Association between NAT2 polymorphisms and acute leukemia risk: A meta-analysis

The rs1801280 SNP is associated with non-small cell lung carcinoma by exhibiting a highly deleterious effect on N-acetyltransferase 2

PURPOSE

N-acetyltransferase 2 is an enzyme that is involved in the detoxification of carcinogens in the human body, so any damage to this protein may lead to the emergence of several metabolic dysfunctions. This work was conducted to determine the association between NAT2 polymorphism and non-small cell lung carcinoma (NSCLC) that is increasingly reported in the Iraqi population.

METHODS

PCR sequencing was conducted to assess the possible association between genetic variants and NSCLC. Several in silico tools were implemented to investigate the effect of the observed SNPs on the structure, function, and stability of the altered NAT2.

RESULTS

Five SNPS of NAT2 (rs1208, rs1041983, rs1799929, rs1799930, and rs1801280) were identified in high frequencies in the amplified fragment. These SNPs showed variable distributions of haplotypes between cases and controls. No significant association of rs1208, rs1041983, rs1799929, and rs1799930 with NSCLC was shown in the investigated population. In contrast, rs1801280: CC genotype showed a highly significant (P = 0.009) association with the NSCLC, and individuals with this genotype had 2.19 more chances for developing NSCLC (OR 2.19; Cl_95% 1.21-3.94). Association analysis of rs1801280 SNP distribution among the investigated patients showed that patients with CC genotype showed a significant (P = 0.02, OR 2.65) association with family history, which entailed a high hereditary possibility of this genotype among Iraqi patients. It was predicted that this SNP showed high damaging effects on the activity of NAT2 enzyme, with various deleterious outcomes on enzyme structure, function, and stability.

CONCLUSION

Data indicated that rs1801280 SNP exerted a tight association with NSCLC since individuals with CC genotype exhibited the most damaging effects on the NAT2 that may be behind the low acetylation rates of this enzyme in patients with NSCLC.

Predictive role of polymorphic variants of phase II drug metabolising enzyme in modulating toxicity in North Indian lung cancer patients undergoing chemotherapy

Genetic polymorphism of drug-metabolizing enzymes such as NQO1, SULT1A1, EPHX1, and NAT2 alters its activity which hampers the detoxification and disposal of chemotherapeutic compounds. Thus, in the present study, we have comprehensively investigated the associations between SNPs of the Phase II detoxifying genes and its relationship towards platinum-induced toxicity of lung cancer patients.A total of 273 samples were enrolled in this study and polymorphisms of gene NQO1 (609C > T), SULT1A1 (Arg²¹³ His), EPHX1 (Tyr¹¹³His, His¹³⁹Arg), and NAT2 (481C > T, 803A > G, 590 G > A, 857 G > A) were evaluated in our study for their associated adverse events caused due to the administration of platinum-based chemotherapy to the lung cancer patients.For NQO1 609C > T polymorphism, the TT genotype showed reduced risk of constipation (OR =0.10, p=0.04) and anorexia (OR =0.15, p=0.03). For SULT1A1 Arg²¹³His, heterozygous genotype (Arg/His) (AOR =0.38, p=0.006) and combined genotype (Arg/His + His/His) were not associated with increased risk of nephrotoxicity (AOR =0.38, p= 0.004). For NAT2, heterozygous (NAT2*4/*6) and combined genotypes (NAT2*4/*4 + *4/*6) for NAT2*6 polymorphism exhibit 2.4 folds (p=0.005), and two-folds (p=0.01) increased risk of hematological toxicity. The heterozygous (AOR =0.45, p=0.004) and variant genotype (AOR =0.39, p=0.02) for NAT2*5C had decreased risk for hematological toxicity. The heterozygous genotype for NAT2*7 polymorphism showed two-fold increased risk for developing thrombocytopenia.This study provides association of NAT2 polymorphic variants in predicting haematological toxicity.

Role of N-acetyltransferase 2 gene polymorphism in the human pathology

Nowadays multiple heterogeneous chemicals affect the human body. They include drugs, household chemicals, dyes, food supplements and others. The human organism can modify, inactivate, and eliminate the chemicals by biotransformation enzymes. But it is well known that biotransformation can lead to toxification phenomenon. Individuals differ from each other by the rate of chemical modification that promotes accumulation of toxins and carcinogens in some patients. An N-acetyltransferase 2 enzyme participates in the aromatic amines second phase metabolism. This work reviews the acetyltransferase gene polymorphism possible role in diseases development including drug-induced organs damage.

Gene of acetyltransferase has polymorphisms associated with two haplotypes of  fast and slow substrate acetylation. Gene alleles combine in three genotypes: fast, intermediate, and slow acetylators. Acetylation rate plays a significant role in side effects development during tuberculosis treatment and cancer pathogenesis. Recently, new data described the role of enzyme in development of non-infectious diseases in the human. Scientists consider that slow acetylation genotype in combination with high xenobiotic load result in accumulation of toxic substances able to damage cells.

Therefore, acetyltransferase genotyping helps to reveal risk groups of cancer and non-infectious disease development and to prescribe more effective and safe doses of drugs. 

[N-aсetyltransferase (NAT2) gene polymorphism and gene network analysis]

To search for new targets of therapy, it is necessary to reconstruct the gene network of the disease, and identify the interaction of genes, proteins, and drug compounds. Using the online bioinformatics tools we have analyzed the current data set related to the metabolism of xenobiotics, mediated by the N-acetyltransferase 2 (NAT2) gene. The study of allelic polymorphism of the NAT2 gene has a prognostic value, allowing to determine the risk of a number of oncological diseases, the degree of increased risk due to smoking and exposure to chemical carcinogens, including drugs. The aim of this study was to determine the frequencies of two important "slow" variants of the NAT2 gene (NAT2*5, rs1801280 and NAT2*7, rs1799931), which significantly affected the rate of xenobiotic acetylation among the indigenous Nenets population of Northern Siberia. The obtained frequencies of polymorphic variants among the Nenets occupy an intermediate value between those for Europeans and Asians, which might indicate specific features of adaptation. We present a model of the distribution of two polymorphic variants of the NAT2 gene involved in the biotransformation of xenobiotics to study the characteristics of their metabolism in the indigenous inhabitants of Yamal.

Evaluation of Genetic Polymorphisms of N-acetyltransferase 2 and Relation with Chronic Myeloid Leukemia

OBJECTIVES

The N-Acetyltransferase 2 (NAT2) gene encodes a key enzyme involved in xenobiotic metabolism, which contributes to the detoxification of numerous cancer therapy-induced products. However, the NAT2 genotype/phenotype is not fully understood and few studies have reported its relationship with CML. The aim of this study was to determine whether its polymorphisms (C481T, G590A, 803A>G and 857G>A) have a role in chronic myeloid leukemia susceptibility (CML) in Sudanese population.

METHODS

We performed a case- control study. DNA from 200 CML patients and 100 controls was analyzed for the NAT2 polymorphisms using PCR-RFLP assay.

RESULTS

The study showed NAT2 polymorphisms 803AG are associated with CML protection by a factor of 2.3, (OR = 0.044, 95% CI: 0.020-0.095, p = 0. 000). The study indicated that the heterozygous (GA) and mutant (AA) variants of the G857A genotype also offer protection, (OR = 0.002, 95% CI: 0.002-0.019, p = 0. 000) and (OR = 0.018, 95% CI: 0.002-0.133, p = 0. 000), respectively.

CONCLUSION

There was no significant difference in CML diagnosis among Sudanese cases with the 481C→T and 590G→A polymorphisms. But patients with the compound NAT2 genotypes 481CT/803 AG, 590AG/ 803AG, 590AG/ 803GG, 590AA/ 803AG and 590GG/ 803AG were found to have a reduced risk. The current study demonstrates that polymorphisms of NAT2 A803G and G857A might also act as protective factors against developing the disease.

Genotype-Environment Interaction Analysis of NQO1, CYP2E1, and NAT2 Polymorphisms and the Risk of Childhood Acute Lymphoblastic Leukemia: A Report From the Mexican Interinstitutional Group for the Identification of the Causes of Childhood Leukemia

Background: Acute lymphoblastic leukemia (ALL) is the main type of cancer in children. In Mexico and other Hispanic populations, the incidence of this neoplasm is one of the highest reported worldwide. Functional polymorphisms of various enzymes involved in the metabolism of xenobiotics have been associated with an increased risk of developing ALL, and the risk is different by ethnicity. The aims of the present study were to identify whether NQO1, CYP2E1, and NAT2 polymorphisms or some genotype-environmental interactions were associated with ALL risk in Mexican children.

Methods: We conducted a case-control study including 478 pediatric patients diagnosed with ALL and 284 controls (children without leukemia). Ancestry composition of a subset of cases and controls was assessed using 32 ancestry informative markers. Genetic-environmental interactions for the exposure to hydrocarbons were assessed by logistic regression analysis.

Results: The polymorphisms rs1801280 (OR 1.54, 95% CI 1.21–1.93), rs1799929 (OR 1.96, 95% CI 1.55–2.49), and rs1208 (OR 1.44, 95% CI 1.14–1.81) were found to increase the risk of ALL; being the risks higher under a recessive model (OR 2.20, 95% CI 1.30–1.71, OR 3.87, 95% CI 2.20–6.80, and OR 2.26, 95% CI 1.32–3.87, respectively). Gene-environment interaction analysis showed that NAT2 rs1799929 TT genotype confers high risk to ALL under exposure to fertilizers, insecticides, hydrocarbon derivatives, and parental tobacco smoking. No associations among NQO1, CYP2E1, and ALL were observed.

Conclusion: Our study provides evidence for the association between NAT2 polymorphisms/gene-environment interactions, and the risk of childhood ALL in Mexican children.

Genetic variants in xenobiotic detoxification enzymes, antioxidant defenses and hormonal pathways as biomarkers of susceptibility to prostate cancer

Cancer is considered a complex disease that in many cases results from the interaction between chemical exposures, either from environmental or dietary sources, and genetic polymorphisms of xenobiotic-metabolizing enzymes (XME) or antioxidant enzymatic defenses. This study explored associations and interactions between genetic and environmental risk factors on the risk of prostate cancer (PCa) in 323 subjects that underwent prostate biopsy due to prostate specific antigen (PSA) levels above 4 ng/ml (161 PCa and 162 non-PCa). Eleven genes involved directly or indirectly in xenobiotic detoxification, oxidative stress and estrogen signaling were studied (GSTM1, GPX1 (rs1050450 and rs17650792), NAT2 (rs1801280), TXNRD1 (rs7310505), PRDX3 (rs3740562), CYP17A1 (rs743572), PON1 (rs662), SOD1 (rs10432782), SOD2 (rs4880), CAT (rs1001179), and ESR1 (rs746432)). A structured questionnaire was administered to all individuals to assess environmental and dietary chemical exposures. Medical data was collected by urologists. GPX1 rs17650792 polymorphism was the only one showing a significant inverse association with PCa risk. PRDX3 and GPX1 (rs17650792) genetic polymorphisms were significantly associated with Gleason score and PSA levels, respectively. The intake of nuts and soya products was associated with a reduced risk of PCa, as well as the performance of physical activity. Moreover, a number of gene-environmental interactions were found to increase the risk of PCa, particularly exposure to pesticides and rs1801280 (NAT2) and tobacco smoking and rs1050450 (GPX1). These findings suggest that the association of genetic and environmental risk factors with PCa risk should be assessed jointly for a better understanding of this complex disease.

Study on Genotyping Polymorphism and Sequencing of N-Acetyltransferase 2 (NAT2) among Al-Ahsa Population

One of the well-studied phase II drug metabolizing enzymes is N-acetyltransferase 2 (NAT2) which has an essential role in the detoxification and metabolism of several environmental toxicants and many therapeutic drugs like isoniazid (antituberculosis, TB) and antimicrobial sulfonamides. According to the variability in the acetylation rate among different ethnic groups, individuals could be classified into slow, intermediate, and fast acetylators; these variabilities in the acetylation rate are a result of single nucleotide polymorphisms (SNPs) in the coding sequence of NAT2. The variety of NAT2 acetylation status is associated with some diseases such as bladder cancer, colorectal cancer, rheumatoid arthritis, and diabetes mellitus. The main objectives of this research are to describe the genetic profile of NAT2 gene among the people of the Al-Ahsa region, to detect the significant SNPs of this gene, to determine the frequency of major NAT2 alleles and genotypes, and then categorize them into fast, intermediate, and slow acetylators. Blood samples were randomly collected from 96 unrelated people from Al-Ahsa population, followed by DNA extraction then amplifying the NAT2 gene by polymerase chain reaction (PCR); finally, functional NAT2 gene (exon 2) was sequenced using the Sanger sequencing method. The well-known seven genetic variants of NAT2 gene are 191G>A, 282C>T, 341T>C, 481C>T, 590G>A, 803A>G, and 857G>A were detected with allele frequencies 1%, 35.4%, 42.7%, 41.1%, 29.2%, 51%, and 5.7%, respectively. The most common NAT2 genetic variant among Al-Ahsa population was 803A>G with a high frequency 0.510 (95% confidence interval 0.44-0.581) followed by 341T>C 0.427 (95% confidence interval 0.357-0.497). The most frequent two haplotypes of NAT2 were NAT2∗6C (25.00%) and NAT2∗5A (22.92%) which were classified as a slow acetylators. According to trimodal distribution of acetylation activity, the predicted phenotype of Al-Ahsa population was found to be 5.21% rapid acetylators, 34.38% intermediate acetylators, and 60.42% were slow acetylators. In addition, this study found four novel haplotypes NAT2∗5TB, NAT2∗5AB, NAT2∗5ZA, and NAT2∗6W which were slow acetylators. This study revealed a high frequency of the NAT2 gene with slow acetylators (60.42%) in Al-Ahsa population, which might alter the drug's efficacy and vulnerability to some diseases.