Alteration of gut microbiota in association with cholesterol gallstone formation in mice.

BACKGROUND: The gut microbiome exerts extensive roles in metabolism of nutrients, pharmaceuticals, organic chemicals. Little has been known for the role of gut microbiota in regulating cholesterol and bile acids in association with gallstone formation. This study investigated the changes in the composition of gut microbiota in mice fed with lithogenic diet (LD). METHODS: Adult male C57BL/6 J mice were fed with either lithogenic diet (1.25% cholesterol and 0.5% cholic acid) or chow diet as control for 56 days. The fecal microbiota were determined by 16S rRNA gene sequencing. RESULTS: LD led to formation of cholesterol gallstone in mice. The richness and alpha diversity of gut microbial reduced in mice fed with LD. Firmicutes was significantly decreased from 59.71% under chow diet to 31.45% under LD, P < 0.01, as well as the ratio of Firmicutes to Bacteroidetes. Differences in gut microbiota composition were also observed at phylum, family and genus levels between the two groups. CONCLUSION: Our results suggested that gut microbiota dysbiosis might play an important role in the pathogenesis of cholesterol gallstone formation in mice.

Genetic and functional identification of the likely causative variant for cholesterol gallstone disease at the ABCG5/8 lithogenic locus.

UNLABELLED: The sterolin locus (ABCG5/ABCG8) confers susceptibility for cholesterol gallstone disease in humans. Both the responsible variant and the molecular mechanism causing an increased incidence of gallstones in these patients have as yet not been identified. Genetic mapping utilized patient samples from Germany (2,808 cases, 2,089 controls), Chile (680 cases, 442 controls), Denmark (366 cases, 766 controls), India (247 cases, 224 controls), and China (280 cases, 244 controls). Analysis of allelic imbalance in complementary DNA (cDNA) samples from human liver (n = 22) was performed using pyrosequencing. Transiently transfected HEK293 cells were used for [(3) H]-cholesterol export assays, analysis of protein expression, and localization of allelic constructs. Through fine mapping in German and Chilean samples, an ∼250 kB disease-associated interval could be defined for this locus. Lack of allelic imbalance or allelic splicing of the ABCG5 and ABCG8 transcripts in human liver limited the search to coding single nucleotide polymorphisms. Subsequent mutation detection and genotyping yielded two disease-associated variants: ABCG5-R50C (P = 4.94 × 10(-9) ) and ABCG8-D19H (P = 1.74 × 10(-10) ) in high pairwise linkage disequilibrium (r(2) = 0.95). [(3) H]-cholesterol export assays of allelic constructs harboring these genetic candidate variants demonstrated increased transport activity (3.2-fold, P = 0.003) only for the ABCG8-19H variant, which was also superior in nested logistic regression models in German (P = 0.018), Chilean (P = 0.030), and Chinese (P = 0.040) patient samples. CONCLUSION: This variant thus provides a molecular basis for biliary cholesterol hypersecretion as the mechanism for cholesterol gallstone formation, thereby drawing a link between "postgenomic" and "pregenomic" pathophysiological knowledge about this common complex disorder. (HEPATOLOGY 2012).

Single nucleotide polymorphism rs3732860 in the 3'-untranslated region of CYP8B1 gene is associated with gallstone disease in Han Chinese.

BACKGROUND AND AIMS: Gallstone disease (GD) is a common disease of multigenetic origin; however, the major susceptibility loci for GD in human populations remain unidentified. This study aimed to identify the genetic factors contributing to gallstone development in Chinese. METHODS: A genome-wide scan was conducted in 12 Han Chinese GD families to identify linkage loci. The linkage region showing the highest logarithm of odds score encompasses the sterol 12α-hydroxylase gene (CYP8B1). Replication analysis with an independent sample of 192 GD patients and 192 unrelated, matched controls was carried out to verify the associations between CYP8B1 polymorphisms and GD. RESULTS: Three loci (D3S1266, D4S406, and D9S1682) showed suggestive or nominal evidence of linkage in all 12 GD families. The logarithm of odds score of D3S1266 reached 2.71 in the families with late-onset patients. The single nucleotide polymorphism rs3732860 in the 3'-untranslated region of CYP8B1 showed significant association to GD (P = 0.022), and carriers of the A allele had lower risk of GD (odds ratio = 1.46, 95% confidence interval: 1.055-2.034) compared with carriers of the G allele. CONCLUSIONS: The single nucleotide polymorphism rs3732860 in the 3'-untranslated region of the CYP8B1 gene is associated with risk of GD in Chinese Han and appears to be responsible for the observed linkage with D3S1266.

Expression of telomerase & its significance in the diagnosis of pancreatic cancer.

Pancreatic cancer has one of the worst prognoses among all types of cancers. The survival rate is less than 5 per cent; this is due to difficulty in diagnosing at an early stage. Despite the improvements in diagnostic imaging techniques such as computed tomography, magnetic resonance imaging, etc., the early diagnosis of pancreatic cancer is still difficult. Alternative methods of diagnosing pancreatic cancer at an early stage are presently been explored. The detection of telomerase activity has been proposed to be a useful tool in the diagnosis of pancreatic cancer. Telomerase is made up of three major parts namely, human telomerase reverse transcriptase, human telomerase and telomerase -associated protein. Several researchers have shown telomerase activity in tissues and fluids of patients with pancreatic and other types of cancers. About 95 per cent telomerase activity has been detected in pancreatic adenocarcinoma. Since telomerase activity is present in a vast majority of human cancers, it might have a role in the diagnosis and treatment of cancer.

[Association of single nucleotide polymorphism in human CYP8B1 gene with gallstone disease].

OBJECTIVE: To identify the single nucleotide polymorphisms of human CYP8B1gene and explore the association of some of these SNPs with gallstone disease in Chinese population. METHODS: The exon and part of promoter were sequenced by a fluorescent labeling automatic method to identify and characterize the SNPs in Chinese population. For SNPs with an allelic frequency of over 10%, a case-control study was performed in patients and controls. RESULTS: Eleven SNPs were found within a 5119 bp region. Among them, 1 was in coding region, 5 in promoter and 5 in 3'-UTR. There were 3 novel SNPs and 12 SNPs in SNP database were not found. The allelic frequency of rs3732860 polymorphism showed a significant difference (P = 0.022) in the association study. The subjects with A allele had a significantly lower frequency of gallstone disease than those with G allele (OR = 1.465, 95%CI 1.055 - 2.034, P = 0.023). CONCLUSION: SNP rs3732860 of CYP8B1 gene is associated with gallstone disease in Chinese population. And A allele may play a protective role in the pathogenesis of gallstone.

A Mitochondrial DNA Variant Elevates the Risk of Gallstone Disease by Altering Mitochondrial Function.

BACKGROUND AND AIMS: Gallstone disease (cholelithiasis) is a cholesterol-related metabolic disorders with strong familial predisposition. Mitochondrial DNA (mtDNA) variants accumulated during human evolution are associated with some metabolic disorders related to modified mitochondrial function. The mechanistic links between mtDNA variants and gallstone formation need further exploration. METHODS: In this study, we explored the possible associations of mtDNA variants with gallstone disease by comparing 104 probands and 300 controls in a Chinese population. We constructed corresponding cybrids using trans-mitochondrial technology to investigate the underlying mechanisms of these associations. Mitochondrial respiratory chain complex activity and function and cholesterol metabolism were assessed in the trans-mitochondrial cell models. RESULTS: Here, we found a significant association of mtDNA 827A>G with an increased risk of familial gallstone disease in a Chinese population (odds ratio [OR]: 4.5, 95% confidence interval [CI]: 2.1-9.4, P=1.2×10-4). Compared with 827A cybrids (haplogroups B4a and B4c), 827G cybrids (haplogroups B4b and B4d) had impaired mitochondrial respiratory chain complex activity and function and activated JNK and AMPK signaling pathways. Additionally, the 827G cybrids showed disturbances in cholesterol transport and accelerated development of gallstones. Specifically, cholesterol transport through the transporter ABCG5/8 was increased via activation of the AMPK signaling pathway in 827G cybrids. CONCLUSIONS: Our findings reveal that mtDNA 827A>G induces aberrant mitochondrial function and abnormal cholesterol transport, resulting in increased occurrence of gallstones. The results provide an important biological basis for the clinical diagnosis and prevention of gallstone disease in the future.

HNF1alpha and SREBP2 are important regulators of NPC1L1 in human liver.

Niemann-Pick C1-like 1 (NPC1L1), a key regulator of intestinal cholesterol absorption, is highly expressed in human liver. Here, we aimed to gain more insight into mechanisms participating in its hepatic regulation in humans. Correlation analysis in livers from Chinese patients with and without gallstone disease revealed strong positive correlations between NPC1L1 and sterol regulatory element binding protein 2 (SREBP2) (r = 0.74, P < 0.05) and between NPC1L1 and hepatic nuclear factor alpha (HNF4alpha) (r = 0.53, P < 0.05) mRNA expression. HNF4alpha is an upstream regulator of HNF1alpha; thus, we also tested whether HNF1alpha participates in the regulation of NPC1L1. We showed a dose-dependent regulation by SREBP2 on the NPC1L1 promoter activity and mRNA expression in HuH7 cells. Chromatin immunoprecipitation assay confirmed the binding of SREBP2 to the promoter in vivo. Surprisingly, HNF4alpha slightly decreased the NPC1L1 promoter activity but had no effect on its gene expression. By contrast, HNF1alpha increased the promoter activity and the gene expression, and an important HNF1 binding site was identified within the human NPC1L1 promoter. ChIP assays confirmed that HNF1alpha can bind to the NPC1L1 promoter in vivo.

Polymorphisms of estrogen receptors and risk of biliary tract cancers and gallstones: a population-based study in Shanghai, China.

Biliary tract cancer encompasses tumors of the gallbladder, bile duct and ampulla of Vater. Gallbladder cancer is more common in women, whereas bile duct cancer is more common in men, suggesting that sex hormones may play a role in the etiology of these cancers. The intracellular action of estrogens is regulated by the estrogen receptor (ESR); thus, we examined the role of common genetic variants in ESR genes on the risk of biliary tract cancers and stones in a population-based case-control study in Shanghai, China (411 cancer cases, 895 stone cases and 786 controls). We genotyped six single-nucleotide polymorphisms (SNPs), four in ESR1 (rs2234693, rs3841686, rs2228480 and rs1801132) and two in ESR2 (rs1256049 and rs4986938). In all participants, the ESR1 rs1801132 (P325P) G allele was associated with excess risks of bile duct [odds ratio (OR) = 1.7, 95% confidence interval (CI) 1.1-2.8] and ampulla of Vater cancers (OR = 2.1, 95% CI 0.9-4.9) compared with the CC genotype. The association with bile duct cancer was apparent among men (OR = 2.8, 95% CI 1.4-5.7) but not among women (P-heterogeneity = 0.01). Also, the ESR2 rs4986938 (38 bp 3' of STP) GG genotype was associated with a higher risk of bile duct cancer (OR = 3.3, 95% CI 1.3-8.7) compared with the AA genotype, although this estimate was based on a small number of subjects. None of the other SNPs examined was associated with biliary tract cancers or stones. False discovery rate-adjusted P-values were not significant (P > 0.1). No association was found for ESR1 haplotype based on four SNPs. These preliminary results suggest that variants in ESR genes could play a role in the etiology of biliary tract cancers, especially bile duct cancer in men.

Decreased NPC1L1 expression in the liver from Chinese female gallstone patients.

BACKGROUND: Cholesterol gallstone disease is a very common disease in both industrialized and developing countries. Many studies have found that cholesterol gallstones are more common in women than men. The molecular mechanisms underlying the relationship between female gallstone disease and hepatic sterol transporters are still undergoing definition and have not been evaluated in humans. AIMS: The aim of this study is to probe for underlying hepatic molecular defects associated with development of gallstones in female. METHODS/RESULTS: Fifty-seven nonobese, normolipidemic Chinese female gallstone patients (GS) were investigated with 12 age- and body mass index-matched female gallstone-free controls (GSF). The bile from the female GS had higher cholesterol saturation than that from the female GSF. The hepatic NPC1L1 mRNA levels were lower in female GS, correlated with SREBP2 mRNA. NPC1L1 downregulation was confirmed at protein levels. Consistently, immunohistochemistry showed decreased NPC1L1 expression in female GS. CONCLUSIONS: The decreased hepatic NPC1L1 levels in female GS might indicate a downregulated reabsorption of biliary cholesterol in the liver, which, in turn, leads to the cholesterol supersaturation of bile. Our data are consistent with the possibility that hepatic NPC1L1 may be mediated by SREBP2.

Early laparoscopic cholecystectomy for acute gallbladder disease in Chinese elderly.

BACKGROUND/AIMS: Evidence now strongly supports that early laparoscopic cholecystectomy (ELC) is the treatment of choice for acute gallbladder disease. However, the optimal time for managing acute gallbladder disease in elderly people is still controversial. The purpose of this study was to evaluate the outcome of ELC in patients aged 65 years old and older. METHODOLOGY: We performed a retrospective case study review of patients undergoing ELC in a single institution between January 2005 and December 2008. RESULTS: A total of 4048 patients were analyzed: 737 patients were older than 65 years old and 3311 younger. In total, 18% of the elderly patients and 3% of the younger patients had American Society of Anesthesiologists (ASA) score III and IV, respectively (p < 0.001). Co-morbidity rates were significantly higher in the elderly group (61.5% vs. 20.7%, p < 0.001). There was no difference in operative time, intraoperative complications, hospital stay and mortality between the two groups, except that the rate of conversion to open cholecystectomy (OC) and postoperative complications were significantly higher in elderly patients. CONCLUSION: Even though elderly patients are more likely to present with several co-morbidities in advanced stages, ELC for elderly patients with acute gallbladder disease is safe and effective, and should be regarded as the standard of care.

Variants in hormone-related genes and the risk of biliary tract cancers and stones: a population-based study in China.

Biliary tract cancers, encompassing gallbladder, extrahepatic bile duct and ampulla of Vater cancers, are uncommon but often fatal malignancies. Hormone-related factors, including parity, oral contraceptive use, obesity, and gallstones, have been implicated in the etiology of these cancers. To further clarify the role of hormones in biliary tract cancers and biliary stones, we genotyped 18 single-nucleotide polymorphisms (SNPs) in nine genes involved in steroid hormone biosynthesis, metabolism and transport in a population-based case-control study in Shanghai, China. This study included subjects who completed an interview and provided blood, which totaled 411 biliary tract cancer and 893 biliary stone patients and 786 healthy Shanghai residents. The CYP1A1 IVS1 + 606 (rs2606345) T allele was associated with gallbladder [odds ratio (OR) = 2.0, 95% confidence interval (CI), 1.3-3.0] and bile duct cancers (OR = 1.8, 95% CI = 1.1-3.1), whereas the CYP1A1 Ex7 + 131 (rs1048943) G allele was associated with ampulla of Vater cancer (OR = 2.9, 95% CI = 1.5-5.4). After taking into account multiple comparisons for SNPs within each gene, CYP1A1 was significantly associated with gallbladder (P = 0.004) and ampulla of Vater cancers (P = 0.01), but borderline with bile duct cancer (P = 0.06). The effect of CYP1A1 IVS1 + 606 on gallbladder cancer was more pronounced among non-obese (body mass index < 23) (OR = 3.3, 95% CI = 1.8-6.1; P interaction = 0.001). Among women taking oral contraceptives, the effect of SHBG Ex8 + 6 (rs6259) on gallbladder cancer (OR = 6.7, 95% CI = 2.2-20.5; P interaction = 0.001) and stones (OR = 2.3, 95% CI = 1.1-4.9; P-interaction = 0.05) was statistically significant. Our findings suggest that common variants in hormone-related genes contribute to the risk of biliary tract cancers and stones, possibly by modulating hormone metabolism.

Increased NPC1L1 and ACAT2 expression in the jejunal mucosa from Chinese gallstone patients.

The incidence of cholesterol gallstones is a very common disease. The aim of this study is to probe for underlying intestinal molecular defects associated with development of gallstones. Twelve Chinese patients with cholesterol gallstone disease (GS) and 31 gallstone-free (GSF) patients were investigated. Quantitation of mRNA levels for individual genes in mucosal biopsies from jejunum was carried out with real-time PCR. The frequency of two SNPs in the ABCG8 gene (Y54C and T400K) was determined by allelic discrimination. The intestinal mRNA expression of NPC1L1 and ACAT2 were significantly higher in GS than GSF (P<0.05). No differences were observed concerning the levels for plasma lipids, plant sterols and 7alpha-hydroxy-4-cholesten-3-one between GS and GSF. No correlations were observed between patients carrying the different genotypes for Y54C or T400K and their mRNA levels for ABCG5 or ABCG8. The increased NPC1L1 and ACAT2 mRNA levels in gallstone patients might indicate an upregulated absorption and esterification of cholesterol in the small intestine.

Genetic determinants of serum lipid levels in Chinese subjects: a population-based study in Shanghai, China.

We examined the associations between 21 single nucleotide polymorphisms (SNPs) of eight lipid metabolism genes and lipid levels in a Chinese population. This study was conducted as part of a population-based study in China with 799 randomly selected healthy residents who provided fasting blood and an in-person interview. Associations between variants and mean lipid levels were examined using a test of trend and least squares mean test in a general linear model. Four SNPs were associated with lipid levels: LDLR rs1003723 was associated with total cholesterol (P-trend = 0.002) and LDL (P-trend = 0.01), LDLR rs6413503 was associated with total cholesterol (P-trend = 0.05), APOB rs1367117 was associated with apoB (P-trend = 0.02), and ABCB11 rs49550 was associated with total cholesterol (P-trend = 0.01), triglycerides (P-trend = 0.01), and apoA (P-trend = 0.01). We found statistically significant effects on lipid levels for LDLR rs6413503 among those with high dairy intake, LPL rs263 among those with high allium vegetable intake, and APOE rs440446 among those with high red meat intake. We identified new associations between SNPs and lipid levels in Chinese previously found in Caucasians. These findings provide insight into the role of lipid metabolism genes, as well as the mechanisms by which these genes may be linked with disease.

[Expression and regulation of megalin in gallbladder mucosa associated with cholesterol gallstone disease].

OBJECTIVE: To explore the relationship between expression and regulation of Megalin in gallbladder mucosa and cholesterol gallstone disease. METHODS: Gallbladder mucosa, gallbladder wall, bile, gallstone were collected from 29 patients with cholesterol gallstone disease (GS) and 12 patients with gallstone free (GSF). Lipids of bile and stone were measured by kits. Expression of Megalin and Cubilin was analyzed by Real-time PCR. GBC-SD cell line were treated with T0901317, 9-cis retinoic acid, chenodeoxycholic acid (CDCA), the agonists of LXR, RXR, FXR, respectively. Gene expressions were detected. RESULTS: Biliary cholesterol % molar and CSI increased significantly in GS group [(7.98 +/- 0.44) mol% vs (4.87 +/- 0.39) mol%, P < 0.01]. Megalin expression in GS group was significantly higher than that in GSF group (P < 0.05) and cubilin expression was similar between two groups. In vitro experiments showed that CDCA markedly increased expression of megalin. CONCLUSION: This study shows that the increased expression Megalin may help to increase cholesterol uptake in gallbladder and play a compensative role in GS. FXR may participate in the transcription regulating of Megalin.

[Detection of early organ dysfunction for the selection of treatment strategy on severe acute pancreatitis.].

OBJECTIVE: To investigate the severity related influencing factor and treatment strategy of severe acute pancreatitis with early organ dysfunction. METHODS: From July 2007 to December 2008, 167 patients with severe acute pancreatitis were treated in the Surgical Department of Ruijin Hospital. The relationships between the happening of early organ dysfunction and outcome of the patients were observed, with operative or nonoperative treatment strategy. RESULTS: Among 167 patients, 68 patients have early organ dysfunction, in which 39 with single organ dysfunction and 29 with multiple organ dysfunction. The early organ dysfunction were involved in 47.1% in cardiovascular system, 35.3% in lung and 29.4% in kidney. Aging (P < 0.05) and higher APACHE II score (P < 0.05) predicted a poor prognosis, which were benefit from early operation. CONCLUSIONS: The mortality of the patients with SAP is related to age, and the degree of organ dysfunction as well. In the first phase of the disease, the selection of operation depends on the trends and the degree of early organ dysfunction before infected necrosis happens, with the aid of SOFA score as a scale.

Selected base excision repair gene polymorphisms and susceptibility to biliary tract cancer and biliary stones: a population-based case-control study in China.

Base excision repair (BER) corrects DNA damage caused by oxidative stress and chronic inflammation, putative risk factors for cancer. To understand the relationship between genetic variation in BER genes and risk of biliary tract cancer and biliary stones, we examined non-synonymous polymorphisms in three key BER genes-x-ray repair cross-complementing group 1 (XRCC1) (R194W, rs1799782; R280H, rs25489 and R399Q, rs25487), apurinic/apyrimidinic endonuclease (APEX1) (D148E, rs3136820) and 8-oxoguanine DNA glycosylase (OGG1) (S326C, rs1052133), in a population-based study of 411 biliary tract cancer cases (237 gallbladder, 127 bile duct and 47 ampulla of Vater), 891 biliary (gallbladder or bile duct) stone cases and 786 population controls conducted in Shanghai, China. Compared with subjects carrying the XRCC1 194RR genotype, those with the WW genotype had a 1.9-fold risk of bile duct cancer [odds ratio (OR) = 1.9, 95% confidence interval (CI) = 1.1-3.5, P(trend) = 0.03], and compared with subjects carrying the XRCC1 280RR genotype, those with the XRCC1 280H allele had a 50% reduced risk of bile duct cancer (OR = 0.5, 95% CI = 0.3-0.9, P(trend) = 0.05). The effect of the R280H polymorphism persisted (P(trend) = 0.03), when all three XRCC1 polymorphisms were jointly considered in the model, a finding supported by the haplotype results (covariate-adjusted global permutation P = 0.03). We also found an inverse association between the APEX1 148E allele and gallbladder stones (P(trend) = 0.03), but no association for the OGG1 polymorphism. This study suggests that genetic variants in XRCC1 and APEX1 may alter susceptibility to biliary tract cancer and stones. Further studies are required to confirm the reported associations.

Polymorphism of genes related to insulin sensitivity and the risk of biliary tract cancer and biliary stone: a population-based case-control study in Shanghai, China.

Biliary tract cancer, encompassing tumors of the gallbladder, extrahepatic bile ducts and ampulla of Vater, is a rare but highly fatal malignancy. Obesity and gallstones, both related to insulin resistance, are linked to an elevated risk of biliary cancer. The peroxisome proliferator-activated receptors (PPARs) and the retinoid X receptors (RXRs), expressed in adipose tissue, play a key role in the regulation of obesity-related insulin sensitivity, thus genetic variants of these two receptor genes may be related to biliary cancer and stones. We examined the associations of seven single-nucleotide polymorphisms in the PPAR-gamma, PPAR-delta, RXR-alpha, RXR-beta and INS genes with biliary cancer and stones in a population-based case-control study in Shanghai, China. We included 237 gallbladder, 127 extrahepatic bile duct and 47 ampulla of Vater cancer cases, 895 stone cases and 786 population controls. Relative to individuals with the RXR-beta C51T (rs2076310) CC genotype, those having the TT genotype had a 1.6-fold risk for bile duct cancer [odds ratio (OR) = 1.67; 95% confidence interval (CI) = 0.99-2.84], with a more pronounced association among men (OR = 2.30; 95% CI = 1.14-4.65; P interaction = 0.07). This marker was also associated with a higher risk of gallstones among subjects with a higher body mass index (BMI) (>or=23 kg/m(2)) (OR = 1.80; 95% CI = 1.09-2.94), although the interaction with BMI was not statistically significant (P interaction = 0.28). No association was found between other variants and biliary cancers and stones. Results from this population-based study suggest that certain genetic variants involved in the regulation of obesity-related insulin sensitivity may increase susceptibility to bile duct cancer and gallstones.

Serum lipid levels and the risk of biliary tract cancers and biliary stones: A population-based study in China.

Biliary tract cancers, encompassing the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Gallstones, the predominant risk factor for biliary cancers, are linked with hyperlipidemia. As part of a population-based case-control study conducted in Shanghai, China, we examined the associations of serum lipid levels with biliary stones and cancers. We included 460 biliary cancer cases (264 gallbladder, 141 extrahepatic bile duct, and 55 ampulla of Vater), 981 biliary stone cases and 858 healthy individuals randomly selected from the population. Participants completed an in-person interview and gave overnight fasting blood samples. Participants in the highest quintile of triglycerides (>/=160 mg/dl) had a 1.4-fold risk of biliary stones (95% CI = 1.1-1.9), a 1.9-fold risk of gallbladder cancer (95% CI = 1.3-2.8), and a 4.8-fold risk of bile duct cancer (95% CI = 2.8-8.1), compared to the reference group (third quintile: 90-124 mg/dl). Participants in the lowest quintile of high-density lipoprotein (HDL) (<30 mg/dl) had a 4.2-fold risk of biliary stones (95% CI = 3.0-6.0), an 11.6-fold risk of gallbladder cancer (95% CI = 7.3-18.5), and a 16.8-fold risk of bile duct cancer (95% CI = 9.1-30.9), relative to the reference group (third quintile: 40-49 mg/dl). In addition, total cholesterol, low-density lipoprotein (LDL) and apolipoprotein A (apo A) were inversely associated with biliary stones; whereas low levels as well as high levels of total cholesterol, LDL, apo A and apolipoprotein B (apo B) were associated with excess risks of biliary tract cancers. Our findings support a role for serum lipids in gallstone development and biliary carcinogenesis.

Polymorphisms of genes in the lipid metabolism pathway and risk of biliary tract cancers and stones: a population-based case-control study in Shanghai, China.

Biliary tract cancers, encompassing the gallbladder, extrahepatic bile duct, and ampulla of Vater, are uncommon yet highly fatal malignancies. Gallstones, the primary risk factor for biliary cancers, are linked with hyperlipidemia. We examined the associations of 12 single nucleotide polymorphisms of five genes in the lipid metabolism pathway with the risks of biliary cancers and stones in a population-based case-control study in Shanghai, China. We included 235 gallbladder, 125 extrahepatic bile duct, and 46 ampulla of Vater cancer cases, 880 biliary stone cases, and 779 population controls. Subjects completed an in-person interview and gave blood. Genotyping was conducted by TaqMan assay using DNA from buffy coats. The effects of APOE IVS1+69 (rs440446) and APOB IVS6+360C>T (rs520354) markers were limited to men. Men carrying the G allele of APOE IVS1+69 had a 1.7-fold risk of stones [95% confidence interval (95% CI), 1.2-2.4], a 1.8-fold risk of gallbladder cancer (95% CI, 1.0-3.3), a 3.7-fold risk of bile duct cancer (95% CI, 2.0-7.0), and a 4-fold risk of ampullary cancer (95% CI, 1.4-12.4). Male carriers of the T allele of APOB IVS6+360C>T had a 2-fold risk of bile duct cancer (95% CI, 1.2-3.4). The APOB T-T haplotype (APOB IVS6+360C>T, EX4+56C>T) was associated with a 1.6-fold risk of bile duct cancer (95% CI, 1.1-2.3). Male and female carriers of the T allele of LDLR IVS9-30C>T (rs1003723) had a 1.5-fold risk of bile duct cancer. Our findings suggest that gene variants in the lipid metabolism pathway contribute to the risk of biliary tract stones and cancers, particularly of the bile duct.

ATP binding cassette G8 T400K polymorphism may affect the risk of gallstone disease among Chinese males.

BACKGROUND: Supersaturation of bile with cholesterol is a primary step in the formation of cholesterol gallstones. ATP binding cassette (ABC) G5 and G8 play an important role in regulating sterol absorption and secretion. To investigate a possible association between transporter gene polymorphism and gallstone formation, we examined five common polymorphisms in the ABCG5 (Q604E) and ABCG8 (D19H, Y54C, T400K, A632V) genes in patients with gallstone disease (GS). METHODS: Study subjects included 287 patients with GS and 219 gallstone free controls (GSF). Polymorphisms were determined using PCR-RFLP analysis or the Taqman MGB assay. Plasma and biliary lipid levels were measured. RESULTS: 2 SNPs of ABCG8 gene (Y54C and T400K) showed strong linkage disequilibrium (D'=0.824, r2=0.579). Male carriers of the less frequent K allele of ABCG8 T400K had a 2.31-fold elevated risk [95% confidence interval (CI) 1.12 approximately 4.76, P=0.023] for gallstone disease compared to male with the common genotype after the adjustment for age, body mass index. Males with the K allele had lower plasma triglyceride (P=0.044) and biliary phospholipid (P=0.035) levels than TT homozygotes. No such association was found in female or other 4 SNPs. CONCLUSIONS: These findings indicate that the T400K polymorphism in ABCG8 may be associated with the incidence of gallstone disease in males.