ABCC2基因单核苷酸多态性对药物临床应用的影响

摘 要 目的： 综述ABCC2基因单核苷酸多态性对药物临床应用的影响。方法: 通过查阅国内外已发表见刊的相关文献,对ABCC2基因单核苷酸突变与药物临床应用的相关性加以归纳总结。结果: ABCC2转运蛋白在许多内源性化合物和外源性化合物的跨膜转运中起到重要作用。大量研究证明了ABCC2的单核苷酸突变可能影响其表达水平或功能活性,进而影响底物药物或有毒物质的吸收、分布和排泄,但这些研究结果多数存在一定的局限性和争议。结论:ABCC2单核苷酸多态性对某些药物的临床应用有一定的影响,对指导临床用药和评估药物疗效有重要的参考价值,但目前并不能作为唯一的指标。     

单核苷酸多态性检测方法的研究进展

单核苷酸多态性（single nucleotide polymorphism,SNP）作为第3代遗传标记,具有数量多、分布广泛等特点,已成为人类后基因组时代的主要研究内容之一,广泛应用于疾病相关分析、群体遗传学及药物研究等领域,因此建立高度自动化和高通量的SNP检测分析技术十分重要。该文介绍了几种SNP检测技术,特别是生物传感器用于检测SNP的原理,并对高通量的SNP检测技术进行了展望。     

RAC1 基因遗传多态性研究进展

Ras相关的C3肉毒素底物1（ras-related C3 botulinum toxin substrate 1,Rac1）是Rho GTP酶超家族里Rac亚家族中的一员,是细胞内重要的信号转导分子,参与众多的生理活动并其重要的调控作用。机体内RAC1基因被激活的水平具有个体差异性,因而研究体内RAC1基因的表达水平及其对某种疾病的易感性或者对某类药物的反应具有重要意义。研究RAC1基因的多态性有助于从序列信息预测蛋白质结构,进而理解蛋白质功能,从而能在基因水平上预测疾病发展和实施个体化医疗。本文将就RAC1基因突变及其上单核苷酸多态性与疾病的联系方面介绍相关研究进展。     

三维凝胶NAT2基因分型芯片的制备与优化

目的研制N-乙酰化酶2(NAT2)基因分型芯片,以快速、准确检测患者的NAT2单核苷酸基因多态性。方法设计并合成中国人中常见的NAT2酶基因5个突变位点的探针对和包含5个突变位点的两对引物;样本经PCR扩增后,采用丙烯酰胺点样液制备芯片,并与TEMED反应固化芯片;分别用探针与芯片杂交,采用博奥晶芯LUXSCAN10K微阵列芯片扫描仪分析结果。结果优化了PCR扩增条件,使两组PCR在相同条件下扩增;优化了芯片制备及杂交条件,双链DNA采用碱变性,清除非特异键合采用电泳方法;建立了NAT2酶基因分型标准:信号强度Cy3∶Cy5≥5为野生型,Cy3∶Cy5为0.6~1.5时为杂合子,Cy3∶Cy5≤0.2为突变型;对20例标本的基因分型结果采用直接测序法进行验证,结果均一致。结论三维凝胶NAT2基因点突变分型芯片法是一种特异性强、高通量的NAT2基因分型方法,适用于临床快速基因分型,指导相关药物合理使用。     

江苏地区汉族儿童多药耐药基因3个单核苷酸多态性位点的单倍型研究

目的分析江苏汉族人群多药耐药基因-1（MDR1）的单核甘酸多态（12外显子1236C→T突变、21外显子2677G→T/A突变、26外显子3435C→T突变）及其构成的单倍型分布。方法通过多重单碱基延伸反应（SNaPshotSNP分型技术）对江苏地区170名健康儿童的MDR1C1236T、G2677T/A、C3435T的SNP位点进行基因分型,统计各基因型频率。UNPHASED软件对MDR1的SNPs（C1236T-G2677T/A-C3435T）进行单倍型分析。结果在170例儿童中,等位基因1236T、2677T、2677A、3435T频率分别为63.5%、37.4%、17.0%和35.0%。基因型频率分布符合Hardy-Weinberg平衡（HWE）,差异无统计学意义（P〉0.05）。MDR1的1236、2677、3435三个位点间（C1236T-G2677T/A-C3435T）存在连锁不平衡性,以TTT（31.8%）、TGC（25.3%）、CGC（17.7%）和CAC（16.2%）四种单倍型为主。结论江苏地区汉族人群MDR1的单核甘酸多态及单倍型分布具有自己的特点。在临床应用相关药物时,进行基因型及单倍型检测,将有助于指导临床个体化用药。     

The influence of polymorphisms in the drug transporter,ABCB1 on the toxicity of glucocorticoids in Saudi children with acute lymphoblastic leukaemia

Background

Glucocorticoids play essential roles in the treatment of childhood acute lymphoblastic leukaemia (ALL); however, treatment with these agents can result in severe side-effects. This study, the first of its kind in a Saudi population, investigates associations of ABCB1 gene polymorphisms (pharmacodynamics and pharmacokinetic) with the development of toxicity and side effects (glucose abnormality, liver toxicity and infection) in a small population of Saudi children with ALL.

The Neuropeptide Galanin and Variants in the GalR1 Gene are Associated with Nicotine Dependence

The neuropeptide galanin and its receptors are expressed in brain regions implicated in drug dependence. Indeed, several lines of evidence support a role for galanin in modulating the effects of drugs of abuse, including morphine, cocaine, amphetamine, and alcohol. Despite these findings, the role of galanin and its receptors in the effects of nicotine is largely underexplored. Here, using mouse models of nicotine reward and withdrawal, we show that there is a significant correlation between mecamylamine-precipitated nicotine withdrawal somatic signs and basal galanin or galanin receptor 1 (GALR1) expression in mesolimbocortical dopamine regions across the BXD battery of recombinant inbred mouse lines. The non-peptide galanin receptor agonist, galnon, also blocks nicotine rewarding effects and reverses mecamylamine-precipitated nicotine withdrawal signs in ICR mice. Additionally, we conducted a meta-analysis using smoking information from six European-American and African-American data sets. In support of our animal data, results from the association study show that variants in the GALR1 gene are associated with a protective effect in nicotine dependence (ND). Taken together, our data suggest that galanin has a protective role against progression to ND, and these effects may be mediated through GALR1.     

ABCB1(2677T>G)和SLCO1B1(521T>C)基因多态性对阿托伐他汀降脂疗效的影响

目的：探讨新乡地区人群ABCB1（2677T>G）、SLCO1B1（521T>C）基因多态性分布及其与阿托伐他汀降脂疗效的相关性。方法：采用荧光原位杂交方法,检测120例血脂异常患者ABCB1（2677T>G）、SLCO1B1（521T>C）基因型分布;入选患者每晚服用阿托伐他汀20 mg,连续用药4周后,检测用药前后血脂水平,评价降脂疗效。结果：在新乡市中心医院的120例入选患者中,ABCB1（2677T>G）和SLCO1B1（521T>C）基因突变频率分别为70.5%和21.8%,该基因分布符合Hardy-Weinberg平衡。携带ABCB1 2677GG型患者对LDL-C的调节作用显著高于同一位点的其他基因型,而其他血脂指标未见相关性。SLCO1B1（521T>C）各基因型患者间血脂变化差异无统计学意义。结论：携带ABCB1 2677GG基因型的患者接受阿托伐他汀治疗时,降脂疗效较佳。     

A case-only study of interactions between metabolic enzyme polymorphisms and industrial pollution in childhood acute leukemia

Cancer risk is modulated by gene–environment interactions between toxic exposure and genetic variation in carcinogen metabolism. Our objective was to assess interactions between exposure to industrial pollutants and polymorphisms affecting cytochrome P450s (CYP1A1 and CYP2E1) and glutathione S-transferases (GSTP1 and GSTT) in childhood acute leukemia (AL). A case-only design was conducted in 123 Chinese children with sporadic AL. Industrial plants in the vicinity were recorded and, if present, their size and proximity to the usual place of residence of AL children was evaluated. Unconditional logistic regression analysis was performed across the AL study group adjusting for age, gender, parental education, occupation and smoking, indoor and outdoor pesticide use, presence of television sets, refrigerators, microwave ovens and furniture material in children's rooms, and electric transformers, power lines, and telecommunication transmitters within 500 m. This analysis revealed an interaction between the GSTT null allele and industrial plants within 500 m of the residences of childhood AL patients (interaction odds ratio, COR = 2.96, 95% CI: 1.09–8.01). Furthermore, the COR for the interaction between GSTT null and industrial plants within 50 m was 5.99 (95% CI: 1.41–25.45). Our results suggest an association between proximity to industrial plants and the GSTT null allele in patients with childhood AL.     

Oral administration of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) yields PhIP-DNA adducts but not tumors in male Syrian hamsters congenic at the N-acetyltransferase 2 (NAT2) locus.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine carcinogen present in well-done meat. PhIP must undergo host-mediated bioactivation to exert its mutagenic and carcinogenic effects. Following N-hydroxylation, N-acetyltransferases catalyze the O-acetylation (activation) of N-hydroxy-PhIP to an electrophile causing DNA damage. A well-defined genetic polymorphism in N-acetyltransferase 2 (NAT2) activity exists in humans and the Syrian hamster. Since some human epidemiological studies suggest an association between acetylator genotype and cancer susceptibility in individuals who consume well done meats, this study was designed to investigate the specific role of acetylator genotype in PhIP-induced tumors using a Syrian hamster model congenic at the NAT2 locus. Following oral administration of PhIP to male rapid and slow acetylator Syrian hamsters, DNA adducts were identified in each tissue examined with levels in the relative order: pancreas > heart and urinary bladder > prostate, small intestine and transverse colon > ascending colon, liver, cecum, descending colon, and rectum. However, no tumors were observed in male rapid and slow acetylator congenic hamsters administered 11 oral doses of PhIP (75 mg/kg) and maintained on a high fat diet for one year.     

Modulation of AP-1 by Natural Chemopreventive Compounds in Human Colon HT-29 Cancer Cell Line

PURPOSE: Activator protein-1 (AP-1) has been implicated as playing important roles in apoptosis and cancer development. In this work, we studied several natural chemopreventive compounds for their potential chemopreventive properties in the modulation of AP-1 signaling pathway in HT-29 colon cancer cells. METHODS: The HT-29 cells were transfected with AP-1-luciferase reporter gene, and one of the stable clones (C-4) was used for subsequent experiments. The HT-29 C-4 cells were treated for 1 h with various natural chemopreventive agents and challenged with AP-1 stimulators such as 12-O-tetradecanoylphorbol-13-acetate (TPA) or hydrogen peroxide (H2O2) for 6 h. The c-Jun N-terminal kinase (JNK) was examined to understand the effect of these compounds on the upstream signaling activator of AP-1. The protein expression level of endogenous cyclin D1, a gene that is under the control of AP-1, was also analyzed after treatments with the agents. In addition, cell death induced by these compounds was evaluated by MTS assay [3-(4.5-dimethylthiazol-2-yl)-5-(3-arboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt]. RESULTS: TPA and H2O2 treatments strongly induced AP-1-luciferase activity as expected. Phenethyl isothiocyanate, sulforaphane, curcumin, and resveratrol increased AP-1-luciferase activity dose-dependently and then decreased at higher doses in the presence or absence of TPA. Allyl isothiocyanate and (-)-epigallocatechin-3-gallate (EGCG) increased AP-1-luciferase activity dose-dependently up to 50 and 100 microM. Other tea catechins and procyanidin dimers, however, had little or no effect on AP-1-luciferase activity. The JNK activity was induced by the isothiocyanates and EGCG. Most of the chemopreventive compounds induced cell death in a dose-dependent manner, with the exception of epicatechin (EC) and the procyanidins, which had little effect. The expression of endogenous cyclin D1 protein was well correlated with those of AP-1-luciferase assay. CONCLUSION: Taken together, these results suggest that natural chemopreventive compounds may have differential biological functions on the signal transduction pathways such as AP-1 in the intervention of colon cancer progression and carcinogenesis.     

Association of MDR1 genotypes with susceptibility to colorectal cancer in older non-smokers

Objective The multidrug resistance gene 1 (MDR1) seems to play a role in the carcinogenesis of colorectal tumors. The importance of MDR1 SNPs 2677G > T/A in exon 21 and 3435C > T in exon 26 for cancer susceptibility, however, has not yet been clearly defined. Methods Two hundred and eighty-five colorectal cancer patients and 275 controls from five hospitals in the European part of Russia were genotyped for the polymorphisms −129T > C (rs3213619) in exon 1b, 2677G > T/A (rs2032582), and 3435C > T (rs1045642) in this population-based case-control study. Genotype-phenotype analysis was performed with simultaneous consideration of lifestyle risk factors. Results Our analysis confirmed the preponderate impact of smoking on colorectal cancer development. The risk of heavy smokers (≥60 pack years) to develop colorectal cancer by far exceeded that of lifelong non-smokers (OR = 3.9, 95% CI: 1.4 to 10.6). Smoking is a more potent risk factor than is the genetic influence of MDR1 in our study. However, a smoking and age-stratified analysis, revealed a statistically significant association between MDR1 genotypes and colorectal cancer in life-long non-smokers with an age ≥63 years (the median age in our sample). The association was stronger for rectal cancer than for colon cancer. Patients who carried the genotypes (−129TT; 2677GG; 3435CC) or (−129TT; 2677TT; 3435TT) developed more frequently colorectal cancer than others (OR = 3.9; 95% CI: 2.0 to 7.7). Conclusions Our results show that the interaction of genetic and lifestyle risk factors should be taken into account to elucidate the genetic influence of MDR1 variability on cancer susceptibility.     

Polymorphic trial in oxidative damage of arsenic exposed Vietnamese

Arsenic causes DNA damage and changes the cellular capacity for DNA repair. Genes in the base excision repair (BER) pathway influence the generation and repair of oxidative lesions. Single nucleotide polymorphisms (SNPs) in human 8-oxoguanine DNA glycosylase (hOGG1) Ser326Cys; apurinic/apyrimidinic endonuclease (APE1) Asp148Glu; X-ray and repair and cross-complementing group 1 (XRCC1) Arg280His and Arg399Gln in the BER genes were analyzed, and the relationship between these 4 SNPs and the urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) concentrations of 100 Vietnamese population exposed to arsenic was investigated. Individuals with hOGG1 326Cys/Cys showed significantly higher urinary 8-OHdG concentrations than did those with 326 Ser/Cys and Ser/Ser. As for APE1 Asp148Glu, heterozygous subjects showed significantly higher urinary 8-OHdG concentrations than did those homozygous for Asp/Asp. Moreover, global ethnic comparison of the allelic frequencies of the 4SNPs was performed in 10 population and previous reported data. The mutant allele frequencies of hOGG1 Ser326Cys in the Asian populations were higher than those in the African and Caucasian populations. As for APE1 Asp148Glu, Caucasians showed higher mutant frequencies than those shown by African and Asian populations. Among Asian populations, the Bangladeshi population showed relatively higher mutant allele frequencies of the APE1 Asp148Glu polymorphism. This study is the first to demonstrate the existence of genetic heterogeneity in a worldwide distribution of SNPs (hOGG1 Ser326Cys, APE1 Asp148Glu, XRCC1 Arg280His, and XRCC1 Arg399Gln) in the BER genes.     

Single nucleotide polymorphism in the promoter region of the CD209 gene is associated with human predisposition to severe forms of tick-borne encephalitis

Tick-borne encephalitis virus (TBEV) is a neurotropic, positive-sense RNA virus of the genus Flavivirus (family Flaviviridae) which can cause a variety of clinical manifestations in humans. Previously the severity and outcome of dengue fever and hepatitis C (diseases caused by viruses from the family Flaviviridae) were associated with the rs4804803 single nucleotide polymorphism (SNP) located in the promoter region of the human CD209 gene. This gene encodes dendritic cell-specific ICAM3-grabbing nonintegrin (DC-SIGN), a C-type lectin pathogen-recognition receptor expressed on the surface of dendritic cells and some types of macrophages. In the current study, a possible association between two SNPs in the promoter region of the CD209 gene (rs4804803 and rs2287886) and predisposition to severe forms of TBEV-induced disease was investigated. The genotypic, allelic and haplotypic frequencies of these SNPs were analyzed in 136 non-immunized Russian patients with different clinical manifestations of tick-borne encephalitis (TBE) and in a control group. An increase in the frequency of the rs2287886 SNP AA homozygotes and the A allele was detected among patients with severe central nervous system disease compared with the group of patients with meningitis (P = 0.003 and 0.019), or a combined group of patients with mild forms (fever and meningitis) (P = 0.003 and 0.026), or the control group (P = 0.007 and 0.035). Thus, our results suggest that the CD209 gene promoter region rs2287886 SNP is associated with predisposition to severe forms of TBE in the Russian population.     

A variation in NOS1AP gene is associated with repaglinide efficacy on insulin resistance in type 2 diabetes of Chinese

Aim:

To investigate a potential association between SNP rs10494366 in the neural nitric oxide synthase adaptor protein (NOS1AP) and efficacy of repaglinide (an insulin secretagogue) in newly diagnosed Shanghai Chinese type 2 diabetes patients.

Methods:

A total of 104 newly diagnosed type 2 diabetes patients (69 men, 35 women) were recruited and treated with repaglinide for 24 weeks. Anthropometric measurements, clinical laboratory tests were obtained at baseline and after 24-week treatment. Genotyping was performed by sequencing.

Results:

The baseline value of BMI, HOMA-IR, HOMA-B, and fasting insulin level were significantly different between GG, GT, and TT genotypes (P=0.024, 0.030, 0.005, and 0.007, respectively). Carriers of TT genotype were in significant insulin resistance at baseline. After 24-week repaglinide monotherapy, the Δ value of fasting insulin (P=0.019) and HOMA-IR (P=0.011) were significantly different. TT carriers had the least insulin resistance after treatment. The mixed model analysis showed that the variation had an interaction effect with repaglinide treatment only on HOMA-IR (P=0.013).

Conclusion:

A common variant in rs10494366 is associated with repaglinide monotherapy efficacy on insulin resistance in newly diagnosed Shanghai Chinese type 2 diabetes patients.     

Global analysis of genetic variation in human arsenic (+ 3 oxidation state) methyltransferase (AS3MT)

Human arsenic (+ 3 oxidation state) methyltransferase (AS3MT) is known to catalyze the methylation of arsenite. The objective of this study was to investigate the diversity of the AS3MT gene at the global level. The distribution of 18 single nucleotide polymorphisms (SNPs) in AS3MT was performed in 827 individuals from 10 populations (Japanese, Korean, Chinese, Mongolian, Tibetans, Sri Lankan Tamils, Sri Lankan Sinhalese, Nepal Tamangs, Ovambo, and Ghanaian). In the African populations, the A allele in A6144T was not observed; the allele frequencies of C35587 were much lower than those in other populations; the allele frequencies of A37616 and C37950 were relatively higher than those in other populations. Among Asian populations, Mongolians showed a different genotype distribution pattern. A lower C3963 and T6144 frequencies were observed, and, in the C37616A and T37950C polymorphism, the Mongolian population showed higher A37616 and C37950 allele frequencies than other Asian populations, similarly to the African populations. A total of 66 haplotypes were observed in the Ovambo, 48, in the Ghanaian, 99, in the Japanese, 103, in the Korean, 103, in the South Chinese, 20, in the Sri Lankan Tamil, 12, in the Sri Lankan Sinhalese, 21, in the Nepal Tamang, 50, in the Tibetan, and 45, in the Mongolian populations. The D’ values between the SNP pairs were extremely high in the Sri Lankan Sinhalese population. Relatively higher D’ values were observed in Mongolian and Sri Lankan Tamil populations. Network analysis showed two clusters that may have different origins, African and Asians (Chinese and/or Japanese). The present study is the first to demonstrate the existence of genetic heterogeneity in a world wide distribution of 18 SNPs in AS3MT.     

替吉奥单药对幽门螺杆菌相关性胃癌中gC1qR的表达影响

目的：探讨替吉奥单药对胃癌中幽门螺杆菌（H. pylori,Hp）的感染及球状C1q受体基因（gC1qR）表达的影响。方法：以胃癌、胃炎病例组织及胃癌细胞系为研究对象,采用实时定量聚合酶链反应（Real_time_PCR）检测gC1qR_mRNA表达水平;采用Hp DNA_PCR方法,对胃窦部组织标本进行Hp水平检测;流式细胞技术进行细胞凋亡的检测及transwell实验进行细胞侵袭能力的检测。结果：在40对配对组织中有33对肿瘤组织gC1qR_mRNA表达低于配对的胃炎病例组织;替吉奥单药可诱导gC1qR基因表达,抑制胃癌细胞Hp感染,同时增加胃癌细胞的凋亡率及降低胃癌细胞侵袭能力。结论：替吉奥单药诱导gC1qR基因表达,影响Hp对胃癌发生发展,是治疗胃癌的首选药物。     

Role of AHR2 in the expression of novel cytochrome P450 1 family genes, cell cycle genes, and morphological defects in developing zebra fish exposed to 3,3',4,4',5-pentachlorobiphenyl or 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Halogenated agonists for the aryl hydrocarbon receptor (AHR), such as 3,3',4,4',5-pentachlorobiphenyl (PCB126) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), cause developmental toxicity in fish. AHR dependence of these effects is known for TCDD but only presumed for PCB126, and the AHR-regulated genes involved are known only in part. We defined the role of AHR in regulation of four cytochrome P450 1 (CYP1) genes and the effect of PCB126 on cell cycle genes (i.e., PCNA and cyclin E) in zebra fish (Danio rerio) embryos. Basal and PCB126-induced expression of CYP1A, CYP1B1, CYP1C1, and CYP1C2 was examined over time as well as in relation to cell cycle gene expression and morphological effects of PCB126 in developing zebra fish. The four CYP1 genes differed in the time for maximal basal and induced expression, i.e., CYP1B1 peaked within 2 days postfertilization (dpf), the CYP1Cs around hatching (3 dpf), and CYP1A after hatching (14-21 dpf). These results indicate developmental periods when the CYP1s may play physiological roles. PCB126 (0.3-100nM) caused concentration-dependent CYP1 gene induction (EC50: 1.4-2.7nM, Lowest observed effect concentration [LOEC]: 0.3-1nM) and pericardial edema (EC50: 4.4nM, LOEC: 3nM) in 3-dpf embryos. Blockage of AHR2 translation significantly inhibited these effects of PCB126 and TCDD. PCNA gene expression was reduced by PCB126 in a concentration-dependent manner, suggesting that PCB126 could suppress cell proliferation. Our results indicate that the four CYP1 genes examined are regulated by AHR2 and that the effect of PCB126 on morphology in zebra fish embryos is AHR2 dependent. Moreover, the developmental patterns of expression and induction suggest that CYP1 enzymes could function in normal development and in developmental toxicity of PCB126 in fish embryos.     

Constitutive and inducible levels of CYP1A1 and CYP1A2 in rat cerebral cortex and cerebellum

We examined the constitutive and inducible levels of microsomal cytochromes P450 1A1 and 1A2 (CYP1A) in rat cerebral cortex and cerebellum at the level of proteins by western blot analysis, and by catalytic activities via ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD). In the cerebral cortex, cytochrome P450 1A1 (CYP1A1) protein was more abundant than cytochrome P450 1A2 (CYP1A2) protein. Treatment with -naphthoflavone (-NF) caused a slight decrease in the level of the former but induced the latter 5.8-fold. In the cerebellum, in contrast to the cerebral cortex, CYP1A1 protein was less abundant than CYP1A2 protein in untreated rats, and while -NF treatment caused a 3.3-fold induction of CYP1A1 protein, it resulted in a 10-fold decrease in CYP1A2 protein. The CYP1A-preferential activity EROD was 2.3-fold higher in the cerebellum than in the cerebral cortex, and was induced 1.5-fold and 1.9-fold in the cerebellum and cerebral cortex, respectively, by -NF treatment. The CYP1A2-preferential activity MROD was 3-fold higher in the cerebellum than in the cerebral cortex, and was repressed 2.2-fold in the cerebellum but induced 3.7-fold in the cerebral cortex following -NF treatment. The results show that CYP1A1 and CYP1A2 proteins and catalytic activities are constitutively expressed in brain but are differentially inducible in the rat cerebral cortex and cerebellum.