Nicotine attenuates global genomic DNA methylation by influencing DNMTs gene expression in human endometrial stromal cells

Smoking-related epigenetic modifications are associated with the prognosis and chemotherapeutics of patients with bladder cancer

OBJECTIVE

Epidemiologic studies have linked smoking to various malignancies, including bladder cancer, but its underlying biological functions remain elusive. Currently, we aimed to identify the smoking-related epigenetic modifications and disclose their impacts on prognosis and therapies in bladder cancer.

METHODS

DNA methylation, transcriptome, and clinical profiles were acquired from The Cancer Genome Atlas (TCGA) using "TCGAbiolinks" Differential expression analyses were performed with "limma" and visualized by the "pheatmap" package. Smoking-related interactions were displayed using Cytoscape. Least absolute shrinkage and selection operator (LASSO) algorithm was for generation of a smoking-related prognostic model. Kaplan-Meier analysis with log-rank test was for survival analysis, followed by a prognostic nomogram. The Gene Set Enrichment Analysis (GSEA) was used for functional analysis. The "oncoPredict" package was applied for drug sensitivity analysis.

RESULTS

We recruited all types of bladder cancers and found that smoking was involved in poor prognosis, with the hazard ratio (HR) of 1.600 (95%CI: 1.028-2.491). A total of 1078 smoking-related DNA methylations (526 hypermethylation and 552 hypomethylation) were identified and 9 methylation-driven genes differentially expressed in bladder cancer. Also, 506lncRNAs (448 upregulated and 58 downregulated lncRNAs) and 102 miRNAs (74 upregulated and 28 downregulated miRNAs) were determined as smoking-related ncRNAs. We then calculated the smoking-related risk score and observed that cases of high risk were predicted with poor prognosis. We constructed a prognostic nomogram to predict the 1-, 3-, and 5-year overall survival rates. Several cancer-related pathways were enriched in the high-risk group, and patients with high-risk were more sensitive to Gemcitabine, Wnt-C59, JAK1_8709, KRAS (G12C) Inhibitor-12, and LY2109761. Whereas, those with low-risk were more sensitive to Cisplatin, AZ960, and Buparlisib.

CONCLUSIONS

Totally, we initially identified the smoking-related epigenetic modifications in bladder cancer and constructed a corresponding prognostic model, which was also linked to disparate sensitivities to chemotherapeutics. Our findings would provide novel insights into the carcinogenesis, prognosis, and therapies in bladder cancer.

Effective bioremediation of tobacco wastewater by microalgae at acidic pH for synergistic biomass and lipid accumulation

Tobacco wastewater is too difficult to decontaminate which poses a significant environmental problem due to the harmful and toxic components. Chlorella pyrenoidosa is a typical microalgal species with potential in removal of organic/inorganic pollutants and proves to be an ideal algal-based system for wastewater treatment. However, the strategy of tobacco related wastewater treatment using microalgae is in urgent need of development. In this study, C. pyrenoidosa was used to evaluate the removal efficiency of artificial tobacco wastewater. Under various solid-to-liquid (g/L) ratios, 1:1 ratio and acidic pH 5.0 were optimal for C. pyrenoidosa to grow with high performance of removal capacity to toxic pollutants (such as COD, NH3-N, nicotine, nitrosamines and heavy metals) with the alleviation of oxidative damage. Algal biomass could reach up to 540.24 mg/L. Furthermore, carbon flux of C. pyrenoidosa was reallocated from carbohydrate and protein biosynthesis to lipogenesis with a high lipid content of 268.60 mg/L at pH 5.0. Overall, this study demonstrates an efficient and sustainable strategy for tobacco wastewater treatment at acidic pH with the production of valuable microalgal products, which provides a promising biorefinery strategy for microalgal-based wastewater bioremediation.

Epigenetic Reprogramming of Tumor-Associated Fibroblasts in Lung Cancer: Therapeutic Opportunities

Simple Summary

Lung cancer is the leading cause of cancer death among both men and women, partly due to limited therapy responses. New avenues of knowledge are indicating that lung cancer cells do not form a tumor in isolation but rather obtain essential support from their surrounding host tissue rich in altered fibroblasts. Notably, there is growing evidence that tumor progression and even the current limited responses to therapies could be prevented by rescuing the normal behavior of fibroblasts, which are critical housekeepers of normal tissue function. For this purpose, it is key to improve our understanding of the molecular mechanisms driving the pathologic alterations of fibroblasts in cancer. This work provides a comprehensive review of the main molecular mechanisms involved in fibroblast transformation based on epigenetic reprogramming, and summarizes emerging therapeutic approaches to prevent or overcome the pathologic effects of tumor-associated fibroblasts.

Abstract

Lung cancer is the leading cause of cancer-related death worldwide. The desmoplastic stroma of lung cancer and other solid tumors is rich in tumor-associated fibroblasts (TAFs) exhibiting an activated/myofibroblast-like phenotype. There is growing awareness that TAFs support key steps of tumor progression and are epigenetically reprogrammed compared to healthy fibroblasts. Although the mechanisms underlying such epigenetic reprogramming are incompletely understood, there is increasing evidence that they involve interactions with either cancer cells, pro-fibrotic cytokines such as TGF-β, the stiffening of the surrounding extracellular matrix, smoking cigarette particles and other environmental cues. These aberrant interactions elicit a global DNA hypomethylation and a selective transcriptional repression through hypermethylation of the TGF-β transcription factor SMAD3 in lung TAFs. Likewise, similar DNA methylation changes have been reported in TAFs from other cancer types, as well as histone core modifications and altered microRNA expression. In this review we summarize the evidence of the epigenetic reprogramming of TAFs, how this reprogramming contributes to the acquisition and maintenance of a tumor-promoting phenotype, and how it provides novel venues for therapeutic intervention, with a special focus on lung TAFs.

Epimutational effects of electronic cigarettes

Electronic cigarettes (e-cigarettes), since they do not require tobacco combustion, have traditionally been considered less harmful than conventional cigarettes (c-cigarettes). In recent years, however, researchers have found many toxic compounds in the aerosols of e-cigarettes, and numerous studies have shown that e-cigarettes can adversely affect the human epigenome. In this review, we provide an update on recent findings regarding epigenetic outcomes of e-cigarette aerosols. Moreover, we discussed the effects of several typical e-cigarette ingredients (nicotine, tobacco-specific nitrosamines, volatile organic compounds, carbonyl compounds, and toxic metals) on DNA methylation, histone modifications, and noncoding RNA expression. These epigenetic effects could explain some of the diseases caused by e-cigarettes. It also reminds the public that like c-cigarettes, inhaling e-cigarette aerosols could also be accompanied with potential epigenotoxicity on the human body.

Protective effects of quercetin against hyperglycemia-induced oxidative stress in hepatic HepG2 cell line

OBJECTIVE

Hyperglycemia is a severe consequence of diabetes mellitus (DM). Throughinduction of oxidative stress, it plays a major role in the pathogenesis of several complications in DM. Therefore, new strategies and antioxidants should be implemented inthe treatment of DM. Quercetin is a flavonoid with strong antioxidant capacity found dominantly in vegetables, fruits, leaves, and grains. The current study aimed to investigate quercetin protective effects under D-glucose-induced oxidative stress by assessing antioxidant defense enzymes inHepG2 cells as an in vitro model.

MATERIALS AND METHODS

HepG2 cells were cultured with different concentrations of D-glucose (5.5, 30 and 50 mM) and/or 25 μM quercetin for 48 and 72 hr, respectively. The effect of treatments on cellular integrity, antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) activity, andcellular levels of glutathione (GSH) and malondialdehyde (MDA) wasdetermined.

RESULTS

D-glucose had various effects on intracellular antioxidant defense atdifferent doses and time-points and quercetin could attenuate oxidative stress and modulate antioxidant defenses.

CONCLUSION

The results of this study indicated that flavonoid quercetin could be proposed as an agent protecting hepatic HepG2 cells against oxidative stress associated with hyperglycemia.