儿童传染性单核细胞增多症与急性淋巴细胞白血病GST基因遗传多态性研究

目的：探讨谷胱甘肽硫转移酶基因GSTT1及GSTM1多态性与儿童传染性单核细胞增多症（IM）、儿童急性淋巴细胞白血病（ALL）易感性的关系。方法：采用多重PCR技术对106例IM患儿、41例ALL患儿和100例非血液系统性疾病、非肿瘤疾病患儿外周血标本进行GSTT1和GSTM1基因多态性检测,分析不同基因型与儿童IM、ALL发病的关系。结果：IM组GSTT1纯合缺失基因型频率明显高于对照组,差异有统计学意义（P<0.05）;携带GSTT1纯合缺失基因型的个体发生IM的风险是携带GSTT1非纯合缺失基因型个体的2.186倍。GSTM1/GSTT1基因联合缺失型个体发生IM的风险是非联合缺失型个体的4.937倍。GSTM1纯合缺失基因型在ALL组的分布频率明显高于对照组,差异有统计学意义(P<0.05)。携带GSTM1纯合缺失基因型的患儿发生ALL的风险是携带GSTM1非纯合缺失基因型个体的2.242倍。GSTM1/GSTT1基因联合缺失型个体发生ALL的风险是非联合缺失型个体的8.552倍。结论：GSTT1或GSTM1纯合缺失基因型的儿童对IM或ALL易感性升高,当同时存在GSTT1和GSTM1纯合缺失时,IM或ALL易感性更高。GSTT1和GSTM1在IM及ALL致病过程中可能都发挥了作用。     

谷胱甘肽S-转移酶M1/T1基因多态性与儿童急性淋巴细胞白血病的相关性

目的 研究谷胱甘肽s-转移酶(GST)M1/T1基因多态性与儿童急性淋巴细胞性白血病(ALL)易感性和预后的相关性.方法 研究组为67例ALL患儿,对照组为146例健康献血员.分别留取外周血标本,提取基因组DNA,用PCR方法测定其GSTM1/T1基因型;同时记录患者的发病年龄、性别、发病时外周血白细胞数、FAB形态学分型,早期治疗反应等影响患者预后的临床资料,并分析GSTM1/T1基因型与这些高危因素之间的关系.结果 ALL患儿GSTM1、GSTM1/T1纯合子缺失率显著高于对照组(P=0.001,P=0.000 1);ALL患儿GSTT1基因纯合子缺失率与对照组比较无显著性差异(P＞0.05).GSTM1/T1基因型与患儿的发病年龄、性别、发病时外周血WBC、FAB形态学分型等均无相关性(Pa＞0.05).GSTM1基因纯合子缺失者的早期治疗反应与有GSTM1功能性等位基因的患儿比较无显著性差异(P=0.733).但GSTT1基因纯合子缺失的患者发生早期治疗反应差的风险较小(P=0.080).结论 GSTM1纯合子缺失基因型是儿童发生ALL的危险基因型,而GSTH基因纯合子缺失者早期治疗效果较好.     

急性淋巴细胞白血病患儿MTHFR基因多态性与大剂量甲氨蝶呤毒副反应的关系

目的：探讨亚甲基四氢叶酸还原酶（MTHFR）基因单核苷酸多态性对急性淋巴细胞白血病（ALL）患儿使用大剂量甲氨蝶呤（HD-MTX）化疗后毒副反应的影响。方法：应用RT-PCR-变性梯度凝胶电泳结合DNA测序技术,对52例ALL患儿MTHFR C677T、A1298C和G1793A基因型进行检测。按照国立癌症研究所常规毒性判定标准（NCI-CTC）对患儿HD-MTX化疗后的不良反应统一评价。结果：MTHFR 1298AC基因型患儿发生血小板减少的风险较AA型提高了13.7倍（OR=13.7,95%CI=1.18～159.36,P=0.036）。MTHFR C677T和G1793A各基因型发生各类HD-MTX化疗不良反应的差异无统计学意义（P>0.05）。结论：MTHFR A1298C多态性可能与ALL患儿HD-MTX化疗后的毒副反应相关。     

汉族儿童Ⅱ相药物代谢酶基因GSTM1和GSTT1的多态性分布

目的 了解谷胱甘肽-S-转移酶M1(GSTM1)和T1(GSTT1)基因多态性在中国汉族儿童中的分布特点,为临床针对不同基因型个体化药物治疗提供理论基础。方法 选择首都医科大学附属北京儿童医院健康查体汉族儿童的血样,提取DNA。应用PCR法检测GSTM1和GSTT1基因型,并判断代谢表型。检索PubMed等数据库,获得亚洲人群、黑种人和高加索人群GSTM1和GSTT1基因多态性分布的数据,与本研究分析人群数据进行比较,分析基因多态性的种族差异。结果 786份研究样本纳入分析。①中国汉族分析人群GSTM1和GSTT1完全缺失基因型/慢代谢型(*0/*0)的频率分别为59.3%(466/786例)和58.4%(459/786例);单拷贝缺失基因型/中间代谢型(*1/*0)的频率分别为34.0%(267/786例)和35.1%(276/786例);未缺失基因型/快代谢型(*1/*1)的频率分别为6.7%(53/786例)和6.5%(51/786例)。②GSTM1和GSTT1基因多态性分布互相独立,无明显关联。③GSTM1和GSTT1基因多态性无显著性别差异。④本研究汉族分析人群GSTM1和GSTT1基因多态性分布与亚洲人群较为接近,与黑种人和高加索人群有显著差异。结论 GSTM1和GSTT1基因在中国汉族儿童中以完全缺失基因型/慢代谢型(*0/*0)为主,具有种族特异性,为不同基因型个体制定合适的用药方案提供了参考依据。     

胸苷酸合成酶基因多态性对甲氨喋呤治疗急性淋巴细胞白血病患儿不良反应的影响

目的探讨不同胸苷酸合成酶(TS)基因型对急性淋巴细胞白血病(ALL)患儿经大剂量甲氨蝶呤(HD-MTX)治疗后不良反应的影响。方法选取2011年3月至2013年3月确诊的ALL患儿73例,提取其基因组DNA,PCR扩增后测序鉴定TS基因型。观察并记录所有ALL患儿经HD-MTX化疗后的不良反应,并监测化疗后42~48 h MTX血药浓度。结果 73例ALL患儿接受HD-MTX治疗后,其不良反应主要包括中性粒细胞减少、血红蛋白降低、血小板减少、肝脏毒性、黏膜损害和胃肠道反应,不同TS基因型患儿化疗后不良反应发生率比较差异均无统计学意义,各基因型与ALL患儿化疗后42~48 h MTX血药浓度的变化无关联。结论 TS基因多态性对ALL患儿HD-MTX化疗后不良反应的发生无影响。     

MTHFR、TS联合作用与ALL患儿HD-MTX化疗毒副作用的关系

目的：探讨 MTHFR、TS基因多态性联合作用对ALL患儿HD-MTX化疗后不良反应的影响,以及与MTX血药浓度变化之间的关系;分析MTHFR、TS基因多态性联合作用在个体化治疗及疾病防治中的作用。方法 ALL患儿73例,提取其基因组DNA,PCR扩增后测序鉴定MTHFR C677T、MTHFR A1298C、TS 5’-UTR的基因型。观察所有ALL患儿HD-MTX化疗后的毒副作用,并监测MTX血药浓度。以Logistic 回归分析基因多态性与化疗毒副作用的危险度;采用Fisher精确概率法比较 HD-MTX 化疗后 MTHFR C677T、MTHFR A1298C、TS 的不同基因型之间42～48 h MTX血药浓度的差异,以P＜0.05为差异有显著性。结果（1）MTHFR677 CT／TT合并1298 AC／CC基因型者,其血红蛋白降低发生的风险下降了2.9倍,而黏膜损害发生的风险则增加了4.3倍,但差异均无显著性。（2）MTHFR1298 AC／CC合并TS 3R／3R基因型者,其发生黏膜损害的风险增加了5.4倍,差异有显著性（χ2＝4.911,P＝0.027）。（3）MTHFR677 CT／TT合并TS 3 R／3R基因型与HD-MTX化疗毒副作用的发生无关。（4）MTHFR677 CT／TT＋MTHFR1298 AC／CC＋TS 3 R／3 R基因型者,其黏膜损害发生的风险增加了7.5倍,且差异有显著性（χ2＝5.295,P ＝0.021）。结论 TS和MTHFRC677T基因多态性可与ALL患儿HD-MTX化疗后黏膜损害的发生有关。     

急性淋巴细胞白血病患儿亚甲基四氢叶酸还原酶基因多态性与大剂量甲氨蝶呤不良反应的相关性

目的探讨急性淋巴细胞白血病(ALL)患儿亚甲基四氢叶酸还原酶(MTHFR)基因677位点多态性与大剂量甲氨蝶呤(HDMTX)体内排泄及不良反应的相关性。方法 2008年3月-2010年2月在本院儿科中心和血液内科住院的完全缓解并接受HDMTX治疗的40例ALL患儿,在接受HDMTX治疗前应用PCR-限制性酶切片段长度多态性(RFLP)技术检测MTHFR基因C677T多态性,在HDMTX静脉输注开始后24 h、48 h应用荧光偏振免疫法(FPIA)测定其血浆MTX水平,密切观察ALL患儿HDMTX化疗后的不良反应,对化疗不良反应进行分级。对MTHFR677的基因多态性与MTX不良反应及HDMTX 48 h的MTX水平(MTX-48 h)的相关性进行分析。结果在有HDMTX相关不良反应的ALL患儿中,肝损害和骨髓抑制发生率最高。MTHFR C677T有肝脏损害的基因型分布频率由低到高为CC型40.0%,TT型60.0%,CT型80.0%,CT基因型者肝脏损害发生的风险是CC基因型者的6倍(OR=6.00,95%CI:1.05～34.32,P=0.044);677CT+TT基因型者肝脏损害发生的风险是CC基因型者的4.13倍(OR=4.13,95%CI:1.02～16.67,P=0.047)。MTHFR C677T基因型与骨髓抑制无明显相关性。携有MTHFR突变基因型(CT+TT)患者的48 hMTX血药质量浓度明显高于携带MTHFR野生型基因CC者(P=0.006)。结论 MTHFR 677位基因型可作为ALL患儿HDMTX化疗不良反应和药物体内排泄的有效预测指标。     

急性淋巴细胞白血病患儿还原叶酸载体基因多态性与甲氨蝶呤不良反应的关系

目的 研究还原叶酸载体基因(RFC1)A80G多态性对急性淋巴细胞白血病(ALL)患儿使用大剂量甲氨蝶呤(HDMTX)化疗的不良反应以及甲氨蝶呤(MTX)排泄延迟的影响.方法 筛选ALL患儿40例,提取其基因组DNA,用DNA直接测序法检测RFC1 80位点基因型,观察所有患儿经HDMTX化疗后的不良反应,并应用荧光偏振免疫分析法(FPIA)测定MTX血药浓度.结果 ALL患儿在HDMTX化疗中,RFC1 80AA基因型者骨髓抑制发生的风险是GG基因型者的8.67倍(OR ＝ 8.67,95% CI:1.05 ～ 71.57,P ＝ 0.045);RFC1 A80G基因型与肝脏损害无明显相关,与MTX排泄延迟亦无明显相关.结论 RFC1 80位基因型可能成为预测ALL患儿HDMTX化疗不良反应的有效遗传学标记,值得进一步进行功能学探讨及大样本人群验证.     

上海地区汉族人谷胱甘肽S转移酶基因多态性分析(英文)

目的：测定GST基因在上海地区健康汉族人中的遗传多态性,筛选出汉族人的GST候选单核苷酸多态性(SNP)位点,为开展GST基因多态性与汉族人群肿瘤易感性及治疗相关性研究作一初步探索。方法：采用荧光标记自动测序法,筛选GSTT1,GSTM1基因在20名上海地区的汉族健康志愿者中的候选SNP位点。结果：4例受检者在GSTT1外显子4和3之间的第86 057位点发生点突变,由腺嘌呤A取代鸟嘌呤G,经与Genebank中SNP数据库比对,可能为一新的GSTT1基因候选SNP位点;在外显子5的第793位点和921位点,所有受检者均为G&A的杂合子。GSTM1在8个外显子中均发现有候选SNP位点,但多为单核苷酸的杂合子。约40%受检者的外显子2出现腺嘌呤A缺失,所有受检者在第1 383位点和1 385位点分别是A&G受C&G杂合子;在第101位点60%个体为A&T杂合,40%个体为腺嘌呤A的纯合子。我们还初步发现在外显子2的190 bp以后可能存在多个碱基或小片段缺失。结论：上海地区健康汉族人的GST基因具有丰富的遗传多态性。这些多态性是否为汉族人所特有、与肿瘤易感性的关系,以及这些可能的候选SNP位点是否会造成其编码氨基酸的改变并引起产物蛋白一级结构的变化、进而导致GST酶活性发生改变而表现为具有不同的表型及基因型,尚需深入探讨。     

神经母细胞瘤患儿应用铂类药物毒性反应监测及其与药物基因多态性的关联性研究

目的总结神经母细胞瘤(NB)患儿应用铂类药物化疗后毒性反应和药物基因多态性检测结果,探索二者之间的关联性,为指导临床个体化治疗提供依据。方法连续纳入2016年2月1日-2017年5月31日期间,北京儿童医院血液肿瘤中心确诊并系统治疗的NB患儿。依据BCH-NB-2007危险度分组标准,分为低危、中危、高危组,接受含顺铂或卡铂方案化疗。化疗前留取外周血,采用荧光杂交方法对两种铂类化疗药物基因组DNA进行检测,化疗后记录患儿各系统毒副反应,并按国立癌症研究所常规毒性标准(NCI-CTCAE 5. 0中文版)进行分级。进一步将3/4级毒性反应与药物基因检测结果进行关联性分析。结果共纳入98例NB患儿,男50例,女48例。中位年龄为46(5～115)个月。中低危组单用卡铂者36例(36. 7%)。高危组62例(63. 3%),其中单用顺铂者46例,顺铂+卡铂者16例。所有NB患儿在病初时留取血标本检测GSTP1基因多态性,AA型61例(62. 2%),AG型33例(33. 7%),GG型4例(4. 1%);部分患儿(51例)还进行了XPC基因多态性的检测,其中GG型8例(15. 7%),GT型24例(47. 1%),TT型19例(37. 3%)。所有NB患儿中,出现3/4级毒性反应共61例(62. 2%),其中以3/4级血液毒性最为常见(55例,56. 1%); 3/4级恶心呕吐、肝损害及电解质紊乱各2例,共占6%。分析3/4级毒副反应与所检测的两种药物基因多态性之间的相关性,GSTP1基因多态性与3/4级毒性反应相关,组间差异具有显著性,AA型毒副反应重于AG型和GG型(P 0. 05); XPC基因多态性与3/4级毒性反应相关性差异无显著性。结论 NB患儿应用铂类化疗毒性反应以血液系统毒性、消化道毒性为主,GSTP1基因多态性与3/4级毒性反应相关,AA型毒副反应最重; XPC基因多态性与3/4级毒性反应无相关性,有待扩大样本量加以验证。     

Gene dose effects of GSTM1, GSTT1 and GSTP1 polymorphisms on outcome in childhood acute lymphoblastic leukemia

Children with acute lymphoblastic leukemia (ALL) react very differently to chemotherapy. One explanation for this is inherited genetic variation. The glutathione S-transferase (GST) enzymes inactivate a number of chemotherapeutic drugs administered in childhood ALL therapy. Two multiplexing methods were applied for genotyping the GSTM1 and GSTT1 genes (distinguishing between 0, 1, or 2 gene copies) and the GSTP1 313 A>G polymorphism, simultaneously. A total of 263 childhood ALL patients were genotyped. No gene dose effect on outcome was demonstrated with either GST polymorphisms. Grouping of GSTM1 and GSTT1 into poor (0 or 1 gene copy)-and good metabolizers (at least 2 gene copies)-showed that the poor metabolizers had a trend toward a better outcome (event-free survival =91.8%) compared with the good metabolizers (event-free survival =83.2%). Similarly, in the adjusted analysis the good metabolizers demonstrated a 2.2-fold higher risk trend of experiencing an event (resistant disease or relapse) compared with the poor metabolizers (P=0.066; hazard ratio =2.248; 95% confidence interval, 0.948-5.327). In conclusion, our results suggest that the combined gene dose of GSTM1 and GSTT1 may influence outcome in childhood ALL.     

Glutathione S transferase theta 1 gene (GSTT1) null genotype is associated with an increased risk for acquired aplastic anemia in children

Two main factors have been implicated in the mechanism underlying the pathogenesis of acquired aplastic anemia: environmental factors and genetic susceptibility. Individuals vary in their ability to metabolize several DNA-damaging agents due to polymorphisms of biotransforming enzymes. Genetically determined differences in the expression of these enzymes could explain interindividual risks in developing acquired aplastic anemia. The aim of the study was to characterize the genetic polymorphism of biotransforming phase I (p450-cyp2E1) and phase II [microsomal epoxide hydrolase (mEh), glutathione S-transferase (GST)] enzymes in pediatric patients with acquired aplastic anemia. The GSTT1 null genotype (absence of both alleles) was associated with a significantly increased risk for acquired aplastic anemia (odds ratio, 2.8; 95% confidence interval, 0.15-5.7). In contrast, the GSTM1 null genotype or polymorphisms within the p450-cyp2E1 and mEh genes was not significantly different in patients and controls. Multivariate analysis was performed to assess whether the enzymes together or with other variables as age, gender, or response to therapy may have any significant association with the tested genotypes. In no combinations of the mentioned parameters was an association found with acquired aplastic anemia. GST are mainly involved in metabolizing hematotoxic and mutagenic substrates such as benzene derivatives. The GSTT1 null genotype may modulate the metabolism of exogenous pollutants or toxic intermediates. The absence of the GSTT1 enzyme, leading to genetic susceptibility toward certain pollutants, might determine the individual risk for development of acquired aplastic anemia in children.     

Polymorphism within the glutathione S-transferase P1 gene is associated with increased susceptibility to childhood malignant diseases

BACKGROUND: Glutathione S-transferases (GSTs) are involved in the metabolism of carcinogens and anticancer drugs. Functional polymorphisms exist in at least three genes that code for the GSTs, such as the GSTM1 and GSTT1 gene deletions or the A-G transition within the GSTP1 gene, which represents distinct GSTP1a and GSTP1b alleles. In the present case-control study, we aimed at estimation of the relationship between the GSTM1, GSTT1, and GSTP1 genotypes and the susceptibility to various types of childhood malignancies and the early relapses of diseases. PROCEDURE: Using the polymerase chain reaction on the DNA extracted from peripheral blood leukocytes, we identified the GSTM1, GSTT1, and GSTP1 genotypes in 234 children at the initial stage of a childhood malignancy as well as in 460 age-and sex-matched healthy subjects who served as controls. The follow-up period for the effects of the anticancer therapy ranged from 11 to 43 months. RESULTS: Compared to the controls, a significant increase in the frequency of the GSTP1b/GSTP1b genotype (odds ratio (OR) 5.7; 95% confidence limit (CL) from 2.4 to 13.8; Pearsons Chi-square P = 0.0001) was detected in the children with neoplasms. The GSTM1 and GSTT1 genotypes did not show any correlation with the risk of the de novo diagnosed neoplasms. During the observation, 62 children (26%) were found to be present with a local or disseminated recurrence of the diseases. The analysis indicated a trend in increasing risk of relapse for carriers of the GSTP1a allele (OR = 3.29; 95% CL from 0.73 to 14.67 P = 0.03). CONCLUSIONS: Our results support the hypothesis that GST genotype affects etiology and outcome of a variety of childhood malignancies.     

ASSOCIATION OF GENETIC POLYMORPHISMS WITH HEPATOTOXICITY IN PATIENTS WITH CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA OR LYMPHOMA

The objective of this study was to identify novel pharmacogenetic determinants of treatment-related hepatotoxicity during the maintenance phase in children with acute lymphoblastic leukemia (ALL) or lymphoblastic lymphoma (LBL). Although the authors first determined whether genotypes of drug-metabolizing enzymes and transporters—glutathione S-transferase (GST) genes, GSTM1 positive/null, GSTT1 positive/null and GSTP1 A313G, methylenetetrahydrofolate reductase (MTHFR) C677T, reduced folate carrier 1 (RFC1) G80A, and breast cancer resistant protein (BCRP) C421A—were associated with hepatotoxicity for 24 patients, no significant difference was detected for genotype and allelic frequencies between the patients with and those without severe treatment-related hepatotoxicity. Therefore, the authors explored potential candidate polymorphisms associated with hepatotoxicity using the Illumina Infinium HumanHap300, encompassing more than 318,000 tag single-nucleotide polymorphisms (SNPs), for 8 of 24 patients with or without severe hepatotoxicity. Genome-wide genotyping uncovered a total of 28 candidate SNPs. rs1966862, in Rho GTPase-activating protein 24 (ARHGAP24), was the most significant of the candidates, and the genotypes of rs13424027 (PARD3B), rs1156304 (KCNIP4), rs10255262 (SLC13A1), rs7403531 (RASGRP1), and rs381423 (unidentified gene) were also significantly associated with severe hepatotoxicity. This study suggested rs1966862 (ARHGAP24) and the other SNPs to be predictive factors for drug-induced hepatotoxicity during the maintenance phase in pediatric patients with ALL or LBL.     

Are glutathione S-transferase gene polymorphisms linked to neonatal jaundice?

Glutathione S-transferases (GSTs) are a major group of phase II detoxification enzymes involved in the metabolism of both endogenous and xenobiotic compounds. In addition to their catalytic function in detoxification, GSTs participate in binding to nonsubstrate ligands such as bilirubin. Ligandin, which is one of the principal hepatic-binding proteins, is also a member of the GST family. The aim of the present study was to investigate the possible relationship between neonatal jaundice and the GST gene polymorphisms. The study cohort consisted of a patient group of 116 newborns (plasma bilirubin levels ≥15 mg/dl) and a control group of 54 newborns (plasma bilirubin levels <13 mg/dl). In the patient group, the null genotype frequencies in GSTM1 and GSTT1 were 52.6 and 19%, respectively; in the control group, these were 63 and 27.8%, respectively. The frequencies of GSTM1 and GSTT1 were similar in the patient and control groups (p > 0.05). Total bilirubin levels were found to be significantly higher in patients with the GSTM1 null genotype than in patients with the GSTM1 wild genotype (p = 0.042). There was no statistically significant difference in total bilirubin levels between patients with the null GSTT1 genotype and those with the wild GSTT1 genotype. It is conceivable that there is a relation between GSTM1 gene polymorphism and total bilirubin levels in neonatal jaundice. We suggest that GSTM1 gene polymorphisms may affect ligandin functions in hepatocytes, which are important in bilirubin transportation. Consequently, patients with the GSTM1 null genotype may have higher total levels of bilirubin.     

Occurrence of Wilms Tumor in a Child with Urofacial (OCHOA) Syndrome

Juvenile nasopharyngeal angiofibroma (JNA) is a vascular tumor of the nasopharynx that accounts for 0.5% of all cancers of the head and neck. It primarily affects males aged 14–25 years. Of the many genes that mediate the development of JNA, GSTM1 has been most frequently associated with this vascular tumor. The loss of expression of GSTM1 (null genotype) is linked to the development of these tumors. The aim of this cross-sectional case study was to examine the prevalence of the GSTM1-null genotype in Brazilian patients with JNA. DNA was extracted from the leukocytes of blood samples from 10 patients. GSTM1 genotypes were analyzed using a PCR-based assay that was designed to identify the wild-type allele of GSTM1. All 10 patients (100%) were males, with a mean age of 17.8 years. The null genotype for GSTM1 was noted in 4 patients (40%)—1 (10%) at Fisch stage I, 1 (10%) at stage III, and 2 (20%) at stage II. No patient with this genotype had stage IV disease. There was no correlation between Fisch classification and GSTM1 genotype (P = .5695). The correlation between age at diagnosis and GSTM1 genotype was not significant (P = .728). The present findings indicate that there is evidence of an association between the GSTM1-null genotype and JNA in this studied Brazilian population.