Polymorphic markers of the CYP1B1 (4326C > G), CYP2F1 (c.14_15insC), CYP2J2 (-76G > T), and CYP2S1 (13106C > T and 13255A > G) genes and genetic predisposition to chronic respiratory diseases induced by smoking and occupational factors

The contribution of the polymorphic markers of cytochrome P450 genes to respiratory diseases caused by smoking and occupational factors has been assessed. For this purpose, PCR-RFLP analysis of the CYP1B1 (rs1056836, 4326C > G), CYP2F1 (rs11399890, c.14_15insC), CYP2J2 (rs890293, -76G > T), and CYP2S1 (rs34971233, 13106C > T and rs338583, 13255A > G) gene polymorphisms has been performed. The analysis has shown that the polymorphic variants of the CYP1B1 (rs1056836, 4326C > G) and CYP2F1 (rs11399890, c. 14_15insC) genes may contribute to the development of occupational chronic bronchitis. The proportion of CYP1B1* 1*3 heterozygotes in the group of patients with occupational chronic bronchitis is considerably greater than in the group of healthy workers (69.16% versus 53.29%; chi2 = 5.94, P = 0.02, P(cor) = 0.04, OR = 1.97, the 95% CI is 1.13-3.42). Patients with occupational chronic bronchitis and healthy workers significantly differed from each other in the frequency distribution of the genotypes ofthe CYP2F1 (rs11399890, c.14_15insC) polymorphic marker (chi2 = 6.18, d.f = 2, P = 0.05). The frequency of the wild type/ins heterozygous genotype for the CYP2F1 gene is higher in healthy workers (36.08%) than in patients (22.22%) (chi2 = 5.48, P = 0.02, P(cor) = 0.04, OR = 0.51, the 95% CI is 0.28-0.90). No association has been found between the CYP2J2 (rs890293, -76G > T) or CYP2S1 (rs34971233, 13106C > T, P466L and rs338583, 13255A > G) gene polymorphisms and respiratory diseases.     

CYP1A1、CYP1B1、NET、DAT1单个和联合基因型与汉族人群乳腺癌易感性的研究（英文）

乳腺癌是最常见的女性癌症,其发生是遗传因素和环境因素相互作用的结果。因此,我们就CYP1A1MspⅠ(m1多态)、CYP1B1 Leu432Val、NET T-182C、DAT1-VNTR等基因多态性对新疆汉族人群乳腺癌易感性的研究进行探讨。在以144例乳腺癌患者和120例正常对照组为研究对象的病例-对照研究中,发现CYP1A1MspⅠ位点CC基因型、C等位基因(OR=3.32,95%CI:1.24~8.86;OR=1.58,95%CI:1.09~2.31)和高风险联合基因型CYP1A1 MspⅠ与CYP1B1 Leu432Val,CYP1A1 MspⅠ与DAT1-VNTR,CYP1B1 Leu432Val与DAT1-VNTR(OR=2.43,95%CI:1.23~4.78;OR=4.53,95%CI:1.26~16.27;OR=2.98,95%CI:1.10~8.06)与乳腺癌风险增加有关。CYP1B1、NET和DAT1基因多态性与乳腺癌易感性无关。这些研究结果表明,CYP1A1 MspⅠ多态性和CYP1A1、CYP1B1、DAT1高风险联合基因型能增加新疆汉族人群患乳腺癌的风险。     

Prognostic Significance of ESR1 Amplification and ESR1 PvuII,CYP2C19*2, UGT2B15*2 Polymorphisms in Breast Cancer Patients

Introduction

Amplification of the ESR1 gene, coding for estrogen receptor alpha, was shown to predict responsiveness to tamoxifen, however its prognostic impact in breast cancer patients has not been thoroughly investigated. Other factors that could contribute to responsiveness to tamoxifen treatment are polymorphisms in ESR1 gene and genes involved in tamoxifen metabolism.The aim of this study was to assess the prognostic role of ESR1 gene dosage in a consecutive group of breast cancer patients and to correlate this feature with clinico-pathological factors. Additionally, ESR1 PvuII, CYP2C19*2 and UGT2B15*2 polymorphisms were analyzed in the tamoxifen-treated subgroup of patients.

Materials and Methods

Primary tumor samples from 281 stage I-III consecutive breast cancer patients were analyzed for ESR1 gene dosage using real-time PCR with locked nucleic acids hydrolysis probes. In the tamoxifen-treated subgroup of patients, ESR1 PvuII, CYP2C19*2 and UGT2B15*2 polymorphism in leukocytes genomic DNA were analyzed. Results were correlated with clinico-pathological factors and with disease-free survival (DFS) and overall survival (OS).

Results

ESR1 amplification (with a cut-off level of 2.0) was found in 12% of the entire group of breast cancer patients, and in 18% of the ER-negative subgroup. This feature was associated with decreased DFS both in the entire group (P=0.007) and in the ER-negative subgroup (P=0.03), but not in the tamoxifen-treated patients.Patients with ESR1 PvuII wt/wt genotype and at least one UGT2B15 wt allele had a worse DFS (P=0.03) and showed a trend towards decreased Os (P=0.08) in comparison to patients with ESR1 PvuII wt/vt or vt/vt genotype and UGT2B15 *2/*2 genotype.

Conclusions

ESR1 amplification can occur in ER-negative tumors and may carry poor prognosis. In the tamoxifen-treated subgroup, poor prognosis was related to the combined presence of ESR1 PvuII wt/wt and UGT2B15wt/wt or wt/*2 genotype.     

Polymorphism G861C of 5-HT receptor subtype 1B is associated with heroin dependence in Han Chinese

The serotoninergic (5-HT) system regulates neuronal activity in broad brain regions, and appears to be particularly important for modulating behavioral and physiological functions such as mood, emotion, sleep and appetite. Central 5-HT deregulation may be involved in many neuropsychological disorders, which include substance abuse and addiction. Previous studies suggest that genetic polymorphisms in some 5-HT receptor genes may relate to heroin dependency. Here we examined potential association between heroin dependence and four single nucleotide polymorphisms (SNPs) of 5-HT receptors (A-1438G and T102C of HTR_2A, and G861C and A1180G of HTR_1B) in a cohort of Han Chinese. Participants included 303 heroin-dependent subjects who were recruited into the Methadone Maintenance Treatment (MMT) Program in the Xi’an Mental Health Center, and 300 healthy controls. The resulting data yielded a significantly higher frequency of the HTR_1B G allele with G861C among the heroin-dependent subjects relative to controls (p = 0.001 after Bonferroni correction). Further genotype and clinical phenotype correlation study of the G861C carriers showed that the amount of heroin self-injection was higher in patients with the GG genotype relative to CC and CG genotypes (p < 0.01). These findings point to a role for HTR_1B polymorphism in heroin dependence among Han Chinese, and may be informative for future genetic or neurobiological studies on heroin dependence.     

Association Study of Germline Variants in CCNB1 and CDK1 with Breast Cancer Susceptibility,Progression, and Survival among Chinese Han Women

The CCNB1 and CDK1 genes encode the proteins of CyclinB1 and CDK1 respectively, which interact with each other and are involved in cell cycle regulation, centrosome duplication and chromosome segregation. This study aimed to investigate whether the genetic variants in these two genes may affect breast cancer (BC) susceptibility, progression, and survival in Chinese Han population using haplotype-based analysis. A total of ten tSNPs spanning from 2kb upstream to 2kb downstream of these genes were genotyped in 1204 cases and 1204 age-matched cancer-free controls. The haplotype blocks were determined according to our genotyping data and linkage disequilibrium (LD) status of these SNPs. For CCNB1, rs2069429 was significantly associated with increased BC susceptibility under recessive model (OR=2.352, 95%CI=1.480-3.737), so was the diplotype TAGT/TAGT (OR=1.947 95%CI=1.154-3.284, P=0.013). In addition, rs164390 was associated with Her2-negative BC. For CDK1, rs2448343 and rs1871446 were significantly associated with decreased BC risk under dominant models, so was the haplotype ATATT. These two SNPs also showed a dose-dependent effect on BC susceptibility. Using stratified association analysis, we found that women with the heterozygotes or minor allele homozygotes of rs2448343 had much less BC susceptibility among women with BMI<23. In CDK1, three closely located SNPs, rs2448343, rs3213048 and rs3213067, were significantly associated with tumor’s PR status: the heterozygotes of rs2448343 were associated with PR-positive tumors, while the minor allele homozygotes of rs3213048 and heterozygotes of rs3213067 were associated with PR-negative BC tumors. In survival analysis, rs1871446 was associated with unfavorable event-free survival under recessive model, so was the CDK1 diplotype ATATG/ATATG, which carried the minor allele homozygote of rs1871446. Our study indicates that genetic polymorphisms of CCNB1 and CDK1 are related to BC susceptibility, progression, and survival in Chinese Han women. Further studies need to be performed in other populations as an independent replication to verify these results.     

Effect of Cytochrome b5 Content on the Activity of Polymorphic CYP1A2, 2B6, and 2E1 in Human Liver Microsomes

Human cytochrome b5 (Cyt b5) plays important roles in cytochrome P450 (CYP)-mediated drug metabolism. However, the expression level of Cyt b5 in normal human liver remains largely unknown. The effect of Cyt b5 on overall CYP activity in human liver microsomes (HLM) has rarely been reported and the relationship between Cyt b5 and the activity of polymorphic CYP has not been systematically investigated. In this study, we found that the median value of Cyt b5 protein was 270.01 pmol/mg from 123 HLM samples, and 12- and 19-fold individual variation was observed in Cyt b5 mRNA and protein levels, respectively. Gender and smoking clearly influenced Cyt b5 content. In addition, we found that Cyt b5 protein levels significantly correlated with the overall activity of CYP1A2, 2B6, and 2E1 in HLM. However, when the CYP activities were sorted by single nucleotide polymorphisms (SNP), the effect of Cyt b5 protein on the kinetic parameters varied greatly. There were significant correlations between Cyt b5 content and V_max and CL_int of CYP1A2 wild-types (3860GG, 2159GG, and 5347CC) as well as homozygous mutants (163AA and 3113GG). In contrast to V_max and CL_int, the K_m of CYP2B6 516GG and 785AA genotypes was inversely associated with Cyt b5 content. Correlations between Cyt b5 content and V_max and CL_int of CYP2E1 -1293GG, -1293GC, 7632TT, 7632TA, -333TT, and -352AA genotypes were also observed. In conclusion, Cyt b5 expression levels varied considerably in the Chinese cohort from this study. Cyt b5 had significant impact on the overall activity of CYP1A2, 2B6, and 2E1 in HLM and the effects of Cyt b5 protein on polymorphic CYP1A2, 2B6, and 2E1 activity were SNP-dependent. These findings suggest that Cyt b5 plays an important role in CYP-mediated activities in HLM and may possibly be a contributing factor for the individual variation observed in CYP enzyme activities.     

Investigation of Type 2 Diabetes Risk Alleles Support CDKN2A/B,CDKAL1, and TCF7L2 As Susceptibility Genes in a Han Chinese Cohort

Background

Recent genome-wide association studies (GWASs) have reported several genetic variants to be reproducibly associated with type 2 diabetes. Additional variants have also been detected from a metaanalysis of three GWASs, performed in populations of European ancestry. In the present study, we evaluated the influence of 17 genetic variants from 15 candidate loci, identified in type 2 diabetes GWASs and the metaanalysis, in a Han Chinese cohort.

Methodology/Principal Findings

Selected type 2 diabetes–associated genetic variants were genotyped in 1,165 type 2 diabetic patients and 1,136 normoglycemic control individuals of Southern Han Chinese ancestry. The OR for risk of developing type 2 diabetes was calculated using a logistic regression model adjusted for age, sex, and BMI. Genotype-phenotype associations were tested using a multivariate linear regression model. Genetic variants in CDKN2A/B, CDKAL1, TCF7L2, TCF2, MC4R, and PPARG showed a nominal association with type 2 diabetes (P≤0.05), of whom the three first would stand correction for multiple testing: CDKN2A/B rs10811661, OR: 1.26 (1.12–1.43) P = 1.8*10⁻⁴; CDKAL1 rs10946398, OR: 1.23 (1.09–1.39); P = 7.1*10⁻⁴, and TCF7L2 rs7903146, OR: 1.61 (1.19–2.18) P = 2.3 * 10⁻³. Only nominal phenotype associations were observed, notably for rs8050136 in FTO and fasting plasma glucose (P = 0.002), postprandial plasma glucose (P = 0.002), and fasting C-peptide levels (P = 0.006) in the diabetic patients, and with BMI in controls (P = 0.033).

Conclusions/Significance

We have identified significant association between variants in CDKN2A/B, CDKAL1 and TCF7L2, and type 2 diabetes in a Han Chinese cohort, indicating these genes as strong candidates conferring susceptibility to type 2 diabetes across different ethnicities.     

Association of Germline Variation in CCNE1 and CDK2 with Breast Cancer Risk,Progression and Survival among Chinese Han Women

Background

Somatic alterations of cyclin-dependent kinase 2 (CDK2)-cyclin E complex have been shown to contribute to breast cancer (BC) development and progression. This study aimed to explore the effects of single nucleotide polymorphisms (SNPs) in CDK2 and CCNE1 (a gene encoding G1/S specific cyclin E1 protein, formerly called cyclin E) on BC risk, progression and survival in a Chinese Han population.

Methodology/Principal Findings

We herein genotyped 6 haplotype-tagging SNPs (htSNPs) of CCNE1 and 2 htSNPs of CDK2 in 1207 BC cases and 1207 age-matched controls among Chinese Han women, and then reconstructed haplotype blocks according to our genotyping data and linkage disequilibrium status of these htSNPs. For CCNE1, the minor allele homozygotes of three htSNPs were associated with BC risk (rs3218035: adjusted odds ratio [aOR] = 3.35, 95% confidence interval [CI] = 1.69–6.67; rs3218038: aOR = 1.81, 95% CI = 1.22–2.70; rs3218042: aOR = 2.64, 95% CI = 1.31–5.34), and these three loci showed a dose-dependent manner in increasing BC risk (P_trend = 0.0001). Moreover, the 5-SNP haplotype CCGTC, which carried none of minor alleles of the 3 at-risk SNPs, was associated with a favorable event-free survival (hazard ratio [HR] = 0.53, 95% CI = 0.32–0.90). Stratified analysis suggested that the minor-allele homozygote carriers of rs3218038 had a worse event-free survival among patients with aggressive tumours (in tumour size>2 cm group: HR = 2.06, 95% CI = 1.06–3.99; in positive lymph node metastasis group: HR = 2.41, 95% CI = 1.15–5.03; in stage II–IV group: HR = 2.03, 95% CI = 1.09–3.79). For CDK2, no significant association was found.

Conclusions/Significance

This study indicates that genetic variants in CCNE1 may contribute to BC risk and survival in Chinese Han population. They may become molecular markers for individual evaluation of BC susceptibility and prognosis. Nevertheless, further validation studies are needed.     

Associations between UCP1 -3826A/G,UCP2 -866G/A,Ala55Val and Ins/Del,and UCP3 -55C/T Polymorphisms and Susceptibility to Type 2 Diabetes Mellitus: Case-Control Study and Meta-Analysis

Background

Some studies have reported associations between five uncoupling protein (UCP) 1–3 polymorphisms and type 2 diabetes mellitus (T2DM). However, other studies have failed to confirm the associations. This paper describes a case-control study and a meta-analysis conducted to attempt to determine whether the following polymorphisms are associated with T2DM: -3826A/G (UCP1); -866G/A, Ala55Val and Ins/Del (UCP2) and -55C/T (UCP3).

Methods

The case-control study enrolled 981 T2DM patients and 534 nondiabetic subjects, all of European ancestry. A literature search was run to identify all studies that investigated associations between UCP1–3 polymorphisms and T2DM. Pooled odds ratios (OR) were calculated for allele contrast, additive, recessive, dominant and co-dominant inheritance models. Sensitivity analyses were performed after stratification by ethnicity.

Results

In the case-control study the frequencies of the UCP polymorphisms did not differ significantly between T2DM and nondiabetic groups (P>0.05). Twenty-three studies were eligible for the meta-analysis. Meta-analysis results showed that the Ala55Val polymorphism was associated with T2DM under a dominant model (OR = 1.27, 95% CI 1.03–1.57); while the -55C/T polymorphism was associated with this disease in almost all genetic models: allele contrast (OR = 1.17, 95% CI 1.02–1.34), additive (OR = 1.32, 95% CI 1.01–1.72) and dominant (OR = 1.18, 95% CI 1.02–1.37). However, after stratification by ethnicity, the UCP2 55Val and UCP3 -55C/T alleles remained associated with T2DM only in Asians (OR = 1.25, 95% CI 1.02–1.51 and OR = 1.22, 95% CI 1.04–1.44, respectively; allele contrast model). No significant association of the -3826A/G, -866G/A and Ins/Del polymorphisms with T2DM was observed.

Conclusions

In our case-control study of people with European ancestry we were not able to demonstrate any association between the UCP polymorphisms and T2DM; however, our meta-analysis detected a significant association between the UCP2 Ala55Val and UCP3 -55C/T polymorphisms and increased susceptibility for T2DM in Asians.     

Induction of A:T to G:C transition mutations by 5-(2-chloroethyl)-2'-deoxyuridine (CEDU), an antiviral pyrimidine nucleoside analogue, in the bone marrow of Muta Mouse

5-(2-chloroethyl)-2'-deoxyuridine (CEDU) is a pyrimidine nucleoside analogue formerly in development for the treatment of herpes simplex virus infections. The compound proved clearly mutagenic in the mouse spot test and exhibited weak activity in the Salmonella reverse mutation test, which led to the termination of the compound's development. In another study, CEDU, administered orally to beta-galactosidase (lacZ) transgenic mice (Muta Mouse) for five days, induced a clear increase in lacZ mutant frequencies in spleen, lung, and bone marrow. In the present follow-up study, we analyzed 32 of those lacZ mutants isolated from the bone marrow of the Muta Mouse animals of the experiments mentioned above, in order to obtain further information on the type of mutations induced by CEDU. CEDU induced a pronounced increase in A:T to G:C transitions. The distribution of A:T to G:C transitions was clearly non-random, showing a bias towards T to C substitutions in the coding DNA strand and a preference to occur in the sequence motif 5'-(G or C)-T-G-3'. Our data support the hypothesis that CEDU, after being phosphorylated, is incorporated into cellular DNA in place of thymidine, which leads to mispairing with guanosine during subsequent DNA replication. As a result, the compound is thought to exert its mutagenicity by inducing mismatches leading to T to C transitions. Our findings point towards a mode of mutagenic action of CEDU that differs fundamentally from that of other antiviral antinucleosides whose clastogenic and recombinogenic activities prevail.     

Ly-1 (CD5), a membrane glycoprotein of mouse T lymphocytes and a subset of B cells, is a natural ligand of the B cell surface protein Lyb-2 (CD72).

CD5 is a 67-kDa glycoprotein expressed on the cell surface membrane of all T lymphocytes and on a small proportion of B lymphocytes. The physiologic role of this Ag is still unknown. Structural and functional studies of CD5 suggest that it might act as a receptor for a positive signal. CD5-specific mAb augment CD3- or mitogen-induced T cell proliferation, IL-2 secretion, and IL-2R expression and induce a rise in intracellular [Ca2+]. In this report, we describe the purification of mouse CD5 protein (mCD5) and its use as a probe to search for the ligand of CD5. We demonstrate that mCD5 specifically interacts with the mouse B cell differentiation Ag CD72/Lyb-2. Three serologically defined allelic forms of mouse CD72/Lyb-2 can all interact with mCD5. We further show that mCD5 can interact with human CD72/Lyb-2, and similarly, that human CD5 can interact with mouse CD72/Lyb-2. These studies may have major implications for the mechanisms of T-B cell communication.