Association Between N-acetyltransferase 2 Polymorphism and Bladder Cancer Risk: Results From Studies of the Past Decade and a Meta-Analysis

Association between cigarette smoking and ovarian reserve among women seeking fertility care

INTRODUCTION

This study examined the association of smoking with ovarian reserve in a cross-sectional study of 207 women enrolled in the Louisville Tobacco Smoke Exposure, Genetic Susceptibility, and Infertility (LOUSSI) Study and assessed effect modification by NAT2 acetylator phenotype.

METHODS

Information on current smoking status was collected using a structured questionnaire and confirmed by cotinine assay. Serum anti-Müllerian hormone (AMH) levels were used to assess ovarian reserve. Diminished ovarian reserve (DOR) was defined as AMH <1ng/mL. Single nucleotide polymorphisms in the NAT2 gene, which metabolizes toxins found in cigarette smoke, were analyzed to determine NAT2 acetylator status. Linear and logistic regression were used to determine the effects of smoking on ovarian reserve and evaluate effect modification by NAT2. Regression analyses were stratified by polycystic ovary syndrome (PCOS) status and adjusted for age.

RESULTS

Current smoking status, either passive or active as measured by urinary cotinine assay, was not significantly associated with DOR. For dose-response assessed using self-report, the odds of DOR increased significantly for every additional cigarette currently smoked (Odds ratio, OR:1.08; 95% confidence interval, 95%CI:1.01-1.15); additionally, every 1 pack-year increase in lifetime exposure was associated with an increased odds of DOR among women without PCOS (OR: 1.08 95%CI: 0.99-1.18). These trends appear to be driven by the heavy or long-term smokers. Effect modification by NAT2 genotype was not established.

CONCLUSION

A history of heavy smoking may indicate increased risk of diminished ovarian reserve.

LncRNA-Associated Genetic Etiologies Are Shared between Type 2 Diabetes and Cancers in the UAE Population

Numerous epidemiological studies place patients with T2D at a higher risk for cancer. Many risk factors, such as obesity, ageing, poor diet and low physical activity, are shared between T2D and cancer; however, the biological mechanisms linking the two diseases remain largely unknown. The advent of genome wide association studies (GWAS) revealed large numbers of genetic variants associated with both T2D and cancer. Most significant disease-associated variants reside in non-coding regions of the genome. Several studies show that single nucleotide polymorphisms (SNPs) at or near long non-coding RNA (lncRNA) genes may impact the susceptibility to T2D and cancer. Therefore, the identification of genetic variants predisposing individuals to both T2D and cancer may help explain the increased risk of cancer in T2D patients. We aim to investigate whether lncRNA genetic variants with significant diabetes and cancer associations overlap in the UAE population. We first performed an annotation-based analysis of UAE T2D GWAS, confirming the high prevalence of variants at or near non-coding RNA genes. We then explored whether these T2D SNPs in lncRNAs were relevant to cancer. We highlighted six non-coding genetic variants, jointly reaching statistical significance in T2D and cancer, implicating a shared genetic architecture between the two diseases in the UAE population.

Gender discrepancies in bladder cancer: potential explanations

INTRODUCTION

Gender differences in urothelial carcinoma of the bladder (UCB) exist. Although men have a higher incidence of UCB, women tend to have poorer outcomes. We have explored and summarized the evidence for gender differences of UCB diagnosis and prognosis, together with reasons for these disparities.

AREAS COVERED

The incidence of UCB is 3-4 times higher in men than women. However, women are more likely to be diagnosed with advanced disease. Women have a higher stage-for-stage mortality compared to men, and their greatest risk of death appears to be within the first 2 years of diagnosis. Survival outcomes following radical cystectomy (RC) and radiotherapy are also poorer in women. Delays in diagnosis, differences in female anatomy, as well as poorer surgical outcomes post-RC appear to contribute significantly to the disparities noted between genders. Other factors such as exposure to risk factors, differential hormone signaling, and carcinogen breakdown may also have a role.

EXPERT OPINION

The gender divide in UCB outcomes has to be addressed. Improved medical and patient education and centralization of RC are recommended.

N-acetyltransferase 2 polymorphism is associated with bladder cancer risk: An updated meta-analysis based on 54 case-control studies

OBJECTIVE

N-acetyltransferase 2 (NAT2) polymorphism could participate in the metabolism of carcinogens through regulating the activity of a series of critical enzymes. However, the effects of NAT2 polymorphism on bladder cancer (BCa) risk were still inconclusive. In order to illustrate whether NAT2 polymorphism may influence the susceptibility to BCa, we conducted this updated meta-analysis.

MATERIALS AND METHODS

Databases including PubMed, Medline, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure(CNKI) were systematically retrieved and we applied MetaGenyo to perform final meta-analysis. Odds ratios (ORs) as well as 95% confidence intervals (CIs) were calculated and Bonferroni method was applied to correct the P-value for multiple comparisons. The registration of this study protocol is at PROSPERO and ID is CRD42019133957.

RESULTS

Ultimately, 54 case-control studies were identified for final meta-analysis (13343 BCa cases and 18,586 controls). Overall analysis indicated that the slow genotype in NAT2 polymorphism was obviously associated with BCa risk (P_Bonferroni < 0.001). Subgroup analyses demonstrated that significant risk with the slow genotype was observed in Caucasians, Asians, smokers, non-exposed individuals, high grade bladder cancer (HGBC) patients and muscle-invasive bladder cancer (MIBC) patients. In addition, the intermediate NAT2 genotype was revealed to increase the BCa risk of Asians and transitional cell carcinoma (TCC) patients. However, no correlation was identified in Africans with the NAT2 polymorphism.

CONCLUSIONS

The slow NAT2 genotype was identified to be the risk genotype for BCa. The intermediate genotype could serve as the candidate risk genotype. The gene-smoking interaction with NAT2 polymorphism might accelerate the tumor progression.

Clinical and therapeutic implications of sex steroid hormone receptor status in urothelial bladder cancer

Studies on the clinical profile of urothelial bladder cancer (UBC) have shown significant gender differences, namely, higher occurrence in males (male-to-female ratio of 3.5:1) and an advanced stage of disease at the time of diagnosis with rapid progression of the disease after initial diagnosis seen more commonly in females. The relationship between gender and UBC is complex and probably influenced by biological and epidemiological factors. Potential contributory factors such as sex steroid hormone pathway, gender difference in environmental carcinogen exposure, metabolic enzyme activity, and disparities in the intensity of diagnostic evaluation could probably explain the demographic trends in UBC. This comprehensive review of Medline publications during the period 2009–2019 attempts to identify the possible role of sex hormone receptors in gender variation and sexual dimorphism in the occurrence and progression of UBC. The clinical implications of identifying sex steroid receptors on factors such as disease prognostication and the therapeutic role of anti-androgens in the prevention and progression of UBC are critically reviewed. There is now significant evidence in literature to suggest the possible role of sex steroid hormone receptor-mediated signals in the genesis and progression of UBC. These receptors include androgen receptors, estrogen receptors, progesterone receptors, and various other orphan receptors. Excessive or reduced expression of these receptors, as well as alterations in their upstream or downstream pathways, correlate well with the clinical and therapeutic outcomes of UBC.

Genetic polymorphisms of NAT2 and risk of acute myeloid leukemia: A case-control study

Our purpose was to investigate the possible associations between N-acetyltransferase-2 (NAT2) gene polymorphisms and the risk of acute myeloid leukemia (AML) in Chinese Han population.A case-control study was conducted including 98 AML cases and 112 healthy controls. NAT2 gene 2 polymorphisms rs1799930 and rs1799931 were genotyped using direct sequencing. Chi-square test was performed to compare the genotype and allele distribution differences between groups. Odds ratio (OR) with 95% confidence interval (CI) was calculated to estimate the association between NAT2 gene polymorphisms and AML onset.A remarkable decrease trend of rs1799931 GA genotype was detected in AML patients compared with controls, whereas the ancestral GG genotype frequency increased in cases (P < .05). And the mutant A allele of rs1799931 significantly reduced the risk of AML by 0.585-fold versus the ancestral G allele carriers (OR = 0.585, 95% CI = 0.361-0.950). But the distributions of rs1799930 genotype and allele were similar between groups (P > .05).Our findings suggested that NAT2 gene polymorphism rs1799931 was associated with decreased risk of AML and was likely to be a protective factor against AML development.

Distribution and Role of N-acetyltransferase 2 Genetic Polymorphisms in Bladder Cancer Risk in a Lebanese Population

Background:

In Lebanon, bladder cancer (BC) has an unusually high prevalence. Individuals who are exposed to aromatic amines from smoking or certain occupations and carrying the slow N-acetyl transferase 2 (NAT2) acetylator’ phenotype may be at a higher risk.

Methods:

Data and DNA from 115 Lebanese BC cases and 306 controls were examined. Ten NAT2 single nucleotide polymorphisms were genotyped, seven of which were then included in haplotype and phenotype analysis.

Results:

BC patients were more likely to be males (87.8% vs. 54.9%) and current smokers (60.9% vs. 26.5%) when compared to controls. In both groups, most participants had the slow NAT2 acetylator phenotype (66.1% of BC cases vs 62.7% of controls; P=0.302) with the NAT2*5B and *6A haplotypes being the most common. The odds ratio (95%CI) of having BC among slow NAT2 acetylators was 1.157 (0.738-1.815) and remained non-significant after adjustment [1.097 (0.666-1.806)]. Sensitivity analysis with a subgroup of 113 cases and 84 controls for which occupational history was available revealed a statistically significant association between slow NAT2 acetylators and BC in females only. The sample size was however very small and the CI quite wide.

Conclusions:

This is the first study to evaluate the distribution of NAT2 haplotypes and their potential role in BC in a Lebanese population. The absence of any significant association may be due to the relatively small sample size, the unavailability of matching by gender, and the lack of evaluation of genetic interactions with extent of active and passive smoking, exposure to environmental pollutants, diet, and other genes. The potential association limited to females needs further evaluation.

Female with bladder cancer: what and why is there a difference?

While men are at a considerable higher risk of developing urothelial carcinoma of the bladder (UCB), women present with more advanced disease stages and seem to experience unfavorable outcomes. Evaluating specific differences in the UCB incidence and outcomes between both genders in the non-muscle invasive, muscle-invasive or locally advanced and metastatic setting, as well as determining the underlying causes of disease, may allow optimizing treatment and improving the quality of urological care among both genders. In this review we summarize the best evidence and most recent findings on gender-specific differences in UCB incidence and outcomes. In addition, we present a comprehensive overview on established and potential reasons for differences in gender-specific UCB outcomes, including disparities in the pelvic anatomy, the diagnostic work-up, the modality and quality of treatment, the exposure to risk factors, the degradation of carcinogens as well as the sex-hormone signaling.