[ effects of CCK-8 and CCK2 receptor antagonists on naloxone-induced jumping in morphine dependent mice]

Opioids are an important group of analgesics that are used extensively to control sever pains. Physical dependence to these drugs is a major problem. There are a few studies regarding the involvement of cholecyctokinin [CCK] in the withdrawal syndromes of opioids. In the present study, the effects of CCK agonist and antagonist on the number of jumping of morphine dependent mice were evaluated. In this experimental study, the effects of CCK-8 and LY225910 [selective CCK2 receptor antagonist] on jumpings of mice after morphine dependence were evaluated. Mice were injected with morphine three times a day [50, 50 and 75 mg/kg] for three days; at the forth day they received 50 mg/kg morphine. Injection of naloxone [5 mg/kg] induced withdrawal signs such as jumping. The experimental groups received different doses of CCK-8 [0.1, 0.3 and 0.6 mg/kg] and LY225910 [0.01, 0.5 and 1 mg/kg] with each injection of morphine. Injection of CCK-8 significantly decreased the naloxone-induced jumpings, while LY225910 did not have any significant effects on these jumpings. Based on the results of the present study, activation of CCK1 receptors probably is involved in morphine dependence. The results also confirm that injection of CCK but not CCK2 selective antagonist probably decreases the jumpings of mice following withdrawal syndrome of morphine

Microarray Analysis of Differentially Expressed Genes in the Brains of Tubby Mice

The tubby mouse is characterized by progressive retinal and cochlear degeneration and late-onset obesity. These phenotypes are caused by a loss-of-function mutation in the tub gene and are shared with several human syndromes, suggesting the importance of tubby protein in central nervous system (CNS) functioning. Although evidence suggests that tubby may act as a transcription factor mediating G-protein coupled receptor (GPCR) signaling, any downstream gene regulated by tubby has yet to be identified. To explore potential target genes of tubby with region-specific transcription patterns in the brain, we performed a microarray analysis using the cerebral cortex and hypothalamus of tubby mice. We also validated the changes of gene expression level observed with the microarray analysis using real-time RT-PCR. We found that expression of erythroid differentiation factor 1 (Erdr1) and caspase 1 (Casp1) increased, while p21-activated kinase 1 (Pak1) and cholecystokinin 2 receptor (Cck2r) expression decreased in the cerebral cortex of tubby mice. In the hypothalamic region, Casp 1 was up-regulated and micro-crystallin (CRYM) was down-regulated. Based on the reported functions of the differentially expressed genes, these individual or grouped genes may account for the phenotype of tubby mice. We discussed how altered expression of genes in tubby mice might be understood as the underlying mechanism behind tubby phenotypes.

The role of p38 MAPK in gastrin-induced u-PA expression in human colon cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the effect of gastrin on the mRNA and protein expression of urokinase-type plasminogen activator (u-PA) in human colon cancer cells and detect the role of p38 MAPK in this process.</p><p><b>METHODS</b>Lipofectin method was used to transfect pCR3. 1/CCK2R vector expressing gastrin receptor into a colon cancer cell line colo320. Gastrin and gastrin antagonist were used to up-regulate and down-regulate the signaling pathway, respectively. Human colon cancer colo320 cells and colo320/ CCK2,R cells were cultured and then stimulated with gastrin for different time; SB203580 was added into culture medium to prevent p38 kinase pathway before incubating with gastrin; Western blot and RT-PCR were used to examine the u-PA expression. Western blot was employed to detect p38 kinase phosphorylation.</p><p><b>RESULTS</b>Gastrin increased evidently the mRNA and protein expressions of u-PA and induced p38 kinase phosphorylation in colo320/CCK,R cells time-dependently. However, the extent of enhancement of u-PA and p38 MAPK expression in colo320 cells was much less than that in colo320/CCK2R cells. The gastrin antagonist L-365, 260 showed an effect of competitive inhibition on gastrin-induced u-PA expression and p38 kinase phosphorylation. The inhibitor SB203580 could sufficiently suppress gastrin-induced p38 kinase phosphorylation and significantly attenuate gastrin-induced u-PA mRNA and protein expressions in colo320/ CCK2 R cells in a dose-dependent manner.</p><p><b>CONCLUSION</b>Gastrin-gastrin receptor signal transduction pathway can obviously induce u-PA expression in human colon cancer cells via activating the phosphorylation of p38 kinase.</p>

Effects of hFRNK on E-cadherin/beta-catenin in colon cancer cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the effects of human FRNK gene on E-cadherin/beta-catenin complex in colon cancer cell line Colo320WT cells stimulated with extrinsic gastrinl7.</p><p><b>METHODS</b>AdEasy system was used to construct pAdhFRNK expressing human FRNK gene by recombination in E. coli. BJ5283. pCR3.1/GR plasmid expressing gastrin receptor CCK-2 was transfected into colon cancer cell line Colo320 cells by Lipofectamine 2000 and expressing stably CCK-2R clones were screened by G418 (500 pg/ml). The expression levels of gastrin receptor in Colo320 cells and the transfected Colo320WT cells were assayed by RT-PCR. Colo320WT cells were treated by 10(-8) mol/L gastrinl7 for 12 h; and after Colo320WT cells were infected by pAdhFRNK (MOI: 100) for 2 d the cells were treated by gastrin17 for 12 h again. The expression levels of E-cadherin and beta-catenin in TX-100 soluble fraction and TX-100 insoluble fraction of Colo320WT cells were assayed by co-immunoprecipation and Western blot. E-cadherin and beta-catenin's distribution in Colo320WT cells were detected by immunocytochemistry.</p><p><b>RESULTS</b>When 10(-8) mol/L gastrin17 stimulated Colo320WT cells for 12 h, the expression levels of E-cadherin and beta-catenin in TX-100-soluble fraction decreased apparently, while the expression levels of E-cadherin and beta-catenin in TX-100-insoluble fraction increased markedly. When pAdhFRNK infected Colo320WT cells for 2 d and 10(-8) mol/L gastrin17 treated the cells for 12 h, the expression levels of E-cadherin and beta-catenin in TX-100-soluble fraction increased apparently again, and the expression levels of E-cadherin and beta-catenin in TX-100-insolutble fraction decreased markedly. Immunocytochemistry showed that the distribution of E-cadherin and beta-catenin was translocated from plasma membrane into cytoplasm and nucleus in the cells stimulated with gastrinl7, and after the cells were infected with pAdhFRNK and stimulated by gastrinl7 again. beta-catenin was mainly observed in cytoplasm and little nuclear immunoreactivity.</p><p><b>CONCLUSION</b>An adenovirus vector pAdhFRNK can inhibit abnormal distribution of E-cadherin and beta-catenin in the gastrin17-stimulated cells. The mechanism is probably that hFRNK can disphosphorylate phosphorylated FAK and block FAK pathway.</p>

Association Studies of the CT Repeat Polymorphism in the Cholecystokinin B Receptor Gene with the Diagnosis and the Response of Pharmacotherapy in Korean Patients with Panic Disorder / 대한정신약물학회지

OBJECTIVE: This study aimed to test the possible association between Cholecystokinin B receptor (CCKBR) promoter gene and panic disorder. METHODS: 262 patients with panic disorder and 76 healthy controls participated in this study. Genotyping was performed by polymerase chain reaction-based method. RESULTS: Allele distribution of CT repeat polymorphism in patients with panic disorder was not different from those of the controls. However, after excluding the patients with panic disorder comorbid with major depressive disorder and other anxiety disorder, we found out the significant association of CCKBR (CT)n repeat with the panic disorder without comorbidities. And we analysed the data as a di-allelic polymorphism with a short (140-162 bp) and a long (164-180 bp) allele. In the di-allelic analysis, there was an excess of the shorter allele in patients with panic disorder. CONCLUSION: The present study suggested that the CCKBR promoter dinucleotide polymorphism may have a potential role for susceptibility to panic disorder in the Korean population and thus calls for consecutive studies in order to pile up the data with larger different ethnic background.

Expression of gastrin in human gastric cancer cell line and effect of anti-gastrin mAb on the cell growth / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the expression of gastrin in human gastric cancer cell line SGC-7901 and the effects of gastrin-17 and anti-gastrin mAb on its growth.</p><p><b>METHODS</b>The expression of gastrin was determined by immunohistochemistry with anti-gastrin mAb prepared by our group. In a series of experiments, the growth of SGC-7901 cells was evaluated by MTT assay on cells grown in serum-free medium and treated with gastrin-17 and/or anti-gastrin mAb.</p><p><b>RESULTS</b>Immunohistochemical examination of SGC-7901 cells revealed a specific gastrin immunoreactivity. Gastrin-17 significantly stimulated cell growth at the concentrations of 1 x 10(-9) mol/L approximately 1 x 10(-5) mol/L in a dose-dependent manner. The growth of SGC-7901 cells treated with anti-gastrin mAb, either alone or in combination with gastrin-17 (1 x 10(-7) mol/L), was significantly inhibited.</p><p><b>CONCLUSION</b>Growth of human gastric cancer cells SGC-7901 can be stimulated in an autocrine fashion. The gastrin-stimulated growth of gastric cancer cells can be blocked by anti-gastrin mAb bound specifically with gastrin. Further study on the significance of anti-gastrin mAb in designing immunotherapy targeting to gastrin or gastrin receptor is warranted.</p>

Human gastric tissues coexpress two different splicing cholecystokinin-B/gastrin receptors / 生物医学工程学杂志

This study was conducted to explore whether cholecystokinin-B/gastrin receptor (CCKBRwt) gene and its alternative splicing variant (CCKBRi4sv) are expressed in human gastric carcinomas cell line and tissues, and to find out their relationship with the development and progression of human gastric carcinoma. The mRNA expression levels of CCKBRwt and CCKBRi4sv were detected in 30 human gastric carcinomas and normal tissues adjacent to cancer, 10 gastritis specimens, 2 autopsied normal stomach specimens as well as in a gastric carcinoma cell line SGC-7901 cells. The results revealed that the transcripts of CCKBRwt and CCKBRi4sv were observed in all of the human gastric specimens tested, but only CCKBRwt was expressed in gastric cancer cell line SGC-7901 cells. The expression levels of the two receptors were not correlated with the differentiation and metastases of gastric cancers. From the results, we infer that human gastric tissues simultaneously express CCKBRwt and CCKBRi4sv, and CCKBRi4sv may have unknown physiological functions in gastric epithelial cells.

The Expression of Gastrin and Gastrin/ CCK-B Receptor mRNA in Cancer and Normal Tissue of Large Intestine

PURPOSE: Gastrin, a peptide hormone produced by the G cells of the gastric antrum, plays a major role in regulating acid secretion in the stomach, and acts as a trophic factor in the gastrointestinal tract. The relationship between gastrin and the development of colorectal cancer remains controversial. To study its possible role in development or proliferation of colorectal cancer, we evaluated the expression of gastrin and gastrin/CCK-B receptor mRNA in cancer and normal tissue from colorectal cancer patients. We also reviewed clinical records to evaluate the correlations between gastrin receptor expression and clinical characteristics of colorectal cancer. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate mRNA expression for gastrin and gastrin/CCK-B receptor in 26 surgical specimens of colorectal cancer. RESULTS: The mRNA expression of gastrin was detected in 24 out of 26 cancer specimens and 9 out of 26 normal colon specimens (p0.05). There was no significant correlation between gastrin receptor expression and clinical characteristics of colorectal cancer. CONCLUSIONS: The gastrin gene products might be more important than gastrin/CCK-B receptor in development or proliferation of colorectal cancer, which supports the hypothesis that gastrin gene products play a role in proliferation of colorectal cancer as an autocrine factor.