Establishment of a Strong Link Between Smoking and Cancer Pathogenesis through DNA Methylation Analysis

Background & Aims Smoking, an independent risk factor for pancreatitis, accelerates the development of alcoholic pancreatitis. Alcohol feeding of mice induces upregulation of spliced X-box binding protein 1 (XBP1s), which regulates the endoplasmic reticulum (ER) unfolded protein response and promotes cell survival upon ER stress. We examined whether smoking affects the adaptive mechanisms induced by alcohol and accelerates disorders of the ER in pancreatic acinar cells. Methods We studied the combined effects of ethanol and cigarette smoke extract (CSE) on ER-stress and cell death responses in mouse and human primary acini and the acinar cell line AR42J. Cells were incubated with ethanol (EtOH, 50 mM), CSE (20–40 μg/ml), or both (CSE+EtOH), and analyzed by immunoblotting, quantitative reverse transcription PCR, and cell death assays. Some cells were incubated with MKC-3946, an inhibitor of endoplasmic reticulum to nucleus signaling 1 (ERN1, also called IRE1) that blocks XBP1s formation. Male Sprague-Dawley rats were fed isocaloric amounts of an ethanol-containing (Lieber-DeCarli) or control diet for 11 weeks and exposed to cigarette smoke or room air in an exposure chamber for 2 hours each day. During the last 3 weeks, a subset of rats received intravenous injections of lipopolysaccharide (LPS, 3 mg/kg per weeks) to induce pancreatitis or saline (control). Pancreatic tissues were collected and analyzed by histology and immunostaining techniques. Results In AR42J and primary acini, CSE+EtOH induced cell death (necrosis and apoptosis), but neither agent alone had this effect. Cell death was associated with a significant decrease in expression of XBP1s. CSE+EtOH, but neither agent alone, slightly decreased ATP levels in AR42J cells, but induced oxidative stress and sustained activation (phosphorylation) of eukaryotic translation initiation factor 2 alpha kinase 3 (EIF2AK3, also called PERK) and increased protein levels of DNA damage inducible transcript 3 (DDIT3, also called CHOP). CHOP regulates transcription to promote apoptosis. Incubation of AR42J or primary mouse or human acinar cells with MKC-3946 reduced expression of XBP1s, increased levels of CHOP and induced cell death. In rats fed ethanol diet, exposure to cigarette smoke increased ER stress in acinar cells and sensitized the pancreas to LPS-induced pathology. Conclusions Cigarette smoke promotes cell death and features of pancreatitis in ethanol-sensitized acinar cells by suppressing the adaptive unfolded protein response signaling pathway. It also activates ER stress pathways that promote acinar cell death.

show abstract

“…28 A recent report demonstrated that AhR ligands promote fibrosis in a mouse model of chronic pancreatitis. 29 …”

Section: Resultsmentioning

confidence: 99%

The Combination of Alcohol and Cigarette Smoke Induces Endoplasmic Reticulum Stress and Cell Death in Pancreatic Acinar Cells

Lugea

Gerloff

et al. 2017

Gastroenterology

View full text Add to dashboard Cite

show abstract

“…Tobacco smoking has been reported to induce epigenomic changes including DNA methylation variation (reviewed in 41 ). Smoking is a well characterized risk factor in cancer 42 and, as more recently discovered, in the aetiology of autoimmunity 43 . Although smoking-related X-linked DNA methylation sites have been discovered 44 , no previous studies, to our knowledge, have investigated the relationship between smoking and XCI patterns.…”

Section: Resultsmentioning

confidence: 99%

Heritability of skewed X-inactivation in female twins is tissue-specific and dependent on age

Zito

Davies

Tsai

et al. 2019

Preprint

View full text Add to dashboard Cite

3To balance the X-linked transcriptional dosages between the sexes, one of the two X-chromosomes 4 is randomly selected to be inactivated in somatic tissues of female placental mammals. Non-5 random, or skewed X-chromosome inactivation (XCI) toward one parental X has been observed in 6 female somatic tissues, and this skewing effect has been associated with several complex human 7 traits. However, the extent of the influence of genetic and environmental factors on XCI skewing is 8 largely unknown. Here, we use RNA-seq and DNA-seq data taken from a large cohort of female twins 9to quantify the degree of skewing of XCI (DS) in multiple tissues and to study the relationship of XCI 10 with age, genetic factors and complex traits. We show that the XCI patterns are highly tissue-specific 11 with a higher prevalence of skewed XCI in blood-derived tissues than in fat or skin tissue. We also 12show that the DS in blood-derived tissues is associated with age and that the acquired DS occurs 13 uniquely in blood-derived tissues with an inflection point at approximately 55 years of age. 14 Heritability analysis indicates that the heritability of DS is both age and tissue specific; DS is heritable 15 in blood tissue of females >55 years-old (h 2 = 0.34) but is not heritable in blood tissues of females 16 <55 years-old (h 2 = 0), nor in skin and fat tissues at any age. We find a positive association between 17 the DS and smoking status in blood tissues of older females (P = 0.02). The high tissue specificity of 18

show abstract

“…It is noteworthy that the top three smoking-related miRNAs (hsa-miR-7704, hsa-miR-3655 and hsa-miR-203-3p) showed a clear relationship between smoking-dose and expression levels, and the top five age-adjusted smoking related pathways are involved with smoking. For example, the cholinergic synapse pathway is associated with nicotine addiction 56 and the relaxin signaling pathway is disrupted by smoking 57 . Our results show that smoking-related pathway RNAs (e.g.…”

Section: Discussionmentioning

confidence: 99%

Circulating small non-coding RNAs associated with age, sex, smoking, body mass and physical activity

Rounge

Umu

Keller

et al. 2018

Preprint

View full text Add to dashboard Cite

Non-coding RNAs (ncRNA) are regulators of cell functions and circulating ncRNAs from the majority of RNA classes, such as miRNA, tRNA, piRNAs, lncRNA, snoRNA, snRNA and miscRNAs, are potential non-invasive biomarkers. Understanding how non-disease traits influence ncRNA expression is essential for assessing their biomarker potential.We studied associations of common traits (sex, age, smoking, body mass, physical activity, and technical factors such as sample storage and processing) with serum ncRNAs. We used RNAseq data from 526 donors from the Janus Serum Bank and traits from health examination surveys. We identified associations between all RNA classes and traits. Ageing showed the strongest association with ncRNA expression, both in terms of statistical significance and number of RNAs, regardless of RNA class. Serum processing modifications and storage times significantly altered expression levels of a number of ncRNAs. Interestingly, smoking cessation generally restored RNA expression to non-smoking levels, although for some isomiRs, mRNA fragments and tRNAs smoking-related expression levels persisted.Our results show that common traits influence circulating ncRNA expression. Therefore it is clear that ncRNA biomarker analyses should be adjusted for age and sex. In addition, for specific ncRNAs identified in our study, analyses should also be adjusted for body mass, smoking, physical activity and serum processing and storage.

show abstract

Establishment of a Strong Link Between Smoking and Cancer Pathogenesis through DNA Methylation Analysis

Cited by 76 publications

References 64 publications

The Combination of Alcohol and Cigarette Smoke Induces Endoplasmic Reticulum Stress and Cell Death in Pancreatic Acinar Cells

The Combination of Alcohol and Cigarette Smoke Induces Endoplasmic Reticulum Stress and Cell Death in Pancreatic Acinar Cells

Heritability of skewed X-inactivation in female twins is tissue-specific and dependent on age

Circulating small non-coding RNAs associated with age, sex, smoking, body mass and physical activity

Contact Info

Product

Resources

About