High risk of ‘de novo’ acute myeloid leukaemia in individuals with cytochrome P450 A1 (CYP1A1) and NAD(P)H:quinone oxidoreductase 1 (NQO1) gene defects

Associations of NQO1 C609T and NQO1 C465T polymorphisms with acute leukemia risk: a PRISMA-compliant meta-analysis

Objective

The NAD(P)H:quinone oxidoreductase (NQO1) C609T and C465T polymorphisms have been widely thought to be associated with the risk of acute leukemia (AL) in recent years, but the correlations are still unclear. A meta-analysis is generally acknowledged as one of the best methods for secondary research, and so it was applied in this study with the aim of elucidating how the NQO1 C609T and C465T polymorphisms are related to the risk of AL.

Methods

Relevant studies were searched in the PubMed, EMBASE, CNKI, and Wanfang databases, and the obtained data were analyzed using Stata (version 12.1). The allele-contrast model was applied, and odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate relationship strengths. Meta-regression was used to identify sources of heterogeneity, and subgroup analyses were conducted. Publication bias was analyzed using funnel plots, with the trim-and-fill method used to analyze the effect of publication bias on pooled results. In addition, sensitivity analysis, the fail-safe number method, and cumulative analysis by publication year were performed to measure the stability of the obtained results.

Results

This meta-analysis included 28 relevant studies involving 5,953 patients and 8,667 controls. Overall, the C609T polymorphism was associated with the risk of acute lymphoblastic leukemia (ALL; OR =1.18, 95% CI =1.00–1.39, P=0.05). Meanwhile, race was found to be a potential source of heterogeneity for the relationship between the C609T polymorphism and acute myeloid leukemia (AML) risk, and the subgroup analysis identified the C609T polymorphism as a risk factor for AML in Asians (OR =1.34, 95% CI =1.03–1.74, P=0.03). The number of studies about C465T polymorphism was too small to pool the data.

Conclusion

There are increased risks of ALL in all subjects and of AML in Asians for carriers of the NQO1 C609T polymorphism. Further studies are needed to verify the associations of the C465T polymorphism with the risk of AL.

Genetic polymorphisms of CYP1A1 and risk of leukemia: a meta-analysis

The associations between CYP1A1 polymorphisms and risk of leukemia have been studied extensively, but the results have been inconsistent. Therefore, in this study, we performed a meta-analysis to clarify associations of three CYP1A1 polymorphisms (T3801C, A2455G, and C4887A) with the risks of acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). Medline, EMBASE, and China National Knowledge Infrastructure databases were searched to collect relevant studies published up to April 20, 2015. The extracted data were analyzed statistically, and pooled odds ratios with 95% confidence intervals were calculated to quantify the associations. Overall, 26 publications were included. Finally, T3801C was associated with an increased risk of AML in Asians under the dominant model. For A2455G, the risk of ALL was increased among Caucasians in the recessive model and the allele-contrast model; A2455G was also associated with an increased risk of CML among Caucasians under the recessive model, dominant model, and allele-contrast model. For C4887A, few of the included studies produced data. In conclusion, the results suggest that Asians carrying the T3801C C allele might have an increased risk of AML and that Caucasians with the A2455G GG genotype might have an increased risk of ALL. Further investigations are needed to confirm these associations.

Effects of the NQO1 609C>T polymorphism on leukemia susceptibility: evidence from a meta-analysis

A functional polymorphism in the NQO1 gene, featuring a 609C>T substitution,leading to proline to serine amino-acid and enzyme activity changes, has been implicated in cancer risk. However, individually published investigations showed inconclusive results, especially for leukemia. In this study, we therefore performed a meta- analysis of 21 publications with a total of 3,634 cases and 4,827controls, mainly for leukemia. We summarized the data on the association between the NQO1 609C>T polymorphism and risk of leukemia and performed subgroup analyses by ethnicity and leukemia type. We found that the variant TT homozygous genotype o was associated with a modestly increased risk of leukemia (TT versus CT/CC: OR = 1.23, 95%CI = 1.00 - 1.51, heterogeneity = 0.76; I2 = 0%). Following further stratified analyses, increased risk was only observed in subgroups of Caucasians. This meta-analysis suggests that the NQO1 609T allele is a high-penetrance risk factor for leukemia in Caucasians. The effect on leukemia may be modified by ethnicity and leukemia type, and the small sample sizes of the subgroup analyses suggest that further larger studies are needed.

A meta-analysis of the association between NQO1 C609T variation and acute myeloid leukemia risk

Quinone oxidoreductase (NQO1) C609T polymorphisms have been implicated in acute myeloblastic leukemia (AML) risk, but previously published studies are inconsistent and recent meta-analyses have not been adequate. To derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, and Web of Science were searched. The quality of studies was evaluated by using the Newcastle-Ottawa Scale (NOS). Crude ORs with 95% CIs were used to assess the strength of association between the NQO1 C609T polymorphisms and AML risk. A total of 14 studies including 2,245 cases and 3,310 controls were involved in this meta-analysis. Overall, significantly elevated AML risk was associated with NQO1 C609T variant genotypes when all studies were pooled into the meta-analysis (TT vs. CC: OR = 1.44, 95% CI = 1.15-1.81; dominant model: OR = 1.35, 95% CI = 1.09-1.68). In the subgroup analysis by ethnicity, significantly increased risks were found for Asians (OR = 1.47, 95% CI = 1.13-1.93, P = 0.005, I(2) = 48.4%, P = 0.071 for heterogeneity). When stratified by studies of adults or children, statistically significantly elevated risks were found among adults (OR = 1.37, 95% CI = 1.06-1.76, P = 0.017, I(2) = 42.2%, P = 0.097 for heterogeneity). The accumulated evidence indicates that NQO1 C609T seems to confer a risk factor for AML among Asians and adults. Significant between-study heterogeneity was observed, thus more studies based on larger case-control population are required to further evaluate the role of NQO1 C609T polymorphism in AML.

Novel insights into etiologies of leukemia: a HuGE review and meta-analysis of CYP1A1 polymorphisms and leukemia risk

We conducted a meta-analysis to investigate the association of 2 single nucleotide polymorphisms in the cytochrome P450, family 1, subfamily 1A1 gene (CYP1A1), CYP1A1*2A and CYP1A1*2C, with the risk of developing different subtypes of leukemia in adults and children. A total of 26 studies published between 1999 and 2011 were identified by searching the PubMed, EMBASE, Medline, and Web of Science databases. The odds ratios for the CYP1A1 polymorphisms and leukemia risk were calculated. The cumulative evidence in genetic associations was graded by using the Venice criteria of the Human Genome Epidemiology Network (Atlanta, Georgia). The results showed that the cumulative evidence was moderate for the association of the CYP1A1*2A variant with leukemia in Caucasians and with childhood acute lymphoid leukemia in Caucasians. In addition, there was moderate evidence that children who carry both the CYP1A1*2A variant and the glutathione S-transferase M1 null genotype have an increased risk of acute lymphoid leukemia. For the CYP1A1*2C polymorphism, the cumulative evidence of an association with leukemia risk was moderate for adults and weak for children. Logistic regression analysis demonstrated an interaction between the CYP1A1*2C polymorphism and age. This meta-analysis showed that the CYP1A1*2A and CYP1A1*2C polymorphisms were associated with an increased risk of leukemia, and that the associations might vary by ethnicity, gene-gene interactions, age, and leukemia subtype.

Association between CYP1A1 Ile462Val variation and acute leukemia risk: meta-analyses including 2164 cases and 4160 controls

BACKGROUND

Previously, CYP1A1 Ile462Val polymorphism has been indicated to be a risk factor for several malignancies. Increasing reports have focused on the association of CYP1A1 Ile462Val polymorphisms with susceptibility to acute leukemia and have generated controversial results. The goal of the present study was to derive a more precise estimation of the relationship.

METHODS

Relevant literature has been rigorously searched and screened. Eligible studies were identified for the period up to Apr 2012. Meta-analyses evaluating the association of CYP1A1 Ile462Val variation with acute leukemia were carried out. Subgroup analyses on ethnicity, clinical types and source of controls were further performed.

RESULTS

A total of thirteen publications including fourteen case-control studies with 2164 cases and 4160 controls were selected for analysis. The overall data indicated a significant association of CYP1A1 Ile462Val polymorphism with acute leukemia risk (Val/Val vs Ile/Ile OR = 1.49; 95% CI = 1.11-1.98; dominant model: OR = 1.26; 95% CI = 1.05-1.51; recessive model: OR = 1.38; 95% CI = 1.04-1.83). In subgroup analysis on ethnicity, increased risk was shown among mixed ethnicities (Val/Val vs Ile/Ile: OR = 2.36; 95% CI = 1.46-3.82; dominant model: OR = 1.37; 95% CI = 1.01-1.86; recessive model: OR = 2.20; 95% CI = 1.37-3.53) but not Asians or Caucasians. In subgroup analysis on clinical types, increased risk was observed in the acute lymphocytic leukemia (ALL) subgroup (Val/Val vs Ile/Ile: OR = 2.06; 95% CI = 1.42-3.01; recessive model: OR = 1.91; 95% CI = 1.32-2.76) but not in the acute myeloid leukemia (AML) subgroup.

CONCLUSION

The results of the present study suggest that CYP1A1 Ile462Val polymorphism might be a low-penetrant risk factor for acute leukemia. Subgroup analyses suggest that homozygous Val/Val alleles might modify the susceptibility to ALL.

CYP1A1 MspI polymorphism and acute myeloid leukemia risk: meta-analyses based on 5018 subjects

Background

Evidence indicates that CYP1A1 MspI polymorphism might be a possible risk factor for several malignancies. A growing body of literature has been devoted to the association of CYP1A1 MspI polymorphism with acute myeloid leukemia (AML). However, the results remain conflicting. The aim of the present study was to derive a more precise estimation of the relationship.

Methods

Meta-analyses assessing the association of CYP1A1 MspI variation with AML were conducted and subgroup analyses on ethnicity and age groups were further performed. Eligible studies were identified for the period up to May 2012.

Results

A total of ten case–control studies including 1330 cases and 3688 controls were selected for analysis. The overall data failed to indicate a significant association of CYP1A1 MspI polymorphism with AML risk (C vs T: OR = 1.13; 95%CI = 0.87-1.48; CC vs TT: OR = 1.72; 95%CI = 0.99-3.01; CC + TC vs TT: OR = 1.16; 95%CI = 0.86-1.55). In subgroup analysis stratified by ethnicity, significant AML risk was shown among Asians (CC + TC vs TT: OR = 1.33; 95%CI = 1.09-1.62) but not Caucasians or mixed races. In subgroup analysis regarding age groups, no associations were observed in either the childhood AML or the adult AML subgroups.

Conclusion

The results of the present study suggested that CYP1A1 MspI polymorphism might be a risk factor for AML among Asians. Further investigations are needed to confirm the conclusions.