Altered glucose metabolism and proteolysis in pancreatic cancer cell conditioned myoblasts: searching for a gene expression pattern with a microarray analysis of 5000 skeletal muscle genes

Sortilin-Driven Cancer Secretome Enhances Tumorigenic Properties of Hepatocellular Carcinoma via de Novo Lipogenesis

A growing body of evidence suggests de novo lipogenesis as a key metabolic pathway adopted by cancers to fuel tumorigenic processes. While increased de novo lipogenesis has also been reported in hepatocellular carcinoma (HCC), understanding on molecular mechanisms driving de novo lipogenesis remains limited. In the present study, the functional role of sortilin, a member of the vacuolar protein sorting 10 protein receptor family, in HCC was investigated. Sortilin was overexpressed in HCC and was associated with poorer survival outcome. In functional studies, sortilin-overexpressing cells conferred tumorigenic phenotypes, namely, self-renewal and metastatic potential, of HCC cells via the cancer secretome. Proteomic profiling highlighted fatty acid metabolism as a potential molecular pathway associated with sortilin-driven cancer secretome. This finding was validated by the increased lipid content and expression of fatty acid synthase (FASN) in HCC cells treated with conditioned medium collected from sortilin-overexpressing cells. The enhanced tumorigenic properties endowed by sortilin-driven cancer secretome were partly abrogated by co-administration of FASN inhibitor C75. Further mechanistic dissection suggested protein stabilization by post-translational modification with O-GlcNAcylation as a major mechanism leading to augmented FASN expression. In conclusion, the present study uncovered the role of sortilin in hepatocarcinogenesis via modulation of the cancer secretome and deregulated lipid metabolism.

Difference of risk of pancreatic cancer in new-onset diabetes and long-standing diabetes: population-based cohort study

CONTEXT

Considering the absence of methods to find pancreatic cancer early, surveillance of high-risk groups is needed for early diagnosis.

OBJECTIVE

The study aimed to investigate the effect in the incidence of pancreatic cancer and the differences between new-onset DM (NODM) and long-standing DM (LSDM) since NODM group is a representative high-risk group.

METHODS

The Korean National Health Insurance Service-National Sample Cohort between 2002 and 2013 data was used. Regarding 88,396 people with DM (case group), we conducted a 1:1 propensity score matching to select a matched non-DM population (control group). To investigate the interaction between DM and the time variable distinguishing NODM and LSDM, we performed a multi-variable time-dependent Cox regression analysis.

RESULTS

The incidence of pancreatic cancer was higher in the DM group compared to the non-DM group (0.52% vs. 0.16%, P < 0.001). The DM group had shown different risk of pancreatic cancer development according to the duration since the DM diagnosis (NODM hazard ratio (HR): 3.81, 95% confidence interval (CI): 2.97-4.88, P < 0.001; LSDM HR: 1.53, 95% CI: 1.11-2.11, P < 0.001). When the NODM and the LSDM groups were compared, the risk of pancreatic cancer was higher in the NODM group than LSDM group (HR: 1.55, P = 0.020). In subgroup analysis, NODM group showed that men (HR = 4.42 95% CI: 3.15-6.19, P < 0.001) and patients who were in their 50 s (HR = 7.54, 95% CI: 3.24-17.56, P < 0.001) were at a higher risk of developing pancreatic cancer than matched same sex or age control group (non-DM population), respectively.

CONCLUSION

The risk of pancreatic cancer was greater in people with DM than non-DM population. Among people with DM, NODM showed a higher risk of pancreatic cancer than long standing DM.

Mitochondrial Genetic and Epigenetic Regulations in Cancer: Therapeutic Potential

Mitochondria are dynamic organelles managing crucial processes of cellular metabolism and bioenergetics. Enabling rapid cellular adaptation to altered endogenous and exogenous environments, mitochondria play an important role in many pathophysiological states, including cancer. Being under the control of mitochondrial and nuclear DNA (mtDNA and nDNA), mitochondria adjust their activity and biogenesis to cell demands. In cancer, numerous mutations in mtDNA have been detected, which do not inactivate mitochondrial functions but rather alter energy metabolism to support cancer cell growth. Increasing evidence suggests that mtDNA mutations, mtDNA epigenetics and miRNA regulations dynamically modify signalling pathways in an altered microenvironment, resulting in cancer initiation and progression and aberrant therapy response. In this review, we discuss mitochondria as organelles importantly involved in tumorigenesis and anti-cancer therapy response. Tumour treatment unresponsiveness still represents a serious drawback in current drug therapies. Therefore, studying aspects related to genetic and epigenetic control of mitochondria can open a new field for understanding cancer therapy response. The urgency of finding new therapeutic regimens with better treatment outcomes underlines the targeting of mitochondria as a suitable candidate with new therapeutic potential. Understanding the role of mitochondria and their regulation in cancer development, progression and treatment is essential for the development of new safe and effective mitochondria-based therapeutic regimens.

Relationship between pancreatic cancer-associated diabetes and cachexia

BACKGROUND

Pancreatic cancer-associated diabetes mellitus (PCDM) is a paraneoplastic phenomenon characterized by worsening hyperglycaemia and weight loss. Galectin-3 and S100A9, mediators of PCDM, have pro-inflammatory functions and might thereby induce systemic inflammation and cachexia. We aimed to examine whether PCDM directly mediates cachexia.

METHODS

Consecutive pancreatic cancer (PC) patients with and without PCDM (n = 88 each) with complete information were included. Cachexia was defined as weight loss >5% within 6 months or weight loss >2% and body mass index <20 kg/m2 or sarcopenia. Skeletal muscle mass was measured with lumbar skeletal muscle index (SMI) using computed tomography images. Cachexia-related parameters (prevalence of cachexia, weight loss, and SMI) were compared between patients with and without PCDM. Relations between cachexia-related parameters and fasting blood glucose or serum levels of galectin-3 and S100A9 were analysed by Spearman correlation and logistic regression analyses.

RESULTS

One hundred two (58.0%) patients had cachexia at diagnosis. No significant differences existed between patients with and without PCDM in prevalence of cachexia (64.8% vs. 51.1%, P = 0.093), percentage of weight loss (median 6.8 vs. 4.0, P = 0.085), and SMI (median 45.8 vs. 45.3 cm2 /m2 in men, P = 0.119; 34.9 vs. 36.3 cm2 /m2 in women, P = 0.418). In patients with cachexia, the percentage of weight loss and SMI were also similar between patients with and without PCDM. In patients with PCDM, fasting blood glucose was comparable between patients with and without cachexia (P = 0.458) and did not correlate with the percentage of weight loss (P = 0.085) or SMI (P = 0.797 in men and 0.679 in women). Serum S100A9 level correlated with fasting blood glucose (correlation coefficient 0.213, P = 0.047) but not with the percentage of weight loss (P = 0.977) or SMI (P = 0.247 in men and 0.458 in women). Serum galectin-3 level also did not correlate with the percentage of weight loss (P = 0.226) and SMI (P = 0.201 in men and 0.826 in women). Primary tumour size was associated with cachexia (adjusted odds ratio per 1 cm increase 1.28, 95% confidence interval 1.02-1.60, P = 0.034), whereas PCDM, fasting blood glucose, and levels of galectin-3 and S100A9 were not predictors of cachexia.

CONCLUSIONS

Neither fasting blood glucose nor levels of galectin-3 and S100A9 were associated with cachexia-related parameters. Mediators of PCDM and hyperglycaemia do not directly mediate PC-induced cachexia.

Pancreatic cancer cells show lower oleic acid oxidation and their conditioned medium inhibits oleic acid oxidation in human myotubes

BACKGROUND

/Objectives: We aimed to metabolically compare healthy primary human pancreatic epithelial cells (hPEC) to a pancreatic cancer cell line (PANC-1) and explore the effect on energy metabolism of exposing primary human myotubes to conditioned medium from hPEC and PANC-1 cells.

METHODS

Differences in metabolism were examined with radiolabeled glucose, oleic acid and lactic acid, and by qPCR. Mass spectrometry-based proteomics was used to study global protein secretion from the two cell types. Pathway analyses were performed.

RESULTS

PANC-1 cells tended to have higher glucose uptake, production of lactic acid, and glucose oxidation compared to hPEC cells. PANC-1 cells had higher uptake but lower oxidation of oleic acid, and mitochondrial reserve capacity from oleic acid was lower in PANC-1 cells. These differences in energy metabolism were reflected by differences in gene expressions and pathway analyses of the secretome. Conditioned medium from PANC-1 cells attenuated oleic acid oxidation in primary human myotubes.

CONCLUSIONS

Metabolic characterization of the PANC-1 cells revealed a glycolytic phenotype since they had an active glucose oxidation. Furthermore, PANC-1 cells showed a lower oleic acid oxidation and secreted a high amount of proteins into conditioned medium that also induced a reduced oleic acid oxidation in myotubes.

Updated risk factors to inform early pancreatic cancer screening and identify high risk patients

Pancreatic adenocarcinoma (PDAC) is associated with poor clinical outcomes and incomplete responses to conventional therapy. Therefore, there is an unmet clinical need to better understand the predisposing factors for pancreatic cancer in hopes of providing early screening to high-risk patients. While select risk factors such as age, race, and family history, or predisposing syndromes are unavoidable, there are several new and established risk factors that allow for intervention, namely by counseling patients to make the appropriate lifestyle modifications. Here, we discuss the best-studied risk factors for PDAC such as tobacco use and chronic pancreatitis, as well as newly emerging risk factors including select nutritional deficits, bacterial infections, and psychosocial factors. As several of these risk factors appear to be additive or synergistic, by understanding their relationships and offering coordinated, multidisciplinary care to high-risk patients, it may be possible to reduce pancreatic cancer incidence and improve clinical outcomes through early detection.

Galectin-3 and S100A9: Novel Diabetogenic Factors Mediating Pancreatic Cancer-Associated Diabetes

OBJECTIVE

Pancreatic cancer-associated diabetes (PCDM) is a paraneoplastic phenomenon accounting for 1% of new-onset diabetes. We aimed to identify the mediators of PCDM and evaluate their usefulness in distinguishing PCDM from type 2 diabetes.

RESEARCH DESIGN AND METHODS

Secreted proteins of MIA PaCa-2 cells were identified by proteomics, and those with ≥10-fold overexpression in transcriptome analysis were assessed by bioinformatics and glucose uptake assay to identify candidate factors. Expression of factors was compared between tumors with and without PCDM by immunohistochemistry. Serum levels were measured in a training set including PC with and without PCDM, type 2 diabetes, pancreatitis, other pancreatic/peripancreatic tumors, and control subjects (n = 50 each). Cutoff values for differentiation between PCDM and type 2 diabetes from the training set were validated in a test set (n = 41 each).

RESULTS

Galectin-3 and S100A9 were overexpressed in tumors with PCDM and dose-dependently suppressed insulin-stimulated glucose uptake in C2C12 myotubes. In the training set, serum galectin-3 and S100A9 levels were exclusively increased in patients with PCDM and distinguished PCDM from type 2 diabetes (area under the curve [AUC] galectin-3: 0.73 [95% CI 0.64-0.83]; S100A9: 0.79 [95% CI 0.70-0.87]). Similar results were observed in the test set (AUC galectin-3: 0.83 [95% CI 0.74-0.92]; S100A9: 0.77 [95% CI 0.67-0.87]), with sensitivity and specificity 72.1% and 86.1%, respectively, for galectin-3 and 69.8% and 58.1% for S100A9 in differentiating between PCDM and type 2 diabetes.

CONCLUSIONS

Galectin-3 and S100A9 are overexpressed in PCDM tumors and mediate insulin resistance. Galectin-3 and S100A9 distinguish PCDM from type 2 diabetes in subjects with new-onset diabetes.

In Silico Analysis of Gene Expression Change Associated with Copy Number of Enhancers in Pancreatic Adenocarcinoma

Understanding the gene regulatory network governing cancer initiation and progression is necessary, although it remains largely unexplored. Enhancer elements represent the center of this regulatory circuit. The study aims to identify the gene expression change driven by copy number variation in enhancer elements of pancreatic adenocarcinoma (PAAD). The pancreatic tissue specific enhancer and target gene data were taken from EnhancerAtlas. The gene expression and copy number data were taken from The Cancer Genome Atlas (TCGA). Differentially expressed genes (DEGs) and copy number variations (CNVs) were identified between matched tumor-normal samples of PAAD. Significant CNVs were matched onto enhancer coordinates by using genomic intersection functionality from BEDTools. By combining the gene expression and CNV data, we identified 169 genes whose expression shows a positive correlation with the CNV of enhancers. We further identified 16 genes which are regulated by a super enhancer and 15 genes which have high prognostic potential (Z-score > 1.96). Cox proportional hazard analysis of these genes indicates that these are better predictors of survival. Taken together, our integrative analytical approach identifies enhancer CNV-driven gene expression change in PAAD, which could lead to better understanding of PAAD pathogenesis and to the design of enhancer-based cancer treatment strategies.

Association of VAMP5 and MCC genetic polymorphisms with increased risk of Hirschsprung disease susceptibility in Southern Chinese children

Hirschsprung disease (HSCR) is a genetic disorder characterized by the absence of neural crest cells in parts of the intestine. This study aims to investigate the association of vesicle-associated membrane protein 5 (VAMP5) and mutated in colorectal cancer (MCC) genetic polymorphisms and their correlated risks with HSCR. We examined the association in four polymorphisms (rs10206961, rs1254900 and rs14242 in VAMP5, rs11241200 in MCC) and HSCR susceptibility in a Southern Chinese population composed of 1473 cases and 1469 controls. Two variants in VAMP5 were replicated as associated with HSCR. Interestingly, we clarified SNPs rs10206961 and rs1254900 in VAMP5 are more essential for patients with long-segment aganglionosis (LHSCR). Relatively high expression correlation was observed between VAMP5 and MCC using data from public database showing there may exist potential genetic interactions. SNP interaction was cross-examined by logistic regression and multifactor dimensionality reduction analysis revealing that VAMP5 rs1254900 and MCC rs11241200 were interacting significantly, thereby contributing to the risk of HSCR. The results suggest that significant associations of the rs10206961 and rs14242 in VAMP5 with an increased risk of HSCR in Southern Chinese, especially in LHSCR patients. This study provided new evidence of epistatic association of VAMP5 and MCC with increased risk of HSCR.

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.

Glucose metabolic phenotype of pancreatic cancer

AIM: To construct a global “metabolic phenotype” of pancreatic ductal adenocarcinoma (PDAC) reflecting tumour-related metabolic enzyme expression.

METHODS: A systematic review of the literature was performed using OvidSP and PubMed databases using keywords “pancreatic cancer” and individual glycolytic and mitochondrial oxidative phosphorylation (MOP) enzymes. Both human and animal studies investigating the oncological effect of enzyme expression changes and inhibitors in both an in vitro and in vivo setting were included in the review. Data reporting changes in enzyme expression and the effects on PDAC cells, such as survival and metastatic potential, were extracted to construct a metabolic phenotype.

RESULTS: Seven hundred and ten papers were initially retrieved, and were screened to meet the review inclusion criteria. 107 unique articles were identified as reporting data involving glycolytic enzymes, and 28 articles involving MOP enzymes in PDAC. Data extraction followed a pre-defined protocol. There is consistent over-expression of glycolytic enzymes and lactate dehydrogenase in keeping with the Warburg effect to facilitate rapid adenosine-triphosphate production from glycolysis. Certain isoforms of these enzymes were over-expressed specifically in PDAC. Altering expression levels of HK, PGI, FBA, enolase, PK-M2 and LDA-A with metabolic inhibitors have shown a favourable effect on PDAC, thus identifying these as potential therapeutic targets. However, the Warburg effect on MOP enzymes is less clear, with different expression levels at different points in the Krebs cycle resulting in a fundamental change of metabolite levels, suggesting that other essential anabolic pathways are being stimulated.

CONCLUSION: Further characterisation of the PDAC metabolic phenotype is necessary as currently there are few clinical studies and no successful clinical trials targeting metabolic enzymes.

Pancreatic cancer cell-derived IGFBP-3 contributes to muscle wasting

Background

Progressive loss of skeletal muscle, termed muscle wasting, is a hallmark of cancer cachexia and contributes to weakness, reduced quality of life, as well as poor response to therapy. Previous studies have indicated that systemic host inflammatory response regarding tumor development results in muscle wasting. However, how tumor directly regulates muscle wasting via tumor-derived secreted proteins is still largely unknown.

Methods

In this study, we performed bioinformatics analysis in two datasets of pancreatic ductal adenocarcinoma, which causes cancer cachexia and muscle wasting with the highest prevalence, and uncovered that IGFBP3, which encodes IGF-binding protein-3 (IGFBP-3), is dramatically up-regulated in pancreatic tumor samples. We also verified the wasting effect of IGFBP-3 on C2C12 muscle cells with biochemical and genetic assays.

Results

IGFBP-3 potently leads to impaired myogenesis and enhanced muscle protein degradation, the major features of muscle wasting, via IGF signaling inhibition. Moreover, conditioned medium from Capan-1 pancreatic cancer cells, which contains abundant IGFBP-3, significantly induces muscle cell wasting. This wasting effect is potently alleviated by IGFBP3 knockdown in Capan-1 cells or IGFBP-3 antibody neutralization. Strikingly, compared to muscle cells, IGF signaling and proliferation rate of Capan-1 cells were rarely affected by IGFBP-3 treatment.

Conclusions

Our results demonstrated that pancreatic cancer cells induce muscle wasting via IGFBP-3 production.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0317-z) contains supplementary material, which is available to authorized users.

Neutrophil-Derived Proteases in the Microenvironment of Pancreatic Cancer -Active Players in Tumor Progression

A hallmark of pancreatic ductal adenocarcinoma (PDAC) is the fibro-inflammatory microenvironment, consisting of activated pancreatic stellate cells, extracellular matrix proteins, and a variety of inflammatory cells, such as T cells, macrophages, or neutrophils. Tumor-infiltrating immune cells, which are found in nearly all cancers, including PDAC, often fail to eliminate the tumor, but conversely can promote its progression by altering the tumor microenvironment. Pancreatic cancer cells are able to attract polymorphonuclear neutrophils (PMN) via tumor secreted chemokines and in human PDAC, PMN infiltrates can be observed in the vicinity of tumor cells and in the desmoplastic tumor stroma, which correlate with undifferentiated tumor growth and poor prognosis. The behavior of tumor-infiltrating neutrophils in the tumor micromilieu is not yet understood at a mechanistic level. It has been shown that PMN have the potential to kill tumor cells, either directly or by antibody-dependent cell-mediated cytotoxicity, but on the other side various adverse effects of PMN, such as promotion of aggressive tumor growth with epithelial-to-mesenchymal transition and increased metastatic potential, have been described. Recent therapeutic approaches for PDAC focus not only the tumor cell itself, but also elements of the tumor microenvironment. Therefore, the role of PMN and their derived products (e.g. cytokines, proteases) as a new vein for a therapeutic target should be critically evaluated in this context. This review summarizes the current understanding of the interplay between proteases of tumor-infiltrating neutrophils and pancreatic tumor cells and elements of the desmoplastic stroma.

Pancreatic Expression of Immunoglobulin G in Human Pancreatic Cancer and Associated Diabetes

OBJECTIVES

The prognosis of pancreatic cancer (PC) is poor and the pathogenesis of PC-associated diabetes is unknown. We investigated the possible expression of immunoglobulin G (IgG) in human pancreatic carcinomas and adjacent pancreatic islets to gain a better understanding of these diseases.

METHODS

We employed immunohistochemistry, Western Blot, real-time polymerase chain reaction, and in situ hybridization to examine IgG expression in PC tissues and adjacent islets with and without cancer-associated diabetes. The IgG mRNA and IgG synthesizing-related enzymes were examined in PC cell lines. The IgG expression and secretion were downregulated with specific small interfering RNA and antibody to IgG followed by flow cytometry to assess its effect on apoptosis of cultured PC cells.

RESULTS

The expression of IgG was detected in pancreatic carcinoma and adjacent islets. Small interfering RNA and antibody treatments induced apoptosis in PC cell lines. In the carcinoma tissue, the levels of IgG expression varied depending on the stages of the cancers with more malignant cancers expressing more IgG (P < 0.05). The IgG levels in cancer cells were also increased when the patients had diabetes or hyperglycemia (P < 0.05). In addition, the extent of IgG expression in the seemingly normal islet cells adjacent to the tumor varied in relation to the grade of cancer differentiation and distance to the cancer nests.

CONCLUSIONS

(1) Immunoglobulin G was locally produced by PC cells and adjacent islet cells. (2) Immunoglobulin G may promote tumor growth by inhibiting cancer cell apoptosis. (3) Locally produced IgG might play a role in PC-associated diabetes.

Analysis of global gene expression profiles suggests a role of acute inflammation in type 3C diabetes mellitus caused by pancreatic ductal adenocarcinoma

AIMS/HYPOTHESIS

Pancreatic ductal adenocarcinoma (PDAC) can cause type 3C diabetes, known as PDAC-associated diabetes mellitus (PDAC-DM), but the mechanism is unknown. This study aimed to reveal the mechanism.

METHODS

PDAC lesions from patients with or without PDAC-DM (n = 4 in each group) were individually profiled for 23,512 mRNAs with microarrays. Bioinformatic analysis and in vivo and in vitro assays were then conducted.

RESULTS

We determined that 2,778 genes were differentially expressed; over-representation of ten genes was validated with quantitative RT-PCR. The analysis of gene ontology showed that the differentially expressed secretory genes were related mainly to inflammation. High levels of a marker of inflammation (C-reactive protein [CRP]) and an inflammatory mediator (TNF super-family member 13 [TNFSF13]) were found in the serum of patients with PDAC-DM. After surgical resection of PDAC lesions, CRP and TNFSF13 levels significantly decreased (p < 0.01). Furthermore, we found that the levels of TNFSF13 in PDAC lesions and TNFSF13 and CRP in serum were significantly correlated with the diabetic status of patients with PDAC-DM (p < 0.01). Assays in vivo showed that after exposure to an inhibitor of inflammation (celecoxib), the fasting blood glucose level in the mouse model of PDAC-DM dramatically decreased from 6.9 ± 0.1 to 5.6 ± 0.1 mmol/l in 2-4 days (p < 0.01).

CONCLUSIONS/INTERPRETATION

We found that acute inflammation was involved in the pathogenesis of PDAC-DM. We contend that acute inflammation is a potential target for the diagnosis and treatment of PDAC-DM.

The early diagnosis of pancreatic cancer and diabetes: what's the relationship?

Pancreatic cancer (PC) has a dismal prognosis as cancer-specific symptoms occur only at an advanced stage. If the cancer is to be discovered early, it will have to be done in asymptomatic individuals. Since the incidence of PC is low, screening for asymptomatic cancer in the general population will not be feasible. Screening will have to be restricted to subjects at high risk for PC. The proportion of PC patients who also have hyperglycemia or diabetes has previously been under appreciated; new data show that up to 80% are either hyperglycemic or diabetic and this can be evident in the pre-symptomatic phase. Diabetes improves following PC resection suggesting that diabetes is caused by the cancer. Conversely, older subjects with new-onset diabetes have an approximately eight fold higher risk of having PC compared to the general population. Recognition of new-onset diabetes as an early manifestation of PC could lead to diagnosis of asymptomatic, early stage PC. However, primary type 2 diabetes is common and PC is relatively uncommon in the general population and the two forms of diabetes are clinically indistinguishable. The success of the strategy to use new-onset hyperglycemia and diabetes as a screening tool to identify subjects with a high likelihood of having asymptomatic PC will depend largely on our ability to differentiate PC-associated diabetes from the more common type 2 diabetes using a (serologic) biomarker.

Baseline hemoglobin-A1c impacts clinical outcomes in patients with pancreatic cancer

An association between diabetes mellitus and pancreatic ductal adenocarcinoma (PDA) has long been recognized. This article assesses the effect of the baseline hemoglobin-A1c (HbA1c) value on the clinical outcomes of patients with PDA. HbA1c values were prospectively collected on 656 consecutive patients presenting to a pancreas multidisciplinary cancer clinic from 2009 to 2012. Patients were diagnosed with benign pancreatic disease (BPD) or biopsy-confirmed resectable (R), borderline/locally advanced (BL), or metastatic (M) PDA. Excluded were those with prior treatment for PDA or a history of chronic diabetes mellitus (>1-year or unknown duration), resulting in a final cohort of 284 patients. Of 284 patients, 44 had benign disease, 62 had R-PDA, 115 had BL-PDA, and 63 had M-PDA. Patients with malignant disease (R-, BL-, and M-PDA) collectively had a higher average HbA1c value than patients with BPD (6.1% vs 5.6%; P<.001). Among patients with PDA (n=240), HbA1c values of 6.5% or greater were significantly associated with inferior overall survival (OS) compared with patients with HbA1c values less than 6.5% (hazard ratio [HR], 1.74; OS, 10.2 vs 13.0 months; P=.007), along with other known prognostic factors, such as age of 65 years or older, ECOG performance status of 1 or greater, carbohydrate antigen 19-9 level greater than 90, tumor size larger than 3 cm, and disease stage. HbA1c values of 6.5% or greater remained in the final predictive model using backward elimination (HR, 1.46; P=.097), indicating that HbA1c values of 6.5% or greater influence OS of patients with PDA even when accounting for other known prognostic factors. HbA1c level at presentation is significantly higher in patients with PDA than patients with BPD and seems to affect survival.

New insights into pancreatic cancer-induced paraneoplastic diabetes

Up to 85% of patients with pancreatic cancer have diabetes or hyperglycaemia, which frequently manifests as early as 2-3 years before a diagnosis of pancreatic cancer. Conversely, patients with new-onset diabetes have a 5-8-fold increased risk of being diagnosed with pancreatic cancer within 1-3 years of developing diabetes. Emerging evidence now indicates that pancreatic cancer causes diabetes. As in type 2 diabetes, β-cell dysfunction and peripheral insulin resistance are seen in pancreatic cancer-induced diabetes. However, unlike in patients with type 2 diabetes, glucose control worsens in patients with pancreatic cancer in the face of ongoing, often profound, weight loss. Diabetes and weight loss, which precede cachexia onset by several months, are paraneoplastic phenomena induced by pancreatic cancer. Although the pathogenesis of these pancreatic cancer-induced metabolic alterations is only beginning to be understood, these are likely mechanisms to promote the survival and growth of pancreatic cancer in a hostile and highly desmoplastic microenvironment. Interestingly, these metabolic changes could enable early diagnosis of pancreatic cancer, if they can be distinguished from the ones that occur in patients with type 2 diabetes. One such possible biomarker is adrenomedullin, which is a potential mediator of β-cell dysfunction in pancreatic cancer-induced diabetes.

Identification of proteins implicated in the development of pancreatic cancer-associated diabetes mellitus by iTRAQ-based quantitative proteomics

Studies have revealed that pancreatic cancer (PC) may lead to diabetes mellitus (DM). We aimed to identify the proteins implicated in the development of PC-associated DM in PC tissues with DM. We used isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional liquid chromatography-tandem mass spectrometry to compare protein expression in PC tissues with DM with that in PC tissues without DM and in adjacent nontumor tissues with or without DM. A total of 80 surgically resected fresh tissues from 40 PC patients were included to identify differential protein expression. Western blotting and immunohistochemistry were then applied to evaluate the differential expression of selected proteins. A total of 1611 proteins were repeatedly identified and quantified by performing the iTRAQ-based experiments twice. Of these, 23 proteins were differentially expressed according to our defined criteria (12 upregulated and 11 downregulated). The S100 calcium binding protein A9 and aldehyde dehydrogenase 2 family were selected to validate the proteomic results by western blotting and immunohistochemistry. The identification of key proteins implicated in the development of PC-associated DM could serve as a foundation to better understand and further explore the etiology and pathogenesis of PC-associated DM.

BIOLOGICAL SIGNIFICANCE

The identification of key proteins implicated in the development of PC-associated DM could serve as a foundation to better understand and further explore the etiology and pathogenesis of PC-associated DM.

Type 2 diabetes mellitus and pancreatic cancer

Tumorigenesis of pancreatic cancer (PC) and the pathophysiology of type 2 diabetes mellitus (DM2) are emerging as intertwined pathways. As the operative morbidity and mortality of pancreatectomy has improved, incidence has increased and survival has remained mostly unchanged. The diagnosis of DM2 suggests pancreatic dysfunction and possible early carcinogenesis. DM2 is a significant comorbidity predicting worse outcomes in patients undergoing pancreatic resection as part of the treatment of PC. This article examines this phenomena and suggests possible approaches to screening and diagnosis.

Adrenomedullin is up-regulated in patients with pancreatic cancer and causes insulin resistance in β cells and mice

BACKGROUND & AIMS

New-onset diabetes in patients with pancreatic cancer is likely to be a paraneoplastic phenomenon caused by tumor-secreted products. We aimed to identify the diabetogenic secretory product(s) of pancreatic cancer.

METHODS

Using microarray analysis, we identified adrenomedullin as a potential mediator of diabetes in patients with pancreatic cancer. Adrenomedullin was up-regulated in pancreatic cancer cell lines, in which supernatants reduced insulin signaling in beta cell lines. We performed quantitative reverse-transcriptase polymerase chain reaction and immunohistochemistry on human pancreatic cancer and healthy pancreatic tissues (controls) to determine expression of adrenomedullin messenger RNA and protein, respectively. We studied the effects of adrenomedullin on insulin secretion by beta cell lines and whole islets from mice and on glucose tolerance in pancreatic xenografts in mice. We measured plasma levels of adrenomedullin in patients with pancreatic cancer, patients with type 2 diabetes mellitus, and individuals with normal fasting glucose levels (controls).

RESULTS

Levels of adrenomedullin messenger RNA and protein were increased in human pancreatic cancer samples compared with controls. Adrenomedullin and conditioned media from pancreatic cell lines inhibited glucose-stimulated insulin secretion from beta cell lines and islets isolated from mice; the effects of conditioned media from pancreatic cancer cells were reduced by small hairpin RNA-mediated knockdown of adrenomedullin. Conversely, overexpression of adrenomedullin in mice with pancreatic cancer led to glucose intolerance. Mean plasma levels of adrenomedullin (femtomoles per liter) were higher in patients with pancreatic cancer compared with patients with diabetes or controls. Levels of adrenomedullin were higher in patients with pancreatic cancer who developed diabetes compared those who did not.

CONCLUSIONS

Adrenomedullin is up-regulated in patients with pancreatic cancer and causes insulin resistance in β cells and mice.

The bidirectional interation between pancreatic cancer and diabetes

The bidirectional interation between pancreatic cancer (PanCa) and diabetes has been confirmed by epidemiological studies, which provide evidence-based medical support for further research into the mechanisms involved in the interaction. We reviewed the literature regarding the role of diabetes in the generation and progression of PanCa and the mechanism by which PanCa induces diabetes for its malignant progression. The effect of antidiabetic drugs on the occurrence and prognosis of PanCa was also reviewed. Diabetes may directly promote the progression of PanCa by pancreatic duct enlargement and hypertension, as well as by enabling an increased tumor volume. Hyperinsulinemia, insulin resistance, cytokines, hyperglycemia and genotype change are also important factors in the progression of PanCa with diabetes. Hyperglycemia may be the first clinical manifestation and is helpful in the early diagnosis of PanCa. Furthermore, antidiabetic drugs can have different effects on the occurrence and prognosis of PanCa. The bidirectional interation between PanCa and diabetes is involved in the occurrence, proliferation, invasion, metastasis and prognosis of PanCa with diabetes. The discovery of biomarkers for the early diagnosis of PanCa, as well as the novel usage of metformin for its antitumor effects and determining the potential mechanisms of these effects, may be the next direction for PanCa research and treatment.

Early diagnosis of pancreatic adenocarcinoma: role of stroma, surface proteases, and glucose-homeostatic agents

OBJECTIVES

New-onset diabetes in pancreatic adenocarcinoma is due to a combination of insulin resistance and decreased β-cell function. Its differentiation from the common type 2 diabetes is the prerequisite for early diagnosis of pancreatic adenocarcinoma. Little attention has been paid to pancreatic stroma and surface proteases.

METHODS

The activated fibroblasts selectively express fibroblast activation protein α, a structural homolog of the ubiquitously expressed dipeptidyl peptidase 4. Their role in pancreatic carcinogenesis is reviewed.

RESULTS

Homodimers and heterodimers of both enzymes display high specificity for peptides and proteins with penultimate proline or alanine. Most glucose-homeostatic agents are candidate substrates of these enzymes. The biological activity of truncated substrates is decreased or absent.

CONCLUSIONS

The interactions of surface proteases with glucose-homeostatic agents may adequately explain the evolution of diabetes associated with pancreatic adenocarcinoma and differentiate it from the common type 2 diabetes.

Clinical profiles and long-term outcomes of patients with pancreatic ductal adenocarcinoma and diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) is considered to be a possible risk factor and/or a manifestation of pancreatic ductal adenocarcinoma (PDAC). This study is aimed at analysing the potential association of diabetes mellitus with the development and pathogenic degrees of PDAC and post-surgical survival of Chinese Han PDAC patients.

METHODS

A total of 1123 patients with PDAC were recruited and included 256 patients with diabetes mellitus within 2 years (new-onset) and 62 patients with diabetes mellitus ≥ 2 years (long-standing). Additional 466 patients with type 2 diabetes mellitus were included in this study. Their clinical characteristics and long-term outcomes were analysed.

RESULTS

In comparison with patients with type 2 diabetes mellitus alone, PDAC patients with new-onset diabetes mellitus had an older onset age of diabetes mellitus and lower body mass index (BMI). Among PDAC cases, patients with new-onset diabetes mellitus were associated with neural invasion, poor tumour differentiation and shorter post-surgical survival. However, more than half of these patients became euglycemic after surgical resection of tumours.

CONCLUSIONS

PDAC patients developed new-onset diabetes mellitus at an older age, and they had shorter post-surgical survival. The underlying mechanisms by which comorbid diabetes mellitus affect the clinical profiles and outcomes of PDAC patients deserve further researches.

Diabetes and pancreatic cancer: chicken or egg?

OBJECTIVES

Although half of all patients with pancreatic cancer are diabetic at the time of diagnosis, it remains unclear whether the diabetes associated with pancreatic cancer is a cause or an effect of the malignancy.

METHODS

Epidemiologic studies were reviewed, the geographic prevalence of diabetes and the incidence of pancreatic cancer were examined, and clinical and laboratory studies were reviewed.

RESULTS

Long-standing diabetes increases the risk of pancreatic cancer by 40% to 100%, and recent-onset diabetes is associated with a 4- to 7-fold increase in risk, such that 1% to 2% of patients with recent-onset diabetes will develop pancreatic cancer within 3 years. Treatment of diabetes or morbid obesity decreases the risk of pancreatic cancer, and metformin therapy decreases the risk due to both its antidiabetic and antineoplastic effects. Recent-onset diabetes associated with pancreatic cancer likely represents secondary or type 3 diabetes. The discrimination of type 3 diabetes from the more prevalent type 2 diabetes may identify the high-risk subgroup of diabetic patients in whom potentially curable pancreatic cancer may be found.

CONCLUSIONS

Type 2 and type 1 diabetes mellitus increase the risk of pancreatic cancer with a latency period of more than 5 years. Type 3 diabetes mellitus is an effect, and therefore a harbinger, of pancreatic cancer in at least 30% of patients.

Diabetes mellitus and risk of pancreatic cancer: A meta-analysis of cohort studies

BACKGROUND

Diabetes mellitus (DM) is widely considered to be associated with risk of pancreatic cancer (PaC), however, whether DM is a cause or a consequence of PaC is still controversial. We examined this association by conducting a detailed meta-analysis of cohort studies.

METHODS

Studies were identified by searching Medline and Embase through November 30, 2010. Summary relative risks (RRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

A total of thirty-five cohort studies were included in this meta-analysis. DM was associated with an increased risk of PaC (the summary RRs=1.94; 95% CI, 1.66-2.27), with significant evidence of heterogeneity among these studies (p<0.001, I²=93.6%). Subgroup analyses revealed that the increased risk of PaC was independent of geographic locations, sex, study design, alcohol consumption, body mass index (BMI) and smoking status. In addition, the relative risk of PaC was correlated negatively with the duration of DM, with the highest risk of PaC found among patients diagnosed within less than 1 year. There was no significant publication bias (p=0.136 for Egger's regression asymmetry test).

CONCLUSIONS

Findings from this meta-analysis strongly support that diabetes is associated with an increased risk of PaC in both males and females and that DM is both an early manifestation and an etiologic factor of pancreatic cancer.

Diabetes mellitus in pancreatic cancer and the need for diagnosis of asymptomatic disease

Pancreatic cancer is strongly associated with the development of hyperglycemia, peripheral insulin resistance and diabetes mellitus, especially when presented as new-onset diabetes mellitus. Peripheral insulin resistance and hyperinsulinemia have been suggested to promote growth of pancreatic cancer cells, and therefore a relation between long-standing diabetes mellitus type 2 and pancreatic cancer has been implied. Epidemiological studies, though, give incongruent results to this problem. There are data supporting a tumor-derived influence on glucose metabolism, insulin secretion and eventually the development of diabetes mellitus in early stages of pancreatic cancer. The only possibility for curative intent in pancreatic cancer is to diagnose the disease before symptoms occur. Patients with newly diagnosed diabetes mellitus type 2 or hyperglycemia as a risk group have been recommended for primary screening for pancreatic cancer. To date, there is no specific biomarker to identify patients with an asymptomatic pancreatic cancer. The review discuss the relationship between pancreatic cancer and diabetes mellitus and the possibility of secondary screening of patients with newly diagnosed diabetes mellitus type 2 or hyperglycemia in an artificial neural network. PubMed was searched for articles using the Mesh term 'pancreatic neoplasms' combined with 'insulin resistance' and 'glucose metabolism disorders'. Additional articles were retrieved through hyperlinks and by manually searching reference lists in original published articles. In total 36 articles were systematically reviewed. and IAP.

The relationship between new-onset diabetes mellitus and pancreatic cancer risk: a case-control study

Diabetes mellitus (DM) is widely considered to be associated with pancreatic cancer, however, whether DM is a cause or consequence of pancreatic cancer is controversial. In the present study, 1458 patients with pancreatic ductal adenocarcinoma (PDAC) and 1528 age-, sex- and sociodemographic variables-matched controls were recruited in two university-affiliated hospitals from 1st January 2000 to 31st December 2009. DM was defined as fasting blood glucose (FBG) level of 7.0 mmol/L or greater. An unconditional multivariable logistic regression analysis was used to estimate adjusted odds ratios (AORs) and 95% confidence interval (CI). Compared with controls, a moderate increased risk of PDAC was observed among cases with long-standing diabetes (≥ 2-year duration), with an AOR (95% CI) of 2.11 (1.51-2.94). Interestingly, a significant higher risk was observed among cases with new-onset DM (<2-year duration), with an AOR of 4.43 (3.44-5.72) compared to controls without DM. In addition, we found a synergistic interaction between cigarette smoking and DM on modifying the risk of pancreatic cancer development (AOR=6.17, 95% CI 3.82-9.94). Similarly, a synergistic interaction between new-onset DM and family history of pancreatic cancer was found for pancreatic cancer risk, with an AOR (95% CI) of 11.04 (2.51-48.53). This study suggested that DM could be both an early manifestation of pancreatic cancer and an aetiologic factor. Possible effect modification on DM by family history of pancreatic cancer and smoking status should be further explored in future aetiologic studies.

Novel target genes responsive to the anti-growth activity of triptolide in endometrial and ovarian cancer cells

Triptolide (TPL), a bioactive component of the Chinese medicinal herb Tripterygium wilfordii Hook F, induces apoptosis in some lines of human tumor cells. However, the effect of TPL on gynecologic cancer cells has not yet been well-described. We investigated the effects of TPL on cell growth, cell cycle, and apoptosis in endometrial and ovarian cancer cell lines. Furthermore, we examined global changes in gene expression after treatment with TPL. By using a list of 20 differentially expressed genes, Western blot analyses were performed on five endometrial and ovarian cancer cell lines. All cell lines were sensitive to the growth-inhibitory effect of TPL. TPL increased the proportion of cells in the S-phase of the cell cycle and induced apoptosis. cDNA microarray assay demonstrated that the treatment with TPL changed the expression of cell cycle regulators, apoptosis-related factors and cell proliferation markers. Of the gene expression changes induced by TPL treatment, up-regulation of LRAP, CDH4, and SFRP1 and down-regulation of cystatin, TNNT 1, and L1-CAM were confirmed using Western blot analysis in all the cell lines examined. We found a strong anticancer activity of TPL and identified some potential target genes of this drug, raising hopes that TPL may become a useful therapy for endometrial and ovarian cancers.

Preoperative diabetes mellitus and long-term survival after resection of pancreatic adenocarcinoma

PURPOSE

To assess clinicopathologic features and postresection survival of diabetes mellitus (DM)-associated pancreatic ductal adenocarcinoma (PDAC).

METHODS

Records of resected PDAC patients from 2000 to 2007 were reviewed. DM was classified as new-onset (<24 months before PDAC) or longstanding (> or =24 months). Clinicopathologic features were compared by univariate and multivariate analyses. Survival was assessed by Kaplan-Meier method and Cox regression.

RESULTS

Of 209 patients, 93 (45%) met criteria for DM (35 longstanding DM, 55 new-onset DM, 3 duration unknown). DM patients were older (DM 66 +/- 9 years, non-DM 63 +/- 12 years, P = 0.06); a majority had additional preoperative comorbidities (DM 64.5%, non-DM 25.9%, P < 0.001). Tumor size was larger in patients with DM (DM 3.8 +/- 1.7 cm, non-DM 3.2 +/- 1.5 cm, P = 0.003). Groups were similar in terms of tumor location, perineural/lymphovascular invasion, and node and margin status. On logistic regression, tumor size >/=3.0 cm was independently associated with both overall DM (odds ratio [OR] 3.60; 95% confidence interval [1.79-7.26]) and new-onset DM (OR 3.69, [1.65-8.24]). Median survival was reduced in patients with DM compared with non-DM (15 versus 17 months, P = 0.015). Multivariate analysis controlling for prognostic variables including age, comorbidities, and tumor size demonstrated that DM was independently associated with reduced survival (hazard ratio [HR] 1.55, [1.02-2.35]). This association was more pronounced for patients with new-onset DM (HR 1.75 [1.10-2.78]) than those with longstanding DM (HR 1.30 [0.75-2.25]).

CONCLUSIONS

Preexisting DM is associated with reduced survival in patients undergoing resection for PDAC. PDAC with new-onset DM may exhibit increased tumor size and decreased postresection survival. Additional investigation is needed to clarify etiology and impact of PDAC-associated DM.

Age and diet affect gene expression profile in canine skeletal muscle

We evaluated gene transcription in canine skeletal muscle (biceps femoris) using microarray analysis to identify effects of age and diet on gene expression. Twelve female beagles were used (six 1-year olds and six 12-year olds) and they were fed one of two experimental diets for 12 months. One diet contained primarily plant-based protein sources (PPB), whereas the second diet contained primarily animal-based protein sources (APB). Affymetrix GeneChip Canine Genome Arrays were used to hybridize extracted RNA. Age had the greatest effect on gene transcription (262 differentially expressed genes), whereas the effect of diet was relatively small (22 differentially expressed genes). Effects of age (regardless of diet) were most notable on genes related to metabolism, cell cycle and cell development, and transcription function. All these genes were predominantly down-regulated in geriatric dogs. Age-affected genes that were differentially expressed on only one of two diets were primarily noted in the PPB diet group (144/165 genes). Again, genes related to cell cycle (22/35) and metabolism (15/19) had predominantly decreased transcription in geriatric dogs, but 6/8 genes related to muscle development had increased expression. Effects of diet on muscle gene expression were mostly noted in geriatric dogs, but no consistent patterns in transcription were observed. The insight these data provide into gene expression profiles of canine skeletal muscle as affected by age, could serve as a foundation for future research pertaining to age-related muscle diseases.

New-onset diabetes: a potential clue to the early diagnosis of pancreatic cancer

Pancreatic cancer has a dismal prognosis because cancer-specific symptoms occur only at an advanced stage. If the cancer is to be discovered early, screening will need to be done in asymptomatic individuals. Because the incidence of pancreatic cancer is low, screening for asymptomatic cancer in the general population is not feasible; therefore, screening will need to be restricted to people at high risk of this disease. The proportion of patients with pancreatic cancer who also have hyperglycaemia or diabetes has previously been under appreciated. New data show that up to 80% of patients are either hyperglycaemic or diabetic, both of which can be detected in the presymptomatic phase. Diabetes has been shown to improve after pancreatic-cancer resection, suggesting that diabetes is caused by the cancer. Conversely, older patients with new-onset diabetes have about an eight-times higher risk of having pancreatic cancer than the general population. Recognition of new-onset diabetes as an early manifestation of pancreatic cancer could lead to the diagnosis of asymptomatic, early-stage pancreatic cancer. However, primary type-2 diabetes is common in the general population and pancreatic cancer is relatively uncommon, and the two forms of diabetes are clinically indistinguishable. The success of a strategy using new-onset hyperglycaemia and diabetes as a screening tool to identify people with a high likelihood of having asymptomatic pancreatic cancer will depend largely on our ability to differentiate pancreatic-cancer-associated diabetes from the more common type-2 diabetes by use of a (serological) biomarker.

New-onset diabetes: a potential clue to the early diagnosis of pancreatic cancer

Pancreatic cancer has a dismal prognosis because cancer-specific symptoms occur only at an advanced stage. If the cancer is to be discovered early, screening will need to be done in asymptomatic individuals. Because the incidence of pancreatic cancer is low, screening for asymptomatic cancer in the general population is not feasible; therefore, screening will need to be restricted to people at high risk of this disease. The proportion of patients with pancreatic cancer who also have hyperglycaemia or diabetes has previously been under appreciated. New data show that up to 80% of patients are either hyperglycaemic or diabetic, both of which can be detected in the presymptomatic phase. Diabetes has been shown to improve after pancreatic-cancer resection, suggesting that diabetes is caused by the cancer. Conversely, older patients with new-onset diabetes have about an eight-times higher risk of having pancreatic cancer than the general population. Recognition of new-onset diabetes as an early manifestation of pancreatic cancer could lead to the diagnosis of asymptomatic, early-stage pancreatic cancer. However, primary type-2 diabetes is common in the general population and pancreatic cancer is relatively uncommon, and the two forms of diabetes are clinically indistinguishable. The success of a strategy using new-onset hyperglycaemia and diabetes as a screening tool to identify people with a high likelihood of having asymptomatic pancreatic cancer will depend largely on our ability to differentiate pancreatic-cancer-associated diabetes from the more common type-2 diabetes by use of a (serological) biomarker.

Prevalence and clinical profile of pancreatic cancer-associated diabetes mellitus

BACKGROUND & AIMS

Information on the clinical profile of pancreatic cancer (PaC) associated diabetes (DM) is limited. We compared the prevalence and clinical characteristics of DM in subjects with and without PaC.

METHODS

We prospectively recruited 512 newly diagnosed PaC cases and 933 controls of similar age, who completed demographic and clinical questionnaires and had fasting blood glucose (FBG) levels measured at recruitment and after pancreaticoduodenectomy (n = 105). Subjects with a FBG level >126 mg/dL or who were on antidiabetic treatment were classified as having DM.

RESULTS

DM was more prevalent (47% vs 7%; P < .001) and predominantly of new onset (<2-year duration) (74% vs 53%; P = .002) among cases compared with controls. Among PaC cases, those with DM (n = 243) were older (68 +/- 10 vs 64 +/- 12 years; P < .001), reported higher usual adult body mass index (30 +/- 6 vs 27 +/- 5 kg/m(2); P < .001), and had a greater frequency of family history of DM (47% vs 31%; P < .001) compared with those without DM (n = 269). After pancreaticoduodenectomy, while DM resolved in 17 of 30 patients (57%) with new-onset DM, its prevalence was unchanged in patients with long-standing DM (n = 11) (P = .009).

CONCLUSIONS

PaC is a powerful diabetogenic state; DM associated with PaC is often new-onset, resolves following cancer resection, and appears to be associated with conventional risk factors for DM. New-onset DM in patients with PaC is likely induced by the tumor.

Pancreatic cancer-associated diabetes mellitus: prevalence and temporal association with diagnosis of cancer

BACKGROUND & AIMS

The temporal association between diabetes mellitus and pancreatic cancer is poorly understood. We compared temporal patterns in diabetes prevalence in pancreatic cancer and controls.

METHODS

We reviewed the medical records of pancreatic cancer cases residing within 120 miles or less of Rochester, Minnesota, seen at the Mayo Clinic between January 15, 1981, and July 9, 2004, and approximately 2 matched controls/case residing locally. We abstracted all outpatient fasting blood glucose (FBG) levels for up to 60 months before index (ie, date of cancer diagnosis for cases) and grouped them into 12-month intervals; 736 cases and 1875 controls had 1 or more outpatient FBG levels in the medical record. Diabetes was defined as any FBG level of 126 mg/dL or greater or treatment for diabetes, and was defined as new onset when criteria for diabetes were first met 24 or fewer months before index, with at least 1 prior FBG level less than 126 mg/dL.

RESULTS

A higher proportion of pancreatic cancer cases compared with controls met the criteria for diabetes at any time in the 60 months before index (40.2% vs 19.2%, P < .0001). The proportions were similar in the -60 to -48 (P = .76) and -48 to -36 (P = .06) month time periods; however, a greater proportion of cases than controls met criteria for diabetes in the -36 to -24 (P = .04), -24 to -12 (P < .001), and -12 to 0 (P < .001) month time periods. Diabetes was more often new onset in cases vs controls (52.3% vs 23.6%, P < .0001).

CONCLUSIONS

Diabetes has a high (40%) prevalence in pancreatic cancer and frequently is new onset. Identification of a specific biomarker for pancreatic cancer-induced diabetes may allow screening for pancreatic cancer in new-onset diabetes.

The expression of Troponin T1 gene is induced by ketamine in adult mouse brain

The glutamatergic system has been implicated in neuropsychiatric disorders, such as schizophrenia, bipolar disorder and Alzheimer's disease, which also have a high prevalence of metabolic syndrome. Treatment with ketamine, a non-competitive glutamate N-methyl-d-aspartic acid (NMDA) receptor antagonist, is known to have paradoxical effects of neuroprotection and neurotoxicity. We investigated gene expression in brain tissue of adult mice treated with ketamine to characterize the expression profiles and to identify the affected metabolic pathways. Adult male mice were treated by a single intraperitoneal (i.p.) injection of either s(+)ketamine (80 mg/kg) or distilled water (as the control). Fifty genes were differentially expressed in ketamine-treated mouse brains compared with control mice using oligonucleotide microarray analysis, and the expression of Troponin T1 (Tnnt1) gene was consistently elevated (2- to 4-fold) (p<0.001). Ketamine-induced Tnnt1 expression was confirmed and characterized using RNA in situ hybridization techniques in paraffin embedded brain tissue sections. Tnnt1 expression was induced in the granule layer of the hippocampus, amygdala, hypothalamus, Purkinje cells of cerebellum (p<0.0001), and cerebral cortex. Tnnt1 gene is known to interact directly with FoxO1, which is involved in multiple peripheral metabolic pathways and central energy homeostasis. Our findings suggest that the induction of Tnnt1 gene expression in adult mouse brains by ketamine may illustrate the genes involved in the metabolic syndromes observed in neuropsychiatric disorders.

Parallel protein and transcript profiles of FSHD patient muscles correlate to the D4Z4 arrangement and reveal a common impairment of slow to fast fibre differentiation and a general deregulation of MyoD-dependent genes

Here, we present the first study of a human neuromuscular disorder at transcriptional and proteomic level. Autosomal dominant facio-scapulo-humeral muscular dystrophy (FSHD) is caused by a deletion of an integral number of 3.3-kb KpnI repeats inside the telomeric region D4Z4 at the 4q35 locus. We combined a muscle-specific cDNA microarray platform with a proteomic investigation to analyse muscle biopsies of patients carrying a variable number of KpnI repeats. Unsupervised cluster analysis divides patients into three classes, according to their KpnI repeat number. Expression data reveal a transition from fast-glycolytic to slow-oxidative phenotype in FSHD muscle, which is accompanied by a deficit of proteins involved in response to oxidative stress. Besides, FSHD individuals show a disruption in the MyoD-dependent gene network suggesting a coregulation at transcriptional level during myogenesis. We also discuss the hypothesis that D4Z4 contraction may affect in trans the expression of a set of genes involved in myogenesis, as well as in the regeneration pathway of satellite cells in adult tissue. Muscular wasting could result from the inability of satellite cells to successfully differentiate into mature fibres and from the accumulation of structural damages caused by a reactive oxygen species (ROS) imbalance induced by an increased oxidative metabolism in fibres.

Pancreatic cancer-derived S-100A8 N-terminal peptide: A diabetes cause?

BACKGROUND

Our aim was to identify the pancreatic cancer diabetogenic peptide.

METHODS

Pancreatic tumor samples from patients with (n=15) or without (n=7) diabetes were compared with 6 non-neoplastic pancreas samples using SDS-PAGE.

RESULTS

A band measuring approximately 1500 Da was detected in tumors from diabetics, but not in neoplastic samples from non-diabetics or samples from non-neoplastic subjects. Sequence analysis revealed a 14 amino acid peptide (1589.88 Da), corresponding to the N-terminal of the S100A8. At 50 nmol/L and 2 mmol/L, this peptide significantly reduced glucose consumption and lactate production by cultured C(2)C(12) myoblasts. The 14 amino acid peptide caused a lack of myotubular differentiation, the presence of polynucleated cells and caspase-3 activation.

CONCLUSIONS

The 14 amino acid peptide from S100A8 impairs the catabolism of glucose by myoblasts in vitro and may cause hyperglycemia in vivo. Its identification in biological fluids might be helpful in diagnosing pancreatic cancer in patients with recent onset diabetes mellitus.

Mitochondrial DNA D-loop in pancreatic cancer: somatic mutations are epiphenomena while the germline 16519 T variant worsens metabolism and outcome

We ascertained the frequency of mitochondrial DNA (mtDNA) D-loop region somatic mutations in pancreatic cancer (PC) and verified whether polymorphisms were linked to diagnosis, prognosis, and PC-associated diabetes mellitus (DM) in 99 PC cases, 42 chronic pancreatitis (CP) cases, 18 pancreatobiliary tract tumors, and 87 healthy control subjects (CSs). Tissue samples were obtained from 19 patients with PC and 5 with CP. The D-loop region was sequenced from all tissue samples and from blood DNA of the same patients and 12 CSs. D-loop somatic mutations were found in 3 PC tissue samples (16%). Four single nucleotide polymorphisms (SNPs; T152C, T16189C, T16519C, A73G), more frequently found in PC than in CS, were analyzed by denaturing high-performance liquid chromatography-restriction fragment length polymorphism using blood DNA as the starting template in all cases. The T allele of 16519 SNP correlated with DM. The survival of patients with PC correlated with tumor stage and grade and with DM at diagnosis. When survival analysis was performed considering only patients with locally advanced disease, the T allele of mtDNA 16519 SNP correlated with shorter life expectancy. mtDNA D-loop somatic mutations, rarely found in PC, cannot be considered causative events for this tumor type and probably are epiphenomena; the mtDNA D-loop 16519 variant, which worsens PC prognosis, seems to be a predisposing genetic factor for DM.

Mitochondrial DNA mutations in human cancer

Somatic mitochondrial DNA (mtDNA) mutations have been increasingly observed in primary human cancers. As each cell contains many mitochondria with multiple copies of mtDNA, it is possible that wild-type and mutant mtDNA can co-exist in a state called heteroplasmy. During cell division, mitochondria are randomly distributed to daughter cells. Over time, the proportion of the mutant mtDNA within the cell can vary and may drift toward predominantly mutant or wild type to achieve homoplasmy. Thus, the biological impact of a given mutation may vary, depending on the proportion of mutant mtDNAs carried by the cell. This effect contributes to the various phenotypes observed among family members carrying the same pathogenic mtDNA mutation. Most mutations occur in the coding sequences but few result in substantial amino acid changes raising questions as to their biological consequence. Studies reveal that mtDNA play a crucial role in the development of cancer but further work is required to establish the functional significance of specific mitochondrial mutations in cancer and disease progression. The origin of somatic mtDNA mutations in human cancer and their potential diagnostic and therapeutic implications in cancer are discussed. This review article provides a detailed summary of mtDNA mutations that have been reported in various types of cancer. Furthermore, this review offers some perspective as to the origin of these of mutations, their functional consequences in cancer development, and possible therapeutic implications.

Gene expression profiling identifies potential relevant genes in alveolar rhabdomyosarcoma pathogenesis and discriminates PAX3-FKHR positive and negative tumors

We analyzed the expression signatures of 14 tumor biopsies from children affected by alveolar rhabdomyosarcoma (ARMS) to identify genes correlating to biological features of this tumor. Seven of these patients were positive for the PAX3-FKHR fusion gene and 7 were negative. We used a cDNA platform containing a large majority of probes derived from muscle tissues. The comparison of transcription profiles of tumor samples with fetal skeletal muscle identified 171 differentially expressed genes common to all ARMS patients. The functional classification analysis of altered genes led to the identification of a group of transcripts (LGALS1, BIN1) that may be relevant for the tumorigenic processes. The muscle-specific microarray platform was able to distinguish PAX3-FKHR positive and negative ARMS through the expression pattern of a limited number of genes (RAC1, CFL1, CCND1, IGFBP2) that might be biologically relevant for the different clinical behavior and aggressiveness of the 2 ARMS subtypes. Expression levels for selected candidate genes were validated by quantitative real-time reverse-transcription PCR.

Pancreatic cancer-associated diabetes mellitus: an open field for proteomic applications

BACKGROUND

Diabetes mellitus is associated with pancreatic cancer in more than 80% of the cases. Clinical, epidemiological, and experimental data indicate that pancreatic cancer causes diabetes mellitus by releasing soluble mediators which interfere with both beta-cell function and liver and muscle glucose metabolism.

METHODS

We analysed, by matrix-assisted laser desorption ionization time of flight (MALDI-TOF), a series of pancreatic cancer cell lines conditioned media, pancreatic cancer patients' peripheral and portal sera, comparing them with controls and chronic pancreatitis patients' sera.

RESULTS

MALDI-TOF analysis of pancreatic cancer cells conditioned media and patients' sera indicated a low molecular weight peptide to be the putative pancreatic cancer-associated diabetogenic factor. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of tumor samples from diabetic and non-diabetic patients revealed the presence of a 1500 Da peptide only in diabetic patients. The amino acid sequence of this peptide corresponded to the N-terminal of an S-100 calcium binding protein, which was therefore suggested to be the pancreatic cancer-associated diabetogenic factor.

CONCLUSIONS

We identified a tumor-derived peptide of 14 amino acids sharing a 100% homology with an S-100 calcium binding protein, which is probably the pancreatic cancer-associated diabetogenic factor.