Body mass index and obesity- and diabetes-associated genotypes and risk for pancreatic cancer

FTO in Lung Cancer: Its Progression and Therapeutic Potential

One of the most fatal and frequent malignancies on the planet is lung cancer. Its occurrence and development are the results of multifactorial and multigenic interactions. In recent years, RNA N6-methyladenosine transferase (FTO) has gained significant attention in the field of oncology. FTO is the first RNA demethylase to be found to control target mRNA demethylation. The growth, proliferation, and metastasis of tumor cells are greatly influenced by FTO. Recent studies have found that imbalanced m6A methylation regulatory proteins can induce disruption of downstream RNA metabolism, strongly affecting tumor development. This paper provides an overview of the relationship between FTO and lung cancer, discussing the mechanisms by which FTO is involved in lung cancer and its potential clinical applications.

The Evaluation of Gallstone Disease in the Year Before Pancreatic Cancer Diagnosis

INTRODUCTION

Patients with pancreatic cancer can present with a variety of insidious abdominal symptoms, complicating initial diagnosis. Early symptoms of pancreatic cancer often mirror those associated with gallstone disease, which has been demonstrated to be a risk factor for this malignancy. This study aims to compare the incidence of gallstone disease in the year before diagnosis of pancreatic ductal adenocarcinoma (PDAC) as compared to the general population, and evaluate the association of gallstone disease with stage at diagnosis and surgical intervention.

METHODS

Patients with PDAC were identified from SEER-Medicare (2008-2015). The incidence of gallstone disease (defined as cholelithiasis, cholecystitis and/or cholecystectomy) in the 1 year before cancer diagnosis was compared to the annual incidence in an age-matched, sex-matched, and race-matched noncancer Medicare cohort.

RESULTS

Among 14,654 patients with PDAC, 4.4% had gallstone disease in the year before cancer diagnosis. Among the noncancer controls (n = 14,654), 1.9% had gallstone disease. Both cohorts had similar age, sex and race distributions. PDAC patients with gallstone disease were diagnosed at an earlier stage (stage 0/I-II, 45.8% versus 38.1%, P < 0.0001) and a higher proportion underwent resection (22.7% versus 17.4%, P = 0.0004) compared to patients without gallstone disease.

CONCLUSIONS

In the year before PDAC diagnosis, patients present with gallstone disease more often than the general population. Improving follow-up care and differential diagnosis strategies may help combat the high mortality rate in PDAC by providing an opportunity for earlier stage of diagnosis and earlier intervention.

FTO plays a crucial role in gastrointestinal cancer and may be a target for immunotherapy: an updated review

Gastrointestinal cancer is a common malignancy with high mortality and poor prognosis. Therefore, developing novel effective markers and therapeutic targets for gastrointestinal cancer is currently a challenging and popular topic in oncology research. Accumulating studies have reported that N6-methyladenosine is the most abundant epigenetic modification in eukaryotes. N6-methyladenosine plays an essential role in regulating RNA expression and metabolism, including splicing, translation, stability, decay, and transport. FTO, the earliest demethylase discovered to maintain the balance of N6-adenosine methylation, is abnormally expressed in many tumors. In this review, we discuss the molecular structure and substrate selectivity of FTO. we focus on the role of FTO in gastrointestinal tumor proliferation, migration, invasion, apoptosis, autophagy, immune microenvironment, and its molecular mechanisms. We also discuss its potential in the treatment of gastrointestinal cancers.

Low expression of exosomal miR-150 predicts poor prognosis in colorectal cancer patients after surgical resections

Liver metastasis is a leading indicator of poor prognosis in patients with colorectal cancer (CRC). Exosomal intercellular communication has been reported to play an important role in cancer invasion and metastasis. Here, we characterized exosomal miRNAs underlying liver metastasis in CRC patients (Cohort 1, n = 30) using miRNA arrays. Exosomal miR-150 was found to be downregulated in CRC patients with liver metastases compared to those without (P = 0.025, fold change [FC] = 2.01). These results were then validated using another independent cohort of CRC patients (Cohort 2, n = 64). Patients with low expression of exosomal miR-150 had significantly shorter overall survival (OS) time (33.3 months versus 43.3 months, P = 0.002). In addition, the low expression of exosomal miR-150 was significantly correlated with advanced tumor node metastasis staging (P = 0.013), higher CA199 level (P = 0.018), and the presence of liver metastasis (P = 0.048). Multivariate analysis showed that low expression of exosomal miR-150 (P = 0.035) and liver metastasis (P < 0.001) were independent prognostic factors for overall survival. In vivo and in vitro studies showed that the viability and invasion of CRC cells were both significantly suppressed by ExomiR-150. Target-prediction assessment and dual-luciferase reporter assay indicated that FTO (the fat mass and obesity-associated gene) was a direct target for miR-150. This study first demonstrated that exosomal miR-150 may be a potential prognostic factor and treatment target for CRC.

Research advances of N6-methyladenosine in diagnosis and therapy of pancreatic cancer

BACKGROUND

N6-methyladenosine (m6A) is the addition of a methyl group on the N6 position of adenosine and is the most prevalent and abundant epigenetic modification in eukaryote mRNA. m6A marks are added to mRNA by the m6A methyltransferase complex ("writers"), removed by m6A demethylases ("erasers"), and recognized by m6A-binding proteins ("readers"). Recent evidence has shown that the m6A modification plays a crucial role in the pathogenic mechanism and malignant progression of pancreatic cancer, with roles in cell survival, proliferation, migration, invasion, tumor metastasis, and drug resistance.

METHODS

Literature was searched in Pubmed and Web of Science for the following keywords: "N6-methyladenosine", "pancreatic cancer", "epigenetic modification", "immunotherapy".

RESULTS

Among classical m6A regulators, while METTL3, METTL14, WTAP, FTO, YTHDF2, IGF2BP1-3, hnRNPC, and NKAP are upregulated in pancreatic cancer, METTL16 and ALKBH5 are downregulated in pancreatic cancer. m6A modification has been investigated in pancreatic cancer therapy.

CONCLUSION

Dysregulated m6A and its related factors in pancreatic cancer cells and patients indicate their potential values as novel biomarkers in pancreatic cancer diagnosis and targeted therapy.

Single Nucleotide Polymorphism in the 3' Untranslated Region of PRKAA2 on Cardiometabolic Parameters in Type 2 Diabetes Mellitus Patients Who Received Metformin

Purpose

This study aimed to explore the association of rs857148 A>C as 3'UTR variants with blood pressure, HbA1c profile, and lipid profiles as cardiometabolic parameters among patients with T2DM receiving metformin.

Patients and Methods

This cross-sectional analytic research was conducted with 114 consecutively selected patients with T2DM. Polymerase chain reaction-restriction fragment length polymorphism was conducted to determine rs857148. A total of 108 patients fulfilled inclusion and exclusion criteria.

Results

Genotype distribution agreed with the Hardy Weinberg Equation for Equilibrium (p>0.05) but wildtype allele was found as the minor allele. Subjects with CC genotype and C allele had enhanced HbA1c levels (OR=7.12; 95% CI=1.05-48.26; p=0.04; OR=1.66; 95% CI=1.06-2.60; p=0.03, respectively). It was confirmed by dominant model whereas subjects with AA tended to have reduced HbA1c compared to AC+CC genotype (OR=0.15; 95% CI=0.02-0.97; p=0.047). AC genotype had significant correlation to total cholesterol (OR=1.05; 95% CI=1.01-1.10; p=0.03) compared to AA genotype.

Conclusion

We conclude that polymorphism of rs87148, specifically CC genotype and C allele, has a significant association with HbA1c and total cholesterol after considering oral hypoglycemia agent dose, age, gender, and combination therapy, compared to AA genotype. Future studies that involve a larger sample population and more rigorous selection criteria are required.

FTO m6A Demethylase in Obesity and Cancer: Implications and Underlying Molecular Mechanisms

Fat mass and obesity-associated protein (FTO) is the first reported RNA N6-methyladenosine (m6A) demethylase in eukaryotic cells. m6A is considered as the most abundant mRNA internal modification, which modulates several cellular processes including alternative splicing, stability, and expression. Genome-wide association studies (GWAS) identified single-nucleotide polymorphisms (SNPs) within FTO to be associated with obesity, as well as cancer including endometrial cancer, breast cancer, pancreatic cancer, and melanoma. Since the initial classification of FTO as an m6A demethylase, various studies started to unravel a connection between FTO’s demethylase activity and the susceptibility to obesity on the molecular level. FTO was found to facilitate adipogenesis, by regulating adipogenic pathways and inducing pre-adipocyte differentiation. FTO has also been investigated in tumorigenesis, where emerging studies suggest m6A and FTO levels are dysregulated in various cancers, including acute myeloid leukemia (AML), glioblastoma, cervical squamous cell carcinoma (CSCC), breast cancer, and melanoma. Here we review the molecular bases of m6A in tumorigenesis and adipogenesis while highlighting the controversial role of FTO in obesity. We provide recent findings confirming FTO’s causative link to obesity and discuss novel approaches using RNA demethylase inhibitors as targeted oncotherapies. Our review aims to confirm m6A demethylation as a risk factor in obesity and provoke new research in FTO and human disorders.

Relationship of sleep duration and annual changes in sleep duration with the incidence of gastrointestinal cancers: a prospective cohort study

Background:

Prospective analyses have yet to identify a consistent relationship between sleep duration and the incidence of gastrointestinal (GI) cancers. The effect of changes in sleep duration on GI cancer incidence has scarcely been studied. Therefore, we aimed to examine the association between baseline sleep duration and annual changes in sleep duration and GI cancer risk in a large population-based cohort study.

Methods:

A total of 123,495 participants with baseline information and 83,511 participants with annual changes in sleep duration information were prospectively observed from 2006 to 2015 for cancer incidence. Cox proportional-hazards models were used to calculate hazard ratios (HRs) and their confidence intervals (CIs) for GI cancers according to sleep duration and annual changes in sleep duration.

Results:

In baseline sleep duration analyses, short sleep duration (≤5 h) was significantly associated with a lower risk of GI cancer in females (HR: 0.31, 95% CI: 0.10–0.90), and a linear relationship between baseline sleep duration and GI cancer was observed (P = 0.010), especially in males and in the >50-year-old group. In the annual changes in sleep duration analyses, with stable category (0 to −15 min/year) as the control group, decreased sleep duration (≤−15 min/year) was significantly associated with the development of GI cancer (HR: 1.29; 95% CI: 1.04–1.61), especially in the >50-year-old group (HR: 1.32; 95% CI: 1.01–1.71), and increased sleep duration (>0 min/year) was significantly associated with GI cancer in females (HR: 2.89; 95% CI: 1.14–7.30).

Conclusions:

Both sleep duration and annual changes in sleep duration were associated with the incidence of GI cancer.

The Role of FTO in Tumors and It's Research Progress

BACKGROUND

A malignant tumor is a disease that seriously threatens human health. At present, more and more research results show that the pathogenesis of different tumors is very complicated, and the methods of clinical treatment are also diverse. This review analyzes and summarizes the role of fat mass and obesity-associated (FTO) genes in different tumors and provides a reference value for research and drug treatment methods.

METHOD

We conducted a comprehensive literature search using the database. According to the article's primary purpose, irrelevant articles were excluded from the research summary and included in the relevant articles. Finally, the relevant information of the article was summarized.

RESULT

In this article, the relationship between malignant tumors and FTO is introduced by citing many documents. In addition, the inhibitors that act on FTO are listed.

CONCLUSION

This article has shown that FTO protein is a demethylase that can regulate N6-methyladenosine (m6A) levels in mRNA and plays a crucial role in the progression and resistance of various tumors such as leukemia, breast cancer, and lung cancer.

Are the FTO Gene Polymorphisms Associated with Colorectal Cancer? A Meta-analysis

BACKGROUND

Colorectal cancer (CRC) is reported to be associated with some gene polymorphisms. However, the effect of the fat mass and obesity associated (FTO) gene on colorectal cancer is not yet clear. This meta-analysis aimed to investigate the association of the FTO gene polymorphism and colorectal cancer.

METHODS

PubMed, Web of science, Scopus, and Embase were explored to identify the studies investigating the relationship between rs9939609 and rs17817449 polymorphisms of FTO gene and colorectal cancer, and the published papers from 2000 to 2019 were collected. This meta-analysis was conducted by using a random-effects model for the best estimation of the desired outcomes.

RESULTS

In this study, 1528 studies were initially included and five eligible case-control studies including 13,460 cases and 22,578 controls were eligible for further analyses. No significant association was found between risk allele of FTO rs9939609 (OR = 0.98, 0.87-1.1) and rs17817449 (OR = 0.9, 0.79-1.03) polymorphisms and colorectal cancer risk. The subgroup analyses considering the source of the control group and race found no significant association between FTO polymorphisms and the risk of colon cancer.

CONCLUSIONS

This study indicated that rs9939609 and rs17817449 FTO gene polymorphisms are not associated with colorectal cancer risk. Individual studies involving different FTO polymorphisms are needed to further evaluation of the associations between the FTO gene and colon cancer.

N6-methyladenosine (m6A) in pancreatic cancer: Regulatory mechanisms and future direction

N6-methyladenosine (m6A), the most abundant RNA modification in eukaryotes, plays a pivotal role in regulating many cellular and biological processes. Aberrant m6A modification has recently been involved in carcinogenesis in various cancers, including pancreatic cancer. Pancreatic cancer is one of the deadliest cancers. It is a heterogeneous malignant disease characterized by a plethora of diverse genetic and epigenetic events. Increasing evidence suggests that dysregulation of m6A regulatory factors, such as methyltransferases, demethylases, and m6A-binding proteins, profoundly affects the development and progression of pancreatic cancer. In addition, m6A regulators and m6A target transcripts may be promising early diagnostic and prognostic cancer biomarkers, as well as therapeutic targets. In this review, we highlight the biological functions and mechanisms of m6A in pancreatic cancer and discuss the potential of m6A modification in clinical applications.

Deciphering the complex interplay between pancreatic cancer, diabetes mellitus subtypes and obesity/BMI through causal inference and mediation analyses

OBJECTIVES

To characterise the association between type 2 diabetes mellitus (T2DM) subtypes (new-onset T2DM (NODM) or long-standing T2DM (LSDM)) and pancreatic cancer (PC) risk, to explore the direction of causation through Mendelian randomisation (MR) analysis and to assess the mediation role of body mass index (BMI).

DESIGN

Information about T2DM and related factors was collected from 2018 PC cases and 1540 controls from the PanGenEU (European Study into Digestive Illnesses and Genetics) study. A subset of PC cases and controls had glycated haemoglobin, C-peptide and genotype data. Multivariate logistic regression models were applied to derive ORs and 95% CIs. T2DM and PC-related single nucleotide polymorphism (SNP) were used as instrumental variables (IVs) in bidirectional MR analysis to test for two-way causal associations between PC, NODM and LSDM. Indirect and direct effects of the BMI-T2DM-PC association were further explored using mediation analysis.

RESULTS

T2DM was associated with an increased PC risk when compared with non-T2DM (OR=2.50; 95% CI: 2.05 to 3.05), the risk being greater for NODM (OR=6.39; 95% CI: 4.18 to 9.78) and insulin users (OR=3.69; 95% CI: 2.80 to 4.86). The causal association between T2DM (57-SNP IV) and PC was not statistically significant (OR_LSDM=1.08, 95% CI: 0.86 to 1.29, OR_NODM=1.06, 95% CI: 0.95 to 1.17). In contrast, there was a causal association between PC (40-SNP IV) and NODM (OR=2.85; 95% CI: 2.04 to 3.98), although genetic pleiotropy was present (MR-Egger: p value=0.03). Potential mediating effects of BMI (125-SNPs as IV), particularly in terms of weight loss, were evidenced on the NODM-PC association (indirect effect for BMI in previous years=0.55).

CONCLUSION

Findings of this study do not support a causal effect of LSDM on PC, but suggest that PC causes NODM. The interplay between obesity, PC and T2DM is complex.

A Decade Later: Revisiting the TGFβ Family's Role in Diabetes

In 2010, we published a review summarizing the role of the transforming growth factor-beta (TGFβ) family of proteins in diabetes. At that time there were still many outstanding questions that needed to be answered. In this updated review, we revisit the topic and provide new evidence that supports findings from previous studies included in the 2010 review and adds to the knowledge base with new findings and information. The most substantial contributions in the past 10 years have been in the areas of human data, the investigation of TGFβ family members other than activin [e.g., bone morphogenetic proteins (BMPs), growth and differentiation factor 11 (GDF11), nodal], and the expansion of β-cell number through various mechanisms including transdifferentiation, which was previously believed to not be possible.

A systematic review and network meta-analysis of single nucleotide polymorphisms associated with pancreatic cancer risk

In this meta-analysis, we systematically investigated the correlation between single nucleotide polymorphisms (SNPs) and pancreatic cancer (PC) risk. We searched PubMed, Network Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Periodical Database (VIP), and Wanfang databases up to January 2020 for studies on PC risk-associated SNPs. We identified 45 case-control studies (36,360 PC patients and 54,752 non-cancer individuals) relating to investigations of 27 genes and 54 SNPs for this meta-analysis. Direct meta-analysis followed by network meta-analysis and Thakkinstian algorithm analysis showed that homozygous genetic models for CTLA-4 rs231775 (OR =0.326; 95% CI: 0.218-0.488) and VDR rs2228570 (OR = 1.976; 95% CI: 1.496-2.611) and additive gene model for TP53 rs9895829 (OR = 1.231; 95% CI: 1.143-1.326) were significantly associated with PC risk. TP53 rs9895829 was the most optimal SNP for diagnosing PC susceptibility with a false positive report probability < 0.2 at a stringent prior probability value of 0.00001. This systematic review and meta-analysis suggest that TP53 rs9895829, VDR rs2228570, and CTLA-4 rs231775 are significantly associated with PC risk. We also demonstrate that TP53 rs9895829 is a potential diagnostic biomarker for estimating PC risk.

The microbiome, genetics, and gastrointestinal neoplasms: the evolving field of molecular pathological epidemiology to analyze the tumor-immune-microbiome interaction

Metagenomic studies using next-generation sequencing technologies have revealed rich human intestinal microbiome, which likely influence host immunity and health conditions including cancer. Evidence indicates a biological link between altered microbiome and cancers in the digestive system. Escherichia coli and Bacteroides fragilis have been found to be enriched in colorectal mucosal tissues from patients with familial adenomatous polyposis that is caused by germline APC mutations. In addition, recent studies have found enrichment of certain oral bacteria, viruses, and fungi in tumor tissue and fecal specimens from patients with gastrointestinal cancer. An integrative approach is required to elucidate the role of microorganisms in the pathogenic process of gastrointestinal cancers, which develop through the accumulation of somatic genetic and epigenetic alterations in neoplastic cells, influenced by host genetic variations, immunity, microbiome, and environmental exposures. The transdisciplinary field of molecular pathological epidemiology (MPE) offers research frameworks to link germline genetics and environmental factors (including diet, lifestyle, and pharmacological factors) to pathologic phenotypes. The integration of microbiology into the MPE model (microbiology-MPE) can contribute to better understanding of the interactive role of environment, tumor cells, immune cells, and microbiome in various diseases. We review major clinical and experimental studies on the microbiome, and describe emerging evidence from the microbiology-MPE research in gastrointestinal cancers. Together with basic experimental research, this new research paradigm can help us to develop new prevention and treatment strategies for gastrointestinal cancers through targeting of the microbiome.

Using genetics to decipher the link between type 2 diabetes and cancer: shared aetiology or downstream consequence?

Recent developments in the field of genetics have accelerated our understanding of the aetiology of complex diseases. Type 2 diabetes mellitus and cancer are no exception, with large-scale genome-wide association studies (GWAS) facilitating exploration of the underlying pathology. Here, we discuss how genetics studies can be used to investigate the relationship between these complex diseases. Observational epidemiological studies consistently report that people with type 2 diabetes have a higher risk of several types of cancer. Indeed, type 2 diabetes and cancer share many common risk factors, such as obesity, ageing, poor diet and low levels of physical activity. However, questions remain regarding the biological mechanisms that link these two diseases. Large-scale GWAS of type 2 diabetes and cancer allow us to consider the evidence for shared genetic architecture. Several shared susceptibility genes have been identified, yet tissue specificity and direction of effect must be taken into account when considering common genetic aetiology. We also consider how GWAS, and associated techniques such as Mendelian randomisation, allow us to dissect the link between the two diseases and address questions such as 'Does type 2 diabetes cause cancer or is the increased risk observed driven by higher adiposity or another associated metabolic feature?' Graphical abstract.

RNA N-6-methyladenosine enzymes and resistance of cancer cells to chemotherapy and radiotherapy

Aim: As one of the early adaptive mechanisms by which cells respond to environmental changes, RNA modification appears to be a very promising target for cancer treatment. Results: RNA modifications are currently a hot topic in epigenetic research. Emerging experimental studies show that expression alterations of multiple m6A enzymes, including demethylase FTO, methyltransferase METTL3 and WTAP, mediate the development of resistance of cancer cells to various treatments. A set of small molecular chemical drugs targeted to these m6A enzymes are under development. Intervention of RNA m6A methylation is a possible therapeutic strategy to overcome drug resistance. Conclusions: RNA m6A methylation may play a crucial role in drug resistance development and intervention in cancer cells.

Validation of genome-wide association study-identified single nucleotide polymorphisms in a case-control study of pancreatic cancer from Taiwan

Background

Due to differences in genetic background, it is unclear whether the genetic loci identified by the previous genome-wide association studies (GWAS) of pancreatic cancer also play significant roles in the development of pancreatic cancer among the Taiwanese population.

Methods

This study aimed to validate the 25 pancreatic cancer GWAS-identified single nucleotide polymorphisms (SNPs) in a case-control study (278 cases and 658 controls) of pancreatic cancer conducted in Taiwan. Statistical analyses were conducted to determine the associations between the GWAS-identified SNPs and pancreatic cancer risk. Gene-environment interaction analysis was conducted to evaluate the interactions between SNPs and environmental factors on pancreatic cancer risk.

Results

Among the 25 GWAS-identified SNPs, 7 (rs2816938 (~ 11 kb upstream of NR5A2), rs10094872 (~ 28 kb upstream of MYC), rs9581943 (200 bp upstream of PDX1) and 4 chromosome 13q22.1 SNPs: rs4885093, rs9573163, rs9543325, rs9573166) showed a statistically significant association with pancreatic cancer risk in the current study. Additional analyses showed two significant gene-environment interactions (between poor oral hygiene and NR5A2 rs2816938 and between obesity and PDX1 rs9581943) on the risk of pancreatic cancer.

Conclusions

The current study confirmed the associations between 7 of the 25 GWAS-identified SNPs and pancreatic risk among the Taiwanese population.

Furthermore, pancreatic cancer was jointly influenced by lifestyle and medical factors, genetic polymorphisms, and gene-environment interaction. Additional GWAS is needed to determine the genetic polymorphisms that are more relevant to the pancreatic cancer cases occurring in Taiwan.

Fat mass and obesity-associated gene polymorphisms, pre-diagnostic plasma adipokine levels and the risk of colorectal cancer: The Japan Public Health Center-based Prospective Study

Although their functional outcomes remain largely unknown, single nucleotide polymorphisms (SNPs) in the fat mass and obesity-associated gene (FTO) may interact with adipokines, especially leptin and adiponectin, to modify the risk of colorectal cancer. We conducted a prospective study of 375 colorectal cancer cases and 750 matched controls to examine the effects of SNPs in the FTO, either alone or in interaction with pre-diagnostic plasma adipokine levels. Using a conditional logistic regression model, we obtained odds ratios (ORs) and their 95% confidence intervals (CIs) of colorectal cancer. Seven SNPs in strong linkage disequilibrium demonstrated a similarly positive association with colorectal cancer, and most evidently for rs1558902, rs8050136, rs3751812, and rs9939609 (Ptrend = 0.02). Of interest, we observed a statistically significant interaction of rs8050136 with plasma total adiponectin levels (Pinteraction = 0.03). Compared to non-carriers in the lowest quintile of plasma total adiponectin, A allele carriers in the same quintile showed a considerably elevated risk of colorectal cancer, with a body mass index-adjusted OR of 2.54 (95% CI, 1.36-4.75). This investigation of the interaction between SNPs in the FTO and pre-diagnostic plasma adipokine levels has revealed the importance of both genetic and hormonal factors associated with adiposity in colorectal carcinogenesis.

The Genome Landscape of Tibetan Sheep Reveals Adaptive Introgression from Argali and the History of Early Human Settlements on the Qinghai-Tibetan Plateau

Tibetan sheep are the most common and widespread domesticated animals on the Qinghai-Tibetan Plateau (QTP) and have played an essential role in the permanent human occupation of this high-altitude region. However, the precise timing, route, and process of sheep pastoralism in the QTP region remain poorly established, and little is known about the underlying genomic changes that occurred during the process. Here, we investigate the genomic variation in Tibetan sheep using whole-genome sequences, single nucleotide polymorphism arrays, mitochondrial DNA, and Y-chromosomal variants in 986 samples throughout their distribution range. We detect strong signatures of selection in genes involved in the hypoxia and ultraviolet signaling pathways (e.g., HIF-1 pathway and HBB and MITF genes) and in genes associated with morphological traits such as horn size and shape (e.g., RXFP2). We identify clear signals of argali (Ovis ammon) introgression into sympatric Tibetan sheep, covering 5.23-5.79% of their genomes. The introgressed genomic regions are enriched in genes related to oxygen transportation system, sensory perception, and morphological phenotypes, in particular the genes HBB and RXFP2 with strong signs of adaptive introgression. The spatial distribution of genomic diversity and demographic reconstruction of the history of Tibetan sheep show a stepwise pattern of colonization with their initial spread onto the QTP from its northeastern part ∼3,100 years ago, followed by further southwest expansion to the central QTP ∼1,300 years ago. Together with archeological evidence, the date and route reveal the history of human expansions on the QTP by the Tang-Bo Ancient Road during the late Holocene. Our findings contribute to a depth understanding of early pastoralism and the local adaptation of Tibetan sheep as well as the late-Holocene human occupation of the QTP.

Identification of clinical tumor stages related mRNAs and miRNAs in cervical squamous cell carcinoma

OBJECTIVES

The aim of this study is to identify the clinical tumor stage related mRNAs and miRNAs, shedding light on the potential molecular mechanisms of cervical squamous cell carcinoma (CSCC).

METHODS

Firstly, the mRNA and miRNA next-generation sequencing data were downloaded. Secondly, clinical tumor stage correlation analysis of mRNAs and miRNA was performed, followed by the functional enrichment analysis of all clinical tumor stage related mRNAs. Thirdly, differentially expression analysis of mRNAs and miRNA between different clinical tumor stages was performed, followed by target gene prediction of these differentially expressed miRNAs.

RESULTS

3 mRNAs (PER1, PRKAB1 and PMM2) and 5 miRNAs (hsa-mir-486, hsa-mir-451, hsa-mir-424, hsa-mir-144 and hsa-mir-450a-2) were overlapped from stage 1, stage 2, stage 3 and stage 4.

CONCLUSIONS

Alterations of differentially expressed mRNAs and miRNAs may offer important insights into the molecular mechanisms in the pathology of CSCC.

Association between NR5A2 and the risk of pancreatic cancer, especially among Caucasians: a meta-analysis of case-control studies

Background

Previous studies have reported that nuclear receptor subfamily 5, group A, member 2 (NR5A2) polymorphisms (rs3790843 G>A, rs3790844 T>C, rs12029406 C>T) are associated with the risk of pancreatic cancer. However, the results of epidemiological investigations are still controversial. In order to explore its potential attributing factors, we pooled the updated literatures to evaluate the association between NR5A2 polymorphism and the risk of pancreatic cancer in this meta-analysis.

Materials and methods

Databases such as PubMed, Google Scholar and China National Knowledge Infrastructure were searched for eligible articles following strict inclusion and exclusion criteria (updated to November 18, 2017). Odds ratios (ORs) and 95% CIs were computed to assess the intensity of association. In addition, heterogeneity, sensitivity analysis and publication bias were explored. All statistical analyses were conducted by STATA 14.0.

Results

Our results showed that the rs3790843 (GA vs GG: OR=0.86, CI=0.76–0.98, P=0.992; GA+AA vs GG: OR=0.83, CI=0.73–0.94, P=0.950; A vs G: OR=0.85, CI=0.78–0.93, P=0.802), rs3790844 (CC vs TT: OR=0.65, CI=0.54–0.78, P=0.617; CC vs TT+CT: OR=0.73, CI=0.62–0.85, P=0.742; C vs T: OR=0.78, CI=0.73–0.84, P=0.555) and rs12029406 (TT vs CC: OR=0.73, CI=0.61–0.89, P=0.483; TT vs CC+CT: OR=0.78, CI=0.66–0.92, P=0.648; T vs C: OR=0.87, CI=0.79–0.95, P=0.837) polymorphisms were associated statistically with the risk of pancreatic cancer. Furthermore, the results of subgroup analysis showed that rs3790843 and rs3790844 polymorphisms were especially related to the risk of pancreatic cancer in Caucasian population.

Conclusion

Our results revealed that NR5A2 may have a protective effect on pancreatic cancer. However, more well-designed researches are needed to verify the relationship between NR5A2 polymorphisms and the risk of pancreatic cancer.

Impact of FTO SNPs rs9930506 and rs9939609 in Prostate Cancer Severity in a Cohort of Puerto Rican Men

Background

Obesity is prevalent in PR and has been associated with prostate cancer (PCa) mortality and aggressiveness. Polymorphisms (SNPs) rs9930506 and rs9939609 in the FTO gene have been associated with both obesity and PCa. The aim of this work was to ascertain whether the presence of these SNPs is associated with PCa risk and severity in a cohort of Puerto Rican men.

Methods and findings

The study population consisted of 513 Puerto Rican men age ranging from 40-79 years old who underwent radical prostatectomy (RP) as the first treatment for PCa and 128 healthy Puerto Rican men age ranging from 40-79 years old. Genomic DNA (gDNA) was extracted and SNPs were determined by Real-Time PCR. PCa severity was defined based on RP stage and Gleason Score. The relationship of FTO SNPs with demographic, clinical characteristics, PCa status and PCa severity were assessed. Logistic regression models with a 95% confidence interval (CI) determined SNPs interaction with PCa risk and severity odds ratio (ORs).

Results and discussion

BMI, age and PSA were considered as confounders. Hardy-Weinberg equilibrium was present for both SNPs. The heterozygous forms (A/G; T/A) were the most prevalent genotypes and the frequency of alleles and genotypes for both SNPs agreed with those published in 1000 genomes. Results suggest an inverse association between the mutated rs9939609 and the risk of having PCa (OR: 0.53, 95% CI: 0.31-0.92) and a positive association with overweight (OR: 1.05, 95% CI: 0.68-1.62). Importantly, among the cases that were overweight, those with mutated rs9939609 had a greater chance of high severity PCa (OR: 1.39, 95% CI: 0.84-2.32) although these results were not statistical significant upon adjustment. Limitations of the study were the relatively small cohort and lack of access to the weight history of all our subjects.

Conclusion

Results offer a research line to be followed with an expanded number of subjects that may provide a better statistical significance, to unravel the high mortality rate in this population.

Is FTO gene variant related to cancer risk independently of adiposity? An updated meta-analysis of 129,467 cases and 290,633 controls

Previous studies have examined the association between the fat mass and obesity-associated (FTO) gene variant and risk of cancer in diverse populations. However, the results have been inconsistent. PubMed and Embase databases were searched for the eligible publications in English language by July, 2016. The associations of FTO variants with cancer risk were estimated by calculating the pooled odds ratios and 95% confidence intervals by meta-analyses. A total of 27 publications (129,467 cancer cases and 290,633 normal controls) were included in our meta-analysis. Overall, FTO rs9939609 variant (or its proxy) was not associated with cancer risk without adjustment for body mass index, as well as additional adjustment for body mss index. However, FTO rs9939609 variant was associated with some types of cancer in the subgroup analysis. In addition, overall, there was no significant association between FTO rs1477196 variant and cancer risk regardless of adjustment for body mass index. However, FTO rs11075995 variant risk allele was associated with breast cancer risk without adjustment for body mass index, but the association disappeared with further adjustment for body mass index. This study overall does not support that the FTO variant is associated with cancer risk independently of the adiposity.

Diabetes, Pancreatogenic Diabetes, and Pancreatic Cancer

The relationships between diabetes and pancreatic ductal adenocarcinoma (PDAC) are complex. Longstanding type 2 diabetes (T2DM) is a risk factor for pancreatic cancer, but increasing epidemiological data point to PDAC as also a cause of diabetes due to unknown mechanisms. New-onset diabetes is of particular interest to the oncology community as the differentiation of new-onset diabetes caused by PDAC as distinct from T2DM may allow for earlier diagnosis of PDAC. To address these relationships and raise awareness of the relationships between PDAC and diabetes, a symposium entitled Diabetes, Pancreatogenic Diabetes, and Pancreatic Cancer was held at the American Diabetes Association's 76th Scientific Sessions in June 2016. This article summarizes the data presented at that symposium, describing the current understanding of the interrelationships between diabetes, diabetes management, and pancreatic cancer, and identifies areas where additional research is needed.

Obesity-associated digestive cancers: A review of mechanisms and interventions

The prevalence of obesity has steadily increased over the past few decades. Previous studies suggest that obesity is an oncogenic factor and that over 20% of all cancers are obesity-related. Among such cancers, digestive system malignancies (including esophageal adenocarcinomas, colorectal cancers, and cancers of the gastric cardia, liver, and pancreas) are reported most frequently. While the 5-year survival rates of cancers of the breast and prostate are 90%, that rate is only 45% for digestive cancers. In this review, the mechanisms of obesity-associated digestive cancers are discussed, with an emphasis on obesity-related gene mutations, insulin and insulin-like growth factor signaling pathways, chronic inflammation, and altered adipokine levels. Evidence that these factors often function interdependently rather than independently in carcinogenesis is presented. Recommended interventions that may reduce the burden of obesity-associated digestive cancers, such as participation in physical activity, diet modulation, and calorie restriction, are also described.

Type 3c (pancreatogenic) diabetes mellitus secondary to chronic pancreatitis and pancreatic cancer

Diabetes mellitus is a group of diseases defined by persistent hyperglycaemia. Type 2 diabetes, the most prevalent form, is characterised initially by impaired insulin sensitivity and subsequently by an inadequate compensatory insulin response. Diabetes can also develop as a direct consequence of other diseases, including diseases of the exocrine pancreas. Historically, diabetes due to diseases of the exocrine pancreas was described as pancreatogenic or pancreatogenous diabetes mellitus, but recent literature refers to it as type 3c diabetes. It is important to note that type 3c diabetes is not a single entity; it occurs because of a variety of exocrine pancreatic diseases with varying mechanisms of hyperglycaemia. The most commonly identified causes of type 3c diabetes are chronic pancreatitis, pancreatic ductal adenocarcinoma, haemochromatosis, cystic fibrosis, and previous pancreatic surgery. In this Review, we discuss the epidemiology, pathogenesis, and clinical relevance of type 3c diabetes secondary to chronic pancreatitis and pancreatic ductal adenocarcinoma, and highlight several important knowledge gaps.

RelA: a tale of a stitch in time

Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer in which NF-κB pathways promote biological aggressiveness. In this issue of the JCI, Lesina et al. investigated the role of RelA, the p65 partner of p50 that together form the most common NF-κB complex, in the early stages of pancreatic malignant transformation and in established PDAC. By deleting Rela in the context of an oncogenic Kras-driven autochthonous model of PDAC, the authors demonstrated that RelA is a mediator of oncogene-induced senescence (OIS) and the senescence-associated secretory phenotype (SASP) that attenuates acinar-to-ductal metaplasia, pancreatic intraepithelial neoplasia (PanIN) formation, and PanIN progression to PDAC. Loss of the tumor-suppressor function of RelA in the early stages of Kras-driven pancreatic neoplastic transformation was associated with decreased OIS and SASP and a protumorigenic tumor microenvironment that harbored more M2 macrophages and myeloid-derived suppressor cells. The beneficial effects of RelA were mediated by increased expression of CXCL1 and its activation of CXCR2. By contrast, in advanced stages of Kras-driven murine PDAC, loss of p53 or p16 was associated with senescence bypass, and RelA deficiency in this context attenuated cancer cell proliferation and prolonged mouse survival, indicating that RelA enhances tumor progression in established PDAC.

Association between FTO gene polymorphism (rs9939609 T/A) and cancer risk: a meta-analysis

Obesity is a risk factor of cancer. Several genes have been found to play an important role in aetiology of obesity and tumourigenesis. Recently, some studies suggested that rs9939609 polymorphism might be significantly associated with cancer risk, while the results of some other studies were controversial. Databases with time limitation from January 1984 to April 2015 were searched. The pooled odds ratio (OR) with 95% confidence interval was calculated to assess the associations, and subgroup meta-analyses were performed according to the type of cancer and ethnicity of the study populations. Overall, the significant association between rs9939609 polymorphism and cancer risk was found in homozygote model and recessive model. As to subgroup classified by cancer type, there was significant association in endometrial cancer and pancreatic cancer, while no statistical significance was detected in other kind of cancers. Besides, in the subgroup analysis of ethnicity, our results indicated that rs9939609 polymorphism was significantly associated with cancer risk in Asians. The rs9939609 polymorphism may be involved the susceptibility of endometrial cancer and pancreatic cancer, especially in Asian populations. Thus, rs9939609 may be a potential biomarker in early diagnosis or gene therapy target of endometrial cancer and pancreatic cancer.

Diabetes Type 2 and Pancreatic Cancer: A History Unfolding

Pancreatic Cancer is the fourth cause of cancer-related deaths in the United States. Up to 80% of pancreatic cancer patients present with either new-onset type 2 diabetes or impaired glucose tolerance at the time of diagnosis. Recent literature suggests that diabetes mellitus type 2 is a risk factor, a manifestation and a prognostic factor for pancreatic cancer. This article is intended to clarify the evidence about diabetes as a risk factor for pancreatic cancer.

Obesity and Cancer: The Oil that Feeds the Flame

Although discussion of the obesity epidemic had become a cocktail party cliché, its impact on public health cannot be dismissed. In the past decade, cancer had joined the list of chronic debilitating diseases whose risk is substantially increased by hypernutrition. Here we discuss recent advances in understanding how obesity increases cancer risk and propose a unifying hypothesis according to which the major tumor-promoting mechanism triggered by hypernutrition is the indolent inflammation that takes place at particular organ sites, including liver, pancreas, and gastrointestinal tract. The mechanisms by which excessive fat deposition feeds this tumor-promoting inflammatory flame are diverse and tissue specific.

Genome-wide association study-identified SNPs (rs3790844, rs3790843) in the NR5A2 gene and risk of pancreatic cancer in Japanese

We genotyped 2 SNPs (rs3790844 T/C and rs3790843 G/A) in the NR5A2 gene that were identified in a genome-wide association study (GWAS) of pancreatic cancer in populations of mainly European ancestry, and we examined their associations with pancreatic cancer risk in a case-control study of 360 patients and 400 control subjects in Japan. Unconditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). The SNPs were in linkage disequilibrium (r² = 0.80). For rs3790843, the multivariable-adjusted OR was 0.75 (95% CI: 0.41–1.36) and 0.60 (95%CI: 0.33–1.08) for subjects with the AG and AA genotype, respectively, compared to subjects with the GG genotype. The per allele OR was 0.78 (0.62–0.99) (P = 0.046). For rs3790844, the multivariable-adjusted OR was 0.65 (95% CI: 0.37–1.14) and 0.47 (95%CI: 0.27–0.83) for subjects with the CT and CC genotype, respectively, compared to subjects with the TT genotype. The per allele OR was 0.70 (0.56–0.89) (P = 0.003). Our case-control study found that rs3790843 and rs3790844 in the NR5A2 gene are associated with pancreatic cancer risk in Japanese subjects. The direction of association is consistent with the prior findings from GWASs.

Risk Factors for Pancreatic Cancer in China: A Multicenter Case-Control Study

Background

Despite having one of the highest mortality rates of all cancers, the risk factors of pancreatic cancer remain unclear. We assessed risk factors of pancreatic cancer in China.

Methods

A case-control study design was conducted using data from four hospital-based cancer registries (Henan Provincial Cancer Hospital, Beijing Cancer Hospital, Hebei Provincial Cancer Hospital, and Cancer Hospital of Chinese Academy of Medical Sciences). Controls were equally matched and selected from family members of non-pancreatic cancer patients in the same hospitals. Face-to-face interviews were conducted by trained staff using questionnaires. Conditional logistic regression models were used to assess odd ratios (ORs) and 95% confident intervals (CIs).

Results

Among 646 recruited participants, 323 were pancreatic cancer patients and 323 were controls. Multivariate logistic analysis suggested that pancreatic cancer family history (adjusted OR 1.23; 95% CI, 1.11–3.70), obesity (adjusted OR 1.77; 95% CI, 1.22–2.57), diabetes (adjusted OR 2.96; 95% CI, 1.48–5.92) and smoking (adjusted OR 1.78; 95% CI, 1.02–3.10) were risk factors for pancreatic cancer, but that drinking tea (adjusted OR 0.49; 95% CI, 0.25–0.84) was associated with reduced risk of pancreatic cancer.

Conclusions

Cigarette smoking, family history, obesity, and diabetes are risk factors of pancreatic cancer, which is important information for designing early intervention and preventive strategies for pancreatic cancer and may be beneficial to pancreatic cancer control in China.

Genetics and Genetic Testing in Pancreatic Cancer

Genetic testing of germline DNA is used in patients suspected of being at risk of pancreatic ductal adenocarcinoma (PDAC) to better define the individual's risk and to determine the mechanism of risk. A high genetic risk increases the pretest probability that a biomarker of early cancer is a true positive and warrants further investigation. The highest PDAC risk is generally associated with a hereditary predisposition. However, the majority of PDAC results from complex, progressive gene-environment interactions that currently fall outside the traditional risk models. Over many years, the combination of inflammation, exposure to DNA-damaging toxins, and failed DNA repair promote the accumulation of somatic mutations in pancreatic cells; PDAC risk is further increased by already present oncogenic germline mutations. Predictive models and new technologies are needed to classify patients into more accurate and mechanistic PDAC risk categories that can be linked to improved surveillance and preventative strategies.

Peroxisome proliferator-activated receptor gamma (PPARG) polymorphisms and breast cancer susceptibility: a meta-analysis

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPARG), a nuclear hormone receptor, plays a critical role in the lipid and glucose homeostasis, adipocyte differentiation, as well as intracellular insulin-signaling events. Several studies have been conducted to explore the associations of PPARG polymorphisms with breast cancer (BC), yet the findings are inconsistent.

METHODS

Databases of Pubmed and Embase were searched until October 5, 2014. The association between PPARG polymorphisms and BC risk was determined by crude odds ratios (ORs) with their 95% confidence intervals (CIs).

RESULTS

Finally, there are nine publications involving 3,931 BC cases and 5,382 controls included in this meta-analysis. No significant association was observed between PPARG rs1801282 C>G variants and overall BC risk in all genetic comparison models. However, in a subgroup analysis by ethnicity, significant association was observed between PPARG rs1801282 C>G variants and decreased BC risk in three genetic models: GG+CG vs. CC (OR, 0.83; 95% CI, 0.71-0.96; P = 0.011), CG vs. CC (OR, 0.82; 95% CI, 0.71-0.96; P = 0.011) and G vs. C (OR, 0.85; 95% CI, 0.75-0.97; P = 0.016) in Caucasians and in a subgroup analysis by menopausal status, significantly decreased BC risk was also found in two genetic models: GG+CG vs. CC (OR, 0.79; 95% CI, 0.67-0.95; P = 0.011) and CG vs. CC (OR, 0.77; 95% CI, 0.64-0.92; P = 0.005) in post-menopause subgroup. For PPARG rs3856806 C>T, we found no significant association between PPARG rs3856806 C>T polymorphism and breast cancer.

CONCLUSIONS

In summary, despite some limitations, the results suggest that PPARG rs1801282 C>G polymorphism may be a protective factor for BC in Caucasians and in post-menopause women.

Peroxisome proliferator-activated receptor gamma (PPARG) rs1801282 C>G polymorphism is associated with cancer susceptibility in asians: an updated meta-analysis

Peroxisome proliferator-activated receptor gamma (PPARG) is related to inflammation and plays an important role in the development of cancer. PPARG rs1801282 C>G polymorphism might influence the risk of cancer by regulating production of PPARG gene. Hence, a comprehensive meta-analysis was conducted to explore the association of PPARG rs1801282 C>G polymorphism with cancer susceptibility. An extensive search of PubMed and Embase databases for all relevant publications was carried out. A total of 38 publications with 16,844 cancer cases and 23,736 controls for PPARG rs1801282 C>G polymorphism were recruited in our study. Our results indicated that PPARG rs1801282 C>G variants were associated with an increased cancer risk in Asian populations and gastric cancer. In summary, the findings suggest that PPARG rs1801282 C>G polymorphism may play a crucial role in malignant transformation and the development of cancer.

Genetic variations of the ADIPOQgene and risk of prostate cancer in Chinese Han men

Adiponectin secreted by adipose tissue has been implicated in prostate carcinogenesis. Genetic variations in ADIPOQ are thought to influence the activity of adiponectin, thus relating to cancer occurrence. In this hospital-based case-control study of 917 prostate cancer (PCa) cases and 1036 cancer-free controls, we evaluated the association of single nucleotide polymorphisms in ADIPOQ with risk of PCa and adiponectin levels in Chinese Han men. Variants of ADIPOQ were genotyped by Taqman polymerase chain reaction method. The plasma adiponectin concentrations were measured by enzyme-linked immunosorbent assay (ELISA) in a subset of cases and controls. We found that the ADIPOQ rs3774262 variant AA genotype was associated with both decreased PCa risk [adjusted odds ratio (OR): 0.66, 95% confidence interval (CI) =0.48–0.92] and increased plasma adiponectin levels (P = 0.036 and 0.043), with significant difference by tumor grade, clinical stage, and aggressiveness. A significant interaction between ADIPOQ rs3774262 and body mass index was observed in modifying the risk of PCa (P = 6.7 × 10⁻³). ADIPOQ rs266729 and rs182052 were not related to PCa risk or plasma adiponectin levels. Our data support that ADIPOQ rs3774262 may affect PCa risk in combination with plasma adiponectin levels in Chinese Han men. It may contribute to the molecular basis for the association between obesity and PCa.

Gene-by-Environment Interactions in Pancreatic Cancer: Implications for Prevention

Pancreatic cancer (PC) has been estimated to have higher incidence and correspondingly higher mortality rates in more developed regions worldwide. Overall, the age-adjusted incidence rate is 4.9/10(5) and age-adjusted mortality rate is at 4.8/10(5). We review here our current knowledge of modifiable risk factors (cigarette smoking, obesity, diet, and alcohol) for PC, genetic variants implicated by genome-wide association studies, possible genetic interactions with risk factors, and prevention strategies to provide future research directions that may further our understanding of this complex disease. Cigarette smoking is consistently associated with a two-fold increased PC risk. PC associations with dietary intake have been largely inconsistent, with the potential exception of certain unsaturated fatty acids decreasing risk and well-done red meat or meat mutagens increasing risk. There is strong evidence to support that obesity (and related measures) increase risk of PC. Only the heaviest alcohol drinkers seem to be at an increased risk of PC. Currently, key prevention strategies include avoiding tobacco and excessive alcohol consumption and adopting a healthy lifestyle. Screening technologies and PC chemoprevention are likely to become more sophisticated, but may only apply to those at high risk. Risk stratification may be improved by taking into account gene environment interactions. Research on these modifiable risk factors is key to reducing the incidence of PC and understanding who in the population can be considered high risk.

ADIPOQ polymorphism rs182052 is associated with clear cell renal cell carcinoma

Recent studies have indicated that low circulating adiponectin concentrations are associated with a higher risk of several cancers, including renal cell carcinoma. In this case–control study, we examined the frequency of single nucleotide polymorphisms (rs182052G>A, rs266729C>G, and rs3774262G>A) in the adiponectin gene (ADIPOQ) in 1004 patients with clear cell renal cell carcinoma (ccRCC) compared with a group of healthy subjects (n = 1108). Fasting serum adiponectin concentrations were also examined. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). The association of serum adiponectin concentration with genetic variants was calculated using a multivariate linear regression model. A significantly higher ccRCC risk was associated with the rs182052 variant A allele (adjusted OR, 1.36 and 95% CI, 1.07–1.74 for AA vs GG, P = 0.013; adjusted OR, 1.27 and 95% CI, 1.04–1.56 for AA vs GG+AG, P = 0.019), and this positive association was more evident in overweight subjects. Fasting serum adiponectin was lower in subjects carrying A alleles of rs182052 in both ccRCC patients (β = −0.399, P = 0.018) and healthy controls (β = −0.371, P = 0.024). These results suggest that ADIPOQ rs182052 is significantly associated with ccRCC risk.

In this case–control study, we examined the frequency of single nucleotide polymorphisms (rs182052G>A, rs266729C>G, and rs3774262G>A) in the adiponectin gene (ADIPOQ) in 1004 patients with clear cell RCC (ccRCC) compared with a group of healthy subjects (n = 1108). Fasting serum adiponectin concentrations were also examined. Fasting serum adiponectin was lower in subjects carrying minor alleles of rs182052 in both ccRCC patients (β = −0.399, P = 0.018) and healthy controls (β = −0.371, P = 0.024). These results suggest that ADIPOQ rs182052 is significantly associated with ccRCC risk.

Single nucleotide polymorphisms of the FTO gene and cancer risk: an overview

The FTO (fat mass and obesity-associated) gene has a strong linkage disequilibrium block, within which SNPs have been identified that are involved in the development of obesity. Recently some of these variants have also been associated with cancer. However, identification of the possible mechanisms that could explain these associations has proven to be elusive. It has been found that FTO polymorphisms can regulate the expression of genes at large kilobases of distance as well as the expression of the FTO gene itself, and regions for transcription factor binding. To date it has been observed that variants rs9939609, rs17817449, rs8050136, rs1477196, rs6499640, rs16953002, rs11075995 and rs1121980 are associated with the risk of developing cancer. Some studies have produced negative results when comparing the same polymorphisms, but make a simple association between polymorphic variants and cancer, have proved difficult because this relation is by nature multifactorial. A certain degree of variation resulting from the improper design of studies or processing of data can lead to erroneous conclusions. However, it is now unquestionable that certain FTO polymorphisms regulate genetic expression related to cancer susceptibility, although this field is just beginning to be understood.

Nuclear receptors and pathogenesis of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with a median overall survival time of 5 mo and the five years survival less than 5%, a rate essentially unchanged over the course of the years. A well defined progression model of accumulation of genetic alterations ranging from single point mutations to gross chromosomal abnormalities has been introduced to describe the origin of this disease. However, due to the its subtle nature and concurring events PDAC cure remains elusive. Nuclear receptors (NR) are members of a large superfamily of evolutionarily conserved ligand-regulated DNA-binding transcription factors functionally involved in important cellular functions ranging from regulation of metabolism, to growth and development. Given the nature of their ligands, NR are very tempting drug targets and their pharmacological modulation has been widely exploited for the treatment of metabolic and inflammatory diseases. There are now clear evidences that both classical ligand-activated and orphan NR are involved in the pathogenesis of PDAC from its very early stages; nonetheless many aspects of their role are not fully understood. The purpose of this review is to highlight the striking connections that link peroxisome proliferator activated receptors, retinoic acid receptors, retinoid X receptor, androgen receptor, estrogen receptors and the orphan NR Nur, chicken ovalbumin upstream promoter transcription factor II and the liver receptor homologue-1 receptor to PDAC development, connections that could lead to the identification of novel therapies for this disease.

Functional logistic regression approach to detecting gene by longitudinal environmental exposure interaction in a case-control study

Most complex human diseases are likely the consequence of the joint actions of genetic and environmental factors. Identification of gene-environment (G × E) interactions not only contributes to a better understanding of the disease mechanisms, but also improves disease risk prediction and targeted intervention. In contrast to the large number of genetic susceptibility loci discovered by genome-wide association studies, there have been very few successes in identifying G × E interactions, which may be partly due to limited statistical power and inaccurately measured exposures. Although existing statistical methods only consider interactions between genes and static environmental exposures, many environmental/lifestyle factors, such as air pollution and diet, change over time, and cannot be accurately captured at one measurement time point or by simply categorizing into static exposure categories. There is a dearth of statistical methods for detecting gene by time-varying environmental exposure interactions. Here, we propose a powerful functional logistic regression (FLR) approach to model the time-varying effect of longitudinal environmental exposure and its interaction with genetic factors on disease risk. Capitalizing on the powerful functional data analysis framework, our proposed FLR model is capable of accommodating longitudinal exposures measured at irregular time points and contaminated by measurement errors, commonly encountered in observational studies. We use extensive simulations to show that the proposed method can control the Type I error and is more powerful than alternative ad hoc methods. We demonstrate the utility of this new method using data from a case-control study of pancreatic cancer to identify the windows of vulnerability of lifetime body mass index on the risk of pancreatic cancer as well as genes that may modify this association.

Preoperative glucose abnormalities in patients with pancreatic tumours

INTRODUCTION

Pancreatic cancer is a neoplasm characterised by poor prognosis. The only effective, possible treatment is radical surgery, but most patients do not qualify for surgery because of delayed diagnosis.

AIM

To determine if assessment of endocrine pancreatic function could serve as a means of screening for pancreatic cancer.

MATERIAL AND METHODS

This prospective study was conducted on a group of 50 patients diagnosed with pancreatic tumour, who were qualified for surgery.

RESULTS

From 1.07.2010 to 4.07.2011 a further 50 patients were added to the study group. They had been admitted to the hospital with pancreatic tumours. During the preoperative period, nine of these people had been treated for diabetes, 14 were newly diagnosed with diabetes and 15 had been diagnosed with impaired glucose tolerance, but only 12 had a normal glucose profile. Afterwards, patients underwent the surgical treatment. Histopathological examination revealed that out of the 50 operated patients, 36 suffered from malignant disease, and of these only four had no impaired glucose tolerance before treatment.

CONCLUSIONS

In most cases, patients with pancreatic tumours have impaired glucose tolerance. Screening patients over 50 years of age could speed up diagnosis and surgical treatment.

Five common haplotype-tagging variants of adiponectin (ADIPOQ) and cancer susceptibility: a meta-analysis

AIMS

The relationship between common haplotype-tagging polymorphisms (rs266729 [11365C>G], rs822395 [-4034A>C], rs822396 [-3964A>G], rs2241766 [45T>G], and rs1501299 [276G>T]) in the ADIPOQ gene and cancer risk has been investigated in different ethnic groups; however, these studies have yielded contradictory results. With this in mind, this meta-analysis was performed in an attempt to draw a more precise conclusion regarding the association between ADIPOQ polymorphisms and cancer risk.

RESULTS

In this study, with a total of 19 eligible articles consisting of 52 studies, the pooled odds ratios (ORs) for the association between ADIPOQ rs1501299 and cancer risk were statistically significant (dominant model, TT/GT vs. GG, OR=0.84, 95% confidence interval [CI]: 0.77-0.92; homozygous model, TT vs. GG, OR=0.80, 95% CI: 0.68-0.94). These results suggested that ADIPOQ rs1501299 might be a protection-associated polymorphism in cancer. The stratified analyses indicated that the variant T allele of ADIPOQ rs1501299 was associated with decreased risk of cancer in both Caucasian and Asian populations when compared with the G allele. No significant association for the rest of the polymorphisms was observed under any genetic model.

CONCLUSIONS

This meta-analysis suggests that the ADIPOQ rs1501299 may be a protective factor for carcinogenesis.

Mechanisms of obesity-induced gastrointestinal neoplasia

Obesity is among the fastest growing diseases worldwide; treatment is inadequate, and associated disorders, including gastrointestinal cancers, have high morbidity and mortality. An increased understanding of the mechanisms of obesity-induced carcinogenesis is required to develop methods to prevent or treat these cancers. In this report, we review the mechanisms of obesity-associated colorectal, esophageal, gastric, and pancreatic cancers and potential treatment strategies.