Polymorphisms In Metabolizing Enzymes Research Articles

Effects of CYP2D6 gene polymorphism on plasma concentration and therapeutic effect of olanzapine

This study aimed to evaluate the relationship between gene polymorphisms of metabolic enzymes, particularly the CYP2D6 gene, and the plasma concentration of olanzapine, as well as treatment response in patients with chronic schizophrenia. We recruited olanzapine-treated patients and examined their plasma olanzapine levels. Additionally, a common mutation site within each of the nine exons of the full-length CYP2D6 sequence was assayed. The Positive and Negative Syndrome Scale, Brief Psychiatric Rating Scale, and Overall Clinical Impression were used to assess schizophrenic symptoms, whereas the Barnes Akathisia Scale and Extrapyramidal Symptom Rating Scale were used to evaluate adverse effects. The results showed no significant differences in plasma olanzapine concentrations, treatment response, or the occurrence of adverse effects among different CYP2D6 genotypes. However, an association between olanzapine concentrations and improvement in clinical symptoms and adverse reactions was observed. In conclusion, the CYP2D6 genotype did not significantly impact plasma olanzapine concentrations, treatment response, or the occurrence of adverse effects.

Влияние генетического полиморфизма генов, кодирующих мишень действия, на эффективность антигипертензивной терапии

Arterial hypertension is one of the main modifiable factors of cardiovascular events, which affects an increasing number of people around the world. In addition to the low adherence of patients to treatment, the wrong choice of medications, the presence of concomitant diseases and an unhealthy lifestyle, the effectiveness of antihypertensive therapy may be associated with genetic polymorphism. Genetic polymorphisms can influence through genes involved in the pathogenesis of hypertension, which are able to modify the effects of drugs; modifications in the mechanisms of interaction of drugs with genes; polymorphisms in metabolic enzymes; genes associated with drug carriers, and genes involved in complex cascades and metabolic reactions. The article reviews the results of studies of the relationship of polymorphic alleles of genes responsible for the pharmacodynamic response to therapy with angiotensin converting enzyme inhibitors and angiotensin II receptor blockers as the main drugs for the treatment of hypertension according to clinical guidelines for the treatment of hypertension in adults.

Genotype-guided new approach for dose optimisation of hydroxychloroquine administration in Chinese patients with SLE

ObjectivesThe study aims to investigate the impact of gene polymorphisms on blood hydroxychloroquine (HCQ) concentrations in patients with SLE and provide guidelines for individualised care.Methods489 Chinese patients with SLE taking...

Клиническое значение генетического полиморфизма ферментов метаболизма и транспортеров тамоксифена при раке молочной железы: результаты популяционного когортного исследования

Клиническое значение генетического полиморфизма ферментов метаболизма и транспортеров тамоксифена при раке молочной железы: результаты популяционного когортного исследования

Analysis of the complications of endocrine therapy with tamoxifen in breast cancer: clinical and pharmacogenetic aspects. Prospective pharmacogenetic cohort study

Background. Tamoxifen is the drug of choice in ER-positive breast cancer (BC) therapy for perimenopausal women and one of the endocrine therapy options for menopausal patients. The pharmacological effect of tamoxifen can be influenced by the activity of cytochrome P450 (CYP) enzymes and P-glycoprotein transporters (Pg), and the genes encoding them have broad polymorphism, affecting serum concentrations of active metabolites. This article presents the overall results of a prospective population-based study of the clinical significance of genetic polymorphism of tamoxifen metabolic enzymes and transporters in breast cancer patients after radical treatment receiving adjuvant endocrine therapy with tamoxifen in outpatient settings during 2018-2019. The study was approved by the Research Ethics Committee of the Russian Medical Academy of Continuing Professional Education.
 Aim. To analyze the clinical presentation of endocrine therapy with tamoxifen in the adjuvant regimen and to assess the association of polymorphisms of genes encoding cytochrome P450 enzymes and drug transporter proteins with adverse events in BC patients.
 Materials and methods. One hundred and four women with stage I-III luminal breast cancer receiving adjuvant tamoxifen were examined for the presence of CYP2D6, CYP2C, and the following CYP3A gene polymorphisms: CYP2D6*4, CYP3A5*3, CYP2C9*2, CYP2C9*3, CYP2C19*2, CYP2C19*3, as well as the ABCB1 gene polymorphic marker (C3435T) encoding the P-glycoprotein. The allelic variants were identified using the real-time polymerase chain reaction; the test was performed in the Research Center of the Russian Medical Academy of Continuing Professional Education. The study material was buccal epithelium (double sampling) taken after informed consent signing.
 Results. Association analysis showed the association of different genetic polymorphisms of CYP2D6, CYP3A5, CYP2C9, and ABCB1 with tamoxifen adverse drug reactions, indicating the clinical significance of these polymorphisms.
 Conclusion. With the implementation of genetic testing of the studied polymorphisms into the routine clinical practice of oncologists prescribing tamoxifen and gynecologists involved in the follow-up of breast cancer patients receiving endocrine therapy in the adjuvant mode, there will be an opportunity for more effective and safer pharmacotherapy.

Effects of gene polymorphisms of CYP1A1, CYP1B1, EPHX1, NQO1, and NAT2 on urinary 1-nitropyrene metabolite concentrations

Nitropyrene (1-NP) is a specific indicator of exposure to diesel exhaust and is partly metabolized to 1-aminopyrene (1-AP) and N-acetyl-1-aminopyrene (1-NAAP), which are excreted in urine. This study was conducted to evaluate the effects of gene polymorphisms of metabolic enzymes for 1-NP on the urinary concentrations of 1-AP and 1-NAAP. The study participants were 70 South Koreans who were occupationally or environmentally exposed to diesel exhaust. To evaluate 1-NP exposure levels, we sampled airborne particulate matters with a personal air sampler and measured urinary 1-AP and 1-NAAP concentrations. The genetic polymorphisms of the 1-NP metabolic enzymes (CYP1A1, CYP1B1, EPHX1, NQO1, and NAT2) were determined by direct sequencing. The mean 1-NP exposure level was 20.40 pg/m3, and the mean urinary concentrations of 1-AP and 1-NAAP were 0.074 nM and 0.213 nM, respectively. The correlation coefficient between the 1-NP exposure level and urinary 1-AP concentrations was 0.0138 and that between the 1-NP exposure level and urinary 1-NAAP concentrations was 0.1493, and neither correlation coefficient was statistically significant. The correlation coefficient between the 1-NP exposure level and urinary 1-AP concentrations showed statistically significant differences according to the CYP1A1 and CYP1B1 genotypes, and that between the 1-NP exposure level and urinary 1-NAAP concentrations was significantly different according to the CYP1A1, CYP1B1, and NAT2 genotypes. The urinary concentration of 1-NAAP is a better biomarker for exposure to 1-NP or DEPs because the former is higher, easier to measure, and more strongly correlated with 1-NP exposure levels than that of 1-AP. The relationship between 1-NP exposure and urinary 1-AP or 1-NAAP concentration depends on the single nucleotide polymorphism types of CYP1A1, CYP1B1, NQO1, and NAT2.

Opioid Rotation: Considerations, Controversy, and Clinical Practice #440.

Opioid Rotation: Considerations, Controversy, and Clinical Practice #440.

A review on the genetic polymorphisms and susceptibility of cancer patients in Bangladesh.

Cancer is one of the major health burdens worldwide, and genetic polymorphisms in individuals are closely associated with cancer susceptibility. Like in many other developing countries, the risk of cancer is increasing among Bangladeshi population. Genetic polymorphisms in xenobiotic metabolic enzymes (CYP1A1, CYP2A6, CYP3A4, CYP3A5, NAT2, SULT1A), cell cycle regulatory proteins (TP53, HER2, MDM2, miR-218-2, TGFB), cell signaling protein (CDH1), DNA repair proteins (BRCA1, BRCA2, EXO1, RAD51, XRCC2, ECCR1, ERCC4, XPC, ERCC2), and others (HLA-DRB1, INSIG2, GCNT1P5) have been found to be associated with various cancers like cancers of breast, bladder, cervix, colon, lung, prostate, etc. in different studies with Bangladeshi population. In this review article, we have discussed these gene polymorphisms associated with cancers in the Bangladeshi population, and also made a comparison with other ethnic groups. This will probably be helpful in understanding drug effects, drug resistance, and personalized medicine in the population of this region.

Effect of CYP4F2 Polymorphisms on Ticagrelor Pharmacokinetics in Healthy Chinese Volunteers.

Background: Ticagrelor belongs to a new class of P2Y12 receptor inhibitor that has been widely used for antiplatelet therapy. This study aimed to explore the effect of single nucleotide polymorphisms (SNPs) in metabolic enzymes, transporters, and other relevant variants on the pharmacokinetics (PK) of ticagrelor and its active metabolite, AR-C124910XX. Methods: The study population comprised 68 healthy Chinese volunteers who were enrolled in a ticagrelor bioequivalence clinical trial. The PK profile of ticagrelor was evaluated after orally administering a single 90-mg dose of ticagrelor in tablet form. The plasma concentrations of ticagrelor and AR-C124910XX were determined through liquid chromatography–tandem mass spectrometry. Plasma DNA samples were used to explore the effect of gene polymorphisms on the PK of ticagrelor and AR-C124910XX with whole-exome sequencing. Results: Female participants had a higher maximum plasma concentration/weight ratio (C max/W; p < 0.001) and a shorter half-life (T 1/2; p < 0.05) for ticagrelor than their male counterparts. In addition, a higher area under the curve/weight ratio (AUC/W; p < 0.001), and longer T 1/2 (p < 0.001) and time to reach the maximum plasma concentration (T max; p < 0.001), as well as a lower apparent drug clearance (CL/F; p < 0.001), were observed among healthy volunteers in the fed trial compared to those enrolled in the fasting trial. For AR-C124910XX, higher C max/W (p < 0.001) and AUC/W (p < 0.001) but lower CL/F (p < 0.001) and apparent volume of distribution (V d/F; p < 0.001) were observed among female participants. Healthy volunteers enrolled in the fasting trial exhibited higher C max/W (p < 0.001) and AUC/W (p < 0.01), shorter T max (p < 0.001), and lower CL/F (p < 0.001) and V d/F (p < 0.001) than those enrolled in the fed trial. Upon confirmation through multivariate analysis, the CYP4F2 rs2074900 A/A carriers were associated with higher C max/W and AUC/W and lower CL/F and V d/F than the CYP4F2 rs2074900 A/G and G/G carriers. Conclusion: This study is the first to show that the CYP4F2 rs2074900 SNP had a remarkable effect on ticagrelor PK, which is significant since it adds to the limited pharmacogenetic information on ticagrelor.

Evaluation of genetic polymorphism of proteins in stellate sturgeon Acipenser stellatus (Pall) in aquaculture with reference to economically valuable traits

One of the main goals of sturgeon aquaculture is the restoration and renewal of wild populations of sturgeon fish in nature, which creates a tension between selective breeding with maintenance of valuable economic traits in a homozygous state and the need to conserve genetic diversity ensuring fitness in natural environments. It is generally assumed that important economic characteristics, such as body weight and size, growth rate, fecundity, etc., as well as fitness in fish, are associated with heterozygosity and genetic polymorphism of some key metabolic enzymes. It remains unclear whether aquaculture conditions can be as a whole selection factor in favor of certain allelic variants of these enzymes. To establish the relationship between some economic traits and enzymatic polymorphism, we studied the distribution of allelic variants of LDH-3, AAT-2, FGM, and Est enzymes in stellate sturgeon reared in aquaculture. We revealed a frequency bias of some allelic variants of the studied enzymes in a cohort of fish from the generation bred in aquaculture compared to the frequencies of those alleles in wild natural populations. Our study suggests that industrial breeding promotes selection in the direction of reducing size but increasing survival rates, which correlates with certain allelic variants.

Impact of Cilostazol Pharmacokinetics on the Development of Cardiovascular Side Effects in Patients with Cerebral Infarction.

This study investigated the impact of polymorphisms of metabolic enzymes on plasma concentrations of cilostazol and its metabolites, and the influence of the plasma concentrations and polymorphisms on the cardiovascular side effects in 30 patients with cerebral infarction. Plasma concentrations of cilostazol and its active metabolites, and CYP3A5*3 and CYP2C19*2 and *3 genotypes were determined. The median plasma concentration/dose ratio of OPC-13213, an active metabolite by CYP3A5 and CYP2C19, was slightly higher and the median plasma concentration rate of cilostazol to OPC-13015, another active metabolite by CYP3A4, was significantly lower in CYP3A5*1 carriers than in *1 non-carriers (p = 0.082 and p = 0.002, respectively). The CYP2C19 genotype did not affect the pharmacokinetics of cilostazol. A correlation was observed between changes in pulse rate from the baseline and plasma concentrations of cilostazol (R = 0.539, p = 0.002), OPC-13015 (R = 0.396, p = 0.030) and OPC-13213 (R = 0.383, p = 0.037). A multiple regression model, consisting of factors of the plasma concentration of OPC-13015, levels of blood urea nitrogen, and pulse rate at the start of the therapy explained 55.5% of the interindividual variability of the changes in pulse rate. These results suggest that plasma concentrations of cilostazol and its metabolites are affected by CYP3A5 genotypes, and plasma concentration of OPC-13015, blood urea nitrogen, and pulse rate at the start of therapy may be predictive markers of cardiovascular side effects of cilostazol in patients with cerebral infarction.

Genetic polymorphisms in metabolic enzymes and transporters have no impact on mycophenolic acid pharmacokinetics in adult kidney transplant patients co-treated with tacrolimus: A population analysis.

Mycophenolate mofetil, an ester prodrug of mycophenolic acid (MPA), is widely used to prevent graft rejection after kidney transplantation. The pharmacokinetic (PK) of MPA has been extensively studied, which revealed a high degree of variability. An integrated population PK (PopPK) model of MPA and its main metabolite mycophenolic acid glucuronide (MPAG) was developed using the adult patients who underwent kidney transplant and were administered oral mycophenolate mofetil combined with tacrolimus. In total, 917MPA and 740MPAG concentrations in191 adult patients were analysed via nonlinear mixed-effects modelling. The concentration-time data were adequately described using a chain compartment model, including central and peripheral compartments for MPA and a central compartment for MPAG. Stepwise forward inclusion and backward elimination procedures were used to investigate the effects of genetic polymorphisms, including in UGT1A8, UGT1A9, UGT2B7, ABCB1, ABCC2, ABCG2, SLCO1B1, SLCO1B3, and HNF1α. These genetic polymorphisms in metabolic enzymes and transporters have no obvious impact on the PK of MPA in adult patients who underwent kidney transplant and were co-treated with tacrolimus. The post-transplant time, serum albumin, and creatinine clearance were identified as significant covariates affecting the PK of MPA and MPAG, which should be considered in the clinical use of mycophenolate mofetil. We established a PopPK model of MPA and MPAG in Chinese adult patients who underwent kidney transplant and were co-treated with tacrolimus. Genetic polymorphisms in metabolic enzymes and transporters showed no obvious impact on MMF PK. A model-informed dosing strategy was proposed by the established model, and MMF dose adjustment should be based on ALB levels and the post-transplantation time.

Association Between Genetic Polymorphisms of Metabolic Enzymes and Azathioprine-Induced Myelosuppression in 1,419 Chinese Patients: A Retrospective Study.

The aim of this study was to investigate the correlation between genetic polymorphisms of azathioprine-metabolizing enzymes and adverse reactions of myelosuppression. To this end, a retrospective analysis was performed on 1,419 Chinese patients involving 40 different diseases and 3 genes: ITPA (94C>A), TPMT*3 (T>C), and NUDT15 (415C>T). Strict inclusion and exclusion criteria were established to collect the relative cases, and the correlation between azathioprine and myelosuppression was evaluated by adverse drug reaction criteria. The mutation rates of the three genes were 29.32, 3.73, and 21.92% and grades I to IV myelosuppression occurred in 54 (9.28%) of the 582 patients who took azathioprine. The highest proportion of myelosuppression was observed in 5 of the 6 (83.33%) patients carrying the NUDT15 (415C>T) TT genotype and 12 of the 102 (11.76%) patients carrying the NUDT15 (415C>T) CT genotype. Only the NUDT15 (415C>T) polymorphism was found to be associated with the adverse effects of azathioprine-induced myelosuppression (odds ratio [OR], 51.818; 95% CI, 5.280–508.556; p = 0.001), which suggested that the NUDT15 (415C>T) polymorphism could be an influencing factor of azathioprine-induced myelosuppression in the Chinese population. Epistatic interactions between ITPA (94C>A) and NUDT15 (415C>T) affect the occurrence of myelosuppression. Thus, it is recommended that the genotype of NUDT15 (415C>T) and ITPA (94C>A) be checked before administration, and azathioprine should be avoided in patients carrying a homozygous NUDT15 (415C>T) mutation. This study is the first to investigate the association between genetic polymorphisms of these three azathioprine-metabolizing enzymes and myelosuppression in a large number of cases with a diverse range of diseases.

Current Pharmacogenetic Perspective on Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Adverse drug reactions are a public health issue that draws widespread attention, especially for Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) which have high mortality and lack of efficacious treatment. Though T-cell-mediated HLA-interacted immune response has been extensively studied, our understanding of the mechanism is far from satisfactory. This review summarizes infection (virus, bacterial, and mycoplasma infection), an environmental risk factor, as a trigger for SJS/TEN. The mutations or polymorphisms of drug metabolic enzymes, transporters, receptors, the immune system genes, and T-cell-mediated apoptosis signaling pathways that contribute to SJS/TEN are discussed and summarized. Epigenetics, metabolites, and mobilization of regulatory T cells and tolerogenic myeloid precursors are emerged directions to study SJS/TEN. Ex vivo lymphocyte transformation test has been exploited to aid in identifying the causative drugs. Critical questions on the pathogenesis of SJS/TEN underlying gene polymorphisms and T cell cytotoxicity remain: why some of the patients carrying the risky genes tolerate the drug and do not develop SJS/TEN? What makes the skin and mucous membrane so special to be targeted? Do they relate to skin/mucous expression of transporters? What is the common machinery underlying different HLA-B alleles associated with SJS/TEN and common metabolites?

Association of Methylene Tetrahydrofolate Reductase Gene A1298C (Rs1801131) Polymorphism with Myocardial Infarction among Sudanese Patients

Background: Myocardial infarction (MI) is among the leading causes of mortality worldwide. Variations in folate metabolism including genetic polymorphisms in the key metabolic enzymes had showed influences in the MI process. Objectives: To determine whether the C1298A transition in the Methylene Tetrahydrofolate Reductase ( MTHFR ) gene is associated with increased risk for MI among Sudanese patients. Material and methods: This is a hospital based case control study in which a total of 140 Sudanese subjects were enrolled, 70 patients with myocardial infarction and 70 age- and sex matched healthy volunteers as a control group. Genomic DNA was extracted by (QIA gene, Korea) kits and the SNPs genotypes were determined using polymerase chain reaction followed by restriction fragment length polymorphism (PCR- RFLP). Data of this study were collected using a structured interview questionnaire and analyzed by statistical package for social sciences (version 21). Results: The frequency of the AA genotype was higher in the patients group compared with control (96%, 71% respectively); while the AC genotype was higher in the control (20%, 5% respectively), while the CC genotype was not observed in this study population. The frequencies of A and C alleles were 0.68 and 0.02 respectively in MI patients while frequencies were 0.60 and 0.10 respectively in the control group. No statistically significant association was observed between MTHFR genotypes and MI (P. values = 0.4 and 0.1 for AA and AC genotypes respectively). Conclusion: In this study population, the A1298C MTHFR polymorphism is not associated with the risk of MI among the Sudanese population.

Pharmacogenomics Drives Lenalidomide Efficacy and MRD Kinetics in Mantle Cell Lymphoma after Autologous Transplantation: Results from the MCL0208 Multicenter, Phase III, Randomized Clinical Trial from the Fondazione Italiana Linfomi (FIL)

Pharmacogenomics Drives Lenalidomide Efficacy and MRD Kinetics in Mantle Cell Lymphoma after Autologous Transplantation: Results from the MCL0208 Multicenter, Phase III, Randomized Clinical Trial from the Fondazione Italiana Linfomi (FIL)

Determinants of gefitinib pharmacokinetics in healthy Chinese male subjects: A pharmacogenomic study of cytochrome p450 enzymes and transporters.

Gefitinib, an inhibitor of the epidermal growth factor receptor tyrosine kinase, exhibited a wide interindividual variability in pharmacokinetics. In the present study, we aimed to evaluate the impact of single-nucleotide polymorphisms in the metabolizing enzymes and transporters on gefitinib disposition in healthy Chinese subjects. Fourteen single-nucleotide polymorphisms, including polymorphisms of ATP-binding cassette (ABC) transporters and cytochrome P450 enzymes, were genotyped by Sanger sequencing, and the concentration of gefitinib was measured by ultrafast liquid chromatography-tandem mass spectrometry. The association between the pharmacokinetic parameters (peak plasma concentration [Cmax ], time to reach Cmax , plasma half-life, area under the concentration-time curve from 0 to 168hours [AUC(0-168h) ], AUC(0-∞) and plasma clearance [CL/F]) and genotypes was evaluated using unpaired t test or Mann-Whitney U test. A stepwise multiple linear regression analysis was applied to assess the relationships between multiple factors and gefitinib pharmacokinetics. Thirty-nine healthy Chinese male subjects were enrolled in the pharmacokinetic study. Subjects carrying an ABCG2 A allele (c.421CA+c.421AA genotypes) exhibited 33 and 37% increases in the mean gefitinib AUC(0-168h) and AUC(0-∞) values (P<.05), respectively, compared to that of subjects carrying wild-type ABCG2 (c.421CC). Additionally, the mean CL/F of the c.421A allele carriers was 32% less than that of the c.421CC carriers (P<.05). No associations were found between polymorphisms in other metabolic enzymes or ABC transporters and gefitinib pharmacokinetics. Our results suggested that a single-nucleotide polymorphism in ABCG2 (c.421C>A) significantly affected the pharmacokinetics of gefitinib. Further studies are required to evaluate the effects of single-nucleotide polymorphism on the pharmacokinetics, pharmacodynamics and toxicity of gefitinib.

Kidney podocyte-associated gene polymorphisms affect tacrolimus concentration in pediatric patients with refractory nephrotic syndrome.

Few studies have investigated the correlation between pharmacogenomics and tacrolimus pharmacokinetics in patients with nephrotic syndrome (NS). This study evaluated the influences of genetic polymorphisms of metabolic enzymes, transporters, and podocyte-associated proteins on tacrolimus concentration in Chinese pediatric patients with refractory NS. A total of 167 pediatric patients with refractory NS were included from July 2013 to December 2017. Age of onset was restricted to <14 years of age. Dose-adjusted tacrolimus trough concentration (C0/D) on the third month was calculated, and 20 single-nucleotide polymorphisms in sixteen genes were genotyped. Age was correlated with tacrolimus C0/D (p = 0.006, r = 0.213). Tacrolimus C0/D was higher in CYP3A5 nonexpressers than in CYP3A5 expressers (p = 0.003). ACTN4 rs62121818, MYH9 rs2239781, CYP3A5*3, and age explained 20.5% interindividual variability of tacrolimus concentration in the total cohort. In CYP3A5 nonexpressers, ACTN4 rs62121818 and MYH9 rs2239781 together explained 14.6% variation of tacrolimus C0/D. MYH9 rs2239781, LAMB2 rs62119873 and age together explained 22.3% variability of tacrolimus level in CYP3A5 expressers. CYP3A5*3 was still an important factor affecting tacrolimus concentration in patients with NS. Podocyte-associated gene polymorphisms, especially ACTN4 rs62121818 and MYH9 rs2239781, were the other most important biomarkers for tacrolimus whole blood levels. Genotyping of CYP3A5, ACTN4, and MYH9 polymorphisms may be helpful for better guiding tacrolimus dosing in pediatric patients with refractory NS.

Associations between Folate Metabolism Enzyme Polymorphisms and Lung Cancer: A Meta-Analysis

Some previous studies already investigated potential associations between folate metabolism enzyme polymorphisms and lung cancer (LC). However, the results of these studies were inconsistent. Thus, we performed this meta-analysis to explore associations between folate metabolism enzyme polymorphisms and LC in a larger pooled population. Systematic literature research of PubMed, WOS, Embase and CNKI was performed to identify eligible studies. Review Manager Version 5.3.3 was used to conduct statistical analyses. Totally 37 genetic association studies were included for analyses. The pooled analyses showed that MTRR rs1801394 (dominant model: p = 0.01; recessive model: p = 0.04; allele model: p = 0.005) and MTHFR rs1801133 (dominant model: p = 0.008; recessive model: p = 0.0003; allele model: p = 0.0002) polymorphisms were both significantly associated with susceptibility to LC in overall population. Subgroup analyses revealed similar significant findings for MTHFR rs1801133 polymorphism in East Asians. Significant associations with LC were also observed for MTRR rs1801394 and MTHFR rs1801133 polymorphisms in smokers. In conclusion, this meta-analysis indicated that MTRR rs1801394 was significantly associated with LC in smokers, and MTHFR rs1801133 polymorphisms was also significantly associated with LC in smokers and East Asians. These results suggested that these two polymorphisms could be used to identify individuals at high risk of developing LC in certain populations.

Associations between folate metabolism enzyme polymorphisms and breast cancer: A meta-analysis.

We performed this meta-analysis to explore associations between folate metabolism enzyme polymorphisms and breast cancer (BC) in a larger pooled population. Systematic literature research was performed to identify eligible studies for pooled analyses. Totally 92 genetic association studies were included for analyses. The pooled analyses revealed significant findings for MTRR rs1801394 polymorphism in South Asians, for MTR rs1805087 polymorphism in Caucasians and East Asians, and for MTHFR rs1801133 polymorphism in East Asians. In conclusion, the present meta-analysis indicated that MTRR rs1801394, MTR rs1805087, and MTHFR rs1801133 polymorphisms could be used to identify individuals at high risk of developing BC.