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Asia-Pacific Journal of Clinical Oncology 2014

doi: 10.1111/ajco.12291

ORIGINAL ARTICLE

N-acetyltransferase 2 gene polymorphism as a biomarker for susceptibility to bladder cancer in Bangladeshi population Md. Bayejid HOSEN,1 Jahidul ISLAM,1 Md. Abdus SALAM,2 Md. Fakhrul ISLAM,3 M Zakir Hossain HAWLADER1 and Yearul KABIR1 1

Department of Biochemistry and Molecular Biology, University of Dhaka, 2Department of Urology, National Institute of Kidney Diseases and Urology, 3Department of Urology, Bangladesh Medical College and Hospital, Dhaka, Bangladesh

Abstract Aim: To investigate the association between the three most common single nucleotide polymorphisms of the N-acetyltransferase 2 gene together with cigarette smoking and the risk of developing bladder cancer and its aggressiveness. Methods: A case-control study on 102 bladder cancer patients and 140 control subjects was conducted. The genomic DNA was extracted from peripheral white blood cells and N-acetyltransferase 2 alleles were differentiated by polymerase chain reaction-based restriction fragment length polymorphism methods. Results: Bladder cancer risk was estimated as odds ratio and 95% confidence interval using binary logistic regression models adjusting for age and gender. Overall, N-acetyltransferase 2 slow genotypes were associated with bladder cancer risk (odds ratio = 4.45; 95% confidence interval = 2.26–8.77). The cigarette smokers with slow genotypes were found to have a sixfold increased risk to develop bladder cancer (odds ratio = 6.05; 95% confidence interval = 2.23–15.82). Patients with slow acetylating genotypes were more prone to develop high-grade (odds ratio = 6.63; 95% confidence interval = 1.15–38.13; P < 0.05) and invasive (odds ratio = 10.6; 95% confidence interval = 1.00–111.5; P = 0.05) tumor. Conclusion: N-acetyltransferase 2 slow genotype together with tobacco smoking increases bladder cancer risk. Patients with N-acetyltransferase 2 slow genotypes were more likely to develop a high-grade and invasive tumor. N-acetyltransferase 2 slow genotype is an important genetic determinant for bladder cancer in Bangladesh population. Key words: acetyltransferase, aromatic amine, bladder cancer, polymorphism, smoking.

INTRODUCTION There is an ongoing debate about genes and environment, their interactions, and the extent of their relative impact on life and health. Susceptibility to the majority of human diseases and disorders is complex and multi-

Correspondence: Dr Yearul Kabir PhD, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka 1000, Bangladesh. Email: [email protected] Conflict of interest: There was no conflict of interest Accepted for publication 7 September 2014.

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factorial, involving both genetic and environmental factors. Although any two unrelated people share about 99.9% of their DNA sequences, the remaining 0.1% is important because it contains the genetic variants that influence how people differ in their risk of disease or their response to drugs and environment exposures.1 Discovering the DNA sequence variants that contribute to common disease risk offers one of the best opportunities for understanding the complex causes of disease in human. Common variants of genes, termed polymorphisms, which influence various metabolic processes or our susceptibility to different types of environmental exposures are a topic of intense research.2–4

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Bladder cancer is the most common cancer of the urinary tract and is the ninth most common cancer among men, accounting for approximately 330 000 new cases and 130 000 deaths per year worldwide.5 Bladder cancer is considerably more common in men than in women, but still approximately 60 000 women are diagnosed with the disease every year worldwide.5 Risk factors associated with bladder carcinogenesis include increasing age, male gender, and exposure to carcinogenic aromatic and heterocyclic amines (such as benzidine, 2-naphthylamine, 4-aminobiphenyl), either through occupation or cigarette smoking.6,7 Genetic polymorphisms in the genes coding for detoxifying enzymes may cause individual variations in metabolizing the exposed carcinogens.8 Nacetyltransferase (NAT) is an important enzyme to detoxify aromatic amines such as nitrosamines and arylamines. Its activity in human is coded by two distinct genes named NAT1 and NAT2. NAT2 has been reported to exhibit a polymorphism, resulting in the potential expression of four mutant alleles (M1, M2, M3 and M4), which can be identified by RFLP (restriction fragment length polymorphism) analysis following NAT2 polymerase chain reaction (PCR). NAT2 activity is predicted from the detected combination of these NAT2 alleles. The presence of at least one wild-type alleles results in fast acetylator whereas the carriages of two mutant alleles are categorized as a slow acetylator.9 The slow NAT2 genotype could be a risk factor for bladder cancer, specifically by interacting with occupational exposures to aromatic amines or cigarette smoking. Lucia et al.10 reported the combined effect of slow genotypes and smoking status in bladder cancer patients. Previous studies showed associations of urinary bladder cancer with NAT2 slow acetylator phenotypes.11,12 However, studies carried out in Europe, Japan, the United States and Spain reported that NAT2 slow acetylators had a significantly increased risk of urinary bladder cancer that was stronger in smokers, particularly heavy or long-term smokers.13–16 The slow allele is predominant in about 90% of Arab population, about 40–60% in Caucasians including Indians, 5–25% in East Asian and 74% in South Indians.17,18 In Bangladesh, the genotype of NAT2 has not yet been studied especially in relation to bladder cancer patients. The phenotype of NAT2 studied in Bangladesh population showed 79.5% are fast acetylators and the rest, 20.5%, are slow acetylators.19 The present study was aimed to investigate NAT2 genotype distribution and the association of slow genotype together with cigarette smoking in bladder cancer patients.

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MB Hosen et al.

MATERIALS AND METHODS Study subjects The study was a case-control study conducted in 242 subjects. The case group comprises 102 bladder cancer patients. There was no significant difference in characteristics between control and cases except in age (Table 1). The bladder cancer patients were recruited from the Department of Urology of different hospitals in Dhaka city without any medical history of other chronic diseases. The patients were histologically diagnosed as suffering from bladder cancer and were treated using different therapeutic regimens. Bladder cancer was classified according to the histological type and grading on the basis of standard method.20 The case group was categorized by grade at diagnosis: 27 had a well-differentiated disease (G1), 37 had a moderately differentiated disease (G2) and 38 had a poorly differentiated disease (G3). In the present study, all the bladder cancer patients were also divided into two groups (G1+G2 or G3 group) on the basis of tumor grade.9 We categorized all the tumors into two terms: “superficial tumors” or those that were limited to the mucosa or the lamina propria, and “invasive tumors” or those that had invaded the muscle layer or deeper.9 In this study, 75 had superficial tumors and 27 had invasive tumors. A total of 140 healthy controls without any history of cancer or other chronic diseases were recruited from different hospitals of Dhaka city where they came for regular health checkup. No family history of chronic diseases or cancer was also found in the study subjects.

Table 1

Characteristics of study subjects

Variables Gender Male Female Age (year)† Smoking status Smokers Nonsmokers Occupation Dye factory Farmer Others

Controls (n = 140, %)

Cases (n = 102, %)

123 (87.9) 17 (12.1) 63.14 ± 10.25

87 (85.3) 15 (14.7) 66.81 ± 14.07

P-value 0.57 0.03

85 (60.7) 55 (39.3)

63 (61.8) 39 (38.2)

0.89

3 (2.1) 64 (45.7) 73 (52.2)

6 (5.9) 43 (42.2) 53 (51.9)

0.25

P < 0.05 was taken as level of significance. Fisher’s and chi-square tests were performed to calculate the statistical significance. †Values are mean ± SD.

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NAT2 polymorphism and bladder cancer

All participants were given an explanation of the nature of the study and informed consent was obtained. They completed a structured questionnaire covering information on age, gender, medical, family history of chronic diseases, smoking history and other exposure histories. Smoking status was summarized as smoker or nonsmoker (Table 1). This study was approved by the ethical committee of Bangladesh Medical Research Council under the guidelines of Ministry of Health and Family Welfare.

Sample collection About 3.0 mL of venous blood was drawn from each individual following all aseptic precautions with the help of a trained person using a disposable syringe. The drawn blood was immediately transferred to a tube containing ethylenediaminetetraacetic acid (1.20 mg/ mL) and kept in an ice box for transportation to the laboratory. The blood sample was stored at −20°C until DNA extraction.

Allele genotyping by PCR-RFLP The NAT2 genotypes were determined using the PCRRFLP method. The genomic DNA was extracted from peripheral leukocytes using the method described by Bailes et al.21 The genomic DNA was amplified by PCR using the primer (forward: 5′-CTT CTC CTG CAG GTG ACC AT-3′; reverse: 5′-AGG ATG AAT CAC TCT GCT TC-3′).9 Genomic DNA (0.5 μg) was added to a PCR mix composed of 50 pmol of each primer, 200 μmol of dNTPs, 2.5 units of Taq polymerase (Go Taq Flexi, Promega Corporation, Madison, WI, USA) and PCR buffer composed of 10 mol/mL Tris-HCl (pH 8.3), 50 mol/mL KCl and 2.5 mol/mL MgCl2 in a volume of 50 μL. Conditions for the amplification included initial step of denaturation at 95°C for 15 min followed by 35 cycles of denaturation at 95°C for 45 s, annealing at 57°C for 45 s and elongation at 72°C for 45 s, and finally a step of final elongation at 72°C for 10 min. PCR assays were performed in a DNA thermal cycler (Applied Biosystem, Forster City, CA, USA). Following PCR, 7 μL of PCR products were taken in four different tubes and digested with three separate enzymes: Kpn I (M1 allele) at 37°C for 3 h, Taq I (M2 allele) at 65°C for 3 h, Bam HI (M3 allele) at 37°C for 3 h (restriction enzymes from Promega Corporation). The digested products were resolved by electrophoresis on a 3% agarose gel, stained with ethidium bromide and photographed under UV light. This method detected the four alleles: WT, M1, M2 and M3. The NAT2 fast acetylating genotypes are wild-type allele homo/

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heterozygotes (WT/WT, WT/M1, WT/M2 and WT/M3); slow acetylating genotypes are those with two mutant alleles (M1/M1, M1/M2, M1/M3, M2/M2, M2/M3 and M3/M3).

Statistical analysis Statistical analyses were performed using Statistical Package for Social Science (SPSS; IBM Corporation, Armonk, NY, USA), Windows version 17.0. The relative association between cases and controls including smoking status was assessed by calculating odds ratios (ORs). ORs as a measure of relative risk at 95% confidence interval (95% CI) were estimated using logistic regression models. Chi-square test was performed using GraphPad Prism version 5 (GraphPad Software Inc., La Jolla, CA, USA). P-values less than 0.05 were considered statistically significant.

RESULTS Determination of NAT2 genotypes The molecular size of the PCR product was 815 base pairs (bp) (nt 322-1136). The M1 allele (rs1799929) lacks a Kpn I site at 477 position, M2 allele (rs1799930) lacks a Taq I site at 589 position, and M3 allele (rs1799931) lacks a Taq I site at 857 position. The genotypes of M1, M2 and M3 alleles were determined by carrying out restriction enzyme digestion with Kpn I, Taq I and Bam HI, respectively (Fig. 1). Digestion by Kpn I illustrated the identity of M1 allele (Fig. 1a). Complete digestion of 815 bp fragment into 659 and 156 bp fragments demonstrated that both were wild-type alleles (lanes 2, 4, 6, 7, 8). Lanes 3, 5 and 9 showed incomplete digestion with Kpn I which indicated that one allele was M1-type allele. Both polymorphic alleles in lane 1 were the M1 type (i.e. M1/ M1) as no digestion occurred. Figure 1b showed the DNA fragment patterns of Taq I digestion of the PCR product that undergoes identification of the M2 allele. There are Taq I sites (two of three Taq I sites) common to all NAT2 polymorphic alleles which generate band 42 and 377 bp in all lanes on digestion with Taq I. There is one Taq I site that is absent from the M2 allele. Informative Taq I digestion products are 396, 226 and 170 bp. The presence of a band of 396 bp indicates the absence of the central Taq I site which characterizes the M2 allele. Lane 4 illustrated an M2 homozygote, as there was no digestion of the 396 bp fragment. Because of incomplete digestion, lane 2 illustrated M2 heterozygotes, while lanes 1 and 3 demonstrated the absence of an M2 allele.

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Figure 1 The electrophoretic patterns of genotyping of NAT2 by polymerase chain reaction-based restriction fragment length polymorphism. (a) Identification of the M1 allele by Kpn I digestion. (b) Identification of the M2 allele by Taq I digestion. (c) Identification of the M3 alleles by Bam H1 digestion. Uncut: control 815 bp PCR product. Markers: 100 bp ladder.

The identification of the M3 allele by Bam HI digestion of the PCR product was shown in Figure 1c. Complete digestion to fragments of 536 and 279 bp demonstrated the presence of wild-type alleles in lanes 2, 4, 5 and 6. Lane 3 showed incomplete digestion with Bam HI, indicating heterozygous M3 allele. Lane 7 indicated the homozygous M3 allele because of the absence of digestion.

The allele frequency In this study, we evaluated the individual allele frequencies of M1, M2 and M3 alleles in study subjects. The frequencies of M1, M2 and M3 alleles in controls were 20.4, 32 and 18.9%, and in patients were 49, 36.8 and 33.8%, respectively. The frequencies of mutant alleles (M1, M2 and M3) were significantly different (P < 0.05) among the study subjects.

Relationship to bladder cancer susceptibility and NAT2 genotypes The risk for bladder cancer in relation to the NAT2 slow genotypes was estimated. NAT2 genotype frequencies and estimated risks were shown in Table 2. The NAT2 slow genotype frequencies in patients with bladder cancer were significantly higher compared with that of control group (OR 4.45; 95% CI 2.26–8.77; P < 0.001). Patients with slow genotypes were in high risk for developing bladder cancer in Bangladesh.

Bladder cancer risk evaluation by the combination of NAT2 genotypes and smoking status The risk associated with the combination of NAT2 genotypes and smoking status was estimated (Table 3).

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Table 2 Comparison of NAT2 genotype frequency in bladder cancer cases and control

NAT2 genotypes Fast (%) Slow (%) OR (95% CI) P-value

Controls (n = 140)

Cases (n = 102)

125 (89.3) 15 (10.7)

65 (63.7) 37 (36.3) 4.45 (2.26–8.77) P < 0.001

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Odds ratio (OR) and 95% confidence interval (95% CI), OR adjusted for ages and gender. Fast genotypes, NAT2 wild-type homozygote or wild/mutant heterozygote; slow genotypes, NAT2 mutant-type homozygote; NAT2, N-acetyltransferase 2.

There were four combined groups while the nonsmoker with NAT2 fast genotype group was considered the reference group. There was no apparent increased risk for individuals who were smokers with NAT2 fast genotypes (OR 1.1; 95% CI 0.58–2.07) or nonsmoker with NAT2 slow genotypes (OR 2.44; 95% CI 0.62–9.51). On the other hand, there was a significantly increased risk (OR 6.05; 95% CI 2.32–15.82) of developing bladder cancer among smoker with NAT2 slow genotypes. Our result suggests that there was a possible interaction between NAT2 slow genotypes and smoking status to develop bladder cancer.

Risk of bladder cancer by NAT2 genotypes according to pathologic classification The frequencies of NAT2 genotypes of the bladder cancer patients in the G1+G2 and G3 grade tumor groups and estimated risks were shown in Table 4. The

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Table 3 Odds ratios of developing bladder cancer for NAT2 genotypes and smoking status among cases NAT2 genotypes

Nonsmokers OR (95% CI) Smokers OR (95% CI)

Fast

Slow

(26/48)‡ 1.1 (0.58–2.07) (39/77)‡

2.44 (0.62–9.51) (13/7)‡ 6.05 (2.32–15.82)* (24/8)‡

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*P < 0.001. †NAT2 fast genotypes and nonsmoker combination were used as a referent group to calculate the OR and 95% CI of another combination of cases. ‡Number of cases/number of controls. Odds ratio (OR) and 95% confidence interval (95% CI), OR adjusted for ages and gender. NAT2, N-acetyltransferase 2.

Table 4

NAT2 genotype frequencies stratified by tumor grade and stage NAT2 genotypes

OR (95% CI)

Fast (%)

Slow (%)

P-value

125 (89.3) 48 (75)

15 (10.7) 16 (25)

17 (44.7)

21 (55.3)

1 1.21 (0.38–3.9) P = 0.75 6.63 (1.15–38.13) P < 0.05

Tumor stage Controls (n = 140) Superficial tumor patients (n = 75)

125 (89.3) 53 (70.7)

15 (10.7) 22 (29.3)

Invasive tumor patients (n = 27)

12 (46.4)

15 (55.6)

Tumor grade Controls (n = 140) G1+G2 patients (n = 64) G3 patients (n = 38)

1 0.81(0.18–3.60) P > 0.05 10.6(1.00–111.5) P = 0.05

Odds ratio (OR) and 95% confidence interval (95% CI). OR adjusted for ages and gender. Fast genotypes, NAT2 wild-type homozygote or wild/mutant heterozygote; slow genotypes, NAT2 mutant-type homozygote; NAT2 mutant types are M1, M2, M3. NAT2, N-acetyltransferase 2.

frequency of NAT2 slow genotypes was nonsignificantly higher among G1+G2 (OR 1.21; 95% CI 0.38–3.9; P = 0.75) groups and significantly higher among G3 (OR 6.63; 95% CI 1.15–38.13; P < 0.05) groups when compared with the controls. Table 4 showed the frequencies of NAT2 genotypes of the bladder cancer patients in the superficial tumor and invasive tumor groups and the estimated risks. The frequency of NAT2 slow genotypes was nonsignificantly higher among the superficial tumor (OR 0.81; 95% CI 0.18–3.60; P = 0.78) and significantly higher among the invasive tumor (OR 10.6; 95% CI 1.00–111.5; P = 0.05) when compared against the controls.

DISCUSSION Human epidemiological studies suggest that NAT2 acetylating polymorphisms modify predisposition of

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urinary bladder cancer but there is inconsistency in the results obtained in different studies.9,10,22 Individual risks associated with NAT2 genotypes are small, but they increase when considered in conjunction with other susceptibility genes and/or aromatic and heterocyclic amine carcinogen exposures. NAT2 genotyping has been increasingly employed to predict the phenotype. The effect of NAT2 genotype on cancer risk varies with organ site, probably reflecting tissuespecific expression of NAT2.23 Ethnic differences in NAT2 genotype frequencies may be a factor in cancer incidence.24 In this case-control study, we investigated the NAT2 (fast/slow acetylator) genotypes in susceptibility to bladder cancer. The additive effect of smoking on the bladder cancer was also investigated. Both patients and healthy controls belonged to the same ethnic background and all shared a common geographic origin.

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The individual allele frequencies of WT, M1, M2 and M3 alleles in control and the bladder cancer patients were estimated. The WT allele was less frequent among cases whereas the M2 allele was more frequent among cases. The overall frequency distributions of the alleles among cases and controls were significantly different. The risk for bladder cancer was calculated in relation to the NAT2 slow genotypes. The frequency of the NAT2 slow or fast genotypes in patients with bladder cancer was compared with that of the control subjects and there was a significant difference between them (Table 2). Numerous studies have shown that individuals in the general population classified as slow acetylators are at an increased risk of bladder cancer.4,9 Dong et al.25 analyzed the results of 161 pooled and metaanalyses encompassing 18 cancer types; 13 of these analyses concerned the association of NAT2 slow acetylator and bladder cancer. More recent studies also confirmed this result; however, some studies have found contradictory results.3,10,22,26 N-acetylation is considered a major detoxification step for carcinogenic aromatic arylamines. Aromatic amines within tobacco smoke are the most important class of bladder carcinogens.27 These compounds may be partially responsible for the increased bladder cancer risk observed among NAT2 slow acetylators that have a decreased capacity to detoxify aromatic amines.9 In our present study, we found a marked difference in the ORs between smokers with the slow genotypes and those with NAT2 rapid genotypes (Table 3), which are in agreement with several previous studies.3,16 The combined effects of the NAT2 genotype and smoking status in increasing bladder cancer risk were confirmed by several pooled and meta-analyses.4,10,13 When we considered the slow genotype in relation to tumor grade, there appeared to be a high-grade tumor (G3) in patients who have slow genotypes (Table 4). Inatomi et al.9 also showed that bladder cancer patients with NAT2 slow genotypes were more likely to have a high-grade tumor (G3). Okkels et al.11 reported that analyses of more (T1–T4) and less (Ta, Tis) aggressive tumors revealed an association between NAT2 slow genotypes, and the frequency of more aggressive bladder cancer was high among smokers. In the present study, the patients with slow acetylating genotypes were more prone to grow invasive tumor (Table 4). Inatomi et al.9 also reported that patients with slow acetylating genotypes were in increased risk of growing invasive tumor. This finding might be explained by the fact that the NAT2 slow acetylating phenotype

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MB Hosen et al.

deactivates carcinogens less frequently and causes mutations more quickly, resulting in aggressive tumors. Miller et al.28 reported that polymorphisms in activating and detoxifying enzymes may interact to affect the level of DNA damage from toxic substances sustained by a specific tissue and ultimately influence disease risk. Imbalances between activation and detoxification processes may result in increased bladder cancer risk due to the accumulation of active carcinogen metabolites mainly coming from cigarette smoking. NAT (predominantly NAT2) detoxifies some carcinogenic intermediate metabolites of smoking-related arylamine in the liver.29 Slow acetylators might be unable to detoxify these arylamines quickly. These arylamine metabolites are absorbed into the bladder epithelium when transported through the circulation into the bladder. In the bladder epithelium, they become bioactivated and form DNA adducts.30 This metabolic pathway of arylamines suggests that individuals with NAT2 slow genotypes/ smoker may have a higher risk of bladder cancer compared with individuals with other combinations.

CONCLUSION In summary, the present population-based case-control study suggested that there was a statistically significant association between NAT2 slow acetylating genotypes and risk of developing bladder cancer. We also found a trend that the frequency of the NAT2 slow genotypes was high in patients with aggressive forms of bladder cancer. So it may be concluded that the NAT2 slow acetylating genotype is an important genetic determinant for bladder cancer in Bangladesh population.

ACKNOWLEDGMENTS This research has been financially supported by Bangladesh Medical Research Council (BMRC), Bangladesh. We thank all the study subjects for participating in this study.

REFERENCE 1 Hung RJ, Boffetta P, Brennan P et al. GST, NAT, SULT1A1, CYP1B1 genetic polymorphisms, interactions with environmental exposures and bladder cancer risk in a high-risk population. Int J Cancer 2004; 110: 598–604. 2 Georgiadis P, Topinka1 J, Vlachodimitropoulos D et al. Interactions between CYP1A1 polymorphisms and exposure to environmental tobacco smoke in the modulation of

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3

4

5 6

7

8

9

10

11

12

13

14

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lymphocyte bulky DNA adducts and chromosomal aberrations. Carcinogenesis 2005; 26 (1): 93–101. Rouissi K, Slah O, Bechr H et al. Smoking and polymorphisms in xenobiotic metabolism and DNA repair genes are additive risk factors affecting bladder cancer in Northern Tunisia. Pathol Oncol Res 2011; 17: 879–86. Marcus PM, Vineis P, Rothman N. NAT2 slow acetylation and bladder cancer risk: a meta-analysis of 22 case-control studies conducted in the general population. Pharmacogenetics 2000; 10: 115–22. Steward BW, Kleinhaus P. World Cancer Report. WHOIARC, Lyon 2003. Bryan RT, Hussain SA, James ND et al. Molecular pathways in bladder cancer. Part 1. BJU Int 2005; 95: 485– 90. Song DK, Xing DL, Zhang LR et al. Association of NAT 2, GSTM1, GSTT1, CYP2A6 and CYP2A13 gene polymorphisms with susceptibility and clinicopathologic characteristics of bladder cancer in Central China. Cancer Detect Prev 2009; 32: 416–42. Longuemaux S, Delomenıe C, Gallou C et al. Candidate genetic modifiers of individual susceptibility to renal cell carcinoma: a study of polymorphic human xenobioticmetabolizing enzymes. Cancer Res 1999; 59: 2903–8. Inatomi H, Katoh K, Kawamoto T et al. NAT2 gene polymorphism as a possible biomarker for susceptibility to bladder cancer in Japanese. Int J Urol 1999; 6: 446– 54. Lucia KK, Viera H, Monika SO et al. Effect of NAT2 gene polymorphism on bladder cancer risk in Slovak population. Mol Biol Rep 2011; 38: 1287–93. Okkels H, Sigsgaard T, Wolf H et al. Arylamine N-acetyltransferase 1 (NAT1) and 2 (NAT2) polymorphisms in susceptibility to bladder cancer: the influence of smoking. Cancer Epidemiol Biomarkers Prev 1997; 6: 225–31. Filiadis IF, Georgiou I, Alamanos Y et al. Genotypes of N-acetyltransferase-2 and risk of bladder cancer: a casecontrol study. J Urol 1999; 161: 1672–5. Vineis P, Marinelli D, Autrup H et al. Current smoking, occupation, N-acetyltransferase-2 and bladder cancer: a pooled analysis of genotype-based studies. Cancer Epidemiol Biomarkers Prev 2001; 10: 1249–52. Tsukino H, Nakao H, Kuroda Y et al. Glutathione S-transferase (GST) M1, T1 and N-acetyltransferase 2 (NAT2) polymorphisms and urothelial cancer risk with tobacco smoking. Eur J Cancer Prev 2004; 13: 509–14. Gu J, Liang D, Wang Y et al. Effects of N-acetyltransferase 1 and 2 polymorphisms on bladder cancer risk in Caucasians. Mutat Res 2005; 581: 97–104.

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16 Garcia-Closas M, Malats N, Silverman D et al. NAT2 slow acetylation, GSTM1 null genotype, and risk of bladder cancer: results from the Spanish Bladder Cancer Study and meta-analyses. Lancet 2005; 366: 649–59. 17 Xie HG, Xu ZH, Ou–Yang DS. Meta-analysis of phenotype and genotype of NAT2 deficiency in Chinese population. Pharmacogenetics 1997; 7: 507–14. 18 Anitha A, Banerjee M. Arylamine N-acetyltransferase 2 polymorphism in the ethnic population of South Indians. Int J Mol Med 2003; 11: 125–31. 19 Zaid RB, Nargis M, Neelotpol S et al. Acetylation phenotype status in a Bangladeshi population and its comparison with that of other Asian population data. Biopharm Drug Dispos 2004; 25: 237–41. 20 Franekova M, Halasova E, Bukovska E, Luptak J, Dobrota D. Gene polymorphisms in bladder cancer. Urol Oncol 2008; 26: 1–8. 21 Bailes SM, Devers JJ, Kirby JD et al. An inexpensive, simple protocol for DNA isolation from blood for highthroughput genotyping by polymerase chain reaction or restriction endonuclease digestion. Poultry Sci 2007; 86: 102–6. 22 Mittal RD, Srivastava DSL, Anil M. NAT2 gene polymorphism in bladder cancer: a study from North India. Int Braz J Urol 2004; 30: 279–88. 23 Hein H. N-acetyltransferase 2 genetic polymorphism: effects of carcinogen and haplotype on urinary bladder cancer risk. Oncogene 2006; 25: 1649–58. 24 Golka K, Prior V, Blaszkewicz M et al. The enhanced bladder cancer susceptibility of NAT2 slow acetylators towards aromatic amines: a review considering ethnic differences. Toxicol Lett 2002; 128: 229–41. 25 Dong LM, Potter JD, White E et al. Genetic susceptibility to cancer: the role of polymorphisms in candidate genes. JAMA 2008; 299: 2423–36. 26 Tania C, Avima MR, Paul AS et al. NAT2 slow acetylation and bladder cancer in workers exposed to benzidine. Int J Cancer 2006; 118: 161–8. 27 Vineis P, Pirastu R. Aromatic amines and cancer. Cancer Causes Control 1997; 8: 346–55. 28 Miller MC, Mohrenweiser HW, Bell DA. Genetic variability in susceptibility and response to toxicants. Toxicol Lett 2001; 120: 269–80. 29 Kadlubar FF, Badawi AF. Genetic susceptibility and carcinogen-DNA adduct formation in human urinary bladder carcinogenesis. Toxicol Lett 1995; 825: 627–32. 30 Badawi AF, Hirvonen A, Bell DA et al. Role of aromatic amine acetyltransferases, NAT1 and NAT2, in carcinogenDNA adduct formation in the human urinary bladder. Cancer Res 1995; 55: 5230–7.

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N-acetyltransferase 2 gene polymorphism as a biomarker for susceptibility to bladder cancer in Bangladeshi population.

To investigate the association between the three most common single nucleotide polymorphisms of the N-acetyltransferase 2 gene together with cigarette...
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