ABSTRACT
Objective To investigate the effects of blocking gastrin receptor on the proliferation,apoptosis and expression of key proteins in the related pathway in gastric cancer cell lines.Methods In the experimental group,the gastric cancer cell lines SGC-7901 and AGS cells were treated with 5 mmol/L proglumide,a kind of a gastrin receptor antagonist.And the normal cultured gastric cancer cells SGC-7901 and AGS were used in control group.The growth of each group was detected by MTT assay;the cell growth curve was drawn by flow cytometry;the cell cycle of each group was detected by flow cytometry.Annexin V-FITC/PI double staining was used to detect the cell growth of apoptosis.The relative mRNA expression of β-catenin,nuclear factor-P65,mammalian target of rapamycin and glycogen synthase kinase 3 beta in Wnt,NF-κB and PI3K-AKT-MTOR pathways were detected by RT-qPCR.The expression of β-catenin protein was detected by Western blotting.Results After treatment with proglumide,the growth of the cells in the experimental group was lower than that in the control group;and the proportion of S phase cells in the cell cycle was also lower than that in the control group,but the proportion of cells in G0/G1 phase was higher than that in the control group(P<0.05).The percentage of apoptotic cells was also increased after treatment with proglumide(P<0.05).Furthermore,proglumide treatment significantly reduced the expression of β-catenin at both mRNA and protein levels(P<0.05).Conclusion Blocking gastrin receptor can down-regulate the expression of β-catenin,inhibit the cell proliferation and promote the cell apoptosis in gastric cancer cells.
ABSTRACT
Objective:To establish an HPLC method for the determination of compound proglumide tablets. Methods:A Diamon-sil C18(250 mm ×4.6 mm,5 μm)column was used. The mobile phase was 2% ammonium acetate-methanol (40∶60), the detection wavelength was 225nm, and an external standard method was employed. Results:The linear range of proglumide was 2. 60-208. 10 μg (r=0. 999 9), and the average recovery was 99. 8%(n=6,RSD=0. 6%). Conclusion: The HPLC determination method for com-pound proglumide tablets is accurate, simple and reproducible.
ABSTRACT
Objective To investigate the effects and mechanisms of extracellular-signal regulated protein kinase-motogenactived protein kinase(ERK-MAPK)signaling pathway in gastrin-induced cell proliferation and apoptosis of colorectal cancer cells.Methods HT-29 cells were incubated in different media,and then were divided into the control group,gastrin group,proglumide group and gastrin + proglumide group.No reagent was added in the control group,and other groups were dealed with reagent in different concentrations.The changes of proliferation of the HT-29 cells were detected by MTT assay,and the optimal concentration of gastrin and proglumide were determined.The changes of proliferation index and apoptotic rates of HT-29 cells were detected by cell cytometry.The mRNA expressions of gastrin receptor/cholecystokinin-B receptor(CCK-BR),ERK1/2 and K-ras were detected by RT-PCR.The protein of ERK1/2,K-ras protein and phosphorylation levels were detected by Western blot.All data were analyzed by analysis of variance and SNK-q test.Results The proliferation of HT-29 was stimulated by gastrin when the concentration of the gastrin was 6.25-100.00 mg/L,and the optimal concentration of gastrin was 25.00 mg/L(F =31.36,P ＜ 0.05).Proglumide had no obvious effects on the proliferation of HT-29 cells,while it significantly inhibited the proliferation of HT-29 cells stimulated by gastrin when the concentration of proglumide was 8.00-128.00 mg/L,and the optimal concentration was 32.00 mg/L(F =24.31,P ＜ 0.05).The proliferation index of the gastrin(25.00 mg/L)group was 37.5 ％ ± 5.2％,which was significantly higher than 27.7％ ± 5.0％ of the control group and 27.3％ ± 5.8％ of the gastrin(25.00 mg/L)+ proglumide(32.00 mg/L)group(q =4.56,4.75,P ＜ 0.05).The apoptotic index of the gastrin(25.00 mg/L)group was 1.9％ ± 0.4％,which was significantly lower than 2.5％ ± 0.4％ of the control group and 2.4％ ± 0.3％ of the gastrin(25.00 mg/L)+ proglumide(32.00 mg/L)group(q =4.23,4.06,P＜0.05).The mRNA expression of CCK-BR was detected in the HT-29 cells.The levels of phosphorylated ERK1/2 protein and phosphorylated K-ras protein were 0.43％ ± 0.04％ and 0.45％ ± 0.06％,which were significantly higher than 0.32％ ± 0.02％ and 0.31％ ± 0.05 ％ of the control group(q =7.78,4.95,P ＜ 0.05),and they were also higher than 0.36％ ± 0.01％ and 0.35 ％ ± 0.04％ of the gastrin(25.00 mg/L)+ proglumide(32.00 mg/L)group(q =5.72,4.08,P ＜0.05).There were no significant differences in the mRNA and protein expressions of ERK1/2 and K-ras among the control group,gastrin(25.00 mg/L)group,proglumide(32.00 mg/L)group and gastrin (25.00 mg/L)+ proglumide(32.00 mg/L)group(F =0.52,0.72,0.78,0.28,P ＞0.05).Conclusion Gastrin could stimulate the proliferation of HT-29 cells and inhibit their apoptosis by upregulate the phosphorylation levels of ERK and K-ras through the Ras→Raf→ MEK1/2→ ERK1/2 pathway,while the effect can be restrained by gastrin receptor antagonist proglumide.
ABSTRACT
Objective To approach on the expression pattern of MMP-2 and E-Cadherin in the effects of gastrin on gastric canc-er cells ,so as to investigate their role in the metastasis and invasion of gastric cancer .Methods Genomic DNA modified by sodium bisulfite was used as a template .RQ-MSP detect the methylation status of the gene promoter .The relative amount of Methylation status was performed with comparative threshold cycle (2- △ t ) method .Results MMP-2 and E-Cadherin genes in gastric cancer cells were at hemimethylated status in gastrin before and after the intervention .Gastrin can reduce the methylation levels of MMP-2 gene(P0 .05) .Gastrin can pro-mote the methylation levels of MMP-2 gene ,but proglumide decrease that effect (P<0 .05) .Conclusion Gastrin plays a certain role in the biological behavior of gastric cancer impact by changeing on the expression pattern of MMP-2 and E-Cadherin in the effects of gastrin on gastric cancer cells .
ABSTRACT
AIM To study if cholecystokinin octapeptide (CCK-8) alter cardiovascular functions by its direct inhibitory effect on carotid sinus baroreceptor (CSB) activity. METHODS The functional curve of carotid baroreceptor (FCCB) was constructed and the functional parameters of carotid baroreceptor were measured by recording sinus nerve afferent discharge in anesthetized male rats with perfused isolated carotid sinus. RESULTS ① CCK-8 0.1, 0.5 and 1.0 μmol·L-1 shifted FCCB to the right and downward, with a marked decrease in peak slope and peak integral value of carotid sinus nerve discharge in a concentration-dependent manner, indicating the inhibitory effect of CCK-8 on CSB activity. ② Pretreatment with proglumide (100 μmol·L-1), a nonselective CCK receptor antagonist, or Bay K8644 (0.5 μmol·L-1), an agonist of calcium channel, partially attenuated the inhibitory effect of CCK-8 (0.5 μmol·L-1) on CSB activity. Pretreatment with L-NAME (100 μmol·L-1), an inhibitor of NO synthase, did not affect the inhibitory action of CCK-8. CONCLUSION CCK-8 inhibits CSB activity, which may be mediated by activating CCK receptors in the carotid sinus area and thereby resulting in an inhibition of stretch-sensitive channels and decrease in Ca2+ influx.
ABSTRACT
Objective To evaluate the effect of cholecystokinin receptor antagonist proglumide on the pancreatic function of post-ERCP. Methods The frequency and mortality of acute pancreatitis of post-ERCP, and the plasma contents of cholecystokinin-octapeptide(CCK-OP) and amylase were compared among control group(group C),octreotide treatment group(group O) and proglumide treatment group(group P). Results The frequency of acute pancreatitis of post-ERCP in group C was 13.6%(3/20), which was significantly higher than that in Group O(5%,1/20) and group P (4.0%,1/25)(P0.05). The contents of plasma CCK-OP were significantly lower in group P than those in groups O and C 4h after ERCP (P0.05). Conclusion Proglumide could inhibit the action of cholecystokinin-octapeptide, and decreas the hyperamylasemia and the frequency of pancreatitis of post-ERCP as octreotide.