Long-term exposure to cigarette smoke extract induces hypomethylation at the RUNX3 and IGF2-H19 loci in immortalized human urothelial cells

Identification of common genetic factors and immune-related pathways associating more than two autoimmune disorders: implications on risk, diagnosis, and treatment

Autoimmune disorders (ADs) are chronic conditions resulting from failure or breakdown of immunological tolerance, resulting in the host immune system attacking its cells or tissues. Recent studies report shared effects, mechanisms, and evolutionary origins among ADs; however, the possible factors connecting them are unknown. This study attempts to identify gene signatures commonly shared between different autoimmune disorders and elucidate their molecular pathways linking the pathogenesis of these ADs using an integrated gene expression approach. We employed differential gene expression analysis across 19 datasets of whole blood/peripheral blood cell samples with five different autoimmune disorders (rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, Crohn's disease, and type 1 diabetes) to get nine key genes-EGR1, RUNX3, SMAD7, NAMPT, S100A9, S100A8, CYBB, GATA2, and MCEMP1 that were primarily involved in cell and leukocyte activation, leukocyte mediated immunity, IL-17, AGE-RAGE signaling in diabetic complications, prion disease, and NOD-like receptor signaling confirming its role in immune-related pathways. Combined with biological interpretations such as gene ontology (GO), pathway enrichment, and protein-protein interaction (PPI) network, our current study sheds light on the in-depth research on early detection, diagnosis, and prognosis of different ADs.

The RUNX Family of Proteins, DNA Repair, and Cancer

The RUNX family of transcription factors, including RUNX1, RUNX2, and RUNX3, are key regulators of development and can function as either tumor suppressors or oncogenes in cancer. Emerging evidence suggests that the dysregulation of RUNX genes can promote genomic instability in both leukemia and solid cancers by impairing DNA repair mechanisms. RUNX proteins control the cellular response to DNA damage by regulating the p53, Fanconi anemia, and oxidative stress repair pathways through transcriptional or non-transcriptional mechanisms. This review highlights the importance of RUNX-dependent DNA repair regulation in human cancers.

Smoking and the Pathophysiology of Peripheral Artery Disease

Smoking is one of the most important preventable factors causing peripheral artery disease (PAD). The purpose of this review is to comprehensively analyze and summarize the pathogenesis and clinical characteristics of smoking in PAD based on existing clinical, in vivo, and in vitro studies. Extensive searches and literature reviews have shown that a large amount of data exists on the pathological process underlying the effects of cigarette smoke and its components on PAD through various mechanisms. Cigarette smoke extracts (CSE) induce endothelial cell dysfunction, smooth muscle cell remodeling and macrophage phenotypic transformation through multiple molecular mechanisms. These pathological changes are the molecular basis for the occurrence and development of peripheral vascular diseases. With few discussions on the topic, we will summarize recent insights into the effect of smoking on regulating PAD through multiple pathways and its possible pathogenic mechanism.

Diallyl trisulfide inhibited tobacco smoke-mediated bladder EMT and cancer stem cell marker expression via the NF-κB pathway in vivo

OBJECTIVE

This study examined the effect of the NF-κB pathway on tobacco smoke-elicited bladder epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) marker expression in vivo. The effect of diallyl trisulfide (DATS) treatment was also examined.

METHODS

BALB/c mice were exposed to tobacco smoke and treated with an NF-κB inhibitor and DATS. Western blotting, quantitative real-time PCR, and immunohistochemical staining were used to detect the changes of relevant indices.

RESULTS

Phosphorylated inhibitor of kappa-B kinase alpha/beta expression and p65 and p50 nuclear transcription were increased by tobacco smoke exposure, whereas inhibitor of kappa-B expression was decreased. In addition, tobacco smoke reduced the expression of epithelial markers but increased that of mesenchymal and CSC markers. Our study further demonstrated that tobacco smoke-mediated EMT and CSC marker expression were attenuated by inhibition of the NF-κB pathway. Moreover, DATS reversed tobacco smoke-induced NF-κB pathway activation, EMT, and the acquisition of CSC properties in bladder tissues.

CONCLUSIONS

These data suggested that the NF-κB pathway regulated tobacco smoke-induced bladder EMT, CSC marker expression, and the protective effects of DATS.

Cigarette smoke-induced alterations in blood: A review of research on DNA methylation and gene expression

Worldwide, smoking remains a threat to public health, causing preventable diseases and premature mortality. Cigarette smoke is a powerful inducer of DNA methylation and gene expression alterations, which have been associated with negative health consequences. Here, we review the current knowledge on smoking-related changes in DNA methylation and gene expression in human blood samples. We identified 30 studies focused on the association between active smoking, DNA methylation modifications, and gene expression alterations. Overall, we identified 1,758 genes with differentially methylated sites (DMS) and differentially expressed genes (DEG) between smokers and nonsmokers, of which 261 were detected in multiple studies (≥4). The most frequently (≥10 studies) reported genes were AHRR, GPR15, GFI1, and RARA. Functional enrichment analysis of the 261 genes identified the aryl hydrocarbon receptor repressor and T cell pathways (T helpers 1 and 2) as influenced by smoking status. These results highlight specific genes for future mechanistic and translational research that may be associated with cigarette smoke exposure and smoking-related diseases. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A 5-lncRNA Signature Associated with Smoking Predicts the Overall Survival of Patients with Muscle-Invasive Bladder Cancer

Increasing evidence demonstrated that noncoding RNA is abnormally expressed in cancer tissues and serves a vital role in tumorigenesis, tumor development, and metastasis. The aim of the present study was to determine an lncRNA signature in order to predict the overall survival (OS) of patients with muscle-invasive bladder cancer (MIBC). A total of 246 patients with pathologically confirmed MIBC in The Cancer Genome Atlas (TCGA) dataset were recruited and included in the present study. We choose patients who have smoked less (including never smoking) or more than 15 years. A total of 44 differentially expressed lncRNAs were identified with a fold change larger than 1.5 and a P value < 0.05 through the limma package. Subsequently, a comparison between patients with no tobacco smoke exposure for <15 years and patients who had been exposed to tobacco smoke for >15 years was performed by using the matchIt package. Among the 44 differentially expressed lncRNAs, 5 lncRNAs were identified to be significantly associated with OS. Based on the characteristic risk scores of these 5 lncRNAs, patients were divided into low-risk and high-risk groups and exhibited significant differences in OS. Multivariate Cox regression analysis demonstrated that the 5-lncRNA signature was independent of age, tumor-node metastasis (TNM) staging, lymphatic node status, and adjuvant postoperative radiotherapy. In the present study, a novel 5-lncRNA signature was developed and was demonstrated to be useful in predicting the survival of patients with MIBC. If validated, this lncRNA signature may assist in the selection of a high-risk subpopulation that requires more aggressive therapeutic intervention. The risk scores involved in several associated pathways were identified using gene set enrichment analysis (GSEA). However, the clinical implications and mechanism of these 5 lncRNAs require further investigation.

Smoking and blood DNA methylation: an epigenome-wide association study and assessment of reversibility

We conducted a genome-wide association study of blood DNA methylation and smoking, attempted replication of previously discovered associations, and assessed the reversibility of smoking-associated methylation changes. DNA methylation was measured in baseline peripheral blood samples for 5,044 participants in the Melbourne Collaborative Cohort Study. For 1,032 participants, these measures were repeated using blood samples collected at follow-up, a median of 11 years later. A cross-sectional analysis of the association between smoking and DNA methylation and a longitudinal analysis of changes in smoking status and changes in DNA methylation were conducted. We used our cross-sectional analysis to replicate previously reported associations for current (N = 3,327) and former (N = 172) smoking. A comprehensive smoking index accounting for the biological half-life of smoking compounds and several aspects of smoking history was constructed to assess the reversibility of smoking-induced methylation changes. This measure of lifetime exposure to smoking allowed us to detect more associations than comparing current with never smokers. We identified 4,496 cross-sectional associations at P < 10-7, including 3,296 annotated to 1,326 genes that were not previously implicated in smoking-associated DNA methylation changes at this significance threshold. We replicated the majority of previously reported associations (P < 10-7) for current and former smokers. In our data, we observed for former smokers a substantial degree of return to the methylation levels of never smokers, compared with current smokers (median: 74%, IQR = 63-86%), corresponding to small values (median: 2.75, IQR = 1.5-5.25) for the half-life parameter of the comprehensive smoking index. Longitudinal analyses identified 368 sites at which methylation changed upon smoking cessation. Our study demonstrates the usefulness of the comprehensive smoking index to detect associations between smoking and DNA methylation at CpGs across the genome, replicates the vast majority of previously reported associations, and quantifies the reversibility of smoking-induced methylation changes.

Effects of Long Noncoding RNA H19 Polymorphisms on Urothelial Cell Carcinoma Development

Urothelial cell carcinoma (UCC) is one of the major malignancies of the genitourinary tract, and it is induced by carcinogenic epidemiological risk factors. H19 is one of the most crucial long noncoding RNAs (lncRNAs) and is involved in various types of bladder cancer. In this study, we examined H19 single-nucleotide polymorphisms (SNPs) to investigate UCC susceptibility and clinicopathological characteristics. Using real-time polymerase chain reaction, we analyzed five SNPs of H19 in 431 UCC patients and 431 controls without cancer. The results showed that patients with UCC carrying the H19 rs217727 CT + TT and rs2107425 CT + TT genetic variants had a high risk of developing muscle invasive tumors (pT2-T4) (p = 0.030; p = 0.025, respectively). With a median follow up of 39 months, CT+TT polymorphisms of rs2107425 were associated with worse disease-specific survival (adjusted hard ratio (AHR) = 2.043, 95% confidence interval (CI) = 1.029-4.059) in UCC patients aged older than 65 years. In conclusion, our results indicate that patients with UCC carrying the H19 rs217727 CT + TT and rs2107425 CT + TT genetic variants have a high risk of developing muscle invasive tumors. Thus, H19 polymorphisms may be applied as a marker or therapeutic target in UCC treatment.

Cigarette smoke extract acts directly on CD4 T cells to enhance Th1 polarization and reduce memory potential

Although cigarette smoke is known to alter immune responses, whether and how CD4 T cells are affected is not well-described. We aimed to characterize how exposure to cigarette smoke extract impacts CD4 T cell effector generation in vitro under Th1-polarizing conditions. Our results demonstrate that cigarette smoke directly acts on CD4 T cells to impair effector expansion by decreasing division and increasing apoptosis. Furthermore, cigarette smoke enhances Th1-associated cytokine production and increases expression of the transcription factor T-bet, the master regulator of Th1 differentiation. Finally, we show that exposure to cigarette smoke extract during priming impairs the ability of effectors to form memory cells. Our findings thus demonstrate that cigarette smoke simultaneously enhances effector functions but promotes terminal differentiation of CD4 T cell effectors. This study may be relevant to understanding how smoking can both aggravate autoimmune symptoms and reduce vaccine efficacy.

Curcumin reversed chronic tobacco smoke exposure induced urocystic EMT and acquisition of cancer stem cells properties via Wnt/β-catenin

Tobacco smoke (TS) is the most important single risk factor for bladder cancer. Epithelial-mesenchymal transition (EMT) is a transdifferentiation process, involved in the initiation of TS-related cancer. Cancer stem cells (CSCs) have an essential role in the progression of many tumors including TS-related cancer. However, the molecular mechanisms of TS exposure induced urocystic EMT and acquisition of CSCs properties remains undefined. Wnt/β-catenin pathway is critical for EMT and the maintenance of CSCs. The aim of our present study was to investigate the role of Wnt/β-catenin pathway in chronic TS exposure induced urocystic EMT, stemness acquisition and the preventive effect of curcumin. Long time TS exposure induced EMT changes and the levels of CSCs' markers were significant upregulated. Furthermore, we demonstrated that Wnt/β-catenin pathway modulated TS-triggered EMT and stemness, as evidenced by the findings that TS elevated Wnt/β-catenin activation, and that TS-mediated EMT and stemness were attenuated by Wnt/β-catenin inhibition. Treatment of curcumin reversed TS-elicited activation of Wnt/β-catenin, EMT and CSCs properties. Collectively, these data indicated the regulatory role of Wnt/β-catenin in TS-triggered urocystic EMT, acquisition of CSCs properties and the chemopreventive effect of curcumin.

ERK5 regulates tobacco smoke‑induced urocystic epithelial‑mesenchymal transition in BALB/c mice

Tobacco smoke (TS) is an important risk factor of bladder cancer. Epithelial‑mesenchymal transition (EMT) is involved in the initiation and development of cancer. The role of extracellular signal‑regulated kinase (ERK) 5 in regulating TS‑induced EMT remains to be elucidated. The aim of the present study was to investigate the regulatory role of ERK5 in TS‑triggered EMT in the bladder of mice. BALB/c mice were used for an in vivo TS exposure model. Mice were treated for 6 h a day for 12 weeks. The results demonstrated that mice exposed to TS had decreased mRNA and protein expression levels of the epithelial markers E‑cadherin and zonula occludens‑1, whereas expression levels of the mesenchymal markers Vimentin and N‑cadherin were increased. Treatment with XMD8‑92, a highly specific ERK5 inhibitor, effectively abrogated TS‑triggered activation of ERK5, activator protein‑1 and EMT alterations in the bladder of BALB/c mice. The data suggested that ERK5 regulates TS‑mediated urocystic EMT. These findings provide insight into the molecular mechanisms of TS‑associated bladder tumorigenesis.

Curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway

We have previously reported that curcumin inhibits urothelial tumor development in a rat bladder carcinogenesis model. In this study, we report that curcumin inhibits urothelial tumor development by suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway. Curcumin inhibits IGF2 expression at the transcriptional level and decreases the phosphorylation levels of IGF1R and IRS-1 in bladder cancer cells and N-methyl-N-nitrosourea (MNU)-induced urothelial tumor tissue. Ectopic expression of IGF2 and IGF1R, but not IGF1, in bladder cancer cells restored this process, suggesting that IGF2 is a target of curcumin. Moreover, introduction of constitutively active AKT1 abolished the inhibitory effect of curcumin on cell proliferation, migration, and restored the phosphorylation levels of 4E-BP1 and S6K1, suggesting that curcumin functions via suppressing IGF2-mediated AKT/mTOR signaling pathway. In summary, our results reveal that suppressing IGF2 and IGF2-mediated PI3K/AKT/mTOR signaling pathway is one of the mechanisms of action of curcumin. Our findings suggest a new therapeutic strategy against human bladder cancer caused by aberrant activation of IGF2, which are useful for translational application of curcumin.

Cigarette smoke extract-induced proliferation of normal human urothelial cells via the MAPK/AP-1 pathway

Bladder cancer (BC) is universally acknowledged as a significant public health issue, worldwide. Numerous studies have demonstrated that cigarette smoke is the primary risk factor for BC. However, the mechanism of cigarette smoke-induced BC has not been fully elucidated. Sustained epithelial cell hyperplasia has been identified as a preneoplastic lesion during the formation of BC. The aim of the present study was to investigate whether exposure to cigarette smoke extract (CSE) induced proliferation in normal human urothelial SV-HUC-1 cells. Furthermore, the role of the mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) pathway in the CSE-induced proliferation of SV-HUC-1 cells was also investigated. The present study revealed that the expression of phosphorylated-extracellular signal regulated protein kinase (ERK)1/2, Jun N-terminal kinase (JNK) and p38 was significantly increased following exposure to CSE in SV-HUC-1 cells. Furthermore, CSE increased the expression of the proliferation markers, cyclin D1 and proliferating cell nuclear antigen. By contrast, CSE attenuated the expression of p21. In addition, the inhibitors of ERK1/2 and JNK reversed the aforementioned effects of CSE. However, p38 inhibition did not reverse CSE-induced proliferation. In conclusion, the results of the present study demonstrated that exposure to CSE induced proliferation in normal human urothelial cells. Furthermore, the results also indicated that the ERK1/2 and JNK pathways are important for the regulation of proliferation via the AP-1 proteins.

Genome-scale long noncoding RNA expression pattern in squamous cell lung cancer

In this study, we aimed to explore the long noncoding RNA expression pattern in squamous cell lung cancer (SQCC) on a genome-wide scale. Total RNAs were extracted from 16 lung SQCC patients’ normal and matched lung cancer tissues by Trizol reagent. The expression level of genome-wide scale lncRNA and mRNA was determined by microarray. qRT-PCR was used to validate the lncRNA expression level in 47 patients. Data analyses were performed using R and Bioconductor. A total of 2,748 up and 852 down regulated probes were identified to be significantly and differentially expressed in tumor tissues. The annotation result of their co-expressed mRNAs showed that the most significantly related category of GO analysis was development and differentiation, while the most significantly related pathway was cell cycle. Subgroup analysis identified that 46 and 18 probes were specifically differentially expressed in smoking and moderately differentiated tumors, respectively. Our study indicated that clusters of lncRNAs were significantly and differentially expressed in SQCC compared with normal tissues in the same subject. They may exert a significant role in lung cancer development and could be potential targets for future treatment of SQCC.

Inhibition of tobacco smoke-induced bladder MAPK activation and epithelial-mesenchymal transition in mice by curcumin

Tobacco smoke (TS) has been shown to cause bladder cancer. Epithelial-mesenchymal transition (EMT) is a crucial pathophysiological process in cancer development. MAPK pathways play central roles in tumorigenesis including EMT process. Curcumin is a promising chemopreventive agent for several types of cancers. In the present study we investigated the effects of TS on MAPK pathway activation and EMT alterations in the bladder of mice, and the preventive effect of curcumin was further examined. Results showed that exposure of mice to TS for 12 weeks resulted in activation of ERK1/2, JNK, p38 and ERK5 MAPK pathways as well as AP-1 proteins in bladder. TS reduced mRNA and protein expression levels of epithelial markers E-cadherin and ZO-1, while mRNA and protein expression levels of the mesenchymal markers vimentin and N-cadherin were increased. Curcumin treatment effectively attenuated TS-triggered activation of ERK1/2, JNK and p38 MAPK pathways, AP-1 proteins and EMT alterations in bladder tissue. These results suggest the protective effects of curcumin in TS-induced MAPK activation and EMT, thus providing new insights into the chemoprevention of TS-associated bladder cancer.

Association of polymorphisms in long non-coding RNA H19 with coronary artery disease risk in a Chinese population

H19 is an imprinted gene transcribing a long non-coding RNA and is downregulated postnatally. Re-expression of H19 has been observed in patients with atherosclerosis. However, to date, no data has been published on the association of H19 polymorphisms with the risk of coronary artery disease (CAD). In this study, four polymorphisms, rs217727, rs2067051, rs2251375, rs4929984, were analyzed in 701 CAD patients and 873 age- and sex-matched control subjects. Polymorphisms were genotyped by TaqMan technology. Our data showed that the T variant of rs217727 was associated with an increased risk of CAD [additive model: odds ratio (OR)=2.05, 95%CI=1.35-3.12; dominant model: OR=1.46, 95% confidence interval (CI)=1.12-1.90; recessive model: OR=1.75, 95%CI=1.18-2.58], while A variant of rs2067051 was associated with a decreased risk of CAD (additive model: OR=0.66, 95%CI=0.45-0.96; recessive model: OR=0.71, 95%CI=0.50-0.99). Combined analysis showed that subjects carrying 3 or 4 risk alleles had a significantly increased risk of CAD, relative to those with 0-2 risk alleles (OR=1.61, 95%CI=1.20-2.15). Moreover, CAD patients with 3 or 4 risk alleles also had significantly higher Gensini scores than those with 0-2 risk alleles (P=0.001). Further haplotype-based analysis revealed that individuals with C-G-C-C, T-G-A-A, and T-A-A-A haplotypes indicated a higher prevalence of CAD (OR=1.88, 95%CI=1.03-3.43; OR=2.26, 95%CI=1.19-4.31; OR=2.66, 95%CI=1.34-5.25, respectively), compared to individuals with the most common C-G-A-C haplotype. In conclusion, our study demonstrates for the first time that common polymorphisms of H19 are associated with the risk and severity of CAD in a Chinese population. Future studies are needed to explore the underlying mechanisms of our findings.

Longitudinal epigenetic drift in mice perinatally exposed to lead

An understanding of the natural change in DNA methylation over time, defined as "epigenetic drift," will inform the study of environmental effects on the epigenome. This study investigates epigenetic drift in isogenic mice exposed perinatally to lead (Pb) acetate at four concentrations, 0 ppm (control), 2.1 ppm (low), 16 ppm (medium), and 32 ppm (high) prior to conception through weaning, then followed until 10 months of age. Absolute values of DNA methylation in a transposon-associated metastable locus, Cdk5-activator binding protein (Cabp(IAP)), and three imprinted loci (Igf2, Igf2r, and H19) were obtained from tail tissue in paired samples. DNA methylation levels in the controls increased over time at the imprinted Igf2 and Igf2r loci (both P = 0.0001), but not at the imprinted H19 locus or the Cabp(IAP) metastable epiallele. Pb exposure was associated with accelerated DNA hypermethylation in Cabp(IAP) (P = 0.0209) and moderated hypermethylation in Igf2r (P = 0.0447), and with marginally accelerated hypermethylation at H19 (P = 0.0847). In summary, the presence and magnitude of epigenetic drift was locus-dependent, and enhancement of drift was mediated by perinatal Pb exposure, in some, but not all, loci.