Cholecystokinin receptor A gene polymorphism in gallstone disease and gallbladder cancer

Using proton pump inhibitors increases the risk of hepato-biliary-pancreatic cancer. A systematic review and meta-analysis

Background: More and more studies are focusing on the adverse effects and damage caused by PPI abuse, we carried out a systematic review and meta-analysis for assessing whether the proton pump inhibitor (PPI) leads to hepato-biliary-pancreatic cancer.

Methods: PubMed, EMBASE and Web of Science were searched until 1 July 2022, 25 studies (17 case-control and 8 cohort studies; 2741853 individuals) included in this study. Pooled Odd Ratios (ORs) were used for random effect models. Sensitivity analysis and dose-response analysis, subgroup analysis were all conducted.

Results: The aggregate OR of the meta-analysis was 1.69 (95% confidence interval (CI): 1.42–2.01, p = 0.01) and heterogeneity (I² = 98.9%, p < 0.001) was substantial. According to stratified subgroup analyses, the incidence of hepato-biliary-pancreatic cancer was associated, expect for study design, study quality and region. Risk of hepato-biliary-pancreatic cancer is highest when people is treated with normal doses of PPI. The risks decrease and become insignificant when the cumulative defined daily dose (cDDD) increases.

Conclusion: The use of PPI may be associated with an increased risk of hepato-biliary-pancreatic cancer. Hence, caution is needed when using PPIs among patients with a high risk of hepato-biliary-pancreatic cancer.

Cholesterol cholelithiasis: part of a systemic metabolic disease, prone to primary prevention

Cholesterol gallstone disease have relationships with various conditions linked with insulin resistance, but also with heart disease, atherosclerosis, and cancer. These associations derive from mechanisms active at a local (i.e. gallbladder, bile) and a systemic level and are involved in inflammation, hormones, nuclear receptors, signaling molecules, epigenetic modulation of gene expression, and gut microbiota. Despite advanced knowledge of these pathways, the available therapeutic options for symptomatic gallstone patients remain limited. Therapy includes oral litholysis by the bile acid ursodeoxycholic acid (UDCA) in a small subgroup of patients at high risk of postdissolution recurrence, or laparoscopic cholecystectomy, which is the therapeutic radical gold standard treatment. Cholecystectomy, however, may not be a neutral event, and potentially generates health problems, including the metabolic syndrome. Areas covered: Several studies on risk factors and pathogenesis of cholesterol gallstone disease, acting at a systemic level have been reviewed through a PubMed search. Authors have focused on primary prevention and novel potential therapeutic strategies. Expert commentary: The ultimate goal appears to target the manageable systemic mechanisms responsible for gallstone occurrence, pointing to primary prevention measures. Changes must target lifestyles, as well as experimenting innovative pharmacological tools in subgroups of patients at high risk of developing gallstones.

Gallbladder cancer epidemiology, pathogenesis and molecular genetics: Recent update

Gallbladder cancer is a malignancy of biliary tract which is infrequent in developed countries but common in some specific geographical regions of developing countries. Late diagnosis and deprived prognosis are major problems for treatment of gallbladder carcinoma. The dramatic associations of this orphan cancer with various genetic and environmental factors are responsible for its poorly defined pathogenesis. An understanding to the relationship between epidemiology, molecular genetics and pathogenesis of gallbladder cancer can add new insights to its undetermined pathophysiology. Present review article provides a recent update regarding epidemiology, pathogenesis, and molecular genetics of gallbladder cancer. We systematically reviewed published literature on gallbladder cancer from online search engine PubMed (http://www.ncbi.nlm.nih.gov/pubmed). Various keywords used for retrieval of articles were Gallbladder, cancer Epidemiology, molecular genetics and bullion operators like AND, OR, NOT. Cross references were manually searched from various online search engines (http://www.ncbi.nlm.nih.gov/pubmed,https://scholar.google.co.in/, http://www.medline.com/home.jsp). Most of the articles published from 1982 to 2015 in peer reviewed journals have been included in this review.

CCK1 receptor is involved in the regulation of protein lysine acetylation in GBC-SD cells and gallbladder carcinoma

BACKGROUND

CCK1 (cholecystokinin receptor 1) and protein lysine acetylation were associated with several cancers, respectively. However, whether they are involved in the alternation of gallbladder carcinoma is unknown.

AIMS

This study investigated the characteristics of CCK1 and protein lysine acetylation in GBC-SD cells and carcinoma of gallbladder.

METHODS

The expression and localization of CCK1 were detected by western blot analysis and indirect immunofluorescence. GBC-SD cells were treated with CCK-8 and CCK-8+CCK1 inhibitor. The protein lysine acetylation from cells, as well as tissues of gallbladder carcinoma, was examined by western blotting.

RESULTS

CCK1 receptor was expressed and localized in the GBC-SD cells. The synthetic octapeptide of CCK (CCK-8) could accelerate the lysine acetylation of a subset of proteins in dose-dependent manners in GBC-SD cells. Further investigation demonstrated that the specific inhibitor (CR1409) of CCK1 receptor could attenuate the CCK8-induced increase of protein lysine acetylation. In addition, we revealed that the rise of CCK1 receptor expression is associated with the increase of protein lysine acetylation in tissues from carcinoma of gallbladder.

CONCLUSIONS

CCK might regulate protein lysine acetylation via CCK1 receptor.

Polymorphism and Expression Profile of Cholecystokinin Type A Receptor in Relation to Gallstone Disease Susceptibility

In the present study, we investigated expression pattern of Cholecystokinin type A receptor (CCKAR) in relation to its commonly studied polymorphism (rs1800857, T/C) in gallstone disease (GSD) patients and controls. A total of 502 subjects (272 GSD and 230 controls) were enrolled, and genotyping was performed by evaluating restriction fragments of PstI digested DNA. For analyzing expression pattern of CCKAR in relation to polymorphism, gallbladder tissue samples from 80 subjects (GSD-55; control-25) were studied. Expression of CCKAR mRNA was evaluated by reverse transcriptase-PCR and confirmed using real-time PCR. Protein expression was evaluated by enzyme-linked immunosorbent assay. We observed significantly (p < 0.0001) lower expression of CCKAR mRNA and protein in GSD tissues as compared with control. Significantly higher frequency of A1/A1 genotype (C/T transition) (p = 0.0005) was observed for GSD as compared with control. Expression of CCKAR protein was found to be significantly lower (p < 0.0001) in A1/A1 genotype as compared with other genotypes for GSD patients. Perhaps, this is the first report providing evidence of alteration in CCKAR expression in relation to its polymorphism elucidating the molecular pathway of the disease. Additional investigations with lager sample size are needed to confirm these findings.

Functional dyspepsia is associated with GNβ3 C825T and CCK-AR T/C polymorphism

BACKGROUND

A polymorphism (C825T) in G-protein β polypeptide-3 (GNβ3) gene alters intracellular signal transduction, which may cause motor or sensory abnormalities in the gastrointestinal tract. Cholecystokinin-A receptor (CCK-AR) gene T/C polymorphism is associated with a defective splicing of the primary transcript of CCK-AR mRNA, which may modulate satiety signal and delay gastric emptying. Therefore, we evaluated the role of these polymorphisms in patients with functional dyspepsia (FD) as compared with healthy controls (HC).

PATIENTS AND METHODS

A total of 237 consecutive patients with FD (Rome III) and 250 HC were genotyped for GNβ3 C825T and CCK-AR T/C polymorphisms (PCR-RFLP).

RESULTS

Patients with FD [173 (73%) men, age: 38 ± 12 years] were comparable with HC [195 (78%) men, age: 37 ± 12 years] with respect to age and sex. Out of 237 patients, 26 (11%) had epigastric pain syndrome (EPS), 55 (23.2%) had postprandial distress syndrome (PDS), and 156 (65.8%) had EPS-PDS overlap. Among 237 patients with FD, TT genotype (associated with increased intracellular signal transduction) of GNβ3 C825T polymorphism was more common among patients than among HC [26 (11%) vs. 12 (4.8%), P=0.014; odds ratio (OR): 2.47, 95% confidence interval (CI): 1.2-5.1]. CC (variant) genotype of CCK-AR T/C polymorphism was infrequent among patients than among HC [19 (8%) vs. 46 (18.4%), P=0.001; OR: 0.36, 95% CI: 0.19-0.66]. However, these polymorphisms were comparable among patients with different subtypes of FD (P=0.80 and 0.44).

CONCLUSION

TT genotype of GNβ3 C825T is more common among patients with FD than among HC, suggesting that increased signal transduction associated with this genotype may be important in its pathophysiology. However, CCK-AR polymorphism is protective against FD.

Expression of CCK Receptors in Carcinoma Gallbladder and Cholelithiasis: A Pilot Study

BACKGROUND

Gastrin and cholecystokinin (CCK) receptors are trophic for various gastrointestinal malignancies. Their role in gallbladder cancer has not been widely studied.

OBJECTIVES

To identify expression of CCK-A and CCK-B receptors in the tissue and blood of patients suffering from carcinoma (CA) gallbladder and gallstone disease and to compare expression of CCK A and B receptors in the gall bladder tissue and blood of healthy individuals and patients of CA gallbladder, and gallstone diseases.

MATERIALS AND METHODS

Forty nine subjects of both genders were recruited, comprising of 22 patients of CA gall bladder, 19 cases of cholelithiasis and, 8 normal gallbladders obtained from patients operated for trauma of the biliary system or Whipple's procedure. RNA extraction and cDNA formation for CCK-A and CCK-B receptors were carried out. Real Time PCR was performed on cDNA and threshold cycle (Ct) value of each sample was obtained and ΔCt was calculated. Chi-square test for comparing two groups and ANOVA test for comparing multiple groups were applied and if p<0.05 then Dunnett-C test was performed.

OBSERVATION AND RESULTS

Both CCK-A and CCK-B receptors were expressed irrespective of its origin in all tissues and blood samples studied; be it normal, Cholelithiasis or CA gallbladder and there was no difference among them (p>0.05).

CONCLUSION

This preliminary study showed higher expression of CCK-A receptors in patients of cholelithiasis and decreased expression of CCK-A receptors in patients of CA gallbladder as compared to normal gallbladder although it did not rise to statistical significance.

Endogenous elevation of plasma cholecystokinin does not prevent gallstones

BACKGROUND

Regular gall bladder contraction reduces bile stasis and prevents gallstone formation. Intraduodenal administration of exogenous pancreatic secretory trypsin inhibitor-I (PSTI-I, also known as monitor peptide) causes cholecystokinin (CCK) secretion.

DESIGN

We proposed that stimulation of CCK release by PSTI would produce gall bladder contraction and prevent gallstones in mice fed a lithogenic diet. Therefore, we tested the effect of overexpression of rat PSTI-I in pancreatic acinar cells on plasma CCK levels and gall bladder function in a transgenic mouse line (TgN[Psti1]; known hereafter as PSTI-I tg).

RESULTS

Importantly, PSTI tg mice had elevated fasting and fed plasma CCK levels compared to wild-type (WT) mice. Only mice fed the lithogenic diet developed gallstones. Both fasting and stimulated plasma CCK levels were substantially reduced in both WT and PSTI-I tg mice on the lithogenic diet. Moreover, despite higher CCK levels PSTI-I tg animals developed more gallstones than WT animals.

CONCLUSIONS

Together with the previously observed decrease in CCK-stimulated gall bladder emptying in mice fed a lithogenic diet, our findings suggest that a lithogenic diet causes gallstone formation by impaired CCK secretion in addition to reduced gall bladder sensitivity to CCK.

Association of caveolin-3 and cholecystokinin A receptor with cholesterol gallstone disease in mice

AIM: To investigate the role of caveolin-3 (CAV3) and cholecystokinin A receptor (CCKAR) in cholesterol gallstone disease (CGD).

METHODS: To establish a mouse model of CGD, male C57BL/6 mice were fed with a lithogenic diet containing 1.0% cholic acid, 1.25% cholesterol and 15% fat; a similar control group was given a normal diet. The fresh liver weights and liver-to-body weight ratio were compared between the two groups after one month. Serum lipid profile and bile composition were determined with an autoanalyzer. The Cav3 and Cckar mRNA and CAV3 and CCKAR protein levels in the liver and gallbladder were determined via real-time polymerase chain reaction and Western blot, respectively.

RESULTS: Establishment of the mouse CGD model was verified by the presence of cholesterol gallstones in mice fed the lithogenic diet. Compared with mice maintained on a normal diet, those fed the lithogenic diet had significantly higher mean liver-to-body weight ratio (0.067 ± 0.007 vs 0.039 ± 0.007, P < 0.01), serum total cholesterol (4.22 ± 0.46 mmol/L vs 2.21 ± 0.11 mmol/L, P < 0.001), bile total cholesterol (1.33 ± 0.33 mmol/L vs 0.21 ± 0.11 mmol/L, P < 0.001), and bile phospholipid concentrations (3.55 ± 1.40 mmol/L vs 1.55 ± 0.63 mmol/L, P = 0.04), but lower total bile acid concentrations (726.48 ± 51.83 μmol/L vs 839.83 ± 23.74 μmol/L, P = 0.007). The lithogenic diet was also associated with significantly lower CAV3 in the liver and lower CAV3 and CCKAR in the gallbladder compared with the control mice (all P < 0.05).

CONCLUSION: CAV3 and CCKAR may be involved in cholesterol gallstone disease.

Differential expression of cholecystokinin A receptor in gallbladder cancer in the young and elderly suggests two subsets of the same disease?

Background. Cholecystokinin type A receptor (CCKAR) is known to be overexpressed in variety of human malignancies but information regarding its expression in gallbladder cancer (GBC) is limited. Attempts were now made to investigate expression pattern of CCKAR mRNA and protein in controls and GBC patients and correlate it with various clinicopathological parameters following surgical resection. Materials and Methods. Gallbladder tissue samples from 64 subjects (GBC: 39; control: 25) were studied. Expression of CCKAR mRNA was evaluated by reverse transcriptase-polymerase chain reaction and confirmed using real-time polymerase chain reaction. Protein expression was studied by enzyme-linked immunosorbent assay. Results. Significantly higher expression of CCKAR mRNA (P < 0.0001) and protein (P < 0.0001) was observed in GBC tissues. Overexpression was also observed for stage III and in moderately and poorly differentiated tumors. When the clinicopathological parameters were compared, we found age dependent decrease in CCKAR expression. Relatively higher expression of CCKAR was observed in younger patients (age < 45 years) having more aggressive disease when compared with elderly ones (age ≥ 45 years). Conclusions. Age related differential expression of CCKAR in GBC may suggest two possible variants of the disease in this endemic belt.

Association of adrenergic receptor gene polymorphisms in gallbladder cancer susceptibility in a North Indian population

PURPOSE

Gallbladder cancer (GBC), the most common gastrointestinal and biliary tract malignancy, often coincides with gallstone disease (GSD). The genetic variants of adrenergic receptor (ADR) have been previously reported to be associated with hypomotility disorder of cardiovascular system and GSD. Since GSD may function as GBC precursor, the present study aimed to investigate the association of common functional genetic variants of ADRA2A C-1291G, ADRβ3 T190C or Trp64Arg, and ADRβ1 C1165G or Arg389Gly with GBC and GSD susceptibility.

METHODS

The present study included a total of 400 histologically confirmed GBC, 230 GSD, and 268 healthy controls. The ADRA2A C-1291G, ADRβ3 T190C, and ADRβ1 C1165G polymorphisms were determined by PCR-RFLP. Statistical analysis was performed by using SPSS version 16.

RESULTS

ADRβ3 T190C polymorphism was significantly associated with increased risk of GBC (CT: Pcorr = 0.015, OR 2.87; CC: Pcorr = 0.038, OR 10.33; C allele: Pcorr = 0.014, OR 2.7; CT + CC: Pcorr = 0.017, OR 3.05). These associations existed even after gallstone and gender stratification. Similarly, ADRβ3 T190C polymorphism was also associated with GSD risk, though limited only to female GSD patients. In contrary, ADRA2A C-1291G conferred a marginally increased risk only in GSD patients. ADRβ1 C1165G polymorphism was not associated with GBC and GSD susceptibility when compared to controls.

CONCLUSION

ADRβ3 T190C polymorphism is significantly associated with GBC and GSD susceptibility. The ADRβ3 T190C may be involved in the pathophysiology of GBC by both gallstone-dependent pathway and by some other independent mechanisms.

Variants in CCK and CCKAR genes to susceptibility to biliary tract cancers and stones: a population-based study in Shanghai, China

BACKGROUND AND AIM

Altered motility of the gallbladder is associated with an increased risk of gallstones and can result in biliary tract cancers. Cholecystokinin (CCK) is an important modulator of gallbladder motility which functions by activating CCK type-A receptor (CCKAR). The aim of this study was to determine whether genetic variants in CCK and CCKAR are associated with the risk of biliary tract cancers and stones.

METHODS

We investigated the associations between nine single nucleotide polymorphisms in CCK and CCKAR in a population-based case-control study, including 439 biliary tract cancer cases (253 gallbladder, 133 extrahepatic bile duct, and 53 ampulla of Vater cancer cases), 429 biliary stone cases, and 447 population controls in Shanghai, China.

RESULTS

We found that women with the CCKAR rs1800855 AA genotype had an increased risk of gallbladder cancer (odds ratio = 2.37, 95% confidence interval (CI): 1.36-4.14) compared with subjects with the TT genotype, and remained significant after Bonferroni correction (P = 0.0056). Additionally, female carriers of the CCKAR haplotype C-T-C-T (rs2071011-rs915889-rs3822222-rs1800855) had a reduced risk of gallbladder cancer (odds ratio = 0.61, 95% confidence interval: 0.43-0.86) compared with those with the G-C-C-A haplotype; the association also remained significant after Bonferroni correction.

CONCLUSIONS

These findings suggest that variants in the CCKAR gene may influence the risk of gallbladder cancer in women. Additional studies are needed to confirm our findings.

Genetics of gallstone disease

Gallstone disease (GSD) is one of the most common biliary tract disorders worldwide. The prevalence, however, varies from 5.9-21.9% in Western society to 3.1-10.7% in Asia. Most gallstones (75%) are silent. Approximately half of symptomatic gallstone carriers experience a second episode of biliary pain within 1 year. These individuals are at increased risk of developing acute cholecystitis, acute cholangitis, and biliary pancreatitis. As can be expected, these complications burden health care systems because of their invasive nature and surgical cost. Factors that contribute to gallstone formation include supersaturation of cholesterol in bile, gallbladder hypomotility, destabilization of bile by kinetic protein factors, and abnormal mucins. Epidemiologic studies have implicated multiple environmental factors and some common genetic elements in gallstone formation. Genetic factors that influence gallstone formation have been elaborated from linkage studies of twins, families, and ethnicities. Accumulating evidence suggests that genetic factors play a role in GSD.

Mucin genes in gallstone disease

Gallstone disease is a complex disorder that can be caused by environmental influences, common genetic factors and their interactions. Three major pathogenic abnormalities are considered to involve in gallstone formation: cholesterol supersaturation in bile, precipitation and nucleation of excess cholesterol, and gallbladder hypomotility, while, mucin takes part in the cholesterol nucleation process. Up to date, more than 20 mucin genes have been reported, 9 of them are identified at the mRNA and/or protein level in native gallbladder and its associated diseases. In the gallbladder, mucin is essential for best protection against detergent effect of high concentration of bile acids. Over the past decade, the properties, expressions and functions of the gallbladder mucins are delineated in animal and human studies. Alteration expressions of mucins are thought to response during the pathogenesis of gallstone formation. Moreover, recent genetic association study demonstrated mucin gene polymorphisms may also influence susceptibility to gallstone disease. This review is not to provide a complete coverage of all the aspects of mucin glycoproteins, but focus on the role and expression of mucins involve in the regulation of cholelithogenesis.

Concept of the pathogenesis and treatment of cholelithiasis

Gallstone disease (GD) is a chronic recurrent hepatobiliary disease, the basis for which is the impaired metabolism of cholesterol, bilirubin and bile acids, which is characterized by the formation of gallstones in the hepatic bile duct, common bile duct, or gallbladder. GD is one of the most prevalent gastrointestinal diseases with a substantial burden to health care systems. GD can result in serious outcomes, such as acute gallstone pancreatitis and gallbladder cancer. The epidemiology, pathogenesis and treatment of GD are discussed in this review. The prevalence of GD varies widely by region. The prevalence of gallstone disease has increased in recent years. This is connected with a change in lifestyle: reduction of motor activity, reduction of the physical load and changes to diets. One of the important benefits of early screening for gallstone disease is that ultrasonography can detect asymptomatic cases, which results in early treatment and the prevention of serious outcomes. The pathogenesis of GD is suggested to be multifactorial and probably develops from complex interactions between many genetic and environmental factors. It suggests that corticosteroids and oral contraceptives, which contain hormones related to steroid hormones, may be regarded as a model system of cholelithiasis development in man. The achievement in the study of the physiology of bile formation and the pathogenesis of GD has allowed expanding indications for therapeutic treatment of GD.

Polymorphism at the mucin-like protocadherin gene influences susceptibility to gallstone disease

BACKGROUND

Gallstone disease (GSD) is a common disease that can be caused by environmental influences, common genetic factors and their interactions. Mucin glycoproteins may be one important factor for GSD. We conducted a case-control study to investigate the relationship between the mucin-like protocadherin (MUPCDH) gene polymorphisms and GSD.

METHODS

The study included 452 GSD cases and 491 healthy controls who had no evidence of gallstones by ultrasound examination. Two common tagging single nucleotide polymorphism (SNP) rs3758650 and rs7932167, and four non-synonymous SNPs rs34362213, rs2740375, rs7108757 and rs2740379 were genotyped. The genetic effects were evaluated using the multivariate regression model.

RESULTS

The genotypes of these SNPs were all in Hardy-Weinberg equilibrium. Three non-synonymous SNPs (rs34362213, rs7108757 and rs2740379) were monomorphic. The single SNP analysis showed two SNPs (rs7932167 and rs2740375) were not associated with GSD and only SNP rs3758650 had the association of the presence of GSD with an odds ratio (OR) of 1.59 (adjusted P=0.013) for the AG genotype and 5.82 (adjusted P=0.007) for the AA genotype when compared with the reference GG genotype. The haplotype analysis of the three polymorphic SNPs showed GCA was significant for GSD (adjusted p=0.001) with an odds ratio (OR) of 1.41 when compared to other haplotypes.

CONCLUSIONS

The MUPCDH genetic polymorphism rs3758650 was considered a genetic marker to predict symptomatic GSD subjects. It may be of importance for GSD patients with the risk SNPs to be frequently checked because they may develop symptomatic GSD.

Candidate gene studies in gallbladder cancer: a systematic review and meta-analysis

Gallbladder cancer (GBC) is the most frequent biliary tract malignancy. Wide variations in GBC incidence and familial and epidemiological data suggest involvement of a genetic component in its etiopathogenesis. A systematic review of genetic association studies in GBC was performed by applying a meta-analysis approach and systematically reviewing PubMed database using appropriate terms. Odds ratios (ORs) and 95% confidence intervals (CIs) were appropriately derived for each gene-disease association using fixed and random effect models. Meta-regression with population size and genotyping method was also performed. Study quality was assessed using a 10-point scoring system designed from published guidelines. Following a review of 44 published manuscripts and one unpublished report, 80 candidate gene variants and 173 polymorphisms were analyzed among 1046 cases and 2310 controls. Majority of studies were of intermediate quality. Four polymorphisms with >3 separate studies were included in the meta-analysis [OGG1 (rs1052133), TP53 (rs1042522), CYP1A1 (rs1048943) and GSTM1 null polymorphism]. The meta-analysis demonstrated no significant associations of any of the above polymorphisms with GBC susceptibility except TP53 (rs1042522) polymorphism. To conclude, existing candidate gene studies in GBC susceptibility have so far been insufficient to confirm any association. Future research should focus on a more comprehensive approach utilizing potential gene-gene, gene-environment interactions and high-risk haplotypes.

Multiple mucin genes polymorphisms are associated with gallstone disease in Chinese men

BACKGROUND

Gallstone is a complex disease caused by multiple environmental and genetic factors. One of these is mucin glycoproteins. This case-control study aimed to investigate the association between single nucleotide polymorphisms (SNPs) at the MUC1-4 genes and gallstone.

METHODS

The study included 475 cases and 941 controls. Eight tagging SNPs were selected: one at MUC1, two at MUC2, and five at MUC4. There was no available tagging SNP at MUC3. Genetic effects were initially evaluated by multivariate logistic regression. The combined effects from multiple genes were further evaluated, as well as the sex-specific effect. Permutation was used to correct for multiple testing.

RESULTS

The genotypes were all in Hardy-Weinberg equilibrium. SNP rs7396030 at MUC2 yielded a p value of 0.03. Further sex-specific analysis showed significance solely with male subjects (p=0.005). Similarly, SNP rs4072037 at MUC1 was only significant (p=0.035) in males. The permutation empirical p values were 0.005 for rs7396030 and 0.02 for rs4072037. For males, the combined genetic effect yielded an OR of 4.68 (p=0.0008).

CONCLUSIONS

The SNPs at MUC1 and MUC2 are significantly associated with gallstone in men but not in women. These genes can work jointly to further increase susceptibility to gallstone in a Chinese population.

Association of CCK(1) Receptor Gene Polymorphisms and Irritable Bowel Syndrome in Korean

INTRODUCTION

Cholecystokinin (CCK) belongs to a group of endogenous molecules known as brain-gut neuropeptides and functions as a neuropeptide as well as a gut hormone. It remains unclear whether genetic variation of the CCK receptor plays a role in irritable bowel syndrome (IBS). The aim of this study was to determine and compare the allele and genotype frequencies of the CCK(1) receptor polymorphisms between healthy controls and patients with IBS.

METHODS

Genotyping of 80 patients with IBS (who met the Rome III criteria) and 76 healthy controls was performed. We performed PCR amplification for the CCK(1) receptor intron 1 779 T > C and Exon 1 G > A. We confirmed polymorphisms by direct sequencing method.

RESULTS

There was a significantly different trend for genotypic distributions of the CCK(1) receptor polymorphism between patients with IBS and healthy controls (p for trend = 0.048). The CCK(1) receptor intron 1 779 T >C polymorphic type was more common in patients with 'IBS-constipation predominant (IBS-C) and IBS-mixed (IBS-M) forms' (19/31, 61.3%) than healthy controls 32/76, 42.1% adjusted odd ratio 2.43, 95% Confidence interval 1.01-5.86). The genotypic distributions of the CCK(1) receptor exon 1 polymorphism were not significantly different between the two groups (p for trend = 0.223).

CONCLUSIONS

CCK(1) receptor polymorphisms were associated with IBS. In particular, the CCK(1) receptor intron 1 779 T > C polymorphic type was associated with 'IBS-C and IBS-M'. Further studies are needed in larger number of patients with an even distribution of IBS subtypes.

Control of gallbladder contractions by cholecystokinin through cholecystokinin-A receptors on gallbladder interstitial cells of cajal

AIM: To identify the cholecystokinin (CCK)-A receptors (CCK-AR) on the guniea pig gallbladder interstitial cells of cajal (ICC) and to study CCK-8 induced gallbladder muscle strip contractions through the CCK-AR.

METHODS: The existence of CCK-AR was examined by immunohistofluorescence on sectioned tissue and cultured cells. In vitro contractile response of guinea pig gallbladder muscle strips and the strips with ICC removed were also studied with CCK-8 receptors added.

RESULTS: In tissue sections, intensely CCKAR-immunoreactive interstitial cells were found mainly in the muscular layers. In cultured cell sections, distinctive double staining of C-kit and CCK-AR ICCs were found. When we removed the ICC of the gallbladder, CCK-8 induced muscle strip contraction dose response curve significantly shifted to the right.

CONCLUSION: We proved that both the existence of CCK-AR on the guinea pig gallbladder ICC and CCK evoked contraction are mediated through direct action on CCK-AR on the gallbladder ICC.