Genetic polymorphisms in the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene and prostate cancer risk in Caucasian men

Background: Catechol-estrogen metabolites can induce carcinogenesis by acting as endogenous tumor initiators. Glucuronidation, mediated by the UDP-glucuronosyltransferase 1A1 (UGT1A1) enzyme, is a main metabolic pathway of estrogen detoxification in steroid target tissues, such as the prostate. The aim of our study was to investigate the possible correlation between UGT1A1 promoter gene polymorphisms and prostate cancer risk. Patients and methods: 129 patients with prostate cancer and 260 healthy controls were included in our study. A(TA)TAA promoter polymorphism of UGT1A1 gene was studied using the Fragment Analysis Software of an automated DNA sequencer and three genotypes (homozygous 7/7, heterozygous 6/7 and normal homozygous 6/6) were identified. Results: No significant differences were observed between the cancer group and controls regarding the genotyping distribution of the three UGT1A1 promoter genotypes (P > 0.05). Also, no association was found between overall disease risk and the presence of the polymorphic homozygous genotype (TA(7)/TA(7) vs TA(6)/TA(7) + TA(6)/TA(6)) (P = 0.18). In addition, no association was revealed between UGT1A1 genotype distribution and Gleason score (P = 0.55). Conclusion: Our data suggest that the TA repeat polymorphism of UGT1A1 gene does not seem to alter prostate cancer risk susceptibility in Caucasian men.     

The Effect of UGT1A1 Promoter Polymorphism in the Development of Hyperbilirubinemia and Cholelithiasis in Hemoglobinopathy Patients

Present study was aimed to explore the effect of (TA)_n UGT1A1 gene promoter polymorphism on bilirubin metabolism, bilirubinaemia, predisposition to cholelithiasis and subsequent cholecystectomy, in Sickle-Cell Anemia (SCA) and beta-Thalasemia major (bTH) in Kuwaiti subjects compared to other population. This polymorphism was analyzed and correlated to total bilirubin and cholelithiasis in 270 age, gender, ethnically matched subjects (92 bTH, 116 SCA and 62 Controls) using PCR, dHPLC, fragment analysis and direct sequencing. Four genotypes of UGT1A1 were detected in this study (TA6/6, TA6/7, TA6/8 and TA7/7). (TA)6/8 was found only in four individuals; hence it was not included in the analysis. There was a statistically significant association of genotypes with serum total bilirubin levels in both bTH and SCA groups (p<0.001). Subjects with (TA)7/7 had the highest total serum bilirubin level (178.7±3.5 µmole/l). A significant association was observed between allele (TA)7 and cholelithiasis development (p = 0.0001). The 40%, 67.5% and 100% of SCA with (TA)6/6, (TA)6/7 and (TA)7/7 respectively developed cholelithiasis and were subsequently cholecystectomized. Our results confirm UGT1A1 (TA)7 allele as one of the factors accounting for the hyperbilirubinemia and cholelithiasis observed in SCA and bTH.     

Genotype frequencies of UDP-glucuronosyltransferase 1A1 promoter gene polymorphism in the population of healthy Croatian pre-scholars

Increased serum bilirubin levels in patients with Gilbert syndrome (GS) are caused by reduction of hepatic activity of bilirubin glucuronosyltranferase to about 30% of normal. UGT1A1 genetic polymorphism with absent or very low bilirubin UDP-glucuronosyltransferase (B-UGT) activity is associated with Gilbert's syndrome (GS) and other hyperbilirubinemias. The genetic basis of GS is the insertion of two additional TA nucleotides (resulting in seven repeats of TA) in the TATAA box, present in proximal promoter of UGT1A1 gene. This study included 323 Croatian pre-scholars, including 164 boys and 159 girls. Statistical analysis showed significant difference for total bilirubin concentration between different genotypes (p < 0.001). Also, statistically significant difference for total bilirubin concentration was emphasized between genotypes 6/6 and 7/7 (p < 0.001) as well as 6/7 and 7/7 (p < 0.001). Higher total plasma bilirubin concentrations are significantly correlated with 7/7 genotype which is present in 9.8% of population studied.     

UGT1A1 sequence variants associated with risk of adult hyperbilirubinemia: A quantitative analysis

Backgrounds and Aims

UDP-glucuronosyltransferase 1 A1 (UGT1A1) is an enzyme that transforms small lipophilic molecules into water-soluble and excretable metabolites. UGT1A1 polymorphisms contribute to hyperbilirubinemia. This study quantitatively associated UGT1A1 variants in patients with hyperbilirubinemia and healthy subjects.

Methods

A total of 104 individuals with hyperbilirubinemia and 105 healthy controls were enrolled for genotyping and DNA sequencing UGT1A1 sequence variants, including the Phenobarbital Response enhancer module (PBREM) region, the promoter region (TATA box), and the 5 exons for quantitative association with hyperbilirubinemia.

Results

Eleven UGT1A1 variants were revealed in the case and control subjects, four of which were novel coding variants. A variant of PBREM (UGT1A1*60) was found in 47.6% of the patients, a TA repeat motif in the 5-primer promoter region [A(TA)₇TAA,UGT1A1*28] was found in 27.9% of the patients, and p.G71R (UGT1A1*6) was in 33.2% of the patients. For the healthy controls, the frequency of UGT1A1*60, UGT1A1*28 and UGT1A1*6 was 26.7%, 9.0% and 15.7%, respectively. Homozygous UGT1A1*28 and homozygous UGT1A1*6 were significantly associated with the risk of adult hyperbilirubinemia, with an odds ratio (OR) of 17.79 (95% CIs, 2.11–133.61) and 14.93 (95% CIs, 1.83–121.88), respectively. Quantitative analysis showed that sense mutation (including UGT1A1*6) and UGT1A1*28/*28, but not UGT1A1*60/*60 or UGT1A1*1/*28, was associated with increased serum total bilirubin (TB) levels. High linkage disequilibrium occurred between UGT1A1*60 and UGT1A1*28 (D′ = 0.964, r² = 0.345).

Conclusions

This study identified four novel UGT1A1 coding variants, some of which were associated with increased serum TB levels. A quantitative approach to evaluate adult hyperbilirubinemia provides a more vigorous framework for better understanding of adult hyperbilirubinemia genetics.     

Identification of Promotor and Exonic Variations,and Functional Characterization of a Splice Site Mutation in Indian Patients with Unconjugated Hyperbilirubinemia

Background

Mild unconjugated hyperbilirubinemia (UH), due to reduced activity of the enzyme uridine diphosphoglucuronate-glucuronosyltransferase family, polypeptide 1 (UGT1A1), is a common clinical condition. Most cases are caused by presence in homozygous form of an A(TA)₇TAA nucleotide sequence instead of the usual A(TA)₆TAA sequence in promoter region of the UGT1A1 gene. In some cases, other genetic variations have been identified which differ between populations. There is need for more data on such genetic variations from India.

Methods

DNA from subjects with unexplained persistent or recurrent UH was tested for the presence of TA promoter insertions. In addition, all five exons and splicing site regions of UGT1A1 gene were sequenced. Several bioinformatics tools were used to determine the biological significance of the observed genetic changes. Functional analysis was done to look for effect of a splice site mutation in UGT1A1.

Results

Of 71 subjects with UH (68 male; median age [range], 26 [16–63] years; serum bilirubin 56 [26–219] μM/L, predominantly unconjugated) studied, 65 (91.5%) subjects were homozygous for A(TA)₇TAA allele, five (7.0%) were heterozygous, and one (1.4%) lacked this change. Fifteen subjects with UH had missense exonic single nucleotide changes (14 heterozygous, 1 homozygous), including one subject with a novel nucleotide change (p.Thr205Asn). Bioinformatics tools predicted some of these variations (p.Arg108Cys, p.Ile159Thr and p.Glu463Val) to be deleterious. Functional characterization of an exonic variation (c.1084G>A) located at a splice site revealed that it results in frameshift deletion of 31 nucleotides and premature truncation of the protein.

Conclusion

Our study revealed several single nucleotide variations in UGT1A1 gene in Indian subjects with UH. Functional characterization of a splice site variation indicated that it leads to disordered splicing. These variations may explain UH in subjects who lacked homozygous A(TA)₇TAA promoter alleles.     

UDP-glucuronosyltransferase 1A7 polymorphisms are associated with liver cirrhosis

Variations in the UDP-glucuronosyltransferase (UGT) 1A7 gene have been found to be related to the development of hepatocellular carcinoma (HCC). Since the pathogenesis of liver cirrhosis is not dissimilar to that of HCC, we hypothesized that UGT1A7 genetic polymorphisms may be associated with liver cirrhosis. PCR-restriction fragment length polymorphism was utilized to determine UGT for 1A7 genotypes for the 159 patients with liver cirrhosis and 263 gender/age matched controls. Simple logistic regression analysis revealed that significant risk factors for liver cirrhosis were (1) hepatitis B virus (HBV) infection, (2) hepatitis C virus (HCV) infection, (3) HBV infection plus HCV infection and (4) low-activity UGT1A7 genotypes. The results of further multivariate logistic regression confirmed these associations. Interaction of low-activity UGT1A7 genotypes and HBV (or HCV) infection produced an additive effect upon the risk for the development of liver cirrhosis [observed odds ratio (OR) (54.59) greater than the expected OR (18.05)]. UGT1A7 low/low genotype was also related to advanced liver cirrhosis (Child-Pugh classes C and/or B) (OR = 7.50, P = 0.009). This study demonstrates the novel findings that carriage of low-activity UGT1A7 genotypes represents a risk factor for the development and functional severity of liver cirrhosis.     

A large-scale meta-analysis of the association between the ANKK1/DRD2 Taq1A polymorphism and alcohol dependence

Alcohol dependence (AD) is a common neuropsychiatric disorder with high heritability. A number of studies have analyzed the association between the Taq1A polymorphism (located in the gene cluster ANKK1/DRD2) and AD. In the present study, we conducted a large-scale meta-analysis to confirm the association between the Taq1A polymorphism and the risk for AD in over 18,000 subjects included in 61 case–control studies that were published up to August 2012. Our meta-analysis demonstrated both allelic and genotypic association between the Taq1A polymorphism and AD susceptibility [allelic: P(Z) = 1.1 × 10^?5, OR = 1.19; genotypic: P(Z) = 3.2 × 10^?5, OR = 1.24]. The association remained significant after adjustment for publication bias using the trim and fill method. Sensitivity analysis showed that the effect size of the Taq1A polymorphism on AD risk was moderate and not influenced by any individual study. The pooled odds ratio from published studies decreased with the year of publication, but stabilized after the year 2001. Subgroup analysis indicated that publication bias could be influenced by racial ancestry. In summary, this large-scale meta-analysis confirmed the association between the Taq1A polymorphism and AD. Future studies are required to investigate the functional significance of the ANKK1/DRD2 Taq1A polymorphism in AD.     

The common SNP (rs9939609) in the FTO gene modifies the association between obesity and high blood pressure in Chinese children

Previous studies have suggested that common variants in fat mass- and obesity-associated (FTO) gene are associated with body mass index (BMI) and the risk of obesity. Since obesity plays an important role in the etiology of high blood pressure (HBP), we aim to investigate the association between obesity and HBP in a population with different variants of the FTO gene. A total of 3,494 children (1,775 boys, 50.8 %) aged 6–18 years were recruited for measuring pubertal status, BMI and systolic and diastolic blood pressure. The single nucleotide polymorphism rs9939609 of the FTO gene was genotyped. The blood pressure levels increased by 1.4, 1.5 and 1.8 mmHg for systolic blood pressure and 0.8, 0.9 and 1.2 mmHg for diastolic blood pressure per 1-unit BMI increase in subjects carrying TT, TA and AA genotypes, respectively. After stratifying for FTO rs9939609 genotypes (TT, TA and AA), the odds ratios (95 % confidence intervals) of HBP in obese versus non-obese children were 4.26 (3.18–5.71), 5.13 (2.96–8.90) and 10.37 (1.59–67.43), respectively, with adjustment for age, gender and pubertal status. The FTO rs9939609 SNP modifies the effect of obesity on HBP in Chinese children, with obese ones carrying the AA homozygous genotype of the FTO rs9939609 having the highest risk of developing HBP.     

Spectrum of UGT1A1 Variations in Chinese Patients with Crigler-Najjar Syndrome Type II

Crigler–Najjar Syndrome type II (CNS-II) is an autosomal recessive hereditary condition of unconjugated hyperbilirubinemia without hemolysis, with bilirubin levels ranging from 102.6 μmol/L to 342 μmol/L. CNS-II is caused by a deficiency of UDP-glucuronyl transferase (UGT), which is encoded by the UDP-glucuronyl transferase 1A1 gene (UGT1A1). In East Asian populations, the compound homozygous UGT1A1 G71R and Y486D variants are frequently observed in cases with bilirubin levels exceeding 200 μmol/L. In this study, we investigated the spectrum of UGT1A1 variations in Chinese CNS-II patients. We sequenced the enhancer, promoter, and coding regions of UGT1A1 in 11 unrelated Chinese CNS-II patients and 80 healthy controls. Nine of these patients carried variations that are here reported for the first time in CNS-II patients, although they have been previously reported for other types of hereditary unconjugated hyperbilirubinemia. These individual variations have less influence on UGT activity than do the compound homozygous variation (combination of homozygous G71R variant and Y486D variant). Therefore, we propose that the spectrum of UGT1A1 variations in CNS-II differs according to the bilirubin levels.     

Amino acid positions 69-132 of UGT1A9 are involved in the C-glucuronidation of phenylbutazone

Phenylbutazone (PB) is known to be biotransformed to its O- and C-glucuronide. Recently, we reported that PB C-glucuronide formation is catalyzed by UGT1A9. Interestingly, despite UGT1A8 sharing high amino acid sequence identity with UGT1A9, UGT1A8 had no PB C-glucuronidating activity. In the present study, we constructed eight UGT1A9/UGT1A8 chimeras and evaluated which region is important for PB C-glucuronide formation. All of the chimeras and UGT1A8 and UGT1A9 had 7-hydroxy-(4-trifluoromethyl)coumarin (HFC) O-glucuronidating activity. The K_m values for HFC glucuronidation of UGT1A8, UGT1A9 and their chimeras were divided into two types, UGT1A8 type (high K_m) and UGT1A9 type (low K_m), and these types were determined according to whether their amino acids at positions 69-132 were those of UGT1A8 or UGT1A9. Likewise, PB O-glucuronidating activity was also detected by all of the chimeras, and their K_m values were divided into two types. On the contrary, PB C-glucuronidating activity was detected by UGT1A9_(1-132)/1A8_(133-286), UGT1A9_(1-212)/1A8_(213-286), UGT1A8_(1-68)/1A9_(69-286), and UGT1A8_(1-68)/1A9_(69-132)/1A8_(133-286) chimeras. The region 1A9_(69-132) was common among chimeras having PB C-glucuronidating activity. Of interest is that UGT1A9_(1-68)/1A8_(69-132)/1A9_(133-286) had lost PB C-glucuronidation activity, but retained activities of PB and HFC O-glucuronidation. These results strongly suggested that amino acid positions 69-132 of UGT1A9 are responsible for chemoselectivity for PB and affinity to substrates such as PB and HFC.     

Interethnic differences in UGT1A4 genetic polymorphisms between Mexican Mestizo and Spanish populations

UDP-glucuronosyltransferase 1A4 (UGT1A4) is a phase II drug-metabolizing enzyme that catalyzes the glucuronidation of many clinically-important drugs. Interethnic differences in the genetic polymorphism of UGT1A4 have been reported; however, there is no information in Mexican Mestizos (MMs) and Spaniards (SPs). Furthermore, MM is an admixed population with 26 % of Caucasian genes mainly from Spain. Therefore, this study aimed to investigate the potential differences between 318 SPs and 248 MMs healthy individuals regarding UGT1A4*1b, UGT1A4*2 and UGT1A4*3 alleles and to compare the observed frequencies with those previously reported in different populations. The allelic frequencies of the three UGT1A4 polymorphisms showed interethnic differences between MMs and SPs (p < 0.05). The analyzed SNPs variants in this genetic region were not in linkage disequilibrium (LD) for the MM population, suggesting that these mutations have arisen independently in the same genetic background. In contrast, UGT1A4*2 and UGT1A4*3 were in LD in the SP population. Comparison of present data with other in different ethnic groups revealed that the frequencies of UGT1A4*2 and UGT1A4*3 in SP were similar to other Caucasians and higher than in Asians, whereas in MMs were lower than in Caucasians and higher than in Asians only for UGT1A4*2. Present results could be helpful to improve the use of UGT1A4 drug substrates in order to adjust them to the ethnic background of a given population, specifically for Hispanics.     

Combined test for UGT1A1 -3279T-->G and A(TA)nTAA polymorphisms best predicts Gilbert's syndrome in Italian pediatric patients

Gilbert's syndrome is a common hereditary chronic or recurrent, mild unconjugated hyperbilirubinemia. Polymorphisms in the bilirubin uridine diphosphate glucuronosyl transferase gene (UGT1A1) causing a decreased enzyme activity are associated with susceptibility to the syndrome. Homozygosity for TA(7) allele of the A(TA)(n)TAA promoter polymorphism is found in the majority of Caucasian patients. We sought to investigate the role of three UGT1A1 polymorphisms (A[TA](n)TAA, -3279T-->G, and G71R) in the susceptibility to Gilbert's syndrome in 53 Italian pediatric subjects compared to 83 unaffected controls. Carriage of two TA(n) risk alleles (TA(7) and TA(8)) and -3279G homozygosity were similarly associated with hyperbilirubinemia (odds ratio [OR] = 11.59, 95% confidence interval [CI] = 4.80-27.98; p < 0.001, and OR = 11.51, 95% CI = 5.06-26.19; p < 0.001, respectively). Homozygosity for both TA7 and -3279G was associated with the highest relative risk estimate (OR = 19.23, 95% CI = 7.34-50.4; p < 0.001), but a significant association was found also for TA7 heterozygosity combined with -3279G/G genotype (OR = 7.98, 95% CI = 2.54-25.06; p < 0.001). The G71R variant was found only in two controls. Our results demonstrate that genotyping of both UGT1A1 A(TA)(n)TAA and -3279T-->G polymorphisms best defines genetic susceptibility to Gilbert's syndrome in Caucasian pediatric patients, and the TA7 heterozygous genotype combined with homozygosity for the -3279G allele can also be associated with pediatric mild hyperbilirubinemia.     

Comprehensive Analysis of UGT1A1 Genetic Polymorphisms in Chinese Tibetan and Han Populations

The study of polymorphism of the UGT1A1 gene has not been reported in the Chinese Tibetan population, and there are no comparisons of genetic polymorphism in the gene between Chinese Han and Tibetan populations. In this study, we directly sequenced the functional regions of the UGT1A1 gene in 200 unrelated healthy Chinese volunteers, detecting 20 variations (including five novel ones). The distributions of allele and genotype frequencies differ between the two groups. UGT1A1*6 is the major reduced functional variant in the populations, and the *27 allele was detected only in the Han group. Differences in the frequencies of the UGT1A1*6/*63 genotype between the Tibetan and Han populations were statistically significant (P?=?0.009). Our genetic data might provide fundamental information for the advance of personalized medicine and will facilitate genotype-phenotype studies in larger populations.     

Effects of Panax ginseng on the nerve growth factor expression in testosterone induced benign prostatic hyperplasia

The prostatic hyperplasia in benign prostatic hyperplasia (BPH) leads to obstructive micturition symptoms. Previous studies showed that pontine micturition center (PMC), ventrolateral periaqueductal gray (vlPAG), and medial preopticnucleus (MPA) regions in the brain have been known to regulate the urinary bladder function. The present study shows the influences of Panax ginseng on nerve growth factor (NGF) expressions in PMC, vlPAG, and MPA regions in the brain. Wistar rats were used for the present study. The rats split into four groups; 4 groups (n = 6) in control group, BPH-induced group, BPH-induced and P. ginseng-treated group, and BPH-induced and finasteride-treated group. BPH in rats was induced by testosterone and the animals were evaluated for NGF expression in PMC, vlPAG, and MPA regions in the brain. The NGF expression was identified using immunohistochemistry (IHC). The NGF expression by IHC showed spots with dark brown color. In our results, NGF expressions in PMC, vlPAG, and MPA regions in the brainstem of the BPH-induced group showed increase than the control animal. These increased NGF expressions in three regions were decreased using treatment with P. ginseng (200 mg/kg). These results suggest that P. ginseng has therapeutic effects on the symptoms of BPH and is associated with the regulation of NGF expression in the brain. In conclusion, the administration of P. ginseng helps nerve growth factor activation.     

Association of the SNP rs1800925(C/T) in the Interleukin-13 Gene Promoter with Pulmonary Function in Chinese Han Patients with Idiopathic Pulmonary Fibrosis

The present report studied potential association of the rs1800925(C/T) single nucleotide polymorphism (SNP) of the Interleukin (IL)-13 gene promoter with idiopathic pulmonary fibrosis (IPF) in patients of Chinese Han ethnicity. Seventy patients with IPF were enrolled and divided into three subgroups: group A (61–79 % pred. D_LCO; n = 22), group B (51–60 % pred. D_LCO; n = 20), and group C (≤50 % pred. D_LCO; n = 28). Control group consisted of 80 healthy individuals of Chinese Han ethnicity. The SNP rs1800925(C/T) was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) analysis. The IL-13 CC genotype was present in 28/70 (40.0 %), homozygous TT in 6/70 (8.6 %) and heterozygous CT in 36/70 (51.4 %) patients with IPF. In control group, these genotypes were present in 30/80 (37.5 %), 11/80 (13.75 %), 39/80 (48.75 %), respectively, indicating that the distribution of the above three genotypes was not significantly different between patients with IPF and healthy controls. When the patients were stratified according to their D_LCO and D_LCO/VA, the frequencies of genotypes CT and TT in the groups A, B, and C were, respectively, 40.9 % (9/22), 50 % (10/20), and 82.1 % (23/28). Thus, significant differences in the distribution of alleles at ?1112 region of IL-13 gene were observed among the study groups A, B, and C, with the highest frequency in group C (p < 0.05). In conclusion, the rs1800925 T allele of the IL-13 gene is associated with worse pulmonary function in patients with IPF of Chinese Han ethnicity.     

Association between melatonin receptor 1A (MTNR1A) gene single-nucleotide polymorphisms and the velvet antler yield of Sika deer

Melatonin, a secretion from pineal gland is ambiguously considered as the key hormone involved in regulation of the antler cycle in Sika deer. To find out more about the roles of melatonin and its receptor gene, we carried out current study to investigate the association between polymorphisms in melatonin receptor 1A (MTNR1A) gene and the antler yield from Sika deer. A total of 251 Sika deer were analyzed in this study, of which consisted of Wusan Sika deer (n = 163) and Dongfeng Sika deer (n = 88). MTNRA gene was amplified by PCR and genotyped by Polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP). Three polymorphism loci (C518T, C629G and C635T) were detected in exon2 of MTNR1A gene. The restriction site Ecol881 was used for C518T while a C629G polymorphism locus was digested with Mval restriction endonucleases. In Wusan Sika deer the allele frequencies of C and T were 0.637 and 0.363 for C518T, Also C and G alleles in C629G locus were 0.206 and 0.794. Genotypic frequencies of allele CC, CT and TT were 33.7, 59.9 and 6.4 % respectively, It showed 1.8, 37.4 and 60.7 % for frequencies of genotypes CC, CG and GG. In Dongfeng Sika deer the allele frequencies of C and T were 0.518 and 0.482 for C518T, C and G alleles were 0.375 and 0.625 for C629G. Genotypic frequencies were 10.6, 82.4 and 7.1 % for genotypes CC, CT and TT respectively, and they were 1.1, 72.7 and 26.2 % for genotypes CC, CG and GG. Among three SNPs, only C629G showed significant association (P < 0.05) with average antler yield in Wusan Sika deer, while no SNP was significant in Dongfeng Sika deer. These preliminary results implied that the identified SNPs of MTNR1A gene might influence the antler yield in Wusan Sika deer.