Evidence for cigarette smoke-induced oxidative stress in the rat pancreas

Threshold dose-response association between smoking pack-years and the risk of gallbladder cancer: A nationwide cohort study

BACKGROUND AND AIMS

The association between smoking and gallbladder cancer (GBC) risk is unclear. We investigated the association between smoking (including pack-years) and GBC risk. We also examined the combined effects of smoking and diabetes or prediabetes on GBC risk.

METHODS

This Korean nationwide cohort study included 9,520,629 adults without cancer who underwent national health screening in 2009 and were followed-up until 2018. Multivariable Cox proportional hazards models were used to determine risk estimates after adjusting for potential confounders.

RESULTS

During 78.4 million person-years (mean 8.2 ± 0.9 years) of follow-up, we identified 6066 patients with newly diagnosed GBC. Current and former smokers were associated with increased GBC risk (hazard ratio [HR], 95% confidence interval [CI]: 1.117, 1.029-1.212 and 1.105, 1.016-1.202, respectively). Smoking of 20 to <30 and ≥30 pack-years was independently associated with increased GBC risk compared with never smoking (HR, 95% CI; 1.241, 1.100-1.400 and 1.231, 1.107-1.370, respectively). However, smoking of <10 and 10 to <20 pack-years was not. This threshold dose-response association between smoking pack-years and GBC risk was observed regardless of the glycaemic status (all P < 0.01). Furthermore, smoking of ≥20 pack-years and hyperglycaemia had a synergistic effect on the GBC risk (all P < 0.01). Smokers with ≥20 pack-years with diabetes had the highest risk of GBC compared to never smokers with normoglycaemia (HR, 1.658; 95% CI, 1.437-1.914).

CONCLUSIONS

Smoking was associated with increased GBC risk with a threshold dose-response effect for smoking pack-years. The risk of GBC increases synergistically when smoking and hyperglycaemia coexist. More individualised cancer prevention education is required to reduce GBC risk.

Nicotine facilitates pancreatic fibrosis by promoting activation of pancreatic stellate cells via α7nAChR-mediated JAK2/STAT3 signaling pathway in rats

AIM

Smoking has been considered as a risk factor of chronic pancreatitis (CP), but the potential mechanism is still unknown. The major pathological feature of CP is pancreatic fibrosis, whose major functional cells are pancreatic stellate cells (PSCs). Nicotine is the major component of cigarette smoke, our recent study suggested that nicotine has the potential to facilitate pancreatic fibrosis in CP. This study was aimed to analyze the function and mechanism of nicotine on PSCs and pancreatic fibrosis in rats.

MATERIALS AND METHODS

In vivo, a rat CP model was induced by intraperitoneal injection of 20 % L-arginine hydrochloride (200 mg/100 g) at 1 h intervals twice per week, nicotine was injected subcutaneously at a dose of 1 mg/kg body weight per day. After four weeks, the pancreatic tissue was collected for H&E, Masson and immunohistochemical staining. In vitro, primary rPSCs were isolated from rats and treated with nicotine (0.1 μM and 1 μM). The proliferation、apoptosis、α-SMA expression、extracellular matrix (ECM) metabolism and α7nAChR-mediated JAK2/STAT3 signaling pathway of rPSCs were detected by CCK-8 assay、flow cytometry、real-time Q-PCR and western blotting analysis. The α7nAChR antagonist α-bungarotoxin (α-BTX) was used to perform inhibition experiments.

KEY FINDINGS

Nicotine increased pancreatic damage, collagen deposition and activation of PSCs in the CP rat model. In rPSCs, the proliferation, α-SMA expression and ECM formation were significantly promoted by nicotine in a dose-dependent manner. Meanwhile, the apoptosis of rPSCs was significantly reduced after nicotine treatment. Moreover, nicotine also activated the α7nAChR-mediated JAK2/STAT3 signaling pathway in rPSCs. These effects of nicotine on rPSCs were blocked by α-BTX.

SIGNIFICANCE

Our finding in this research suggests that nicotine facilitates pancreatic fibrosis by promoting activation of pancreatic stellate cells via α7nAChR-mediated JAK2/STAT3 signaling pathway in rats, partly revealing the mechanism of smoking on chronic pancreatitis.

Using the Risk Factors of Pancreatic Cancer and Their Interactions in Cancer Screening: A Case-Control Study in Shanghai, China

Background:

The incidence of pancreatic cancer has increased annually, but the risk factors and their interactions are still unknown.

Objective:

The aim of this study was to identify risk factors and the effects of their interactions on pancreatic cancer occurrence among patients in Shanghai, China.

Methods:

We conducted a hospital-based case-control study. The case group consisted of pathologically diagnosed pancreatic cancer patients, and the control group consisted of a healthy population. The Pearson Chi-square test was used to compare the distribution frequencies of data between groups. Multivariate analysis and interaction analysis were conducted to explore possible risk factors and interactions between various variables.

Findings:

Among the 4,821 recruited participants, 1,392 were pancreatic cancer patients and 3,429 were controls. Multivariate logistic analysis suggested that age (>50 years old) (AOR: 16.20 [95% CI 6.78; 38.69]), diabetes (AOR: 5.40 [95% CI 2.70; 10.80]), chronic pancreatitis (AOR: 27.43 [95% CI 2.14; 351.77]), smoking (AOR: 8.86 [95% CI 3.07; 25.58]), and family cancer history (AOR: 2.10 [95% CI 1.09; 8.56]) were the primary risk factors for pancreatic cancer. Interestingly, synergistic interactions between risk factors were found, especially between age and chronic pancreatitis (RERI = 447.93, API = 96.74%, SI = 32.78), age and smoking (RERI = 187.42, API = 94.97%, SI = 21.99), and diabetes and smoking (RERI = 14.39, API = 48.06%, SI = 1.99).

Conclusions:

Age, diabetes, chronic pancreatitis, smoking, and family cancer history have been verified as the primary risk factors for pancreatic cancer in this study. Moreover, the interaction effects between old age, diabetes, chronic pancreatitis, and smoking substantially increase the probability of the development of pancreatic cancer. Cancer screening should be conducted extensively among people with these multiple factors to improve the efficiency.

Relationship between somatostatin and interleukin-6: A cross-sectional study in patients with acute pancreatitis

OBJECTIVES

The aim of the analysis is to determine dynamic changes in somatostatin (SS) and interleukin-6 (IL-6) concentrations during in acute pancreatitis (AP).

METHODS

The influence of tobacco smoking on IL-6 and SS levels in the serum of non-smoking (n = 10) and smoking (n = 27) patients with diagnosed AP and control group: non-smoking (n = 44), smoking (n = 42) and passive smoking (n = 29) healthy persons was proved. The concentration of IL-6 and SS was determined by means of ELISA. Differences between the groups analyzed were tested using the U Mann Whitney test. The Spearman rank correlation analysis was used to evaluate the correlations.

RESULTS

The concentrations of IL-6 and SS were significantly higher in smoking patients with AP and healthy persons when compared with non-smoking population on every day (1 day: p = 0.0002, p = 0.015; 3 day: p = 0.005, p = 0.001 and 7 day: p = 0.025, p = 0.038). Dynamic changes in concentrations of IL-6 and SS in the serum of patients with AP were demonstrated in the ensuing days of the disease. In case of non-smoking and smoking patients, significant positive correlations between IL-6 and SS was observed.

CONCLUSIONS

These findings suggest that some of the antiinflammatory effects of SS against acute pancreatitis may be mediated by reducing the local proinflammatory cytokine secretion in the pancreas.

Diabetes mellitus secondary to pancreatic diseases (type 3c): The effect of smoking on the exocrine-endocrine interactions of the pancreas

The present study was conducted to ascertain how cigarette smoke affects the exocrine-endocrine interactions of the human pancreas with diabetes mellitus secondary to pancreatic diseases (type 3c). Blood has been collected from smoking and non-smoking healthy individuals as well as from patients with diagnosed chronic pancreatitis and diabetes type 3c. The concentrations of interleukin-6, endothelin-1 and insulin in the plasma were determined by enzyme-linked immunosorbent assay (ELISA) tests. The activities of amylase and lipase in the serum, as well as the lipid profile, creatinine, uric acid and urea concentrations, were measured using colorimetric methods. Samples of normal pancreatic tissue and chronic pancreatitis were verified histopathologically and then interleukin-6, endothelin-1, insulin and glucagon were localized by immunohistochemical staining using a monoclonal anti-human antibody. The highest levels of interleukin-6 and endothelin-1 and the lowest levels of insulin and glucagon intensity from the immunostaining were observed in smoking patients with diabetes. In all smoking patients with pancreatitis and diabetes, there was a significant elevation in interleukin-6 and endothelin-1 concentration and amylase and lipase activities, hyperlipidaemia and a lower value of estimated glomerular filtration rate and blood urea nitrogen when compared to non-smokers. Our study confirmed that smoking exerts a pro-inflammatory effect and disturbs the exocrine-endocrine interactions of the pancreas.

Analysis of Factors Associated with the Severity of Acute Pancreatitis according to Etiology

Background

The objective of this study was to determine the factors associated with severity of acute pancreatitis (AP) according to two major etiologies: alcohol and gallstones.

Methods

We reviewed the medical records of consecutive patients who were admitted with AP between January 2003 and January 2013. A total of 905 patients with AP (660 alcohol-induced, 245 gallstone-induced) were enrolled. Among them, severe AP (SAP) occurred in 72 patients (53 alcohol-induced, 19 gallstone-induced). Contributing factors between patients with and without SAP were analyzed according to the etiology.

Results

Multivariate analysis demonstrated that current smoking, pancreatic necrosis, and bacteremia were associated with AP severity in both alcohol- and gallstone-induced AP. Pancreatic fluid collection was significantly associated with alcohol-induced SAP (p = 0.04), whereas dyslipidemia was significantly associated with gallstone-induced SAP (p = 0.01). Body mass index was significantly correlated with the Bedside Index of Severity in Acute Pancreatitis score in both alcohol- and gallstone-induced AP (p = 0.03 and 0.01, resp.).

Conclusions

Current smoking, pancreatic necrosis, and bacteremia can aggravate the clinical course of AP. Pancreatic fluid collection and dyslipidemia were associated with AP severity according to the different etiologies. Obesity may also be associated with AP severity in both etiologies.

Chronic pancreatitis: Multicentre prospective data collection and analysis by the Hungarian Pancreatic Study Group

Introduction

Chronic pancreatitis is an inflammatory disease associated with structural and functional damage to the pancreas, causing pain, maldigestion and weight loss and thus worsening the quality of life.

Aims and methods

Our aim was to find correlations from a multicentre database representing the epidemiological traits, diagnosis and treatment of the disease in Hungary. The Hungarian Pancreatic Study Group collected data prospectively from 2012 to 2014 on patients suffering from chronic pancreatitis. Statistical analysis was performed on different questions.

Results

Data on 229 patients (74% male and 26% female) were uploaded from 14 centres. Daily alcohol consumption was present in the aetiology of 56% of the patients. 66% of the patients were previously treated for acute exacerbation. One third of the patients had had previous endoscopic or surgical interventions. Pain was present in 69% of the cases, endocrine insufficiency in 33%, diarrhoea in 13% and weight loss in 39%. Diagnosis was confirmed with US (80%), CT scan (52%), MRI-MRCP (6%), ERCP (39%), and EUS (7,4%). A functional test was carried out in 5% of the patients. In 31% of the cases, an endoscopic intervention was performed with the need for re-intervention in 5%. Further elective surgical intervention was necessitated in 44% of endoscopies. 20% of the registered patients were primarily treated with surgery. The biliary complication rate for surgery was significantly smaller (2%) than endoscopy (27%); however, pancreatic complications were higher in the patients treated with surgery. Patients who smoked regularly needed significantly more surgical intervention following endoscopy (66.7% vs. 26.9%, p = 0.002) than non-smokers, and the ratio of surgical intervention alone was also significantly higher (27.3% vs. 10.8%, p = 0.004). The ratio of surgery in patients who smoked and drank was significantly higher (30.09% vs. 12.5%, p = 0.012) than in abstinent and non-smoking patients, similarly to the need for further surgical intervention after endoscopic treatment (71.43% vs. 27.78%, p = 0.004).

Conclusions

According to the data analysed, the epidemiological data and the aetiological factors in our cohort differ little from European trends. The study highlighted the overuse of ERCP as a diagnostic modality and the low ratio of use of endoscopic ultrasonography. The results proved that alcohol consumption and smoking represent risk factors for the increased need for surgical intervention. Chronic pancreatitis should be treated by multidisciplinary consensus grounded in evidence-based medicine.

Inhibition of pancreatic acinar mitochondrial thiamin pyrophosphate uptake by the cigarette smoke component 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone

Thiamin is essential for normal metabolism in pancreatic acinar cells (PAC) and is obtained from their microenvironment through specific plasma-membrane transporters, converted to thiamin pyrophosphate (TPP) in the cytoplasm, followed by uptake of TPP by mitochondria through the mitochondrial TPP (MTPP) transporter (MTPPT; product of SLC25A19 gene). TPP is essential for normal mitochondrial function. We examined the effect of long-term/chronic exposure of PAC in vitro (pancreatic acinar 266-6 cells) and in vivo (wild-type or transgenic mice carrying the SLC25A19 promoter) of the cigarette smoke toxin, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), on the MTPP uptake process. Our in vitro and in vivo findings demonstrate that NNK negatively affects MTPP uptake and reduced expression of MTPPT protein, MTPPT mRNA, and heterogenous nuclear RNA, as well as SLC25A19 promoter activity. The effect of NNK on Slc25a19 transcription was neither mediated by changes in expression of transcriptional factor NFY-1 (known to drive SLC25A19 transcription), nor due to changes in methylation profile of the Slc25a19 promoter. Rather, it appears to be due to changes in histone modifications that involve significant decreases in histone H3K4-trimethylation and H3K9-acetylation (activation markers). The effect of NNK on MTPPT function is mediated through the nonneuronal α7-nicotinic acetylcholine receptor (α7-nAChR), as indicated by both in vitro (using the nAChR antagonist mecamylamine) and in vivo (using an α7-nAchR(-/-) mouse model) studies. These findings demonstrate that chronic exposure of PAC to NNK negatively impacts PAC MTPP uptake. This effect appears to be exerted at the level of Slc25a19 transcription, involve epigenetic mechanism(s), and is mediated through the α7-nAchR.

Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells

Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes.

Smoking and risk for acute pancreatitis: a systematic review and meta-analysis

We aimed to better understand the relationship between smoking and a risk for acute pancreatitis (AP) in existing observational studies. We identified studies by searching the PubMed, Scopus, and Web of Science databases (from inception through August 31, 2013) and by searching bibliographies of relevant articles. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated with fixed-effects and random-effects models. A total of 5 studies met inclusion criteria for analysis. Both current smoking (summary RR, 1.74; 95% CI, 1.39-2.17; n = 5 studies) and former smoking (summary RR, 1.32; 95% CI, 1.03-1.71; n = 4 studies) were associated with an increased risk for AP. The positive association of current smoking and risk for AP remained when we limited the meta-analysis to studies that controlled for alcohol intake and body mass index (summary RR, 1.76; 95% CI, 1.31-2.36; n = 4 studies). Both current and former smoking are associated with increased risk for AP. Further investigations, both epidemiological and mechanistic, are needed to establish the extent to which the association can be explained by a causal link and whether smoking cessation can prevent the occurrence and development of AP.

Treatment options for chronic pancreatitis

This Review covers the latest developments in the treatment options for chronic pancreatitis. Pain is the most frequent and dominant symptom in patients with chronic pancreatitis, which ranges from severe disabling continuous pain to mild pain attacks and pain-free periods. Conventional treatment strategies and recent changes in the treatment of pain in patients with chronic pancreatitis are outlined. The different treatment options for pain consist of medical therapy, endoscopy or surgery. Their related merits and drawbacks are discussed. Finally, novel insights in the field of genetics and microbiota are summarized, and future perspectives are discussed.

Effect of the cigarette smoke component, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), on physiological and molecular parameters of thiamin uptake by pancreatic acinar cells

Thiamin is indispensable for the normal function of pancreatic acinar cells. These cells take up thiamin via specific carrier-mediated process that involves thiamin transporter-1 and -2 (THTR-1 and THTR-2; products of SLC19A2 and SLC19A3 genes, respectively). In this study we examined the effect of chronic exposure of pancreatic acinar cells in vitro (pancreatic acinar 266-6 cells) and in vivo (wild-type and transgenic mice carrying the SLC19A2 and SLC19A3 promoters) to the cigarette smoke component 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on physiological and molecular parameters of the thiamin uptake process. The results show that chronic exposure of 266-6 cells to NNK (3 µM, 24 h) leads to a significant inhibition in thiamin uptake. The inhibition was associated with a significant decrease in the level of expression of THTR-1 and -2 at the protein and mRNA levels as well as in the activity of SLC19A2 and SLC19A3 promoters. Similarly chronic exposure of mice to NNK (IP 10 mg/100 g body weight, three times/week for 2 weeks) leads to a significant inhibition in thiamin uptake by freshly isolated pancreatic acinar cells, as well as in the level of expression of THTR-1 and -2 protein and mRNA. Furthermore, activity of the SLC19A2 and SLC19A3 promoters expressed in transgenic mice were significantly suppressed by chronic exposure to NNK. The effect of NNK on the activity of the SLC19A2 and SLC19A3 promoters was not mediated via changes in their methylation profile, rather it appears to be exerted via an SP1/GG and SP1/GC cis-regulatory elements in these promoters, respectively. These results demonstrate, for the first time, that chronic exposure of pancreatic acinar cells to NNK negatively impacts the physiological and molecular parameters of thiamin uptake by pancreatic acinar cells and that this effect is exerted, at least in part, at the level of transcription of the SLC19A2 and SLC19A3 genes.

Pain in chronic pancreatitis: Managing beyond the pancreatic duct

Chronic pancreatitis (CP) continues to be a clinical challenge. Persistent or recurrent abdominal pain is the most compelling symptom that drives patients to seek medical care. Unfortunately, in spite of using several treatment approaches in the clinical setting, there is no single specific treatment modality that can be earmarked as a cure for this disease. Traditionally, ductal hypertension has been associated with causation of pain in CP; and patients are often subjected to endotherapy and surgery with a goal to decompress the pancreatic duct. Recent studies on humans (clinical and laboratory based) and experimental models have put forward several mechanisms, including neuroimmune alterations, which could be responsible for pain. This might explain the partial or no response to single modality treatment in a significant proportion of patients. The current review discusses the recent concepts of pain generation in CP and evidence based therapeutic approaches (other than ductal decompression) to handle persistent or recurrent pain. We focus primarily on parenchymal and neural components; and discuss the role of antioxidants and the existing controversies, drugs that interfere with neural transmission, pancreatic enzyme supplementation, celiac neurolysis, and pancreatic resection procedures. The review concludes with the treatment approach that we follow at our institute.

Vegetables, fruit and risk of non-gallstone-related acute pancreatitis: a population-based prospective cohort study

OBJECTIVE

To examine the association of vegetable and fruit consumption with the risk of non-gallstone-related acute pancreatitis.

DESIGN

A population-based prospective cohort of 80,019 women and men, aged 46-84 years, completed a food-frequency questionnaire at baseline and was followed up for incidence of non-gallstone-related acute pancreatitis from 1 January 1998 to 31 December 2009. Participants were categorised into quintiles according to consumption of vegetables and consumption of fruit. Cox proportional hazards models were used to estimate RRs and 95% CIs.

RESULTS

In total, 320 incident cases (216 men and 104 women) with non-gallstone-related acute pancreatitis were identified during 12 years of follow-up (891,136 person-years). After adjustment for potential confounders, the authors observed a significant inverse linear dose-response association between vegetable consumption and risk of non-gallstone-related acute pancreatitis; every two additional servings per day were associated with 17% risk reduction (RR=0.83; 95% CI 0.70 to 0.98; p=0.03). Among participants consuming >1 drink of alcohol per day and among those with body mass index ≥25 kg/m2, the RR for the highest compared with the lowest quintile of vegetable consumption was 0.29 (95% CI 0.13 to 0.67) and 0.49 (95% CI 0.29 to 0.85), respectively. Fruit consumption was not significantly associated with the risk of non-gallstone-related acute pancreatitis; the RR comparing extreme quintiles of consumption was 1.20 (95% CI 0.81 to 1.78).

CONCLUSIONS

Vegetable consumption, but not fruit consumption, may play a role in the prevention of non-gallstone-related acute pancreatitis.

Risk models for post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP): smoking and chronic liver disease are predictors of protection against PEP

OBJECTIVES

We investigated which variables independently associated with protection against or development of postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) and severity of PEP. Subsequently, we derived predictive risk models for PEP.

METHODS

In a case-control design, 6505 patients had 8264 ERCPs, 211 patients had PEP, and 22 patients had severe PEP. We randomly selected 348 non-PEP controls. We examined 7 established- and 9 investigational variables.

RESULTS

In univariate analysis, 7 variables predicted PEP: younger age, female sex, suspected sphincter of Oddi dysfunction (SOD), pancreatic sphincterotomy, moderate-difficult cannulation (MDC), pancreatic stent placement, and lower Charlson score. Protective variables were current smoking, former drinking, diabetes, and chronic liver disease (CLD, biliary/transplant complications). Multivariate analysis identified seven independent variables for PEP, three protective (current smoking, CLD-biliary, CLD-transplant/hepatectomy complications) and 4 predictive (younger age, suspected SOD, pancreatic sphincterotomy, MDC). Pre- and post-ERCP risk models of 7 variables have a C-statistic of 0.74. Removing age (seventh variable) did not significantly affect the predictive value (C-statistic of 0.73) and reduced model complexity. Severity of PEP did not associate with any variables by multivariate analysis.

CONCLUSIONS

By using the newly identified protective variables with 3 predictive variables, we derived 2 risk models with a higher predictive value for PEP compared to prior studies.

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

Cigarette smoking is the single most important epidemiological risk factor for bladder cancer but it is not known whether exposure of urothelial cells to the systemic soluble contents of cigarette smoke is directly causative to bladder cancer and the associated epigenetic changes such as tumor suppressor gene hypermethylation. We undertook this study to investigate if long-term treatment of human urothelial cells with cigarette smoke extract (CSE) results in tumor suppressor gene hypermethylation, a phenotype that was previously associated with long-term constant CSE treatment of airway epithelial cells. We chronically treated an immortalized human urothelial cell line UROtsa with CSE using a cyclic daily regimen but the cells were cultured in CSE-free medium between daily treatments. Bisulfite sequencing and real-time PCR array-based methylation profiling were employed to evaluate methylation changes at tumor suppressor gene loci in the chronically CSE-treated cells versus the passage-matched untreated control cells. The RUNX3 tumor suppressor gene promoter was hypomethylated with a significant increase in proportion of the completely unmethylated haplotype after the long-term CSE treatment; whereas RUNX3 promoter hypermethylation was previously reported for bladder cancers of smokers. Hypomethylation induced by the long-term CSE treatment was also observed for the IGF2-H19 locus. The methylation status at the PRSS8/prostasin and 16 additional loci however, was unaffected by the chronic CSE treatment. Transient CSE treatment over 1 daily regimen resulted in transcriptional down-regulation of RUNX3 and H19, but only the H19 transcription was down-regulated in the chronically CSE-treated urothelial cells. Transcription of a key enzyme in one-carbon metabolism, dihydrofolate reductase (DHFR) was greatly reduced by the long-term CSE treatment, potentially serving as a mechanism for the hypomethylation phenotype via a reduced supply of methyl donor. In conclusion, chronic cyclic CSE treatment of urothelial cells induced hypomethylation rather than hypermethylation at specific loci.

Immunohistochemical localization of somatostatin and pancreatic polypeptide in smokers with chronic pancreatitis

Recent studies have demonstrated a significant role of tobacco smoking in the development of chronic pancreatitis. Although there are published papers on the effects of cigarette smoking on insulin secretion in patients, no data are available on the effects of smoking on pancreatic endocrine cells secreting somatostatin and pancreatic polypeptide. The aim of the study was to evaluate the effects of cigarette smoking on endocrine pancreatic function by immunolocalization of somatostatin and pancreatic polypeptide in the pancreas from smokers and non-smoking patients with chronic pancreatitis in comparison with healthy controls. The LSAB2-HRP technique with polyclonal antibodies was used for the immunolocalization of somatostatin and pancreatic polypeptide in histological preparations of the pancreas. The intensity of immunohistochemical reaction was calculated with digital image analysis. The study demonstrated increased numbers of somatostatin (D) secreting cells and pancreatic polypeptide (PP) cells and their altered location in pancreatic islets and parenchyma of smoking patients with chronic pancreatitis, as compared to non-smoking patients and healthy controls. Smoking patients showed significantly higher immunostaining of the hormones in the pancreas compared to non-smoking patients and healthy persons. This study indicates that smoking may play a significant role in the development of endocrine disturbances in the development of chronic pancreatitis.

Interplay between smoking-induced genotoxicity and altered signaling in pancreatic carcinogenesis

Despite continuous research efforts directed at early diagnosis and treatment of pancreatic cancer (PC), the status of patients affected by this deadly malignancy remains dismal. Its notoriety with regard to lack of early diagnosis and resistance to the current chemotherapeutics is due to accumulating signaling abnormalities. Hoarding experimental and epidemiological evidences have established a direct correlation between cigarette smoking and PC risk. The cancer initiating/promoting nature of cigarette smoke can be attributed to its various constituents including nicotine, which is the major psychoactive component, and several other toxic constituents, such as nitrosamines, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and polycyclic aromatic hydrocarbons. These predominant smoke-constituents initiate a series of oncogenic events facilitating epigenetic alterations, self-sufficiency in growth signals, evasion of apoptosis, sustained angiogenesis, and metastasis. A better understanding of the molecular mechanisms underpinning these events is crucial for the prevention and therapeutic intervention against PC. This review presents various interconnected signal transduction cascades, the smoking-mediated genotoxicity, and genetic polymorphisms influencing the susceptibility for smoking-mediated PC development by modulating pivotal biological aspects such as cell defense/tumor suppression, inflammation, DNA repair, as well as tobacco-carcinogen metabolization. Additionally, it provides a large perspective toward tumor biology and the therapeutic approaches against PC by targeting one or several steps of smoking-mediated signaling cascades.

The effect of smoking on expression of IL-6 and antioxidants in pancreatic fluids and tissues in patients with chronic pancreatitis

OBJECTIVES

The present study was conducted to ascertain whether cigarette smoke induces oxidative stress in the human pancreas concurrently with inflammation.

MATERIALS AND METHODS

The influence of tobacco smoking on the serum level of interleukin-6 (IL-6), on the activities of glutathione peroxidase (GPx) and copper-zinc superoxide dismutase (Cu/Zn SOD) as well as on the metallothionein (MT) level in the pancreatic pseudocyst fluid and its immunohistochemical localization in tissues of non-smoking (n = 9) and smoking (n = 12) patients with diagnosed chronic pancreatitis (CP) was measured. The concentration of interleukin-6 and metallothionein was determined by means of ELISA and the radioisotopic method, respectively. The enzyme activities in the fluid were assayed by the colorimetric method. Samples of tissues of normal pancreas (n = 4) and CP (non-smoking n = 7; smoking n = 12) were verified histopathologically and then IL-6, MT and enzymes were localized by immunohistochemical staining using the monoclonal anti-human antibody.

RESULTS

The concentrations of metallothionein and interleukin-6 were significantly higher in smoking patients with CP (as compared with the non-smoking population (p < 0.01; p < 0.001). Interestingly, the ratio of MT/IL-6 in smoking patients with CP was reduced in comparison to non-smoking patients (respectively: 1.1; 5.6). In smoking patients, a significant elevation of the Cu/Zn SOD and GPx activities was revealed as compared with the non-smokers (p < 0.04; p < 0.0007). These studies clearly demonstrate a moderate and strong expression of IL-6 and enzymes in acinar, islet and duct cells of smoking patients.

CONCLUSIONS

These observations favor the role of the oxidative stress in the induction of pancreatitis associated with chronic cigarette smoke inhalation.

Smoking is related to pancreatic fibrosis in humans

OBJECTIVES

Smokers are at risk for pancreatic cancer (PC) and other pancreatic diseases. Cigarette smoking also aggravates the risk of PC in patients with hereditary and chronic pancreatitis (CP) and results in a higher incidence of acute pancreatitis and relapses in CP. Both PC and CP are characterized by a progressive fibrosis. Recently, two studies on rats reported that tobacco smoking is associated with chronic pancreatic inflammation with fibrosis and scarring of pancreatic acinar structures. In this study, we aimed to confirm a relationship between cigarette smoking and pancreatic fibrosis (PF) in humans.

METHODS

In this retrospective study, pancreatic and liver tissue acquired during autopsy was collected and analyzed. PF was scored by assessing severity of intralobular, extralobular, and total PF: grade 0 (normal or mild; 0-25% PF), grade 1 (moderate; 25-50% PF), and grade 2 (severe; >50%). Information on smoking habits was extracted from (electronic) medical records.

RESULTS

Of 900 autopsies performed from January 2005 to December 2007, a minority of patients (n=111) met all inclusion criteria for analysis. Grade 2-3 total PF and intralobular PF was significantly more present in smokers vs. "never-smokers" (total: 42.9 vs. 26.5%, P=0.027 and intralobular: 39.3 vs. 15.6%, P=0.013), whereas no differences could be found between never-smokers and ex-smokers and between ex-smokers and smokers. When we took into account interlobular PF, no differences between all groups were observed. No relationship between PF and age (P=0.893), body mass index (P=0.707), and pancreatic lipomatosis (P=0.916) was observed.

CONCLUSIONS

To our knowledge, no study in humans had studied the effect of tobacco smoking on pancreatic tissue. We have demonstrated for the first time that current cigarette smoking is associated with total PF-specifically, intralobular PF-as compared with nonsmokers.

Chronic pancreatitis

Chronic pancreatitis is a progressive fibroinflammatory disease that exists in large-duct (often with intraductal calculi) or small-duct form. In many patients this disease results from a complex mix of environmental (eg, alcohol, cigarettes, and occupational chemicals) and genetic factors (eg, mutation in a trypsin-controlling gene or the cystic fibrosis transmembrane conductance regulator); a few patients have hereditary or autoimmune disease. Pain in the form of recurrent attacks of pancreatitis (representing paralysis of apical exocytosis in acinar cells) or constant and disabling pain is usually the main symptom. Management of the pain is mainly empirical, involving potent analgesics, duct drainage by endoscopic or surgical means, and partial or total pancreatectomy. However, steroids rapidly reduce symptoms in patients with autoimmune pancreatitis, and micronutrient therapy to correct electrophilic stress is emerging as a promising treatment in the other patients. Steatorrhoea, diabetes, local complications, and psychosocial issues associated with the disease are additional therapeutic challenges.

Superoxide dismutase and nicotinamide adenine dinucleotide phosphate: quinone oxidoreductase polymorphisms and pancreatic cancer risk

OBJECTIVES

Pancreatic carcinoma etiology and molecular pathogenesis is weakly understood. According to the assumption that genetic variation in carcinogen metabolism further modifies the risk of exposure-related cancers, an association of functional polymorphisms in oxidative stress-modifying genes superoxide dismutase 2 (SOD2 [Ala16Val, rs4880]), SOD3 (Arg231Gly, rs1799895), nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase (NQO1 [Pro187Ser, rs1800566], and NQO2 (Phe47Leu, rs1143684) with pancreatic cancer risk was studied.

METHODS

Polymorphisms were studied by allelic discrimination.

RESULTS

In a hospital-based case-control study on 500 individuals (235 cases and 265 controls) of Czech white origin, SOD2, SOD3, NQO1, and NQO2 polymorphisms showed no significant association with pancreatic cancer risk. Major lifestyle factors such as smoking and alcohol, coffee, or tea consumption did not modify the effect of the studied polymorphisms.

CONCLUSIONS

The first European study of the SOD2, SOD3, NQO1, and NQO2 roles in pancreatic cancer etiology did not find significant associations. Despite this observation, other populations with different lifestyle(s) may be at risk and should be further studied.

Chronic pancreatitis

PURPOSE OF REVIEW

We review important new clinical observations in chronic pancreatitis made in the past year.

RECENT FINDINGS

Cigarette smoking is a dose-dependent risk factor for acute pancreatitis, recurrent acute pancreatitis, and chronic pancreatitis. A minority of chronic alcohol consumers develop recurrent acute pancreatitis but very heavy drinking associates with chronic pancreatitis. More patients with alcohol-induced chronic pancreatitis have cirrhosis than patients with cirrhosis have chronic pancreatitis (39 vs. 18%). Most patients with asymptomatic hyperenzymemia have no pancreatic lesions. Pancreatic calcifications are most frequently due to chronic pancreatitis, followed by cystic neoplasms and other disorders. The new Rosemont consensus classification of endoscopic ultrasonography criteria for chronic pancreatitis is unvalidated. Zinc deficiency correlates only with severe chronic pancreatitis and the fecal elastase test is an inaccurate marker of pancreatic steatorrhea. Patients commonly receive insufficient lipase to abolish pancreatic steatorrhea. Ultrastructural neuropathies are common to chronic pancreatitis and pancreatic cancer and correlate with pain severity.

SUMMARY

Results of this year's investigations further elucidated risk factors for pancreatic disease, the natural history of alcoholic pancreatitis, the differential diagnosis of pancreatic calcifications, the diagnosis of chronic pancreatitis with the Rosemont criteria, the limited diagnostic utility of fecal elastate test and zinc measurements, the proper dosing of pancreatic enzyme supplements, and treatment of pancreatic pain.