Exploring the role of N-acetyltransferases in diseases:a focus on N-acetyltransferase 9 in neurodegeneration

Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and disease.Protein acetylation is a common post-translational modification pivotal to basic cellular processes.Close to 80%-90%of proteins are acetylated during translation,which is an irreversible process that affects protein structure,function,life,and localization.In this review,we have discussed the various N-acetyltransferases present in humans,their function,and how they might play a role in diseases.Furthermore,we have focused on N-acetyltransferase 9 and its role in microtubule stability.We have shed light on how N-acetyltransferase 9 and acetylation of proteins can potentially play a role in neurodegenerative diseases.We have specifically discussed the N-acetyltransferase 9-acetylation independent function and regulation of c-Jun N-terminal kinase signaling and microtubule stability during development and neurodegeneration.

Polymorphism of N-acetyltransferase 2 (NAT2) Gene Polymorphism in Shanghai population: Occupational and Non-occupational Bladder Cancer Patient Groups

Objective Arylamine N-acetyltransferases (NATs) are involved in the detoxification of aromatic amines and hydrazine. In order to explore the possible association of NAT2 polymorphism with bladder cancer risk in benzidine exposed or non-exposed Chinese individuals, healthy subjects, subjects with bladder cancer of a former benzidine exposed cohort in Shanghai dyestuff industry and a group of bladder cancer patients without known occupational exposure to aromatic amines were genotyped for NAT2 gene polymorphism. Methods NAT2 genotyping was performed with a set of RFLP procedures at seven major polymorphic loci of gene coding area: G191A, C282T, T341C, C481T, G590A, A803G and G857A. Results The wild allele NAT2 *4 was the most prevalent allele (59%) in healthy individuals. The alleles NAT2*6A and NAT2*7B were also frequently observed (21% and 17%, respectively). In contrast to Caucasians, the percentage of slow acetylators was lower (12% in Chinese vs. 58% in Caucasians, P<0.001). No relevant differences were observed for homogenous rapid, heterogeneous rapid/slow and homogeneous slow acetylation genotypes between the healthy subjects and both groups of bladder cancer patients. Conclusion The present work did not support the association of slow acetylating genotypes of NAT2 gene with elevated risk of bladder cancer in Chinese whereas it was documented as an important genetically determined risk factor in Caucasians. Different mechanisms might play a role in individual susceptibility to bladder cancer related with aromatic amine exposure in various races or ethnic groups.

Crohn's disease in Japanese is associated with a SNP-haplotype of N-acetyltransferase 2 gene

AIM： To investigate the frequency and distribution of /V-acetyltransferase 2 （NAT2） and uridine 5＇-diphosphate （UDP）-glucuronosyltransferase 1A7 （UGT1A7） genes in patients with ulcerative colitis （UC） and Crohn＇s disease （CD）. METHODS： Frequencies and distributions of IVAT2 and UGT1A7SNPs as well as their haplotypes were investigated in 95 patients with UC, 60 patients with CD, and 200 gender-matched, unrelated, healthy, control volunteers by PCR-restriction fragment length polymorphism （RFLP）, PCR-denaturing high-performance liquid chromatography （DHPLC）, and direct DNA sequencing. RESULTS： Multiple logistic regression analysis revealed that the frequency of haplotype, NAT2＊7B, significantly increased in CD patients, compared to that in controls （P= 0.0130, OR = 2.802, 95%CI = 1.243-6.316）. However, there was no association between NAT2 haplotypes and UC, or between any UGT1A7haplotypes and inflammatory bowel disease （IBD）. CONCLUSION： It is likely that the NAT2 gene is one ofthe determinants for CD in Japanese. Alternatively, a new CD determinant may exist in the 8p22 region, where NAT2 is located.

N-Acetyltransferase 2 genetic polymorphisms and risk of colorectal cancer

AIM:To investigate the possible association between meat intake,cigarette smoking and N-acetyltransferase 2 (NAT2) genetic polymorphisms on colorectal cancer (CRC) risk.METHODS:Patients with CRC were matched for gender and age to healthy controls.Meat intake and cigarette smoking were assessed using a specific frequency questionnaire.DNA was extracted from peripheral blood and the genotypes of the polymorphism were assessed by polymerase chain reaction-restriction fragment length polymorphism.Five NAT2 alleles were studied (WT,M1,M2,M3 and M4) using specific digestion enzymes.RESULTS:A total of 147 patients with colorectal cancer (76 women and 90 men with colon cancer) and 212 controls were studied.The mean age of the two groups was 62 years.More than half the subjects (59.8% in the case group and 51.9% in the control group) were NAT2 slow acetylators.The odds ratio for colorectal cancer was 1.38 (95% CI:0.90-2.12) in slow acetylators.Although the number of women was small (n=76 in the case group),the cancer risk was found to be lower in intermediate (W/Mx) acetylators [odds ratio (OR):0.55,95% confidence interval (95% CI):0.29-1.02].This difference was not observed in men (OR:0.56,95% CI:0.16-2.00).Among NAT2 fast acetylators (W/W or W/Mx),meat consumption more than 3 times a week increased the risk of colorectal cancer (OR:2.05,95% CI:1.01-4.16).In contrast,cigarette smoking increased the risk of CRC among slow acetylators (OR:1.97,95% CI:1.02-3.79).CONCLUSION:The risk of CRC was higher among fast acetylators who reported a higher meat intake.Slow NAT2 acetylation was associated with an increased risk of CRC.

Are polymorphisms of N-acetyltransferase genes susceptible to primary liver cancer in Luoyang, China?

AIM: To identify whether the polymorphisms of the Nacetyltransferase (NAT) genes are susceptible to primary liver cancer (PLC) in Luoyang, a PLC low-incidence area of China.METHODS: The NAT1 and NAT2 genotypes of 96 PLC cases and 173 controls were determined by PCR-RFLP.Both interaction between NAT1 or NAT2 and environmental risk factors were analyzed based on case control study.RESULTS: Compared to the control group, the frequencies of alleles NAT1*3, NAT1*4, NAT1*10, NAT1*14B and alleles NAT2*4, NAT2*6, NAT2*7 in PLC group showed no statistically significant difference (x2 = 2.61 and 4.16,respectively, both P＞0.05). The frequencies of NAT1 genotypes NAT1*3/*3, NAT1*3/*4, NAT1*3/*10,NAT1*3/*14B, NAT1*4/*4, NAT1*4/*10, NAT1*4/*14B,NAT1*10/*10, NAT1*10/*14B, and NAT2 genotypes NAT2*4/*4, NAT2*4/*6, NAT2*4/*7, NAT2*6/*6,NAT2*6/*7 and NAT2*7/*7 also had no statistically significant difference between the two groups (x2 = 11.86 and 2.94respectively both, P＞0.05). Neither the frequencies of rapid and slow NAT1 acetylators nor the frequencies of rapid and slow NAT2 acetylators were significantly different between the two groups (x2 = 0.598 and 0.44,respectively, both P＞0.05). The interaction betweenNAT1*10 and occupational exposures was found significant with an odds ratio of 3.40 (x2 = 8.42, P = 0.004,OR 95%CI:1.03-11.22). But no interaction was found between NAT2 and any environmental risk factors.CONCLUSION: The polymorphisms of NAT1 and NAT2are not susceptible to PLC in Luoyang. Allele NAT1*10interacts with occupational exposures.

Inflammatory cytokines suppress arylamine N-acetyltransferase 1 in cholangiocarcinoma cells

AIM： To evaluate the effect of inflammatory cytokines on arylamine N-acetyltransferase 1 （NAT1）, which is a phase-U enzyme involved in the biotransformation of aromatic and heterocyclic amines found in food, drugs and the environment. METHODS： Human cholangiocarcinoma KKU-100 cells were treated with a mixture of proinflammatory cytokines （interferon-7, interleukin-l and tumor necrosis factor-m） for 48 h, and the effect on NAT1 activity was assessed by high performance liquid chromatography, while NAT1 expression was determined by reverse-transcription polymerase chain reaction. The oxidative stress on the cells was examined by the formation of nitric oxide, superoxide anion and glutathione （GSH） levels. The cells were also treated with S-nitroso-glutathione （GSNO）, a nitric oxide donor, to see if the responses were similar to those obtained with the inflammatory cytokines. RESULTS： Cytokines suppressed NAT1 activity, reducing the Vmax without affecting the Am. Cytokines also had a significant impact on the induction of nitric oxide production and in reducing the redox ratios of glutathione （GSH） and GSH disulfide. Treatment with GSNO for 2-48 h reduced NAT1 activity without affecting the GSH ratio. Moreover, inflammatory cytokines and GSNO suppressed NAT1 mRNA expression. CONCLUSION： These findings indicate an association between inflammation and suppression of NAT1, which perhaps contributes to chemical-mediated toxicity and carcinogenesis,

Density Functional Theory Study on the Histidine-assisted Mechanism of Arylamine N-Acetyltransferase Acetylation

Arylamine N-acetyltransferases （NATs, EC 2.3.1.5） catalyze the N-acetylation of primary arylamines, and play a key role in the biotransformation and metabolism of drugs, carcinogens, etc. In this paper, three possible reaction mechanisms are investigated and the results indicate that if the acetyl group directly transfers from the donor to the acceptor, the high activation energies will make it hard to obtain the target products. When using histidine to mediate the acetylation process, these energies will drop in the 15-45 kJ/mol range. If the histidine residue is protonated, the corresponding energies will be decreased by about 35-87 kJ/mol. The calculations predict an enzymatic acetylation mechanism that undergoes a thiolate-imidazolium pair, which agrees with the experimental results very well.

Night-time Rise in Rat Pineal N-Acetyltransferase due to Carbaryl Administration Is Reduced by Propranolol Treatment

The purpose of the present study was to examine the effects of administration of sublethal doses of carbaryl on nighttime rat pineal melatonin synthesis in the presence and absence of propranolol, a β-adrenergic receptor antagonist. Two groups of adult male albino rats were administered orally N-methyl-l-naphthylcarbamate (carbaryl) (8. 33mg/kg BW daily in corn oil) for six successive days; another two groups received corn oil only.On the last day of carbaryl treatment, half of the animals received an intraperitoneal injection of propranolol (20 mg/kg body weight, one hour before lights off). The other two groups were given a saline injection. Four hours after darkness onset, pineal N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT) activities as well as pineal concentrations of 5-hydroxytryptophan (5HTP), serotonin (5HT),5-hydroxyindole acetic acid (5HIAA) and pineal and serum melatonin levels were measured. Nocturnal NAT activity was increased due to carbaryl administration but the pesticide was ineffective in stimulating NAT activity in rats treated with propranolol.Pineal 5HT was decreased due to carbaryl administration but 5HTP and 5HIAA levels were unaffected. Pineal and serum melatonin levels were decreased due to propranolol treatment. The results indicate that carbaryl may influence pineal NAT activity by a mechanism that involves β-adrenergic neural transmission.

N-acetyltransferase 2: Slow, intermediate or fast? A booming question of the molecular epidemiology in cancer research

Throughout history, humanity has referred to reactions occurring with food, plants and, recently, medicines or drugs. The increase in pulmonary tuberculosis cases and the availability of treatment showed that genetic human differences can interfere in the capacity to metabolize drugs. There are remarkable genetic polymorphisms of N-acetyltransferase 2 (NAT2) activity that have been associated with different levels of susceptibility to developing many kinds of cancers. This review considers the field as an open window for the application of molecular epidemiology tools that led to the development of pharmacogenomics. We cover historical data and the most recent knowledge about NAT2 genetic polymorphisms and its distribution in different populations, which is an important concept being incorporated in epidemiological studies of cancer risk. We present up to date information about these studies, including meta-analysis based on the NAT2 distribution in different types of cancer. A critical broad at advances in NAT2 research, high-lighting recent studies related to NAT2 alleles in cancer susceptibility. Although there are multifactorial aspects involved in cancer risk, the variability in NAT2 allelic frequency can be related to carcinogenesis through alterations in the metabolic rate after exposure to carcinogens.

N-acetyltransferase 10 promotes colon cancer progression by inhibiting ferroptosis through N4-acetylation and stabilization of ferroptosis suppressor protein 1 (FSP1) mRNA

Background:N-acetyltransferase 10(NAT10)is the only enzyme known tomediate the N4-acetylcytidine(ac4C)modification of mRNA and is crucial formRNA stability and translation efficiency.However,its role in cancer development and prognosis has not yet been explored.This study aimed to examine the possible role of NAT10 in colon cancer.Methods:The expression levels ofNAT10were evaluated by immunohistochemical analyses with a colon cancer tissue microarray,and its prognostic value in patients was further analyzed.Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blotting were performed to analyze NAT10 expression in harvested colon cancer tissues and cell lines.Stable NAT10-knockdown and NAT10-overexpressing colon cancer cell lines were constructed using lentivirus.The biological functions of NAT10 in colon cancer cell lines were analyzed in vitro by Cell Counting Kit-8(CCK-8),wound healing,Transwell,cell cycle,and ferroptosis assays.Xenograft models were used to analyze the effect of NAT10 on the tumorigenesis and metastasis of colon cancer cells in vivo.Dot blotting,acetylated RNA immunoprecipitation-qPCR,and RNA stability analyses were performed to explore the mechanism by which NAT10 functions in colon cancer progression.Results:NAT10 was upregulated in colon cancer tissues and various colon cancer cell lines.This increased NAT10 expression was associated with shorter patient survival.Knockdown of NAT10 in two colon cancer cell lines(HT-29 and LoVo)impaired the proliferation,migration,invasion,tumor formation and metastasis of these cells,whereas overexpression of NAT10 promoted these abilities.Further analysis revealed that NAT10 exerted a strong effect on the mRNA stability and expression of ferroptosis suppressor protein 1(FSP1)in HT-29 and LoVo cells.In these cells,FSP1 mRNA was found to be modified by ac4C acetylation,and this epigenetic modification was associated with the inhibition of ferroptosis.Conclusions:Our study revealed that NAT10 plays a critical role in colon cancer development by affecting FSP1 mRNA stability and ferroptosis,suggesting that NAT10 could be a novel prognostic and therapeutic target in colon cancer.

A pilot study of the modulation of sirtuins on arylamine N-acetyltransferase 1 and 2 enzymatic activity

Arylamine N-acetyltransferase(NAT; E.C. 2.3.1.5) enzymes are responsible for the biotransformation of several arylamine and hydrazine drugs by acetylation. In this process, the acetyl group transferred to the acceptor substrate produces NAT deacetylation and, in consequence, it is susceptible of degradation. Sirtuins are protein deacetylases, dependent on nicotine adenine dinucleotide,which perform post-translational modifications on cytosolic proteins. To explore possible sirtuin participation in the enzymatic activity of arylamine NATs, the expression levels of NAT1, NAT2,SIRT1 and SIRT6 in peripheral blood mononuclear cells(PBMC) from healthy subjects were examined by flow cytometry and Western blot. The in situ activity of the sirtuins on NAT enzymatic activity was analyzed by HPLC, in the presence or absence of an agonist(resveratrol) and inhibitor(nicotinamide) of sirtuins. We detected a higher percentage of positive cells for NAT2 in comparison with NAT1, and higher numbers of SIRT1t cells compared to SIRT6 in lymphocytes. In situ NAT2 activity in the presence of NAM inhibitors was higher than in the presence of its substrate, but not in the presence ofresveratrol. In contrast, the activity of NAT1 was not affected by sirtuins. These results showed that NAT2 activity might be modified by sirtuins.

Arylamine N-acetyltransferase 2 genotype-dependent N-acetylation of isoniazid in cryopreserved human hepatocytes

Cryopreserved human hepatocytes were used to investigate the role of arylamine N-acetyltransferase 2 (NAT2; EC 2.3.1.5) polymorphism on the N-acetylation of isoniazid (INH). NAT2 genotype was determined by Taqman allelic discrimination assay and INH N-acetylation was measured by high performance liquid chromatography. INH N-acetylation rates in vitro exhibited a robust and highly significant (P<0.005) NAT2 phenotype-dependent metabolism. N-acetylation rates in situ were INH concentration- and time-dependent. Following incubation for 24 h with 12.5 or 100 µmol/L INH, acetyl-INH concentrations varied significantly (P = 0.0023 and P = 0.0002) across cryopreserved human hepatocytes samples from rapid, intermediate, and slow acetylators, respectively. The clear association between NAT2 genotype and phenotype supports use of NAT2 genotype to guide INH dosing strategies in the treatment and prevention of tuberculosis.

Identification of arylamine N-acetyltransferase inhibitors as an approach towards novel anti-tuberculars

New anti-tubercular drugs and drug targets are urgently needed to reduce the time for treatment and also to identify agents that will be effective against Mycobacterium tuberculosis persisting intracellularly.Mycobacteria have a unique cell wall.Deletion of the gene for arylamine N-acetyltransferase(NAT)decreases mycobacterial cell wall lipids,particularly the distinctive mycolates,and also increases antibiotic susceptibility and killing within macrophage of Mycobacterium bovis BCG.The nat gene and its associated gene cluster are almost identical in sequence in M.bovis BCG and M.tuberculosis.The gene cluster is essential for intracellular survival of mycobacteria.We have therefore used pure NAT protein for high-throughput screening to identify several classes of small molecules that inhibit NAT activity.Here,we characterize one class of such molecules—triazoles—in relation to its effects on the target enzyme and on both M.bovis BCG and M.tuberculosis.The most potent triazole mimics the effects of deletion of the nat gene on growth,lipid disruption and intracellular survival.We also present the structure-activity relationship between NAT inhibition and effects on mycobacterial growth,and use ligand-protein analysis to give further insight into the structure-activity relationships.We conclude that screening a chemical library with NAT protein yields compounds that have high potential as anti-tubercular agents and that the inhibitors will allow further exploration of the biochemical pathway in which NAT is involved.

Probing the architecture of the Mycobacterium marinum arylamine N-acetyltransferase active site

Treatment of latent tuberculosis infection remains an important goal of global TB eradication.To this end,targets that are essential for intracellular survival of Mycobacterium tuberculosis are particularly attractive.Arylamine N-acetyltransferase(NAT)represents such a target as it is,along with the enzymes encoded by the associated gene cluster,essential for mycobacterial survival inside macrophages and involved in cholesterol degradation.Cholesterol is likely to be the fuel for M.tuberculosis inside macrophages.Deleting the nat gene and inhibiting the NAT enzyme prevents survival of the microorganism in macrophages and induces cell wall alterations,rendering the mycobacterium sensitive to antibiotics to which it is normally resistant.To date,NAT from M.marinum(MMNAT)is considered the best available model for NAT from M.tuberculosis(TBNAT).The enzyme catalyses the acetylation and propionylation of arylamines and hydrazines.Hydralazine is a good acetyl and propionyl acceptor for both MMNAT and TBNAT.The MMNAT structure has been solved to 2.1Åresolution following crystallisation in the presence of hydralazine and is compared to available NAT structures.From the mode of ligand binding,features of the binding pocket can be identified,which point to a novel mechanism for the acetylation reaction that results in a 3-methyltriazolo[3,4-a]phthalazine ring compound as product.

Evolutionary genomics analysis reveals gene expansion and functional diversity of arylalkylamine N-acetyltransferases in the Culicinae subfamily of mosquitoes

Arylalkylamine N-acetyltransferase(aaNAT),considered a potential new insecticide target,catalyzes the acetylation of arylalkylamine substrates such as serotonin and dopamine and,hence,mediates diverse functions in insects.However,the origin of insect aaNATs(iaaNATs)and the evolutionary process that generates multiple aaNATs in mosquitoes remain largely unknown.Here,we have analyzed the genomes of 33 species to explore and expand our understanding of the molecular evolution of this gene family in detail.We show that aaNAT orthologs are present in Bacteria,Cephalochordata,Chondrichthyes,Cnidaria,Crustacea,Mammalia,Placozoa,and Teleoste,as well as those from a number of insects,but are absent in some species of Annelida,Echinozoa,and Mollusca as well as Arachnida.Particularly,more than 10 aaNATs were detected in the Culicinae subfamily of mosquitoes.Molecular evolutionary analysis of aaNAT/aaNAT-like genes in mosquitoes reveals that tandem duplication events led to gene expansion in the Culicinae subfamily of mosquitoes more than 190 million years ago.Further selection analysis demonstrates that mosquito aaNATs evolved under strongly positive pressures that generated functional diversity following gene duplication events.Overall,this study may provide novel insights into the molecular evolution of the aaNAT family in mosquitoes.

Arylalkalamine N-acetyltransferase-1 functions on cuticle pigmentation in the yellow fever mosquito,Aedes aegypti

Arylalkylamine N-acetyltransferase(aaNAT)catalyzes the acetylation of dopamine,5-hydroxy-tryptamine,tryptamine,octopamine,norepinephrine and other ary-lalkylamines to form respective N-acetyl-arylalkylamines.Depending on the products formed,aaNATs are involved in a variety of physiological functions.In the yellow fever mosquito,Aedes aegypti,a number of aaNATs and aaNAT-like proteins have been reported.However,the primary function of each individual aaNAT is yet to be identified.In this study we investigated the function of Ae.aegypti aaNAT 1(Ae-aaNATl)in cuticle pigmentation and development of morphology.Ae-aaNAT1 transcripts were detected at all stages of development with highest expressions after pupation and right before adult eclosion.Ae-aaNATl mutant mosquitoes generated using clustered regularly interspaced palindromic repeats(CRISPR)-CRISPR-associated protein 9 had no obvious effect on larval and pupal development.However,the mutant mosquitoes exhibited a roughened ex-oskeletal surface,darker cuticles,and color pattern changes suggesting that Ae-aaNAT1 plays a role in development of the morphology and pigmentation of Ae.aegypti adult cuticles.The mutant also showed less blood feeding efficiency and lower fecundity when compared with the wild-type.The mutation of Ae-aaNAT1 influenced expression of genes involved in cuticle formation.In summary,Ae-aaNAT1 mainly functions on cuticular pigmentation and also affects blood feeding efficiency and fecundity.

What a Role did Histidine Residue Play in Arylamine N-Acetyltransferase 2 Acetylation？ A Quantum Chemistry Study

Arylamine N-acetyltransferases （NATs, EC 2.3.1.5） catalyze an acetyl group transfer from acetyl coenzyme A （AcCoA） to primary arylamines and play a very important role in the metabolism and bioactivation of drugs and carcinogens. Experiments revealed that His-107 was likely the residues responsible for mediating acetyl transfer. The full catalytic mechanism of acetylation process has been examined by density functional theory. The results indicate that, if the acetyl group is directly transferred from the donor, p-nitrophenyl acetate, to the acceptor, cysteine, the high activation energy will be a great hindrance. These energies have dropped in a little range of 20-25 kJ/mol when His-107 assisted the transfer process. However, when protonated His-107 mediated the reaction, the activation energies have been dropped about 73-85 kJ/mol. Our calculations strongly supported an enzyme acetylation mechanism that experiences a thiolate-imidazolium pair, and verified the presumption from experiments.

N-乙酰基转移酶2(NAT2)基因多态性与肺癌易感性关系的Meta分析

目的探讨分析NAT2多态性与肺癌易感性的关系。方法在中英文数据库中按照统一的检索策略,全面检索至2013年8月1日有关NAT2多态性与肺癌风险关系的观察性研究相关文献。按照纳入与排除标准选择文献、提取资料和评价质量进行Meta分析。结果共纳入23篇文献,分别来自15个国家,累计肺癌病例4 425人,对照病例6 663人。结论本Meta分析结果表明:NAT2基因多态性与肺癌易感性之间未见显著关联。

Relationship between metabolic enzyme polymorphism and colorectal cancer

AIM: To clarify the influence of genetic polymorphisms on colorectal cancer. METHODS: The results of 42 related studies from 1990 to 2001 were analyzed by meta-analysis. Mantel-Haenzel fixed-effect model or Dersimonian-Laird random-effect model and ReviewManager 4.1 statistical program were applied in processing the data. RESULTS: Meta analysis of these studies showed that GSTT1 deletion (pooled OR= 1.42), N-acetyltransferase 2 (NAT2)-rapid acetylator phenotype and genotye (pooled OR = 1.08) and NAT2-rapid acetylator phenotype (pooled OR = 1.15) had a significantly increased risk for colorectal cancer (P<0.05), other genotypes like GSTM1 deletion, GSTP1 1le105Val, NAT1*10, NAT2-rapid acetylator genotype CYP1A1 Lle462Val, CYP1A1 MspI*C, MTHFR C677T and MTR A2759G had no significant relationship with colorectal cancer (P>0.05). CONCLUSION: Risks for colorectal cancer are significantly associated with the genetic polymorphisms of GSTT1 deletion, NAT2-rapid acetylator phenotype and genotye and NAT2-rapid acetylator phenotype.

Frequent loss of heterozygosity at 8p22 chromosomal region in diffuse type of gastric cancer

AIM: To study the loss of heterozygosity (LOH) at 8p21-23 locus in diffuse gastric cancer.METHODS: To evaluate the involvement of this region in gastric cancer, we used eight microsatellite markers covering two Mb of mentioned region, to perform a high-resolution analysis of allele loss in 42 cases of late diffuse gastric adenocarcinoma.RESULTS: Six of these STS makers: D8S1149, D8S1645, D8S1643, D8S1508, D8S1591, and D8S1145 showed 36%, 28%, 37%, 41%, 44% and 53% LOH, respectively.CONCLUSION: A critical region of loss, close to the NAT2 locus and relatively far from FEZ1 gene currently postulated as tumor suppressor gene in this region.