Polymorphisms of xenobiotic metabolizing enzymes in bladder cancer patients of the Semmelweis University Budapest, Hungary

Polymorphisms in drug-metabolizing genes and urinary bladder cancer susceptibility and prognosis: Possible impacts and future management

Epidemiological studies have shown the association of genetic variants with risks of occupational and environmentally induced cancers, including bladder (BC). The current review summarizes the effects of variants in genes encoding phase I and II enzymes in well-designed studies to highlight their contribution to BC susceptibility and prognosis. Polymorphisms in genes codifying drug-metabolizing proteins are of particular interest because of their involvement in the metabolism of exogenous genotoxic compounds, such as tobacco and agrochemicals. The prognosis between muscle-invasive and non-muscle-invasive diseases is very different, and it is difficult to predict which will progress worse. Web of Science, PubMed, and Medline were searched to identify studies published between January 1, 2010, and February 2023. We included 73 eligible studies, more than 300 polymorphisms, and 46 genes/loci. The most studied candidate genes/loci of phase I metabolism were CYP1B1, CYP1A1, CYP1A2, CYP3A4, CYP2D6, CYP2A6, CYP3E1, and ALDH2, and those in phase II were GSTM1, GSTT1, NAT2, GSTP1, GSTA1, GSTO1, and UGT1A1. We used the 46 genes to construct a network of proteins and to evaluate their biological functions based on the Reactome and KEGG databases. Lastly, we assessed their expression in different tissues, including normal bladder and BC samples. The drug-metabolizing pathway plays a relevant role in BC, and our review discusses a list of genes that could provide clues for further exploration of susceptibility and prognostic biomarkers.

The Interplay between Oxidative Stress, Inflammation and Angiogenesis in Bladder Cancer Development

In 2018, 550,000 people were diagnosed with bladder cancer (BC), of which nearly 200,000 people died. Moreover, men are 4 times more likely than women to be diagnosed with BC. The risk factors include exposure to environmental and occupational chemicals, especially tobacco smoke, benzidine and genetic factors. Despite numerous studies, the molecular basis of BC development remains unclear. A growing body of evidence suggests that inflammation, oxidant-antioxidant imbalance and angiogenesis disorders may play a significant role in the development and progression of bladder cancer. The patients with bladder cancer were characterised by an increased level of reactive oxygen species (ROS), the products of lipid peroxidation, proinflammatory cytokines and proangiogenic factors as compared to controls. Furthermore, it was shown that polymorphisms localised in genes associated with these pathways may modulate the risk of BC. Interestingly, ROS overproduction may induce the production of proinflammatory cytokines, which finally activated angiogenesis. Moreover, the available literature shows that both inflammation and oxidative stress may lead to activation of angiogenesis and tumour progression in BC patients.

Sickle Cell Anemia: Variants in the CYP2D6, CAT, and SLC14A1 Genes Are Associated With Improved Hydroxyurea Response

Differences in hydroxyurea response in sickle cell anemia may arise due to a series of factors with genetic factors appearing to be predominant. This study aims to investigate the effects of single nucleotide polymorphisms in genes encoding drug-metabolizing enzymes and solute carriers on hydroxyurea response, in patients with sickle cell anemia. For that purpose, a total number of 90 patients with sickle cell anemia were recruited, 45 were undergoing hydroxyurea treatment, while 45 were not under the treatment. Association analyses were performed between CYP3A4 (rs2740574), CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and laboratory parameters. According to our findings, patients with hydroxyurea treatment demonstrated higher HbF levels and a significant improvement in hemolytic, hepatic, inflammatory, and lipid parameters in comparison to those without the treatment. We also found significant associations between the CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and an improvement of the therapeutic effects, specifically the hemolytic, hepatic, inflammatory, lipid, and renal parameters. In conclusion, our results highlight the importance of the investigated variants, and their strong association with hydroxyurea efficacy in patients with sickle cell anemia, which may be considered in the future as genetic markers.

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.