Nicotine Reduces Survival via Augmentation of Paracrine HGF-MET Signaling in the Pancreatic Cancer Microenvironment

Investigation of the α9-nicotinic receptor single nucleotide polymorphisms induced oncogenic properties and molecular mechanisms in breast cancer

α9-nAChR, a subtype of nicotinic acetylcholine receptor, is significantly overexpressed in female breast cancer tumor tissues compared to normal tissues. Previous studies have proposed that specific single nucleotide polymorphisms (SNPs) in the CHRNA9 (α9-nAChR) gene are associated with an increased risk of breast cancer in interaction with smoking. The study conducted a breast cancer risk assessment of the α9-nAChR SNP rs10009228 (NM_017581.4:c.1325A > G) in the Taiwanese female population, including 308 breast cancer patients and 198 healthy controls revealed that individuals with the heterozygous A/G or A/A wild genotype have an increased susceptibility to developing breast cancer in the presence of smoking compared to carriers of the G/G variant genotype. Our investigation confirmed the presence of this missense variation, resulting in an alteration of the amino acid sequence from asparagine (N442) to serine (S442) to facilitate phosphorylation within the α9-nAchR protein. Additionally, overexpression of N442 (A/A) in breast cancer cells significantly enhanced cell survival, migration, and cancer stemness compared to S442 (G/G). Four-line triple-negative breast cancer patient-derived xenograft (TNBC-PDX) models with distinct α9-nAChR rs10009228 SNP genotypes (A/A, A/G, G/G) further demonstrated that chronic nicotine exposure accelerated tumor growth through sustained activation of the α9-nAChR downstream oncogenic AKT/ERK/STAT3 pathway, particularly in individuals with the A/G or A/A genotype. Collectively, our study established the links between genetic variations in α9-nAChR and smoking exposure in promoting breast tumor development. This emphasizes the need to consider gene-environment interactions carefully while developing effective breast cancer prevention and treatment strategies.

Smoking history is associated with reduced efficacy of neoadjuvant therapy in pancreatic adenocarcinoma

BACKGROUND

Differential responses to neoadjuvant therapy (NAT) exist in pancreatic ductal adenocarcinoma (PDAC); however, contributing factors are poorly understood. Tobacco smoke is a common risk factor for PDAC, with nicotine-induced chemoresistance observed in other cancers. This study aimed to explore the potential association between tobacco use and NAT efficacy in PDAC.

METHODS

A single-center, retrospective analysis was conducted that included all consecutive patients with PDAC who underwent surgical resection after NAT with a documented smoking history (N = 208). NAT response was measured as percentage fibrosis in the surgical specimen. Multivariable models controlled for covariates and survival were modeled using the Kaplan-Meier method.

RESULTS

Postoperatively, major responses to NAT (>95% fibrosis) were less frequently observed in smokers than in nonsmokers (13.7% vs 30.4%, respectively; P = .021). Pathologic complete responses were similarly less frequent in smokers than in nonsmokers (2.1% vs 9.9%, respectively; P = .023). On multivariate analysis controlling for covariates, smoking history remained independently associated with lower odds of major fibrosis (odds ratio [OR], 0.25; 95% CI, 0.10-0.59; P = .002) and pathologic complete response (OR, 0.21; 95% CI, 0.03-0.84; P = .05). The median overall survival was significantly longer in nonsmokers than in smokers (39.1 vs 26.6 months, respectively; P = .05).

CONCLUSION

Tobacco use was associated with diminished pathologic responses to NAT. Future research to understand the biology underlying this observation is warranted and may inform differential NAT approaches or counseling among these populations.

Cell signaling and epigenetic regulation of nicotine-induced carcinogenesis

Nicotine, a naturally occurring tobacco alkaloid responsible for tobacco addiction, has long been considered non-carcinogenic. However, emerging evidence suggests that nicotine may possess carcinogenic properties in mice and could be a potential carcinogen in humans. This review aims to summarize the potential molecular mechanisms underlying nicotine-induced carcinogenesis, with a specific focus on epigenetic regulation and the activation of nicotinic acetylcholine receptors (nAChRs) in addition to genotoxicity and excess reactive oxygen species (ROS). Additionally, we explore a novel hypothesis regarding nicotine's carcinogenicity involving the downregulation of stem-loop binding protein (SLBP), a critical regulator of canonical histone mRNA, and the polyadenylation of canonical histone mRNA. By shedding light on these mechanisms, this review underscores the need for further research to elucidate the carcinogenic potential of nicotine and its implications for human health.

GCF2 mediates nicotine-induced cancer stemness and progression in hepatocellular carcinoma

Cigarette smoking is one of the most impactful behavior-related risk factors for multiple cancers including hepatocellular carcinoma (HCC). Nicotine, as the principal component of tobacco, is not only responsible for smoking addiction but also a carcinogen; nevertheless, the underlying mechanisms remain unclear. Here we report that nicotine enhances HCC cancer stemness and malignant progression by upregulating the expression of GC-rich binding factor 2 (GCF2), a gene that was revealed to be upregulated in HCC and whose upregulation predicts poor prognosis, and subsequently activating the Wnt/ꞵ-catenin/SOX2 signaling pathway. We found that nicotine significantly increased GCF2 expression and that silencing of GCF2 reduced nicotine-induced cancer stemness and progression. Mechanistically, nicotine could stabilize the protein level of GCF2, and then GCF2 could robustly activate its downstream Wnt/β-catenin signaling pathway. Taken together, our results thus suggest that GCF2 is a potential target for a therapeutic strategy against nicotine-promoted HCC.

A systematic review of preclinical studies evaluating the association between nicotine and the initiation and progression of cancer

Background

The association between cigarette smoking and the increased risk of many cancers is well established. Conversely, epidemiological studies of smokeless tobacco demonstrate decreased risk, or no elevated risk, of certain cancers versus smoking. However, it is unclear what role, if any, nicotine plays in these associations. The objective of this systematic review was to synthesize the available evidence from preclinical studies that examined the potential association between nicotine and the initiation and/or progression of cancer.

Methods

MEDLINE, Embase, PsychInfo, and Cochrane Database of Systematic Reviews were searched for articles published from inception until February 13, 2022. Studies were eligible for inclusion if they evaluated animal cancer or tumor models, compared nicotine and non-nicotine groups, and evaluated measures of cancer initiation or progression.

Results

Among 1,137 identified articles, 61 were included in qualitative synthesis. Twelve studies reported data on tumor initiation, and 54 studies reported data on tumor progression. The majority of the tumor initiation studies did not identify an association between nicotine exposure and an increased risk of spontaneous tumor initiation. Results of tumor progression studies were inconsistent and varied across the reported measures, cancer type being evaluated, and animal cancer model used. Overall, the quality of reporting was poor, with many studies not demonstrating a high level of internal and/or external validity.

Conclusions

In conclusion, although animal models have provided invaluable data for human health risk assessments of chemical exposures, the heterogeneity across the studies included in this systematic review make the interpretation and generalizability of the results difficult.

Ephexin3/ARHGEF5 Together with Cell Migration Signaling Partners within the Tumor Microenvironment Define Prognostic Transcriptional Signatures in Multiple Cancer Types

Cancer cell migration involves a repertoire of signaling proteins that lead cytoskeleton reorganization as a critical step in metastatic dissemination. RhoGEFs are multidomain effectors that integrate signaling inputs to activate the molecular switches that orchestrate actin cytoskeleton reorganization. Ephexins, a group of five RhoGEFs, play oncogenic roles in invasive and metastatic cancer, leading to a mechanistic hypothesis about their function as signaling nodes assembling functional complexes that guide cancer cell migration. To identify clinically significant Ephexin signaling partners, we applied three systematic data mining strategies, based on the screening of essential Ephexins in multiple cancer cell lines and the identification of coexpressed signaling partners in the TCGA cancer patient datasets. Based on the domain architecture of encoded proteins and gene ontology criteria, we selected Ephexin signaling partners with a role in cytoskeletal reorganization and cell migration. We focused on Ephexin3/ARHGEF5, identified as an essential gene in multiple cancer cell types. Based on significant coexpression data and coessentiality, the signaling repertoire that accompanies Ephexin3 corresponded to three groups: pan-cancer, cancer-specific and coessential. To further select the Ephexin3 signaling partners likely to be relevant in clinical settings, we first identified those whose high expression was statistical linked to shorter patient survival. The resulting Ephexin3 transcriptional signatures represent significant accumulated risk, predictive of shorter survival, in 17 cancer types, including PAAD, LUAD, LGG, OSC, AML, KIRC, THYM, BLCA, LIHC and UCEC. The signaling landscape that accompanies Ephexin3 in various cancer types included the tyrosine kinase receptor MET and the tyrosine phosphatase receptor PTPRF, the serine/threonine kinases MARK2 and PAK6, the Rho GTPases RHOD, RHOF and RAC1, and the cytoskeletal regulator DIAHP1. Our findings set the basis to further explore the role of Ephexin3/ARHGEF5 as an essential effector and signaling hub in cancer cell migration.

Smoking impairs the effect of neoadjuvant FOLFIRINOX on postresection survival in pancreatic cancer

INTRODUCTION

Smoking plays an important role in carcinogenesis, including pancreatic ductal adenocarcinoma (PDAC). However, little is known about the association between smoking status and prognosis in resected PDAC.

METHODS

All patients who underwent resection for PDAC were identified from two prospective institutional databases. Clinicopathologic data as well as demographics including smoking status were extracted. Survival analysis and multivariable Cox regression modelling was performed. Restricted cubic splines were used for linear data to define cut-off points.

RESULTS

Out of 848 patients, 357 (42.1%) received neoadjuvant treatment (NAT), 491 upfront resection (57.9%), and 475 (56%) adjuvant therapy. The median overall survival (OS) was 27.8 months, 36.1 months, and 23.0 months for the entire cohort, after NAT and upfront resection. 464 patients were never smokers (54.7%), 250 former smokers (29.5%), and 134 active smokers (15.8%). In the multivariable model, the interaction of neoadjuvant FOLFIRINOX and active smoking was associated with the highest risk for decreased OS (harzard ratio (HR) 2.35; 95% confidence interval 1.13-4.90) and strongly mitigated the benefit of FOLFIRNOX (HR 0.40; 95% CI 0.25-0.63). Adjusted median OS in NAT patients with FOLFIRINOX was not reached for never and former smokers, compared to 26.2 months in active smokers. Based on the model, a nomogram was generated to illustrate the probability of 5-year survival after PDAC resection.

CONCLUSION

The present study confirms that neoadjuvant FOLFIRINOX is associated with excellent survival and demonstrates that active smoking reduces its benefit. The nomogram can assist in daily clinical practice and emphasises the importance of smoking cessation in patients with PDAC, especially prior to NAT with FOLFIRINOX.

Classification of Pancreatic Ductal Adenocarcinoma Using MALDI Mass Spectrometry Imaging Combined with Neural Networks

Despite numerous diagnostic and therapeutic advances, pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate, and is the fourth leading cause of cancer death in developing countries. Besides its increasing prevalence, pancreatic malignancies are characterized by poor prognosis. Omics technologies have potential relevance for PDAC assessment but are time-intensive and relatively cost-intensive and limited by tissue heterogeneity. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can obtain spatially distinct peptide-signatures and enables tumor classification within a feasible time with relatively low cost. While MALDI-MSI data sets are inherently large, machine learning methods have the potential to greatly decrease processing time. We present a pilot study investigating the potential of MALDI-MSI in combination with neural networks, for classification of pancreatic ductal adenocarcinoma. Neural-network models were trained to distinguish between pancreatic ductal adenocarcinoma and other pancreatic cancer types. The proposed methods are able to correctly classify the PDAC types with an accuracy of up to 86% and a sensitivity of 82%. This study demonstrates that machine learning tools are able to identify different pancreatic carcinoma from complex MALDI data, enabling fast prediction of large data sets. Our results encourage a more frequent use of MALDI-MSI and machine learning in histopathological studies in the future.

Pancreatic Tumorigenesis: Precursors, Genetic Risk Factors and Screening

Pancreatic cancer (PC) is a highly malignant and aggressive tumor. Despite medical advancement, the silent nature of PC results in only 20% of all cases considered resectable at the time of diagnosis. It is projected to become the second leading cause in 2030. Most pancreatic cancer cases are diagnosed in the advanced stages. Such cases are typically unresectable and are associated with a 5-year survival of less than 10%. Although there is no guideline consensus regarding recommendations for screening for pancreatic cancer, early detection has been associated with better outcomes. In addition to continued utilization of imaging and conventional tumor markers, clinicians should be aware of novel testing modalities that may be effective for early detection of pancreatic cancer in individuals with high-risk factors. The pathogenesis of PC is not well understood; however, various modifiable and non-modifiable factors have been implicated in pancreatic oncogenesis. PC detection in the earlier stages is associated with better outcomes; nevertheless, most oncological societies do not recommend universal screening as it may result in a high false-positive rate. Therefore, targeted screening for high-risk individuals represents a reasonable option. In this review, we aimed to summarize the pathogenesis, genetic risk factors, high-risk population, and screening modalities for PC.

Risk Factors Associated with Pancreatic Cancer in the UK Biobank Cohort

Evidence on pancreatic cancer (PaCa) risk factors from large population-based cohort studies is limited. This study investigated the PaCa risk factors and the population attributable fraction (PAF) of modifiable risk factors in the UK Biobank cohort. The UK Biobank is a prospective cohort consisting of 502,413 participants with a mean follow-up time of 8.2 years. A binomial generalized linear regression model was used to calculate relative risks for PaCa risk factors. PAF was calculated to estimate the proportional reduction in PaCa if modifiable risk factors were to be eliminated. A total of 728 (0.14%) PaCa incident cases and 412,922 (82.19%) non-PaCa controls were analyzed. The non-modifiable risk factors included age and gender. The modifiable risk factors were cigarette smoking, overweight and obesity, increased waist circumstance, abdominal obesity, Diabetic Mellitus (DM), and pancreatitis history. The PAF suggested that eliminating smoking and obesity can contribute around a 16% reduction in PaCa cases while avoiding abdominal obesity can eliminate PaCa cases by 22%. Preventing pancreatitis and DM could potentially reduce PaCa cases by 1% and 6%, respectively. This study has identified modifiable and non-modifiable PaCa risk factors in the UK population. The PAF of modifiable risk factors can be applied to inform PaCa prevention programs.

Nicotine-induced miR-21-3p promotes chemoresistance in lung cancer by negatively regulating FOXO3a

Lung cancer is the leading cause of cancer-related mortality worldwide and cigarette smoking is reported to contribute to the lung cancer-related mortality. The present study aimed to investigate the molecular mechanism underlying nicotine-induced chemoresistance in lung cancer. The expression of microRNA (miR)-21-3p and its predicted target FOXO3a in lung cancer cells was detected via reverse transcription-quantitative PCR, in the presence or absence of nicotine. The regulatory effect of miR-21-3p and FOXO3a on lung cancer cell proliferation and apoptosis induced by docetaxel or cisplatin treatment was evaluated by performing Cell Counting Kit-8 and Annexin V/PI staining assays, respectively. The interaction between miR-21-3p and FOXO3a was analyzed by performing luciferase reporter assays and western blotting. FOXO3a overexpression rescue experiments were conducted in vitro and in vivo using a xenograft mouse model to assess the function of miR-21-3p/FOXO3a in lung cancer. Nicotine induced miR-21-3p expression in lung cancer cells in a dose-dependent manner. miR-21-3p downregulated FOXO3a expression by directly binding to the 3′-untranslated region of FOXO3a. Moreover, miR-21-3p knockdown sensitized lung cancer cells to docetaxel or cisplatin treatment. Mechanistically, FOXO3a was predicted as a direct target of miR-21-3p. FOXO3a overexpression promoted the chemosensitivity of lung cancer cells to docetaxel or cisplatin treatment. Furthermore, FOXO3a overexpression antagonized the regulatory function of miR-21-3p on docetaxel- or cisplatin-treated lung cancer cells. In the docetaxel- or cisplatin-treated lung cancer xenograft mouse model, miR-21-3p promoted chemoresistance via negatively regulating FOXO3a. Therefore, the present study demonstrated that nicotine-induced miR-21-3p promoted chemoresistance to docetaxel or cisplatin treatment via negatively regulating FOXO3a, which may serve as a novel therapeutic strategy for the treatment of patients with chemoresistant lung cancer.

The role of cancer stromal fibroblasts in mediating the effects of tobacco-induced cancer cell growth

Tobacco products cause a variety of cancers, nicotine and carcinogens are two major factors to link the tobacco products and various cancers. The mechanism of tobacco inducing carcinogenesis and promoting cancer progression have been studied for a long time. However, mainstream studies just focus on the mutagenic characteristics of tobacco product and its properties to induce carcinogenesis of epithelial cells. In the past decades, people began to aware of the significant role of tumor stroma in cancer development and progression. Fibroblasts, which is associated with various cancer in all stage of disease progression, are the dominant cell type in the tumor microenvironment. While only a few studies explore the crosstalk between tobacco-induced fibroblasts and surrounding epithelial cells. Our purpose is to systematically review the effects of tobacco products on fibroblasts and further discuss how these effects affect the development of cancer cells.

Roles of MET in human cancer

The MET proto-oncogene was first identified in osteosarcoma cells exposed to carcinogens. Although expressed in many normal cells, MET is overexpressed in many human cancers. MET is involved in the initiation and development of various human cancers and mediates proliferation, migration and invasion. Accordingly, MET has been successfully used as a biomarker for diagnosis and prognosis, survival, post-operative recurrence, risk assessment and pathologic grading, as well as a therapeutic target. In addition, recent work indicates that inhibition of MET expression and function has potential clinical benefit. This review summarizes the role, mechanism, and clinical significance of MET in the formation and development of human cancer.

Impact of diabetes and modifiable risk factors on pancreatic cancer survival in a population-based study after adjusting for clinical factors

PURPOSES

Our study aimed to examine the impact of diabetes, smoking and BMI on pancreatic cancer survival in a population-based setting by adjusting both sociodemographic and clinical factors and measuring their attributable risk.

METHODS

Data on pancreatic adenocarcinoma patients diagnosed in 2011-2017 were acquired from the Louisiana Tumor Registry. Diabetes, smoking, height, and weight were abstracted from medical records and linked with Hospital Inpatient Discharge Data to enhance the completeness of the diabetes data. The Cox regression model was used to assess effect sizes of diabetes, smoking, and BMI on cancer-specific survival and survival rate. The partial population attributable risk was employed to measure the attributable risk of these risk factors.

RESULTS

Of the 3,200 eligible patients, 34.6% were diabetics, 23.9% were current smokers, and 52.3% had BMI ≥ 25 kg/m². After adjusting for sociodemographic and clinical factors, diabetic patients had an increased cancer-specific death risk of 15% (95% CI, 1.06-1.25), 36% (95% CI, 1.19-1.44) for current smokers, and 24% (95% CI, 1.00-1.54) for patients with a BMI ≥ 40 when compared to their counterparts. Diabetic current smokers had significantly lower 2- and 3-year adjusted cancer-specific survival rates, 13.1% and 10.5%, respectively. By eliminating diabetes and modifiable risk factors, an estimated 16.6% (95% CI, 6.9%-25.9%) of the cancer-specific deaths could be avoided during a nine-year observational period between 2011 and 2019.

CONCLUSIONS

Diabetes and smoking contributed substantially to the reduction of pancreatic cancer survival even after controlling for sociodemographic and clinical factors; however, BMI ≥ 35 was observed to increase risk of mortality among stage III-IV patients only.

Pancreatic cancer: A review of epidemiology, trend, and risk factors

Despite rapid advances in modern medical technology and significant improvements in survival rates of many cancers, pancreatic cancer is still a highly lethal gastrointestinal cancer with a low 5-year survival rate and difficulty in early detection. At present, the incidence and mortality of pancreatic cancer are increasing year by year worldwide, no matter in the United States, Europe, Japan, or China. Globally, the incidence of pancreatic cancer is projected to increase to 18.6 per 100000 in 2050, with the average annual growth of 1.1%, meaning that pancreatic cancer will pose a significant public health burden. Due to the special anatomical location of the pancreas, the development of pancreatic cancer is usually diagnosed at a late stage with obvious clinical symptoms. Therefore, a comprehensive understanding of the risk factors for pancreatic cancer is of great clinical significance for effective prevention of pancreatic cancer. In this paper, the epidemiological characteristics, developmental trends, and risk factors of pancreatic cancer are reviewed and analyzed in detail.

A nicotine-induced positive feedback loop between HIF1A and YAP1 contributes to epithelial-to-mesenchymal transition in pancreatic ductal adenocarcinoma

BACKGROUND

Nicotine, an active ingredient in tobacco, can promote epithelial-to-mesenchymal transition (EMT) processes that enhance the aggressiveness of a number of human cancers. In the present study, we investigated whether cigarette smoke/nicotine drives EMT in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Quantitative real-time PCR, western blot, immunohistochemistry, and immunofluorescence assays were used to evaluate Yes-associated protein 1 (YAP1) expression associated with cigarette smoking in human PDAC tissue samples and with nicotine exposure in PDAC cell lines. Bioinformatics, loss- and gain- of- function experiments, luciferase reporter assays, chromatin immunoprecipitation (ChIP), and murine tumor xenograft models were performed to examine the function of YAP1 in PDAC and to identify potential mechanisms of action.

RESULTS

Exposure to smoking or nicotine promoted EMT and tumor growth in PDAC cells and in xenograft tumors. Functional studies revealed that YAP1 might drive nicotine-stimulated EMT and oncogenic activity in vitro and in vivo. In human PDAC tissues, upregulation of YAP1 was associated with "ever smoking" status and poor overall survival. In term of mechanism, hypoxia inducible factor (HIF)1A promoted YAP1 nuclear localization and YAP1 transactivation by directly binding to the hypoxia responsive elements of the YAP1 promoter upon nicotine treatment. Nicotine stimulated HIF1A and YAP1 expression by activating cholinergic receptor nicotinic alpha7 (CHRNA7). In addition, YAP1 increased and sustained the protein stability of HIF1A.

CONCLUSIONS

These data demonstrate that YAP1 enhances nicotine-stimulated EMT and tumor progression of PDAC through a HIF1A/YAP1 positive feedback loop. Developing inhibitors that specifically target YAP1 may provide a novel therapeutic approach to suppress PDAC growth, especially in PDAC patients who have a history of smoking.

From Malignant Progression to Therapeutic Targeting: Current Insights of Mesothelin in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC), accounting for 90% of all pancreatic tumors, is a highly devastating disease with poor prognosis and rising incidence. The lack of available specific diagnostics tests and the limited treatment opportunities contribute to this pejorative issue. Over the last 10 years, a growing interest pointing towards mesothelin (MSLN) as a promising PDAC-associated antigen has emerged. The limited expression of MSLN in normal tissues (peritoneum, pleura and pericardium) and its overexpression in 80 to 90% of PDAC make it an attractive candidate for therapeutic management of PDAC patients. Moreover, its role in malignant progression related to its involvement in tumor cell proliferation and resistance to chemotherapy has highlighted the relevance of its targeting. Hence, several clinical trials are investigating anti-MSLN efficacy in PDAC. In this review, we provide a general overview of the different roles sustained by MSLN during PDAC progression. Finally, we also summarize the different MSLN-targeted therapies that are currently tested in the clinic.

Nicotine promotes tumor progression and epithelial-mesenchymal transition by regulating the miR-155-5p/NDFIP1 axis in pancreatic ductal adenocarcinoma

BACKGROUND

Nicotine, the major component of cigarette smoke, has been reported to promote pancreatic ductal adenocarcinoma (PDAC) growth and invasion. Deregulation of microRNA (miRNA) expression is found in many cancers, including PDAC. The effects of nicotine on miRNAs change in PDAC progression remain unknown.

METHODS

The effects of cigarette smoking/nicotine exposure on PDAC cell lines and tissues were evaluated. Quantitative real-time PCR and in situ hybridization assays were used to determine miR-155-5p expression in human PDAC tissue and cell lines upon cigarette smoking/nicotine exposure. Bioinformatics, loss-of-function experiments, luciferase reporter assay were performed to validate Nedd4 family interacting protein 1 (NDFIP1) as a direct target of miR-155-5p. The potentials of systemic miR-155-5p inhibitor-based therapy in overcoming nicotine exposure were evaluated in tumor xenograft model.

RESULTS

Nicotine promoted PDAC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in a dose-response manner. MiR-155-5p was found to be highly expressed in PDAC cell lines and tissues upon cigarette smoking/nicotine exposure. Functional studies showed that miR-155-5p knockdown could override the enhancement of oncogenic activity due to nicotine exposure in vitro and in vivo by directly interacting with the 3' untranslated regions (UTRs) of NDFIP1.

CONCLUSIONS

These data demonstrate that nicotine-regulated miR-155-5p/NDFIP1 promotes tumor progression and EMT of PDAC.

The Impact of obesity and diabetes mellitus on pancreatic cancer: Molecular mechanisms and clinical perspectives

The incidence of obesity and type 2 diabetes (T2DM) in the Western world has increased dramatically during the recent decades. According to the American Cancer Society, pancreatic cancer (PC) is the fourth leading cause of cancer‐related death in the United States. The relationship among obesity, T2DM and PC is complex. Due to increase in obesity, diabetes, alcohol consumption and sedentary lifestyle, the mortality due to PC is expected to rise significantly by year 2040. The underlying mechanisms by which diabetes and obesity contribute to pancreatic tumorigenesis are not well understood. Furthermore, metabolism and microenvironment within the pancreas can also modulate pancreatic carcinogenesis. The risk of PC on a population level may be reduced by modifiable lifestyle risk factors. In this review, the interactions of diabetes and obesity to PC development were summarized, and novel strategies for the prevention and treatment of diabetes and PC were discussed.

Nicotine Induces IL-8 Secretion from Pancreatic Cancer Stroma and Worsens Cancer-Induced Cachexia

Smoking is highly associated with pancreatic cancer. Nicotine, the addictive component of tobacco, is involved in pancreatic cancer tumorigenesis, metastasis, and chemoresistance. This work aimed to describe the role of nicotine within the pancreatic cancer tumor microenvironment. Nicotine treatment was used in vitro to assess its effect on tumor-associated stromal cells and pancreatic cancer cells. Nicotine treatment was then used in a pancreatic cancer patient-derived xenograft model to study the effects in vivo. Nicotine induced secretion of interleukin 8 (IL-8) by tumor-associated stroma cells in an extracellular signal-regulated kinase (ERK)-dependent fashion. The secreted IL-8 and nicotine acted on the pancreatic cancer cell, resulting in upregulation of IL-8 receptor. Nicotine treatment of mice bearing pancreatic cancer patient-derived xenografts had significantly increased tumor mass, increased tumor-free weight loss, and decreased muscle mass. These represent important pathways through which nicotine acts within the tumor microenvironment and worsens pancreatic cancer-induced cachexia, potentially representing future therapeutic targets.

Cigarette Smoking and Mortality in Patients With Pancreatic Cancer: A Systematic Review and Meta-analysis

Current evidence on cigarette smoking associated with pancreatic cancer mortality is limited. We searched MEDLINE, Web of Science, and Embase databases to identify relevant studies published through January 31, 2018. A random-effects model was used to estimate summary hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 20 studies were retrieved, involving 2,517,623 participants. Of these, more than 15,341 patients with pancreatic cancer died. Compared with never smokers, current (summary HR, 1.56; 95% CI, 1.34-1.83) and former (summary HR, 1.15; 95% CI, 1.06-1.26) smokers had elevated risk of total mortality in patients diagnosed with pancreatic cancer. This effect of cigarette smoking is observed both in the Western regions and the Asia-Pacific regions. This effect of smoking is independent of alcohol use, body mass index, and history of diabetes but is modified by tumor stage and study settings. Dose-response associations between smoking and pancreatic cancer mortality were revealed for smoking intensity, cumulative amount of cigarettes smoked, and duration of smoking. Cigarette smoking was associated with an increase in total mortality for patients with pancreatic cancer. Future studies should further clarify the role of smoking as an effect modifier in treatment trials of pancreatic cancer.

Pancreatic ductal adenocarcinoma: biological hallmarks, current status, and future perspectives of combined modality treatment approaches

Pancreatic ductal adenocarcinoma (PDAC) is a highly devastating disease with poor prognosis and rising incidence. Late detection and a particularly aggressive biology are the major challenges which determine therapeutic failure. In this review, we present the current status and the recent advances in PDAC treatment together with the biological and immunological hallmarks of this cancer entity. On this basis, we discuss new concepts combining distinct treatment modalities in order to improve therapeutic efficacy and clinical outcome - with a specific focus on protocols involving radio(chemo)therapeutic approaches.

Increase in motility and invasiveness of MCF7 cancer cells induced by nicotine is abolished by melatonin through inhibition of ERK phosphorylation

Through activation of the ERK pathway, nicotine, in both normal MCF-10A and low-malignant breast cancer cells (MCF7), promotes increased motility and invasiveness. Melatonin antagonizes both these effects by inhibiting almost completely ERK phosphorylation. As melatonin has no effect on nonstimulated cells, it is likely that melatonin can counteract ERK activation only downstream of nicotine-induced activation. This finding suggests that melatonin hampers ERK phosphorylation presumably by targeting a still unknown intermediate factor that connects nicotine stimulation to ERK phosphorylation. Furthermore, downstream of ERK activation, melatonin significantly reduces fascin and calpain activation while restoring normal vinculin levels. Melatonin also counteracts nicotine effects by reshaping the overall cytoskeleton architecture and abolishing invasive membrane protrusion. In addition, melatonin decreases nicotine-dependent ROCK1/ROCK2 activation, thus further inhibiting cell contractility and motility. Melatonin actions are most likely attributable to ERK inhibition, although melatonin could display other ERK-independent effects, namely through a direct modulation of additional molecular and structural factors, including coronin, cofilin, and cytoskeleton components.

Endogenous CHRNA7-ligand SLURP1 as a potential tumor suppressor and anti-nicotinic factor in pancreatic cancer

Smoking is associated with increased risk and poorer prognosis of pancreatic ductal adenocarcinoma (PDAC). Nicotine acts through cholinergic nicotinic receptors, preferentially α7 (CHRNA7) that also binds the endogenous ligand SLURP1 (Secreted Ly-6/uPAR-Related Protein 1). The clinical significance of SLURP1 and its interaction with nicotine in PDAC are unclear. We detected similar levels of SLURP1 in sera from healthy donors and patients with chronic pancreatitis or PDAC; higher preoperative values were associated with significantly better survival in patients with resected tumors. Pancreatic tissue was not a source of circulating SLURP1 but contained diverse CHRNA7-expressing cells, preferentially epithelial and immune, whereas stromal stellate cells and a quarter of the tumor cells lacked CHRNA7. The CHRNA7 mRNA levels were decreased in PDAC, and CHRNA7^high-PDAC patients lived longer. In CHRNA7^high COLO357 and PANC-1 cultures, opposing activities of SLURP1 (anti-malignant/CHRNA7-dependent) and nicotine (pro-malignant/CHRNA7-infidel) were exerted without reciprocally interfering with receptor binding or downstream signaling. These data suggested that the ligands act independently and abolish each other’s effects through a mechanism resembling functional antagonism. Thus, SLURP1 might represent an inborn anti-PDAC defense being sensitive to and counteracting nicotine. Boosting SLURP1-CHRNA7 interaction might represent a novel strategy for treatment in high-risk individuals, i.e., smokers with pancreatic cancer.

Do smoking and alcohol behaviours influence GI cancer survival?

Little is known about the role of alcohol and smoking in GI cancer survival compared to GI cancer development. We systematically reviewed the evidence for a role of smoking and alcohol in prognosis among GI cancer patients and inform whether smoking or alcohol cessation interventions or guidelines for GI cancer patients are likely to improve prognosis. A total of 84 relevant studies were identified. Continued smokers, particularly heavy smokers, had worse prognosis than never smokers in most GI cancers. However, more evidence is needed to establish the likely impact of smoking cessation interventions amongst GI cancer patients. Heavy alcohol drinkers had worse prognosis in oesophageal squamous cell carcinoma and hepatocellular carcinoma patients. Light alcohol consumption was not associated with worse prognosis from any GI cancer, though further studies are needed. UK guidelines for the general population recommending under 14 units (∼7 drinks) per week may be sufficient for GI cancer patients, until further evidence is available.

Effects of alcohol drinking and smoking on pancreatic ductal adenocarcinoma mortality: A retrospective cohort study consisting of 1783 patients

The effects of alcohol drinking and smoking on pancreatic ductal adenocarcinoma (PDAC) mortality are contradictory. Individuals who were diagnosed as PDAC and hospitalized at the China National Cancer Center between January 1999 and January 2016 were identified and included in the study. Ultimately, 1783 consecutive patients were included in the study. Patients were categorized as never, ex-drinkers/smokers or current drinkers/smokers. Hazard ratios (HRs) of all-cause mortality and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. Compared with never drinkers, the HRs were 1.25 for ever drinkers, 1.24 for current drinkers, and 1.33 for ex-drinkers (trend P = 0.031). Heavy drinking and smoking period of 30 or more years were positive prognostic factors for PDAC. For different smoking and alcohol drinking status, only subjects who are both current smokers and current drinkers (HR, 1.45; 95% CI, 1.03–2.05) were associated with reduced survival after PDAC compared to those who were never smokers and never drinkers. Patients who are alcohol drinkers and long-term smokers before diagnosis have a significantly higher risk of PDAC mortality. Compared to those who neither smoker nor drink, only patients who both smokers and drinkers were associated with reduced survival from PDAC.

The role of c-Met in prognosis and clinicopathology of renal cell carcinoma: Results from a single-centre study and systematic review

BACKGROUND AND OBJECTIVES

The c-Met proto-oncogene pathway plays an important role in the progression of various cancers. However, the effect of the c-Met pathway on renal cell carcinoma (RCC) remains controversial. We decided to clarify the role of c-Met in prognosis and clinicopathology of RCC.

METHODS

A total of 10 pairs of tumour and adjacent tissues were obtained from patients with primary RCC between 2013 and 2014 and tissue microarrays to assess c-Met expression in tumour tissues from 90 patients with RCC by Western blot and immunohistochemical staining. We also presented a meta-analysis to explore the correlation between c-Met and pathological grade and stage of RCC. The two-tailed Pearson's χ² and Fischer exact tests were used to compare categorical variables. Multivariate analysis was performed using the multivariate Cox proportional hazards model.

RESULTS

C-Met protein levels were increased in 8 of 10 RCC tissue samples compared with their adjacent normal tissue and c-Met expression levels were positively associated with a high nuclear grade (P = 0.008) and pT stage (P = 0.002). Multivariate analysis showed that a high expression of c-Met was an independent predictor of disease-specific survival (P = 0.017). A meta-analysis found that increased c-Met expression in RCC tissues was closely correlated with high tumour grade (P<0.001) and high pT stage (P = 0.001). Most importantly, c-Met expression was significantly correlated with disease-specific survival (P<0.001).

CONCLUSIONS

Because c-Met is strongly associated with pathological grade, stage and disease-specific survival, c-Met levels may have potential to predict patient prognosis and to guide clinical diagnosis and treatment.

Cigarette Smoking and Pancreatic Cancer Survival

Purpose Cigarette smoking is associated with increased incidence of pancreatic cancer. However, few studies have prospectively evaluated the association of smoking with patient survival. Patients and Methods We analyzed survival by smoking status among 1,037 patients from two large US prospective cohort studies diagnosed from 1986 to 2013. Among 485 patients from four prospective US cohorts, we also evaluated survival by prediagnostic circulating levels of cotinine, a metabolite of nicotine that is proportional to tobacco smoke exposure. On the basis of prediagnosis cotinine levels, we classified patients as nonsmokers (< 3.1 ng/mL), light smokers (3.1-20.9 ng/mL), or heavy smokers (≥ 21.0 ng/mL). We estimated hazard ratios (HRs) for death by using Cox proportional hazards models, with adjustment for age, sex, race/ethnicity, body mass index, diabetes status, diagnosis year, and cancer stage. Results The multivariable-adjusted HR for death was 1.37 (95% CI, 1.11 to 1.69) comparing current smokers with never smokers ( P = .003). A statistically significant negative trend in survival was observed for increasing pack-years of smoking ( P_trend = .008), with HR for death of 1.49 (95% CI, 1.05 to 2.10) for > 60 pack-years of smoking versus never smoking. Survival among former smokers was similar to that for never smokers, regardless of time since quitting. Heavy smokers defined by prediagnostic circulating cotinine levels had a multivariable-adjusted HR for death of 1.76 (95% CI, 1.23 to 2.51) compared with nonsmokers. Among patients with circulating cotinine levels measured within 5 years before diagnosis, heavy smokers had a multivariable-adjusted HR for death of 2.47 (95% CI, 1.24 to 4.92) compared with nonsmokers. Conclusion Cigarette smoking was associated with a reduction in survival among patients with pancreatic cancer.

Risk Factors for Sporadic Pancreatic Neuroendocrine Tumors: A Case-Control Study

The current study examined risk factors for sporadic pancreatic neuroendocrine tumors (PNETs), including smoking, alcohol use, first-degree family history of any cancer (FHC), and diabetes in the Han Chinese ethnic group. In this clinic-based case-control analysis on 385 patients with sporadic PNETs and 614 age- and sex-matched controls, we interviewed subjects using a specific questionnaire on demographics and potential risk factors. An unconditional multivariable logistic regression analysis was used to estimate adjusted odds ratios (AORs). No significant differences were found between patients and controls in terms of demographic variables. Most of the patients with PNETs had well-differentiated PNETs (G1, 62.9%) and non-advanced European Neuroendocrine Tumor Society (ENETS) stage (stage I or II, 83.9%). Ever/heavy smoking, a history of diabetes and a first-degree FHC were independent risk factors for non-functional PNETs. Only heavy drinking was found to be an independent risk factor for functional PNETs (AOR = 1.87; 95% confidence interval [CI], 1.01–3.51). Ever/heavy smoking was also associated with advanced ENETS staging (stage III or IV) at the time of diagnosis. This study identified first-degree FHC, ever/heavy smoking, and diabetes as risk factors for non-functional PNETs, while heavy drinking as a risk factor for functional PNETs.

Targeting tumor tolerance: A new hope for pancreatic cancer therapy?

With a 5-year survival rate of just 8%, pancreatic cancer (PC) is projected to be the second leading cause of cancer deaths by 2030. Most PC patients are not eligible for surgery with curative intent upon diagnosis, emphasizing a need for more effective therapies. However, PC is notoriously resistant to chemoradiation regimens. As an alternative, immune modulating strategies have recently achieved success in melanoma, prompting their application to other solid tumors. For such therapeutic approaches to succeed, a state of immunologic tolerance must be reversed in the tumor microenvironment and that has been especially challenging in PC. Nonetheless, knowledge of the PC immune microenvironment has advanced considerably over the past decade, yielding new insights and perspectives to guide multimodal therapies. In this review, we catalog the historical groundwork and discuss the evolution of the cancer immunology field to its present state with a specific focus on PC. Strategies currently employing immune modulation in PC are reviewed, specifically highlighting 66 clinical trials across the United States and Europe.