cells, but it could inhibit the expression level of apoptosis-related proteins in HEK293-CCK2R cells induced by METH. The inhibitory effect of CCK-8 on METH-induced apoptosis was blocked by the knockdown of β-arrestin 2 expression in SH-SY5Y cells. CONCLUSIONS CCK-8 can bind to CCK2R and exert an inhibitory effect on METH-induced apoptosis by activating the β-arrestin 2 signal.
Apoptosis/physiology* ; Central Nervous System Stimulants/pharmacology* ; HEK293 Cells ; Humans ; Methamphetamine/pharmacology* ; Sincalide/pharmacology*

OBJECTIVE: To observe the effects of Casitas B lymphoma (CBL) protein on proliferation, migration and invasion of breast cancer cells and explore its mechanism of action. METHODS: Cultured breast cancer cell lines MDA-MB-231 and MCF7A were transfected with a CBL-overexpressing plasmid and a specific siRNA targeting CBL (siRNA-CBL), respectively, and the changes in cell proliferation, migration and invasion were examined using colony-forming assay, cell counting kit-8 (CCK-8), scratch test and Transwell assay. Flow cytometry and Western blotting were performed to examine the effects of CBL overexpression on cell cycle and epithelial-mesenchymal transition (EMT) of MDA-MB-231 cells, and the changes in the number of filamentous pseudopodia were observed by rhodamine- labeled phalloidin staining of the cytoskeleton. IP-mass spectrometry identified NCK2 as the interacting proteins of CBL, and their interaction was verified by immunoprecipitation and immunofluorescence co-localization experiments in HEK-293T cells transfected with the plasmids for overexpression of CBL, NCK2, or both. Cycloheximide tracking and ubiquitination assays were used for assessing the effects of CBL on stability and ubiquitination of NCK2 protein in MDA-MB-231 cells; CCK-8 and Transwell assays were used to determine the effect of NCK2 overexpression on CBL-mediated proliferation and migration of the cells. RESULTS: The proliferation, migration and invasion were significantly suppressed in MDA-MB-231 cells overexpressing CBL (P < 0.05) and significantly enhanced in MCF7 cells with CBL silencing (P < 0.01). Silencing of CBL promoted G1/S transition in MCF7 cells (P < 0.05). Overexpression of CBL significantly decreased the expressions of CDK2/4 (P < 0.01), cyclinA2/B1/D1/D3/E2 (P < 0.05), Snail, N-cadherin, claudin-1 (P < 0.05), and upregulated the expression of E-cadherin (P < 0.05). CBL silencing upregulated the expressions of CDK2/4/6 (P < 0.05), cyclin A2/B1/D1/D3/E2 (P < 0.05), Snail, vimentin, and claudin-1 (P < 0.05) and down-regulated E-cadherin expression (P < 0.05). CBL overexpression obviously reduced the number of filamentous pseudopodia in MDA-MB-231 cells, and the reverse changes were observed in MCF7 cells with CBL silencing. In MDA-MB-231 cells, CBL overexpression lowered NCK2 protein stability (P < 0.05) and promoted its ubiquitin-mediated degradation (P < 0.01). Overexpression of NCK2 obviously reversed CBL-mediated inhibition of cell proliferation and migration (P < 0.01). CONCLUSION CBL can inhibit the proliferation, migration and invasion of breast cancer cells through ubiquitination-mediated degradation of NCK2.
Humans ; Sincalide ; Lymphoma ; Cytoskeleton ; Cadherins ; MCF-7 Cells ; Oncogene Proteins ; Adaptor Proteins, Signal Transducing