Polymorphisms of human 8-oxoguanine DNA glycosylase 1 and 8-hydroxydeoxyguanosine increase susceptibility to arsenic methylation capacity-related urothelial carcinoma

Overexpression of BMAL-1 is related to progression of urothelial carcinoma in arsenic exposure area

BACKGROUND

Environmental exposure to arsenic has long been associated with various clinical and pathophysiological aspects of urothelial carcinoma (UC), although the role of arsenic in UC and its impact on circadian proteins, particularly BMAL-1, remains unestablished. Previous research suggests that arsenic upregulates Aurora kinase A (AURKA), subsequently inhibiting GSK-3β, which might lead to overexpression of BMAL-1; nevertheless, the underlying pathway and its clinical significance in UC with arsenic exposure have yet to be validated. This study focuses on two potential upstream regulators of BMAL-1, AURKA and GSK-3β.

METHODS

Ninety-nine tumor tissue samples were retrospectively collected along with their respective clinical data. Immunohistochemistry was employed to assess the expression of each protein.

RESULTS

A positive relationship was observed between the expression levels of AURKA and BMAL-1 (p < 0.001), while negative correlations were noted between the expression levels of GSK-3β and AURKA (p < 0.001), and between GSK-3β and BMAL-1 (p = 0.003). Tissue samples exposed to arsenic exhibited significantly higher levels of AURKA (p < 0.001) and BMAL-1 (p < 0.001), a markedly lower expression of GSK-3β (p = 0.001), alongside a decreased survival status (p = 0.025) compared to non-exposed samples. Furthermore, patients with UC of higher tumor grade tended to show increased levels of AURKA (p < 0.001), BMAL-1 (p < 0.001), and decreased levels of GSK-3β (p < 0.001). Elevated expression of AURKA (p < 0.001) and BMAL-1 (p = 0.002), as well as reduced expression of GSK-3β (p = 0.003), were also associated with a decreased survival status.

CONCLUSIONS

This study highlights the differential expression of BMAL-1, AURKA, and GSK-3β in association with arsenic exposure and their significant impact on clinical and pathological features of UC. Moreover, BMAL-1, AURKA, and GSK-3β emerge as potential prognostic markers for UC in regions with arsenic exposure.

Exploring the mechanism of Suxin Hugan Fang in treating ulcerative colitis based on network pharmacology

As a traditional Chinese medicine formula used in clinical practice for an extended period, Suxin-Hugan-Fang (SXHGF) exhibits excellent anti-inflammatory properties. However, the efficacy of SXHGF in treating ulcerative colitis (UC) and its mechanism of action are still unclear. In this study, the therapeutic effects of SXHGF on UC were evaluated using network pharmacology and experimental validation, while also investigating its mechanism of action. By administering DSS to C57BL/6 mice to construct a mouse model of ulcerative colitis, the therapeutic effect of SXHGF on ulcerative colitis was evaluated based on weight loss percentage, disease activity index, colon length changes, and pathological conditions as indicators. The main chemical components of SXHGF were determined by LC-MS-QTOF method. The potential targets and mechanisms of action of SXHGF in the treatment of UC were inferred using bioinformatics methods, and further validated through ELISA, IHC, and Western blotting assays. The experimental results demonstrate that SXHGF can suppress oxidative stress and oxidative damage in the colon tissue of UC mice, and alleviate DSS-induced ulcerative colitis by inhibiting the JAK2/STAT3 and NFκB pathways.

OGG1: An emerging multifunctional therapeutic target for the treatment of diseases caused by oxidative DNA damage

Oxidative DNA damage-related diseases, such as incurable inflammation, malignant tumors, and age-related disorders, present significant challenges in modern medicine due to their complex molecular mechanisms and limitations in identifying effective treatment targets. Recently, 8-oxoguanine DNA glycosylase 1 (OGG1) has emerged as a promising multifunctional therapeutic target for the treatment of these challenging diseases. In this review, we systematically summarize the multiple functions and mechanisms of OGG1, including pro-inflammatory, tumorigenic, and aging regulatory mechanisms. We also highlight the potential of OGG1 inhibitors and activators as potent therapeutic agents for the aforementioned life-limiting diseases. We conclude that OGG1 serves as a multifunctional hub; the inhibition of OGG1 may provide a novel approach for preventing and treating inflammation and cancer, and the activation of OGG1 could be a strategy for preventing age-related disorders. Furthermore, we provide an extensive overview of successful applications of OGG1 regulation in treating inflammatory, cancerous, and aging-related diseases. Finally, we discuss the current challenges and future directions of OGG1 as an emerging multifunctional therapeutic marker for the aforementioned challenging diseases. The aim of this review is to provide a robust reference for scientific researchers and clinical drug developers in the development of novel clinical targeted drugs for life-limiting diseases, especially for incurable inflammation, malignant tumors, and age-related disorders.

hOGG1 promoter methylation, hOGG1 genetic variants and their interactions for risk of coal-borne arsenicosis: A case-control study

To identify the effect of hOGG1 methylation, Ser326Cys polymorphism and their interactions on the risk of coal-borne arsenicosis, 113 coal-borne arsenicosis subjects and 55 reference subjects were recruited. Urinary arsenic contents were analyzed with ICP-MS. hOGG1 methylation and Ser326Cys polymorphism was measured by mehtylation-specific PCR and restriction fragment length polymorphism PCR in PBLCs, respectively. The results showed that the prevalence of methylated hOGG1 and variation genotype (326 ^Ser/Cys & 326 ^Cys/Cys) were increased with raised levels of urinary arsenic in arsenicosis subjects. Increased prevalence of methylated hOGG1 and variation genotype were associated with raised risk of arsenicosis. Moreover, the results revealed that variant genotype might increase the susceptibility to hOGG1 methylation. The interactions of methylated hOGG1 and variation genotype were also found to contribute to increased risk of arsenicosis. Taken together, hOGG1 hypermethylation, hOGG1 variants and their interactions might be potential biomarkers for evaluating risk of coal-borne arsenicosis.

The Association of Arsenic Metabolism with Cancer, Cardiovascular Disease, and Diabetes: A Systematic Review of the Epidemiological Evidence

BACKGROUND

The available evidence on the role of arsenic metabolism in individual susceptibility to the development of cancer, cardiovascular disease, and diabetes has not been formally and comprehensively reviewed.

OBJECTIVES

Our goal was to systematically investigate the association of arsenic metabolism with cancer, cardiovascular disease, and diabetes-related outcomes in epidemiologic studies. As a secondary objective, we characterized the variation of arsenic metabolism in different populations worldwide.

METHODS

We searched Medline/PubMed and EMBASE from inception to January 2016 and applied predetermined exclusion criteria. Compositional data analysis was used to describe the distribution of arsenic metabolism biomarkers and evaluate the association between arsenic exposure and metabolism.

RESULTS

Twenty-eight studies met the inclusion criteria, 12 on cancer, nine on cardiovascular disease, and seven on diabetes-related outcomes. The median (interquartile range) for mean iAs%, MMA%, and DMA% was 11.2 (7.8-14.9)%, 13.0 (10.4-13.6)%, and 74.9 (69.8-80.0)%, respectively. Findings across studies suggested that higher arsenic exposure levels were associated with higher iAs% and lower DMA% and not associated with MMA%. For cancer, most studies found a pattern of higher MMA% and lower DMA% associated with higher risk of all-site, urothelial, lung, and skin cancers. For cardiovascular disease, higher MMA% was generally associated with higher risk of carotid atherosclerosis and clinical cardiovascular disease but not with hypertension. For diabetes-related outcomes, the pattern of lower MMA% and higher DMA% was associated with higher risk of metabolic syndrome and diabetes.

CONCLUSIONS

Population level of iAs% and DMA%, but not MMA%, were associated with arsenic exposure levels. Overall, study findings suggest that higher MMA% was associated with an increased risk of cancer and cardiovascular disease, while lower MMA% was associated with an increased risk of diabetes and metabolic syndrome. Additional population-based studies and experimental studies are needed to further evaluate and understand the role of arsenic exposure in arsenic metabolism and the role of arsenic metabolism in disease development. https://doi.org/10.1289/EHP577.

Arsenic toxicity and epimutagenecity: the new LINEage

Global methylation pattern regulates the normal functioning of a cell. Research have shown arsenic alter these methylation landscapes within the genome leading to aberrant gene expression and inducts various pathophysiological outcomes. Long interspersed nuclear elements (LINE-1) normally remains inert due to heavy methylation of it's promoters, time and various environmental insults, they lose these methylation signatures and begin retro-transposition that has been associated with genomic instability and cancerous outcomes. Of the various high throughput technologies available to detect global methylation profile, development of LINE-1 methylation index shall provide a cost effect-screening tool to detect epimutagenic events in the wake of toxic exposure in a large number of individuals. In the present review, we tried to discuss the state of research and whether LINE-1 methylation can be considered as a potent epigenetic signature for arsenic toxicity.