Pancreatic cancer: the potential clinical relevance of alterations in growth factors and their receptors

Biological evaluation of novel gemcitabine analog in patient-derived xenograft models of pancreatic cancer

Gemcitabine (Gem) has been a standard first-line drug for pancreatic cancer (PCa) treatment; however, Gem's rapid metabolism and systemic instability (short half-life) limit its clinical outcome. The objective of this study was to modify Gem into a more stable form called 4-(N)-stearoyl-gemcitabine (4NSG) and evaluate its therapeutic efficacy in patient-derived xenograft (PDX) models from PCa of Black and White patients.Methods 4NSG was synthesized and characterized using nuclear magnetic resonance (NMR), elemental analysis, and high-performance liquid chromatography (HPLC). 4NSG-loaded solid lipid nanoparticles (4NSG-SLN) were developed using the cold homogenization technique and characterized. Patient-derived pancreatic cancer cell lines labeled Black (PPCL-192, PPCL-135) and White (PPCL-46, PPCL-68) were used to assess the in vitro anticancer activity of 4NSG-SLN. Pharmacokinetics (PK) and tumor efficacy studies were conducted using PDX mouse models bearing tumors from Black and White PCa patients.Results 4NSG was significantly stable in liver microsomal solution. The effective mean particle size (hydrodynamic diameter) of 4NSG-SLN was 82 ± 6.7 nm, and the half maximal inhibitory concentration (IC50) values of 4NSG-SLN treated PPCL-192 cells (9 ± 1.1 µM); PPCL-135 (11 ± 1.3 µM); PPCL-46 (12 ± 2.1) and PPCL-68 equaled to 22 ± 2.6 were found to be significantly lower compared to Gem treated PPCL-192 (57 ± 1.5 µM); PPCL-135 (56 ± 1.5 µM); PPCL-46 (56 ± 1.8 µM) and PPCL-68 (57 ± 2.4 µM) cells. The area under the curve (AUC), half-life, and pharmacokinetic clearance parameters for 4NSG-SLN were 3-fourfold higher than that of GemHCl. For in-vivo studies, 4NSG-SLN exhibited a two-fold decrease in tumor growth compared with GemHCl in PDX mice bearing Black and White PCa tumors.Conclusion 4NSG-SLN significantly improved the Gem's pharmacokinetic profile, enhanced Gem's systemic stability increased its antitumor efficacy in PCa PDX mice bearing Black and White patient tumors.

Liquid biopsy approach to pancreatic cancer

Pancreatic cancer (PC) continues to pose a major clinical challenge. There has been little improvement in patient survival over the past few decades, and it is projected to become the second leading cause of cancer mortality by 2030. The dismal 5-year survival rate of less than 10% after the diagnosis is attributable to the lack of early symptoms, the absence of specific biomarkers for an early diagnosis, and the inadequacy of available chemotherapies. Most patients are diagnosed when the disease has already metastasized and cannot be treated. Cancer interception is vital, actively intervening in the malignization process before the development of a full-blown advanced tumor. An early diagnosis of PC has a dramatic impact on the survival of patients, and improved techniques are urgently needed to detect and evaluate this disease at an early stage. It is difficult to obtain tissue biopsies from the pancreas due to its anatomical position; however, liquid biopsies are readily available and can provide useful information for the diagnosis, prognosis, stratification, and follow-up of patients with PC and for the design of individually tailored treatments. The aim of this review was to provide an update of the latest advances in knowledge on the application of carbohydrates, proteins, cell-free nucleic acids, circulating tumor cells, metabolome compounds, exosomes, and platelets in blood as potential biomarkers for PC, focusing on their clinical relevance and potential for improving patient outcomes.

Inhibition of cell migration and invasion by ICAM-1 binding DNA aptamers

Cancer is the second leading cause of death worldwide and most of the cancer-related deaths result from metastasis. As expressed on the surface of various cancer cell types, intercellular adhesion molecule-1 (ICAM-1) has been shown to play a role in the attachment, invasion and migration of tumor cells. In this study, DNA aptamers were generated against ICAM-1 by cell-SELEX and protein SELEX method using ICAM-1⁽⁺⁾ CHO-ICAM-1 cells and ICAM-1 protein, respectively. The pools obtained at the end of the 10th round of both SELEX were sequenced and the most enriched sequences were characterized for their binding behaviors and affinities to ICAM-1⁽⁺⁾ CHO-ICAM-1 and ICAM-1^(-) MIA PaCa-2 cells. Moreover, the inhibition abilities of sequences on migration and invasion were measured. The seven aptamer sequences were obtained selectively binding to CHO-ICAM-1 cells with K_d values in the ranging from 13.8 to 47.1 nM. Four of these aptamers showed inhibition in both migration and invasion of CHO-ICAM-1 cells at least 61%. All these results suggested that these aptamers have potential to detect specifically ICAM-1 expressing tumor cells and inhibit migration and invasion by blocking ICAM-1 related interactions of circulating tumor cells.

Enhancing efficacy of gemcitabine in pancreatic patient-derived xenograft mouse models

Gemcitabine (Gem), a nucleoside analog, is a preferred choice of treatment for pancreatic cancer (PCa) and often used in combination therapy against wide range of solid tumors. It is known to be rapidly inactivated in blood by cytidine deaminase. The objective of the study was to improve the systemic stability and anticancer activity of modified Gem termed 4-N-stearoylGem (4NSG) In this study, the IC50 values of 4NSG treated MiaPaCa-2 and primary pancreatic cancer (PPCL-46) cultures were significantly lower when compared with gemcitabine hydrochloride (GemHCl) treated cultures. In acute toxicity study, liver enzyme level of aspartate aminotransferase (AST) of the control mice was not significantly different from AST levels of 4NSG and GemHCl treated mice. However, alanine aminotransferase (ALT) level of control mice (67 ± 5 mUnits/mL) was significantly lower compared with ALT levels of GemHCl (232 ± 28 mUnits/mL) and that of 4NSG (172 ± 22 mUnits/mL) (p < 0.0001). More importantly, ALT level of 4NSG was lower than ALT level of GemHCl (p < 0.05). Although ALT levels were elevated, pathological images of liver and kidney tissues of control, GemHCl and 4NSG treated mice revealed no architectural changes and no significant change in mice weight was observed during treatment. The bioavailability (AUC) of 4NSG was 3-fold high and significantly inhibited the tumor growth as compared with equivalent dose of GemHCl. Immunohistochemical staining revealed that 4NSG significantly inhibited the expression vascular endothelial growth factor (VEGF) receptor. The study is unique because it established, for the first time, enhanced anticancer activity of 4NSG against pancreatic patient-derived xenograft (PDX) mouse model and PPCL-46 cells compared with Gem. 4SGN enhanced pharmacokinetic profile and improved the therapeutic efficacy of the standard-of-care Gem. Lastly, 4GSN showed a remarkable tumor growth inhibition and revealed significant antiangiogenic activity in 4GSN treated pancreatic PDX tumor.

Identification of hub genes and analysis of prognostic values in pancreatic ductal adenocarcinoma by integrated bioinformatics methods

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers in the world, and more molecular mechanisms should be illuminated to meet the urgent need of developing novel detection and therapeutic strategies. We analyzed the related microarray data to find the possible hub genes and analyzed their prognostic values using bioinformatics methods. The mRNA microarray datasets GSE62452, GSE15471, GSE102238, GSE16515, and GSE62165 were finally chosen and analyzed using GEO2R. The overlapping genes were found by Venn Diagrams, functional and pathway enrichment analyses were performed using the DAVID database, and the protein-protein interaction (PPI) network was constructed by STRING and Cytoscape. OncoLnc, which was linked to TCGA survival data, was used to investigate the prognostic values. In total, 179 differentially expressed genes (DEGs) were found in PDAC, among which, 130 were up-regulated genes and 49 were down-regulated. DAVID showed that the up-regulated genes were significantly enriched in extracellular matrix and structure organization, collagen catabolic and metabolic process, while the down-regulated genes were mainly involved in proteolysis, reactive oxygen species metabolic process, homeostatic process and cellular response to starvation. From the PPI network, the 21 nodes with the highest degree were screened as hub genes. Based on Molecular Complex Detection (MCODE) plug-in, the top module was formed by ALB, TGM, PLAT, PLAU, EGF, MMP7, MMP1, LAMC2, LAMA3, LAMB3, COLA1, FAP, CDH11, COL3A1, ITGA2, and VCAN. OncoLnc survival analysis showed that, high expression of ITGA2, MMP7, ITGB4, ITGA3, VCAN and PLAU may predict poor survival results in PDAC. The present study identified hub genes and pathways in PDAC, which may be potential targets for its diagnosis, treatment, and prognostic prediction.

99mTc-LHRH in tumor receptor imaging

Detection of gonadotropin-releasing hormone (GnRH) also known as luteinizing hormone-releasing hormone (LHRH) in the relevant tumor tissue and normal tissues and organs in vivo expression was investigated. To examine the method of direct radio labeling of LHRH by ^99mTc with relatively high radiochemical purity and stability, screening the best labeling conditions, to establish a simple and reliable method of preparation of ^99mTc-LHRH was undertaken. The detection of radioisotope-labeled LHRH distribution in mice, LHRH receptor imaging for the study and treatment of cancer basis were evaluated. i) Immunohistochemical staining test was used in 23 patients with hepatocellular carcinoma (HCC), 20 patients with breast cancer, 10 patients with prostate cancer, 20 patients with lung cancer, 20 patients with endometrial cancer tumor cells and normal tissue LHRH-R De Biaoda levels; ii) pre-tin method use direct labeling of LHRH, marking completion of saline or human serum were added at room temperature, the chromatography was measured at different times, to calculate the rate of labeled product and the radiochemical purity of the label, in vivo observation of its stability, and comparative analysis of selected optimal condition; iii) rat pituitary cell membrane protein, the product of in vitro radio-receptor marker analysis, through the saturation and inhibition experiments, was used to test its receptor binding activity; iv) Ch-T method labeled ¹²⁵I-LHRH, tail vein injection of normal mice at different times were sacrificed, blood and major organs were determined and calculated per gram organization percentage injected dose rate (%, ID/g). Detected by immunohistochemistry in 23 cases of HCC in the LHRH-positive rate was 82.61%, in the corresponding normal tissues, the positive rate was 15%; 20 cases of breast cancer positive rate of 95%, the corresponding normal tissues, the positive rate was 20%; 10 cases of prostate cancer positive rate of 70%, the corresponding normal tissues, the positive rate of 40%; 20 cases of lung cancer positive rate of 85%, the corresponding normal tissues, the positive rate of 15.79%; 20 cases of endometrial cancer positive rate of 80% in the corresponding normal tissues was 16.67% positive. ^99mTc-LHRH mark was 97.9–100.0%, the radiochemical purity of 93.9–96.4%, marking the reaction gel content of <5%. Great product receptor marker analysis showed ^99mTc-LHRH with saturable receptor binding characteristics and inhibition, and high affinity, RT = 23.2174 pmol, KD = 0.4348 nmol; intravenous injection of ¹³¹I-LHRH within 72 h after the mice rapidly cleared the blood radioactivity, the major radioactive accumulation in the liver and kidneys and by the liver, renal clearance, and other tissues and organs of the radioactivity gradually decreased with time. In conclusion, i) the liver, lung, breast, prostate, endometrial cancer exist in both LHRHR; ii) ^99mTc-LHRH preparation is simple, rapid, radiochemical purity product obtained higher marks, better stability, no further purification; and iii) LHRH ^99mTc labeled, still has a high receptor binding ability, biological activity; and has an ideal and realistic dynamics in animals, there is hope, as with the clinical value of imaging agent of GnRH receptors.

Serine protease inhibitor Kazal type 1 and epidermal growth factor receptor are expressed in pancreatic tubular adenocarcinoma, intraductal papillary mucinous neoplasm, and pancreatic intraepithelial neoplasia

BACKGROUND

Serine protease inhibitor Kazal type 1 (SPINK1) is expressed in normal human pancreatic acinar cells and in a variety of tumors, and binds to the epidermal growth factor receptor (EGFR), mediating cell proliferation through the mitogen-activated protein kinase cascade in pancreatic cancer cell lines. Here, we aimed to assess SPINK1 and EGFR expression in various neoplastic lesions, including tissues demonstrating precancerous changes.

METHODS

Surgical specimens of pancreatic ductal adenocarcinoma (n = 23), intraductal papillary mucinous neoplasm (IPMN;n = 21), pancreatic neoplasms other than ductal adenocarcinoma (n = 8), chronic pancreatitis (n = 11), and pancreatic intraepithelial neoplasia (PanIN) lesions within the resected specimens were analyzed immunohistochemically for SPINK1 and EGFR expression.

RESULTS

Sixty-five PanIN-1A, 32 PanIN-1B, 17 PanIN-2, and 6 PanIN-3 were identified. Both SPINK1 and EGFR were expressed in almost all PanIN lesions. All tubular ductal adenocarcinoma, IPMN, and mucinous cystadenocarcinoma samples (neoplasms of ductal origin) expressed SPINK1, whereas acinar cell carcinoma, anaplastic carcinoma, adenosquamous carcinoma, insulinoma, and islet cell carcinoma did not. EGFR was expressed in 87 % of tubular adenocarcinoma and 48 % of IPMN lesions. Among IPMN lesions, malignant lesions (IPMC) expressed EGFR more often than benign lesions (IPMA) did. Scattered expression of EGFR was observed in normal pancreatic ducts and within the tubular complex within chronic pancreatitis lesions.

CONCLUSIONS

These results indicate that SPINK1 plays a role as a growth factor, signaling through the EGFR pathway in pancreatic ductal adenocarcinoma and neoplasms, and that the EGFR is involved in the malignant transformation of IPMN.

Pylorus-preserving pancreaticoduodenectomy (pp Whipple) versus pancreaticoduodenectomy (classic Whipple) for surgical treatment of periampullary and pancreatic carcinoma

BACKGROUND

Pancreatic cancer is the fourth-leading cause of cancer death for both, men and women. The standard treatment for resectable tumours consists of a classic Whipple (CW) operation or a pylorus-preserving pancreaticoduodenectomy (PPW). It is unclear which of these procedures is more favourable in terms of survival, postoperative mortality, complications, and quality of life.

OBJECTIVES

The objective of this systematic review was to compare the effectiveness of CW and PPW techniques for surgical treatment of cancer of the pancreatic head and the periampullary region.

SEARCH METHODS

We conducted searches on 28 March 2006, 11 January 2011, 9 January 2014, and 18 August 2015 to identify all randomised controlled trials (RCTs), while applying no language restrictions. We searched the following electronic databases on 18 August 2015: the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Database of Systematic Reviews (CDSR) and the Database of Abstracts of Reviews of Effects (DARE) from the Cochrane Library (2015, Issue 8); MEDLINE (1946 to August 2015); and EMBASE (1980 to August 2015). We also searched abstracts from Digestive Disease Week and United European Gastroenterology Week (1995 to 2010); we did not update this part of the search for the 2014 and 2015 updates because the prior searches did not contribute any additional information. We identified two additional trials through the updated search in 2015.

SELECTION CRITERIA

RCTs comparing CW versus PPW including participants with periampullary or pancreatic carcinoma.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the included trials. We used a random-effects model for pooling data. We compared binary outcomes using odds ratios (ORs), pooled continuous outcomes using mean differences (MDs), and used hazard ratios (HRs) for meta-analysis of survival. Two review authors independently evaluated the methodological quality and risk of bias of included trials according to the standards of The Cochrane Collaboration.

MAIN RESULTS

We included eight RCTs with a total of 512 participants. Our critical appraisal revealed vast heterogeneity with respect to methodological quality and outcome parameters. Postoperative mortality (OR 0.64, 95% confidence interval (CI) 0.26 to 1.54; P = 0.32), overall survival (HR 0.84, 95% CI 0.61 to 1.16; P = 0.29), and morbidity showed no significant differences, except of delayed gastric emptying, which significantly favoured CW (OR 3.03, 95% CI 1.05 to 8.70; P = 0.04). Furthermore, we noted that operating time (MD -45.22 minutes, 95% CI -74.67 to -15.78; P = 0.003), intraoperative blood loss (MD -0.32 L, 95% CI -0.62 to -0.03; P = 0.03), and red blood cell transfusion (MD -0.47 units, 95% CI -0.86 to -0.07; P = 0.02) were significantly reduced in the PPW group. All significant results were associated with low-quality evidence based on GRADE (Grades of Recommendation, Assessment, Development and Evaluation) criteria.

AUTHORS' CONCLUSIONS

Current evidence suggests no relevant differences in mortality, morbidity, and survival between the two operations. However, some perioperative outcome measures significantly favour the PPW procedure. Given obvious clinical and methodological heterogeneity, future high-quality RCTs of complex surgical interventions based on well-defined outcome parameters are required.

Pylorus-preserving pancreaticoduodenectomy (pp Whipple) versus pancreaticoduodenectomy (classic Whipple) for surgical treatment of periampullary and pancreatic carcinoma

Background Pancreatic cancer is the fourth leading cause of cancer death for men and the fifth for women. The standard treatment for resectable tumours consists of a classic Whipple (CW) operation or a pylorus-preserving pancreaticoduodenectomy (PPW). It is unclear which of these procedures is more favourable in terms of survival, mortality, complications and quality of life.Objectives The objective of this systematic review is to compare the effectiveness of CW and PPW techniques for surgical treatment of cancer of the pancreatic head and the periampullary region.Search methods We conducted searches on 28 March 2006, 11 January 2011 and 9 January 2014 to identify all randomised controlled trials (RCTs),while applying no language restrictions. We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Database of Systematic Reviews (CDSR) and the Database of Abstracts of Reviews of Effects(DARE) from The Cochrane Library (2013, Issue 4); MEDLINE (1946 to January 2014); and EMBASE (1980 to January 2014). We also searched abstracts from Digestive Disease Week and United European Gastroenterology Week (1995 to 2010). We identified no additional studies upon updating the systematic review in 2014.Selection criteria We considered RCTs comparing CW versus PPW to be eligible if they included study participants with periampullary or pancreatic carcinoma. Data collection and analysis Two review authors independently extracted data from the included studies. We used a random-effects model for pooling data. We compared binary outcomes using odds ratios (ORs), pooled continuous outcomes using mean differences (MDs) and used hazard ratios (HRs) for meta-analysis of survival. Two review authors independently evaluated the methodological quality and risk of bias of included studies according to the standards of The Cochrane Collaboration.Main results We included six RCTs with a total of 465 participants. Our critical appraisal revealed vast heterogeneity with respect to methodological quality and outcome parameters. In-hospital mortality (OR 0.49, 95% confidence interval (CI) 0.17 to 1.40; P value 0.18), overall survival (HR 0.84, 95% CI 0.61 to 1.16; P value 0.29) and morbidity showed no significant differences. However, we noted that operating time (MD -68.26 minutes, 95% CI -105.70 to -30.83; P value 0.0004) and intraoperative blood loss (MD -0.76 mL, 95%CI -0.96 to -0.56; P value < 0.00001) were significantly reduced in the PPW group. All significant results are associated with low quality of evidence as determined on the basis of GRADE (Grades of Recommendation, Assessment, Development and Evaluation) criteria.Authors' conclusions No evidence suggests relevant differences in mortality, morbidity and survival between the two operations. Given obvious clinical and methodological heterogeneity, future research must be undertaken to perform high-quality randomised controlled trials of complex surgical interventions on the basis of well-defined outcome parameters.

Genetic determinants and potential therapeutic targets for pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer deaths in both men and women in the United States, carrying a 5-year survival rate of approximately 5%, which is the poorest prognosis of any solid tumor type. Given the dismal prognosis associated with PDAC, a more thorough understanding of risk factors and genetic predisposition has important implications not only for cancer prevention, but also for screening techniques and the development of personalized therapies. While screening of the general population is not recommended or practicable with current diagnostic methods, studies are ongoing to evaluate its usefulness in people with at least 5- to 10-fold increased risk of PDAC. In order to help identify high-risk populations who would be most likely to benefit from early detection screening tests for pancreatic cancer, discovery of additional pancreatic cancer susceptibility genes is crucial. Thus, specific gene-based, gene-product, and marker-based testing for the early detection of pancreatic cancer are currently being developed, with the potential for these to be useful as potential therapeutic targets as well. The goal of this review is to provide an overview of the genetic basis for PDAC with a focus on germline and familial determinants. A discussion of potential therapeutic targets and future directions in screening and treatment is also provided.

Role of Peroxisome Proliferator-Activated Receptor β/δ and B-Cell Lymphoma-6 in Regulation of Genes Involved in Metastasis and Migration in Pancreatic Cancer Cells

PPARβ/δ is a ligand-activated transcription factor that regulates various cellular functions via induction of target genes directly or in concert with its associated transcriptional repressor, BCL-6. Matrix remodeling proteinases are frequently over-expressed in pancreatic cancer and are involved with metastasis. The present study tested the hypothesis that PPARβ/δ is expressed in human pancreatic cancer cells and that its activation could regulate MMP-9, decreasing cancer cells ability to transverse the basement membrane. In human pancreatic cancer tissue there was significantly higher expression of MMP-9 and PPARβ/δ, and lower levels of BCL-6 mRNA. PPARβ/δ activation reduced the TNF α -induced expression of various genes implicated in metastasis and reduced the invasion through a basement membrane in cell culture models. Through the use of short hairpin RNA inhibitors of PPARβ/δ, BCL-6, and MMP-9, it was evident that PPARβ/δ was responsible for the ligand-dependent effects whereas BCL-6 dissociation upon GW501516 treatment was ultimately responsible for decreasing MMP-9 expression and hence invasion activity. These results suggest that PPARβ/δ plays a role in regulating pancreatic cancer cell invasion through regulation of genes via ligand-dependent release of BCL-6 and that activation of the receptor may provide an alternative therapeutic method for controlling migration and metastasis.

Akt kinase mediates the prosurvival effect of smoking compounds in pancreatic ductal cells

OBJECTIVES

Cigarette smoking is a major risk factor for pancreatic cancer (PaCa). However, the mechanisms of smoking-induced PaCa remain unknown. Here we investigated the effect of smoking compounds on cell death pathways in pancreatic ductal cells, precursors of PaCa.

METHODS

Human pancreatic ductal cells (HPDE6-c7) were cultured with cigarette smoke extract (CSE) or smoking compound 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Apoptosis and autophagy were assessed by DNA fragmentation and immunofluorescence, respectively.

RESULTS

Exposure to CSE or NNK decreased DNA fragmentation and up-regulated BclXL. Akt kinase was activated by smoking compounds through reactive oxygen species-dependent mechanism. Specifically, Akt activation was prevented by inhibition of nicotinamide adenine dinucleotide oxidase. Molecular or pharmacologic inhibitions of Akt prevented the antiapoptotic effect of smoking compounds. Smoking compounds stimulated rapid (1 hour) and transient activation of 5'-adenosine monophosphate-activated protein kinase and formation of autophagic vacuoles, indicating stimulation of autophagy. Repeated exposure to CSE/NNK (48 hours or longer) abolished the early activation of autophagic markers. Inhibition of Akt prevented the antiautophagic effect of long exposure to smoking compounds, indicating that smoking-induced late activation of Akt prevents autophagy.

CONCLUSIONS

Long exposure of pancreatic ductal cells to smoking compounds inhibited apoptosis and autophagy. The results revealed a central role for Akt kinase in mediating key procarcinogenic effects of smoking compounds.

EGF receptor is required for KRAS-induced pancreatic tumorigenesis

Initiation of pancreatic ductal adenocarcinoma (PDA) is definitively linked to activating mutations in the KRAS oncogene. However, PDA mouse models show that mutant Kras expression early in development gives rise to a normal pancreas, with tumors forming only after a long latency or pancreatitis induction. Here, we show that oncogenic KRAS upregulates endogenous EGFR expression and activation, the latter being dependent on the EGFR ligand sheddase, ADAM17. Genetic ablation or pharmacological inhibition of EGFR or ADAM17 effectively eliminates KRAS-driven tumorigenesis in vivo. Without EGFR activity, active RAS levels are not sufficient to induce robust MEK/ERK activity, a requirement for epithelial transformation.

Tumour-associated trypsin inhibitor TATI is a prognostic marker in colorectal cancer

BACKGROUND

The tumour-associated trypsin inhibitor TATI is expressed together with trypsin in many cancer forms, and an elevated serum level associates with poor prognosis. TATI can reduce tissue destruction by inhibiting trypsin and other proteinases, and in some cancer forms, its high tissue expression is associated with favourable prognosis. We analyzed the prognostic values of TATI, trypsinogen-1 and trypsinogen-2 immunoexpression from tissue array blocks constructed from surgical specimens of 592 colorectal cancer patients.

RESULTS

TATI positivity correlated negatively with differentiation (p < 0.001) and positively with the histological type of adenocarcinoma (p < 0.001). Trypsinogen-1 and trypsinogen-2 positivity correlated with Dukes' stage (p = 0.045, p = 0.050); the percentage of trypsinogen-1- and trypsinogen-2-positive tumours was lower in metastasized (Dukes' stage C-D) than in local (Dukes' stage A-B) disease. In addition, trypsinogen-2 correlated inversely with differentiation (p = 0.012). In univariate analysis, the expression of TATI associated with more favourable cancer-specific survival (p = 0.010). In multivariate analysis, low TATI (p = 0.044), age (p < 0.001), Dukes' stage (p < 0.001), tumour differentiation (p = 0.020) and location in the rectum (p = 0.006) were independent prognostic factors for adverse outcome. Furthermore, TATI expression was an independent prognostic factor in a subgroup of trypsinogen-1- (p = 0.007) and trypsinogen-2-positive (p = 0.006) tumours.

CONCLUSION

TATI tissue expression is an independent prognostic marker in colorectal cancer.

Oncogenic Kras is required for both the initiation and maintenance of pancreatic cancer in mice

Pancreatic cancer is almost invariably associated with mutations in the KRAS gene, most commonly KRASG12D, that result in a dominant-active form of the KRAS GTPase. However, how KRAS mutations promote pancreatic carcinogenesis is not fully understood, and whether oncogenic KRAS is required for the maintenance of pancreatic cancer has not been established. To address these questions, we generated two mouse models of pancreatic tumorigenesis: mice transgenic for inducible KrasG12D, which allows for inducible, pancreas-specific, and reversible expression of the oncogenic KrasG12D, with or without inactivation of one allele of the tumor suppressor gene p53. Here, we report that, early in tumorigenesis, induction of oncogenic KrasG12D reversibly altered normal epithelial differentiation following tissue damage, leading to precancerous lesions. Inactivation of KrasG12D in established precursor lesions and during progression to cancer led to regression of the lesions, indicating that KrasG12D was required for tumor cell survival. Strikingly, during all stages of carcinogenesis, KrasG12D upregulated Hedgehog signaling, inflammatory pathways, and several pathways known to mediate paracrine interactions between epithelial cells and their surrounding microenvironment, thus promoting formation and maintenance of the fibroinflammatory stroma that plays a pivotal role in pancreatic cancer. Our data establish that epithelial KrasG12D influences multiple cell types to drive pancreatic tumorigenesis and is essential for tumor maintenance. They also strongly support the notion that inhibiting KrasG12D, or its downstream effectors, could provide a new approach for the treatment of pancreatic cancer.

Advances in biomarker research for pancreatic cancer

Pancreatic cancer (PC) is a leading cause of cancer related deaths in United States. The lack of early symptoms results in latestage detection and a high mortality rate. Currently, the only potentially curative approach for PC is surgical resection, which is often unsuccessful because the invasive and metastatic nature of the tumor masses makes their complete removal difficult. Consequently, patients suffer relapses from remaining cancer stem cells or drug resistance that eventually lead to death. To improve the survival rate, the early detection of PC is critical. Current biomarker research in PC indicates that a serum carbohydrate antigen, CA 19-9, is the only available biomarker with approximately 90% specificity to PC. However, the efficacy of CA 19-9 for assessing prognosis and monitoring patients with PC remains contentious. Thus, advances in technology and the detection of new biomarkers with high specificity to PC are needed to reduce the mortality rate of pancreatic cancer.

Pylorus-preserving pancreaticoduodenectomy (pp Whipple) versus pancreaticoduodenectomy (classic Whipple) for surgical treatment of periampullary and pancreatic carcinoma

BACKGROUND

Pancreatic cancer is the fourth leading cause of cancer death for men and the fifth for women. The standard treatment for resectable tumours is either a classic Whipple (CW) operation or a pylorus-preserving pancreaticoduodenectomy (PPW). It is unclear which of the procedures is more favourable in terms of survival, mortality, complications and quality of life.

OBJECTIVES

The objective of this systematic review is to compare the effectiveness of each operation.

SEARCH STRATEGY

We conducted searches on 28 March 2006 and 11 January 2011 to identify all randomised controlled trials (RCTs), applying no language restrictions. We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL), CDSR and DARE from The Cochrane Library (2010, Issue 4), MEDLINE (1966 to January 2011), and EMBASE (1980 to January 2011). Abstracts from Digestive Disease Week and U nited European Gastroenterology Week (1995 to 2010). No additional studies were indentified upon updating the systematic review in 2011.

SELECTION CRITERIA

We considered RCTs comparing the CW with PPW to be eligible if they included patients with periampullary or pancreatic carcinoma.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from the included studies. We used a random-effects model for pooling data. We compared binary outcomes using odds ratios (OR), pooled continuous outcomes using mean differences (MD) and used hazard ratios (HR) for meta-analysis of survival. Two authors independently evaluated the methodological quality and risk of bias of the included studies according to Cochrane standards.

MAIN RESULTS

We included six randomised controlled trials with a total of 465 patients. Our critical appraisal revealed vast heterogeneity with respect to methodological quality and outcome parameters. In-hospital mortality (OR 0.49; 95% confidence interval (CI) 0.17 to 1.40; P = 0.18), overall survival (HR 0.84; 95% CI 0.61 to 1.16; P = 0.29) and morbidity showed no significant differences. However, we noted that operating time (MD -68.26 minutes; 95% CI -105.70 to -30.83; P = 0.0004) and intra-operative blood loss (MD -0.76 millilitres; 95% CI -0.96 to -0.56; P < 0.00001) were significantly reduced in the PPW group. All significant results have low quality of evidence based on GRADE criteria.

AUTHORS' CONCLUSIONS

There is no evidence of relevant differences in mortality, morbidity and survival between the two operations. Given obvious clinical and methodological heterogeneity, future research must be undertaken to perform high-quality randomised controlled trials of complex surgical interventions on the basis of well-defined outcome parameters.

WITHDRAWN: Pancreaticoduodenectomy (classic Whipple) versus pylorus-preserving pancreaticoduodenectomy (pp Whipple) for surgical treatment of periampullary and pancreatic carcinoma

BACKGROUND

Pancreatic cancer is the fourth leading cause of cancer death for men and the fifth for women. The standard treatment for resectable tumours is either a classic Whipple operation or a pylorus-preserving pancreaticoduodenectomy. It is unclear which of the procedures is more favourable in terms of survival, mortality, complications and quality of life.

OBJECTIVES

Several publications have highlighted advantages and disadvantages of the two techniques and the current basis of evidence remains unclear. The objective of this systematic review is to compare the effectiveness of each operation.

SEARCH STRATEGY

We conducted a search on 28/03/2006 to identify all RCTs, applying no language restriction.We searched the following electronic databases: CENTRAL, CDSR and DARE from The Cochrane Library (2006, issue 2), MEDLINE (1966 to 2006) and EMBASE (1980 to 2006). We handsearched abstracts from 1995 to 2006 from the American Digestive Disease Week (DDW), published in Gastroenterology, and the United European Gastroenterology Week (UEGW), published in Gut.

SELECTION CRITERIA

We considered randomised controlled trials comparing the classic Whipple operation with pylorus-preserving pancreaticoduodenectomy to be eligible if they included patients with periampullary or pancreatic carcinoma.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from the included studies. We used a random-effects model for pooling data. We compared binary outcomes using odds ratios (OR), pooled continuous outcomes using weighted mean differences (WMD), and used hazard ratios (HR) for meta-analysis of survival. Two authors independently evaluated the methodological quality of included studies according to quality standards and by using a questionnaire.

MAIN RESULTS

We retrieved 1235 abstracts and checked these for eligibility, including seven randomised controlled trials. Our critical appraisal revealed vast heterogeneity with respect to methodological quality and outcome parameters. Our comparisons of in-hospital mortality (OR 0.49; 95% confidence interval (CI) 0.17 to 1.40; P = 0.18), overall survival (HR 0.84; 95% CI 0.61 to 1.16; P = 0.29) and morbidity showed no significant differences. However, we noted that operating time (WMD -68.26 minutes; 95% CI -105.70 to -30.83; P = 0.0004) and intra-operative blood loss (WMD -0.76 millilitres; 95% CI -0.96 to -0.56; P < 0.00001) were significantly reduced in the pylorus-preserving pancreaticoduodenectomy group.

AUTHORS' CONCLUSIONS

There is no evidence of relevant differences in mortality, morbidity and survival between the two operations. Given obvious clinical and methodological heterogeneity, future research must be undertaken to perform high-quality randomised controlled trials of complex surgical interventions on the basis of well-defined outcome parameters.

Serine protease inhibitor Kazal type 1 promotes proliferation of pancreatic cancer cells through the epidermal growth factor receptor

Serine protease inhibitor, Kazal type 1 (SPINK1) is expressed not only in normal human pancreatic acinar cells but also in a variety of pancreatic ductal neoplasms. There are structural similarities between SPINK1 and epidermal growth factor (EGF). Hence, we hypothesized that SPINK1 binds to EGF receptor (EGFR) to activate its downstream signaling. We first showed that SPINK1 induced proliferation of NIH 3T3 cells and pancreatic cancer cell lines. We showed that SPINK1 coprecipitated with EGFR in an immunoprecipitation experiment and that the binding affinity of SPINK1 to EGFR was about half of that of EGF using quartz-crystal microbalance (QCM) technique. As expected, EGFR and its downstream molecules, signal transducer and activator of transcription 3, v-Akt murine thymoma viral oncogene homologue, and extracellular signal-regulated kinase 1/2, were phosphorylated by SPINK1 as well as EGF. To determine which pathway is the most important for cell growth, we further analyzed the effect of inhibitors. Growth stimulation by EGF or SPINK1 was completely inhibited by EGFR and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase inhibitor but not by Janus-activated kinase and phosphoinositide 3-kinase inhibitors. To further analyze the clinical importance of SPINK1 in the development of pancreatic cancer, we examined the expression of SPINK1 and EGFR in pancreatic tubular adenocarcinomas and pancreatic intraepithelial neoplasm. Both SPNK1 and EGFR were coexpressed not only in the early stage of cancer, PanIN-1A, but also in advanced stages. Taken together, these results suggest that SPINK1 stimulates the proliferation of pancreatic cancer cells through the EGFR/mitogen-activated protein kinase cascade.

Confirmation of DNA microarray-derived differentially expressed genes in pancreatic cancer using quantitative RT-PCR

The fact that pancreatic ductal adenocarcinoma (PDAC) is still an exceptionally lethal disease with an annual mortality almost equivalent to its annual incidence has stimulated intense research efforts directed at understanding the underlying molecular mechanisms. By enabling simultaneous expression analysis of thousands of genes, microarray technology has significantly contributed to illuminating the pathophysiology of PDAC. Gene expression profiling studies have been performed for molecular classification of clinically relevant tumor subtypes and have shed light on various signaling pathways associated with tumor progression. Altered expression levels of several genes have been identified as correlating with functional in vitro data as well as patient survival, indicating the potential clinical value of transcriptional profiling. However, broad clinical use of array techniques for patient characterization has been hampered by their cost intensity and by limited inter-study comparability. Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR), as the most sensitive technique for mRNA detection and quantification, will complement arrays for the confirmation of individual transcripts in larger sample cohorts. This review highlights recent studies that addressed gene expression analysis with both methodologies and that identified components of the TGF-beta signaling pathway, BNIP3, or periostin to be differentially expressed in PDAC. These studies demonstrated that the combination of microarray and RT-PCR technologies is a highly efficient and reliable approach for the identification of clinically important diagnostic and prognostic biomarkers, as well as for the discovery of novel therapeutic target candidates.

[Precursors of Pancreatic cancer: Intraepithelial Neoplasia (PanIN) and Intraductal Papillary Mucinous Neoplasms (IPMN)]

Pancreatic Intraepithelial Neoplasia (PanIN1-3) and Intraductal Papillary Mucinous Neoplasms (IPMN) putative precursors of and associated to pancreatic cancer represent a distinct, however pathologically heterogenous entity. Recently a new classification and nomenclature was established. We review the clinicopathologic and cytogenetic characteristics of PanIN and IPMN highlighting the nonaggressive biological behavior of intraepithelial and intraductal neoplasms which, in part explain their favorable prognosis.

Medical management of pancreatic adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer death in the United States. In 2008, an estimated 34,290 people died from pancreatic cancer and 37,680 new cases were diagnosed. Despite modern treatment, 90% of patients die within 1 year of diagnosis. Pancreatectomy is still the only potentially curative approach, but most patients have incurable disease by the time they are diagnosed, and fewer than 20% are candidates for surgery. In the present paper the English-language literature addressing the medical management in pancreatic cancer was reviewed. Based on these data we will discuss the role of currently used chemotherapy and target therapy in pancreatic cancer, as well as perspectives of the emerging strategies that are arising in order to improve the outcomes of this complex disease.

[Genetic abnormalities of digestive tract adenocarcinomas and correlation with the histologic sequence of their development]

Over 90% of digestive tract malignancies are adenocarcinomas (ADC) and almost 95% of them have gastric (G), colorectal (CR) or pancreatic (P) localizations. The objectives of this work are to review the genetic abnormalities of ADC in these locations and their potential coincidences, along with the histogenetic correlation of their emergence. Genetic abnormalities affecting over 50% of cases include: in G-ADC, inactivation of suppressor genes of p53, APC and DCC tumor in its intestinal variant, hypoexpression of of caderine E in the diffuse variant and hyperexpression of cyclooxygenase-2 and cyclyn D in the intestinal form; in in CR-ADC, inactivation of of genes p53, APC and DCC together with mutational activation of k-ras oncogen, and in P-ADC, the inactivation of suppressor genes p53, p16 and DPC4 along with mutational activation of k-ras oncogen. P-ADC is the one showing a more characteristic and exclusive genetic mark, followed by CR-ADC. Finally, the histogenetic correlation in the tumorigenic sequence is more evident in CR-ADC, followed by P-ADC. The complex biologic reality of G-ADC makes it more difficult to draw its genetic profile and its histogenetic correlation. In order to understand better the arguments of this work, the authors comment on the genetic-molecular basis governing the life and death of normal somatic cells and the biologic profile of the groups of genes mainly involved in tumorigenesis.

[Genetic profile and molecular bases of pancreatic carcinogenesis]

The possibility that carcinogenesis is a multiphasic process has been well demonstrated in colorectal cancer, at least in cancers arising from a benign adenomatous polyp. However, because of the difficulty of performing histopathological studies of the pancreas, the multiphasic nature of carcinogenesis is proving more difficult to demonstrate in pancreatic ductal adenocarcinoma (d-ADC), although a series of findings, reviewed in the present article, strongly support this characteristic. Firstly, d-ADC shows a fairly exclusive genetic-molecular profile, found in 70% of cases; this profile consists of the association of the K-ras oncogene and inactivation of the tumor suppressor genes p16, p53 and DPC4. Secondly, a series of lesions in the ductal epithelium, in healthy pancreatic tissue close to a d-ADC, have been identified, which seem to represent precancerous histopathological stages. Lastly, there is the suspicion that the mutations defining this genetic-molecular profile appear gradually, in a certain sequence, throughout the stages of progression. Most probably, rather than the order of appearance, the accumulation of these genetic-molecular events are what prompt quiescent ductal epithelium to progress to mitogenic cellular hyperplasia, leading to irreversible mutagenic cellular dysplasia.

Targeting of extracellular proteases required for the progression of pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDA) is the fourth leading cause of cancer-related death in the United States. Its lethality is due, in large part, to its resistance to traditional chemotherapeutics. As a result, there is an enormous effort being put into basic research to identify proteins that are required for PDA progression so that they may be specifically targeted for therapy.

OBJECTIVE

To compile and analyze the evidence that suggests that extracellular proteases are significant contributors to PDA progression.

METHODS

We focus on three different extracellular protease subclasses expressed in PDA: metalloproteases, serine proteases and cathepsins. Based on data from PDA and other cancers, we suggest their probable roles in PDA.

RESULTS/CONCLUSIONS

Of the proteases expressed in PDA, many appear to have overlapping functions, based on the substrates they process, making therapeutics complicated. Two protease families most likely to have unique, critical functions during tumor progression, and therefore strong potential as therapeutic targets, are the a disintegrin and metalloproteases (ADAMs) and the cathepsins.

A phase II trial of imatinib mesylate in patients with metastatic pancreatic cancer

OBJECTIVES

The aim of the study was to assess the clinical efficacy and toxicity of single-agent imatinib mesylate in patients with advanced, unresectable metastatic pancreatic cancer.

METHODS

Previously treated or untreated patients with histologically proven, unresectable pancreatic adenocarcinoma with adequate organ and bone marrow function were enrolled. Patients received imatinib 400 mg orally twice a day for a 28-day cycle. Response was evaluated every 4 weeks by imaging scans. Response was defined as lack of tumor progression at 3 months.

RESULTS

Eleven patients were enrolled, and 9 were evaluable for response. Best response was stable disease in 3 patients after 2 cycles of therapy. All of them subsequently progressed. No patients remained on treatment for 3 months or longer, which was the response end point. Median time to tumor progression was 47 days (range, 19-76 days) and median overall survival was 118 days (range, 40-221 days). The first 3 patients received imatinib 400 mg orally twice a day. Due to unexpected grades 2 and 3 toxicities, the dose was reduced to 600 mg daily which was well tolerated. Most common adverse events included grades 1 to 2 edema, liver enzyme elevations, nausea, and rash.

CONCLUSION

Single-agent imatinib does not have a significant activity in pancreatic cancer.

Pancreatic stellate cells: partners in crime with pancreatic cancer cells

Pancreatic stellate cells (PSC) produce the stromal reaction in pancreatic cancer, but their role in cancer progression is not fully elucidated. We examined the influence of PSCs on pancreatic cancer growth using (a) an orthotopic model of pancreatic cancer and (b) cultured human PSCs (hPSC) and human pancreatic cancer cell lines MiaPaCa-2 and Panc-1. Athymic mice received an intrapancreatic injection of saline, hPSCs, MiaPaCa-2 cells, or hPSCs + MiaPaCa-2. After 7 weeks, tumor size, metastases, and tumor histology were assessed. In vitro studies assessed the effect of cancer cell secretions on PSC migration and the effect of hPSC secretions on cancer cell proliferation, apoptosis, and migration. Possible mediators of the effects of hPSC secretions on cancer cell proliferation were examined using neutralizing antibodies. Compared with mice receiving MiaPaCa-2 cells alone, mice injected with hPSCs + MiaPaCa-2 exhibited (a) increased tumor size and regional and distant metastasis, (b) fibrotic bands (desmoplasia) containing activated PSCs within tumors, and (c) increased tumor cell numbers. In vitro studies showed that, in the presence of pancreatic cancer cells, PSC migration was significantly increased. Furthermore, hPSC secretions induced the proliferation and migration, but inhibited the apoptosis, of MiaPaCa-2 and Panc-1 cells. The proliferative effect of hPSC secretions on pancreatic cancer cells was inhibited in the presence of neutralizing antibody to platelet-derived growth factor. Our studies indicate a significant interaction between pancreatic cancer cells and stromal cells (PSCs) and imply that pancreatic cancer cells recruit stromal cells to establish an environment that promotes cancer progression.

Pancreaticoduodenectomy (classic Whipple) versus pylorus-preserving pancreaticoduodenectomy (pp Whipple) for surgical treatment of periampullary and pancreatic carcinoma

BACKGROUND

Pancreatic cancer is the fourth leading cause of cancer death for men and the fifth for women. The standard treatment for resectable tumours is either a classic Whipple operation or a pylorus-preserving pancreaticoduodenectomy but it is still unclear which of the two procedures is more favourable in terms of survival, mortality, complications, perioperative factors and quality of life.

OBJECTIVES

Several publications pointed out both advantages and disadvantages of both techniques and the current basis of evidence remains unclear. The objective of this systematic review is to compare the effectiveness of each technique.

SEARCH STRATEGY

A search was conducted to identify all published and unpublished randomised controlled trials. Trials were identified by searching the following electronic databases - The Cochrane Library, MEDLINE, EMBASE and Current Contents. Reference lists from trials selected by electronic searching were hand-searched to identify further relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the classical Whipple (CW) with the pylorus-preserving pancreaticoduodenectomy (PPW) were considered eligible if patients with periampullary or pancreatic carcinoma were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data for included studies. A random-effects model was used for pooling data from the different trials. Binary outcomes were compared using odds ratios, continuous outcomes were pooled using weighted mean differences and hazard ratios were used to for the meta-analysis of survival data. The methodological quality of included studies was evaluated independently by two authors according to quality standards and by using a questionnaire that covers different aspects of quality.

MAIN RESULTS

1235 abstracts were retrieved and checked for eligibility and seven RCTs were finally included. The critical appraisal revealed vast heterogeneity with respect to methodological quality and outcome parameters. The comparison of overall in-hospital mortality (odds ratio 0.49; 95% CI 0.17 to 1.40; P=0.18), overall survival (hazard ratio 0.84; 95% CI 0.61 to 1.16; P=0.29) and morbidity showed no significant difference. However, operating time (weighted mean difference -68.26 min; 95% CI -105.70 to -30.83; P=0.0004) and intra-operative blood loss (weighted mean difference -0.76 ml; 95% CI -0.96 to -0.56; P<0.00001) were significantly reduced in the PPW group.

AUTHORS' CONCLUSIONS

There is no evidence of relevant differences in mortality, morbidity and survival between the PPW and the CW. Given obvious clinical and methodological inter-study heterogeneity, future efforts have to be undertaken to perform high quality RCTs of complex surgical interventions on the basis of well defined outcome parameters.

Future strategies for targeted therapies and tailored patient management in pancreatic cancer

Pancreatic cancer represents the fourth leading cause of cancer-related mortality in the United States. The vast majority of patients are diagnosed at advanced stages of the disease, at which time gemcitabine-based chemotherapy is typically offered as the standard of care. However, as investigators have arrived at a greater understanding of pancreatic tumor biology, newer therapeutic agents that "target" specific pathways or molecules governing the growth, spread, and maintenance of tumor cells have gained considerable interest. Erlotinib, an orally bioavailable small molecule inhibitor of the epidermal growth factor receptor, is the first of these targeted compounds to be approved for use in combination with gemcitabine for patients with advanced pancreatic cancer. Other targeted agents, including monoclonal antibodies and small molecule inhibitors aimed at a variety of targets, also have been extensively evaluated, with limited success to date. A newer strategy worth pursuing involves tailoring an individual patient's therapy according to the molecular characteristics of both host and tumor, as has shown promise in other solid tumor types.

Aberrant Expression of a Disintegrin and Metalloproteinase 17/Tumor Necrosis Factor-α Converting Enzyme Increases the Malignant Potential in Human Pancreatic Ductal Adenocarcinoma

A disintegrin and metalloproteinase (ADAM) molecules are known for their unique potential to combine adhesion, proteolysis, and signaling. To understand the role of ADAM17/tumor necrosis factor-alpha (TNF-alpha) converting enzyme (TACE) in pancreatic ductal adenocarcinoma (PDAC), we investigated its expression, function, and in vitro regulation. ADAM17/TACE mRNA was expressed in 3 of 10 normal pancreatic tissues, 6 of 8 samples from patients with chronic pancreatitis, 10 of 10 PDAC tissues, and 9 of 9 pancreatic cancer cell lines, but it was absent in primary duct epithelial cells. Immunohistochemical staining revealed positive cancer cells in 8 of 10 PDACs but no staining of ducts in normal pancreas. ADAM17/TACE was found in 0 of 16 pancreatic intraepithelial neoplasia (PanIN)-1A lesions, 1 of 30 PanIN-1B lesions, 2 of 13 PanIN-2 lesions but, in 13 of 15 PanIN-3 lesions, associated with PDAC. Western blot, flow cytometry, and confocal microscopy analyses showed the aberrant expression of ADAM17/TACE protein in pancreatic cancer cell lines. The proteolytic activity of ADAM17/TACE, assessed by the release of TNF-alpha, was inhibited by TNF-alpha protease inhibitor. ADAM17/TACE gene silencing using small interfering RNA technique in vitro reduced invasion behavior dramatically, whereas proliferation was unaffected. Furthermore, ADAM17/TACE mRNA expression was down-regulated in pancreatic cancer cells arrested in G2-M phase as well as in a time-dependent manner after TNF-alpha and interleukin-6 incubation. In conclusion, our findings provide evidence of aberrant expression of the proteolytically active ADAM17/TACE in advanced precursor lesions (PanIN-3) and PDAC while identifying its critical involvement in the invasion process.

Genetics and biology of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death in the United States with a median survival of <6 mo and a dismal 5-yr survival rate of 3%-5%. The cancer's lethal nature stems from its propensity to rapidly disseminate to the lymphatic system and distant organs. This aggressive biology and resistance to conventional and targeted therapeutic agents leads to a typical clinical presentation of incurable disease at the time of diagnosis. The well-defined serial histopathologic picture and accompanying molecular profiles of PDAC and its precursor lesions have provided the framework for emerging basic and translational research. Recent advances include insights into the cancer's cellular origins, high-resolution genomic profiles pointing to potential new therapeutic targets, and refined mouse models reflecting both the genetics and histopathologic evolution of human PDAC. This confluence of developments offers the opportunity for accelerated discovery and the future promise of improved treatment.

Expression of nerve growth factor receptors is correlated with progression and prognosis of human pancreatic cancer

BACKGROUND AND AIM

The aim of the present study was to investigate the prognostic value of the two types of nerve growth factor receptors (NGFR), namely high-affinity receptor TrkA and low-affinity receptor p75NGFR, in pancreatic cancer.

METHODS

The mRNA expression of NGFR for TrkA and p75NGFR was examined in 56 human primary pancreatic cancers using real-time quantitative reverse transcription-polymerase chain reaction.

RESULTS

Nerve growth factor (NGF) receptors were found in all tumor specimens. It appears that the growth of pancreatic cancer cells stimulated by NGF depended on the expression levels and the ratio of TrkA to p75NGFR. TrkA and p75NGFR were negatively correlated and both were associated with abdominal or back pain and perineural invasion. Regarding this, patients with high TrkA expression levels exhibited more frequent perineural invasion and a higher degree of pain, whereas the results of p75NGFR were opposite. For Cox univariate analyses in the overall survival study, high expression of p75NGFR was associated with longer overall survival, but TrkA exhibited opposite effects and included an effect on perineural invasion and pain. Histoprognostic grading, tumor size and node involvement were not prognostic factors. In Cox multivariate analyses, TrkA and p75NGFR were both prognostic parameters.

CONCLUSIONS

The present study found that the expression of TrkA in pancreatic cancer is a marker of tumor aggressiveness. Conversely, we also found that elevated p75NGFR expression is associated with a favorable prognosis. We demonstrated that NGF exerts both stimulatory and inhibitory effects on pancreatic cancers, with the overall effect determined by the expression levels and the ratio of TrkA to p75NGFR.

The tyrosine kinase inhibitor imatinib fails to inhibit pancreatic cancer progression

Imatinib targets KIT and platelet-derived growth factor receptors (PDGFR) and is highly effective in the treatment of CML and GIST patients. Pancreatic cancers express KIT and PDGFRs. Therefore, 26 patients with unresectable pancreatic cancer were randomized to either gemcitabine (1000 mg/m2 weekly) or imatinib (2x400 mg po) treatment daily. Pancreatic adenocarcinoma was confirmed histologically and expression of KIT and PDGFRbeta was determined immunohistochemically in the biopsy specimens. Quality of life was assessed with two standard questionnaires. No objective responses were seen in either group. Median time to progression was 77 and 29 days (P=0.411) and median survival time was 140 and 60 days (P=0.517) for gemcitabine and imatinib, respectively. Survival and treatment responses were independent of KIT and PDGFRbeta expression in patients treated with imatinib. Grade 3/4 toxicities of imatinib treatment were anemia, elevated liver enzymes, vomiting, and dyspnea. Patients treated with imatinib reported diarrhoea and/or altered bowel function more frequently, which were treatable symptomatically. Quality of life was similar in both groups. In this small series of pancreatic cancer patients, treatment with imatinib was not associated with a significant control of cancer progression.

Antitumor activity of epidermal growth factor receptor-related protein is mediated by inactivation of ErbB receptors and nuclear factor-kappaB in pancreatic cancer

The erbB family of receptor tyrosine kinases plays critical roles in human cancers, including pancreatic cancer. Discovering a specific agent, which targets multiple members of the erbB family, would be important in pancreatic cancer therapy. Recently, we isolated a novel negative regulator of epidermal growth factor receptor (EGFR), termed EGFR-related protein (ERRP), whose expression attenuates EGFR activation. In the current study, we examined the effects of recombinant ERRP on the growth and ligand-induced activation of multiple members of erbB family in three pancreatic cancer cell lines that express varying levels of EGFR and other member(s) of its family, specifically HER-2. Additionally, we compared the growth inhibitory effect of ERRP with that of Erbitux or Herceptin. Our results showed that ERRP is most effective in inhibiting proliferation of BxPC-3, HPAC, and PANC-1 pancreatic cancer cells. ERRP also inhibited ligand-induced activation of EGFR, HER-2, and HER-3 (ErbB3). In contrast, Erbitux and Herceptin only partially or modestly inhibited activation of EGFR, HER-2, and HER-3. Most importantly, ERRP was found to inhibit pancreatic tumor growth in a severe combined immunodeficient mouse xenograft model. The antitumor activity of ERRP correlates well with tumor differentiation and down-regulation of nuclear factor-kappaB activity. In summary, our results suggest that ERRP is an effective pan-erbB inhibitor, which could be a potential therapeutic agent for pancreatic cancers expressing different levels and subclasses of erbB family of proteins.

Growth factor-induced shedding of syndecan-1 confers glypican-1 dependence on mitogenic responses of cancer cells

The cell surface heparan sulfate proteoglycan (HSPG) glypican-1 is up-regulated by pancreatic and breast cancer cells, and its removal renders such cells insensitive to many growth factors. We sought to explain why the cell surface HSPG syndecan-1, which is also up-regulated by these cells and is a known growth factor coreceptor, does not compensate for glypican-1 loss. We show that the initial responses of these cells to the growth factor FGF2 are not glypican dependent, but they become so over time as FGF2 induces shedding of syndecan-1. Manipulations that retain syndecan-1 on the cell surface make long-term FGF2 responses glypican independent, whereas those that trigger syndecan-1 shedding make initial FGF2 responses glypican dependent. We further show that syndecan-1 shedding is mediated by matrix metalloproteinase-7 (MMP7), which, being anchored to cells by HSPGs, also causes its own release in a complex with syndecan-1 ectodomains. These results support a specific role for shed syndecan-1 or MMP7-syndecan-1 complexes in tumor progression and add to accumulating evidence that syndecans and glypicans have nonequivalent functions in vivo.

Role of Mononuclear Cells and Inflammatory Cytokines in Pancreatic Cancer-Related Cachexia

BACKGROUND AND PURPOSE

The mechanism behind aggressive development of cachexia in patients suffering from pancreatic cancer is not well understood. In this study, we investigated which factors are associated with the cachectic status of the patients and evaluated cachexia-promoting capacity of cancer and inflammatory cells.

EXPERIMENTAL DESIGN

DNA microarray analysis and quantitative reverse transcription-PCR were used to screen for cachexia-associated factors in pancreatic specimens obtained from noncachectic and cachetic patients diagnosed with pancreatic ductal adenocarcinoma. The expression pattern of the most prominently altered cachexia-associated factor, interleukin-6 (IL-6), was further analyzed in patients sera by ELISA, in pancreatic specimens by immunohistochemistry, and in a coculture system by quantitative reverse transcription-PCR using pancreatic cancer cell lines T3M4 (IL-6 positive) and Panc-1 (IL-6 negative) and peripheral blood mononuclear cells (PBMC) obtained from donors and noncachectic and cachectic patients.

RESULTS

Among numerous analyzed factors, IL-6 was significantly overexpressed in pancreatic specimens and elevated in serum of cachectic patients. The coculture system revealed that pancreatic cancer T3M4 cells but not Panc-1 cells were able to stimulate IL-6 exclusively in cachectic PBMC (by 14-fold) and this triggering was reduced by half in the presence of IL-6-neutralizing antibodies.

CONCLUSION

IL-6 represents a prominent cachexia-associated factor in pancreatic cancer. IL-6 overexpression in cachectic patients is related to the ability of certain tumors to sensitize PBMC and induce cytokine expression in cachectic PBMC.

ErbB2 growth factor receptor, a marker for neuroendocrine cells?

BACKGROUND/AIMS

The overexpression of ErbB2 in pancreatic cancer has been reported with a varying incidence ranging between 1 and 80%. Our routine examination, however, revealed a consistently strong immunoreactivity of three anti-ErbB2 growth factor receptor antibodies in pancreatic islets and intrapancreatic ganglia. To validate our findings and to understand the reasons for the reported differences in the frequency of ErbB2 overexpression in pancreatic cancer, the following studies were performed.

MATERIALS AND METHODS

Tissue samples from 12 normal pancreata, 7 surgical chronic pancreatitis cases, 21 primary pancreatic adenocarcinomas, 9 metastatic pancreatic adenocarcinomas, and 4 islet cell tumors were subjected to immunohistochemical examination using antibodies from three manufacturers. Cultured human islet cells and pancreatic cancer cell lines, as well as samples from the gastrointestinal tract, the CNS, and the adrenal gland were included in the study. For comparison, mammary cancer tissue and mammary cancer cells, as well as selected tissues from Syrian golden hamsters, were used. To verify the results, Western blot and Northern slot-blot analyses were performed.

RESULTS

Pancreatic cancer cells, in vitro and in vivo, showed a remarkable heterogeneity in the immunostaining of ErbB2, ranging from very faintly to strongly stained. On the other hand, in both humans and hamsters, a consistently strong immunostaining was found in the Langerhans' islets, in the ganglia of intrapancreatic and extrapancreatic nerves, as well as in the CNS, spinal cord and adrenal gland.

CONCLUSIONS

ErbB2 appears to play an important role in neuroendocrine tissues and is probably involved in the development and functional regulation of these cells. The concomitant expression of these factors and islet cell hormones very likely results in the activation of multiple growth-promoting pathways in pancreatic cancer and its aggressive behavior.

Immunohistochemical analysis of molecular biological factors in intraductal papillary-mucinous tumors and mucinous cystic tumors of the pancreas

BACKGROUND

To investigate the malignancy and differentiation of intraductal papillary-mucinous tumors (IPMTs) and mucinous cystic tumors (MCTs) of the pancreas, clinicopathologic characteristics and immunohistochemical features were analyzed.

METHODS

The clinicopathologic characteristics and immunohistochemical features of 24 patients with IPMT and 8 with MCT who underwent pancreatic resections at our hospital were examined. Immunohistochemical features analyzed included expression of p53 protein, proliferating cell nuclear antigen, integrins, interleukin-1 receptor type I, and hormone-associated receptors, and the factors correlated with malignancy were identified by multiple logistic regression.

RESULTS

Among the IPMTs, there were 16 intraductal papillary adenomas, 5 intraductal papillary adenocarcinomas, and 3 moderate dysplasias. Among the MCTs, there were 6 mucinous cyst adenomas and 2 mucinous cyst adenocarcinomas. Multivariate analysis revealed that of the clinicopathologic characteristics, only the presence of mural nodules (odds ratio (OR) 7.12, P = 0.044) was independently correlated with the malignancy of IPMTs, and that of the immunohistochemical features, only alpha integrin subunit expression was independently correlated with malignancy of pancreatic mucinous tumors (OR 15.6, P = 0.036), especially IPMTs (OR 35.7, P = 0.012).

CONCLUSION

These results indicate that alpha-containing integrin expression can be a significant marker of malignancy in pancreatic mucinous tumors.

Activated Kras and Ink4a/Arf deficiency cooperate to produce metastatic pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma ranks among the most lethal of human malignancies. Here, we assess the cooperative interactions of two signature mutations in mice engineered to sustain pancreas-specific Cre-mediated activation of a mutant Kras allele (KrasG12D) and deletion of a conditional Ink4a/Arf tumor suppressor allele. The phenotypic impact of KrasG12D alone was limited primarily to the development of focal premalignant ductal lesions, termed pancreatic intraepithelial neoplasias (PanINs), whereas the sole inactivation of Ink4a/Arf failed to produce any neoplastic lesions in the pancreas. In combination, KrasG12D expression and Ink4a/Arf deficiency resulted in an earlier appearance of PanIN lesions and these neoplasms progressed rapidly to highly invasive and metastatic cancers, resulting in death in all cases by 11 weeks. The evolution of these tumors bears striking resemblance to the human disease, possessing a proliferative stromal component and ductal lesions with a propensity to advance to a poorly differentiated state. These findings in the mouse provide experimental support for the widely accepted model of human pancreatic adenocarcinoma in which activated KRAS serves to initiate PanIN lesions, and the INK4A/ARF tumor suppressors function to constrain the malignant conversion of these PanIN lesions into lethal ductal adenocarcinoma. This faithful mouse model may permit the systematic analysis of genetic lesions implicated in the human disease and serve as a platform for the identification of early disease markers and for the efficient testing of novel therapies.

Molecular pathogenesis of precursor lesions of pancreatic ductal adenocarcinoma

Precursor lesions are assuming greater importance in the study of pancreatic ductal adenocarcinoma. As pancreatic cancer is almost universally fatal due to late clinical presentation and biological aggressiveness, characterisation of its precursor lesions may create scope for early diagnosis and improved outcome with conventional therapies as well as the development of novel therapeutic and preventative strategies. Pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous tumours (IPMTs) are thought to be precursor lesions of ductal adenocarcinoma of the pancreas. Recent work has focused on the molecular aberrations associated with these lesions leading to the formulation of a progression model for pancreatic cancer. Progressive histopathological changes along the progression model are associated with aberrations of cell cycle regulatory and growth factor signalling molecules that occur in pancreatic cancer at high frequency and are common to many cancers. Characterisation of these molecular aberrations provides scope for the development of novel diagnostic and treatment strategies that will ultimately impact on the outcome for people who develop pancreatic cancer.

Marked increase of the growth factors pleiotrophin and fibroblast growth factor-2 in serum of testicular cancer patients

BACKGROUND

Malignant tumors of the testis are among the most common cancers in men between the ages of 15 and 30 years. The sensitivity of detection of known tumor markers depends upon the tumor histology and stage. In other cancers, increased serum concentrations of various angiogenic growth factors have been described as potential markers for tumor progression and metastasis. One main histological feature of testicular cancer is profound angiogenesis.

DESIGN

In this study, we investigated by sensitive enzyme-linked immunosorbent assays (ELISAs) the levels of various growth and angiogenesis factors in the serum of testicular cancer patients as compared with normal control subjects. For the most profoundly increased growth factors, pleiotrophin (PTN) and fibroblast growth factor-2 (FGF-2), we furthermore analyzed tumor lysates by northern blotting, RT-PCR and ELISA.

RESULTS

We demonstrate a marked elevation of average serum levels of PTN ( approximately 20-fold) and of FGF-2 ( approximately 7-fold) in patients and expression of both growth factors in tumor biopsies. To a lesser extent, vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) serum levels were increased, whereas FGF-4 and transforming growth factor-beta levels were similar to those in normal control subjects. Elevation of PTN, FGF-2, EGF and VEGF was detected in seminomatous as well as non-seminatous tumors, and even in early stages.

CONCLUSIONS

PTN and FGF-2 may represent promising new diagnostic markers for testicular cancer with high sensitivity even in early-stage testicular cancer. Further studies are warranted to extend our analyses.

Serum vascular endothelial growth factor levels in pancreatic cancer patients correlate with advanced and metastatic disease and poor prognosis

The serum concentrations of vascular endothelial growth factor (VEGF) were measured by an enzyme linked immunosorbent assay in 51 healthy controls and in 58 patients with pancreatic cancer before and 30 days after surgery. Pancreatic cancer patients had significantly higher serum VEGF levels compared with healthy controls with a significant association between serum VEGF levels, disease stage and the presence of both lymph node and distant metastases. Serum levels of VEGF decreased significantly after radical resection of the tumor. Elevated preoperative serum VEGF level was a significant prognostic factor, although not independent of stage, for patient survival. These findings suggest that serum VEGF concentrations may reflect pancreatic cancer progression and that their determination may be clinically useful.

Genetic alterations in pancreatic carcinoma

Cancer of the exocrine pancreas represents the fifth leading cause of cancer death in the Western population with an average survival after diagnosis of 3 to 6 months and a five-year survival rate under 5%. Our understanding of the molecular carcinogenesis has improved in the last few years due to the development of novel molecular biological techniques. Pancreatic cancer is a multi-stage process resulting from the accumulation of genetic changes in the somatic DNA of normal cells. In this article we describe major genetic alterations of pancreatic cancer, mutations in the proto-oncogene K-RAS and the tumor suppressors INK4A, TP53 and DPC4/SMAD4. The accumulation of these genetic changes leads to a profound disturbance in cell cycle regulation and continuous growth. The knowledge of the underlying molecular mechanisms will offer new therapeutic and diagnostic options and hopefully improve the outcome of this aggressive disease.

Pancreatic cancer biology and genetics

Pancreatic ductal adenocarcinoma is an aggressive and devastating disease, which is characterized by invasiveness, rapid progression and profound resistance to treatment. Advances in pathological classification and cancer genetics have improved our descriptive understanding of this disease; however, important aspects of pancreatic cancer biology remain poorly understood. What is the pathogenic role of specific gene mutations? What is the cell of origin? And how does the stroma contribute to tumorigenesis? A better understanding of pancreatic cancer biology should lead the way to more effective treatments.

Human aspartyl (asparaginyl) beta-hydroxylase monoclonal antibodies: potential biomarkers for pancreatic carcinoma

INTRODUCTION

Pancreatic adenocarcinoma is among the top 10 leading causes of death due to cancer in the United States. The lack of reliable and sensitive biomarkers for this disease makes it difficult to render an early diagnosis.

AIMS

To evaluate carcinoma-associated monoclonal antibodies (MoAbs), including AF-20, SF-25, and FB-50, for their binding specificity to pancreatic adenocarcinoma relative to normal pancreatic tissue. In addition, binding of the Th9 MoAb to human Reg 1 protein was studied because of its potential role in cell growth.

METHODOLOGY

Adjacent histologic sections were immunostained with each of the MoAbs and graded on a scale of 0 to 4+, corresponding to the relative distribution and intensity of immunoreactivity within the tumor and normal adjacent tissue.

RESULTS

Intense levels (grade 3 or 4) of FB50 immunoreactivity were detected in 19 of 19 tumors but not in normal adjacent pancreatic tissue. In addition, increased levels of FB50 immunoreactivity were detected in at least 75% of the tumor cells in 18 of the 19 cases. SF-25 immunoreactivity similarly distinguished pancreatic adenocarcinoma from normal pancreas in 14 of 19 cases. In contrast, AF20 immunoreactivity was detected in 6 of 19 pancreatic adenocarcinomas, and for the most part, the labeling was focal and of a low level. TH9 immunoreactivity was detected in 5 of 19 tumors but also in normal as well as inflamed adjacent pancreatic tissue.

CONCLUSION

These results suggest that the FB50 and SF25 MoAbs represent excellent potential biomarkers of pancreatic adenocarcinoma and could be configured in an immunoassay for detecting pancreatic adenocarcinoma cells in biologic fluids.

Genetic basis of pancreatic cancer

Because in the normal state, cells of the pancreas show a very low rate of proliferation, entering the cell cycle is assumed to be the initial event during tumorigenesis. So-called checkpoints monitor cell cycle progression and guarantee the proper duplication of the entire genome. Loss of one or more checkpoints causes subsequent accumulation of genetic alterations which finally results in cancer. Cancer cells are characterized by unrestricted growth, invasion of adjacent tissue and metastasis. All of these features can be explained in terms of genetic changes and the functional consequence of these changes. Activation of the proto-oncogene K-Ras and inactivation of the tumour suppressor gene loci INK4a, p53 and SMAD4 are characteristic for pancreatic cancer. The progression model of pancreatic cancer proposes that pancreatic intraepithelia neoplasia is the pre-cancerous lesion. A preferred genetic pathway has started to evolve. Germ-line mutations in specific genes are responsible for cases in which there is a familial predisposition to pancreatic cancer.

Activation of IRS-2-mediated signal transduction by IGF-1, but not TGF-alpha or EGF, augments pancreatic beta-cell proliferation

Transforming growth factor (TGF)-alpha- and epidermal growth factor (EGF)-induced signal transduction was directly compared with that of glucose and insulin-like growth factor-1 (IGF-1) in INS-1 cells. TGF-alpha/EGF transiently (<20 min) induced phosphorylation of extracellular-regulated kinase (Erk)-1/2 (>20-fold), glycogen synthase kinase (GSK)-3 (>10-fold), and protein kinase B (PKB) (Ser(473) and Thr(308)), but did not increase [(3)H]thymidine incorporation. In contrast, phosphorylation of Erk1/2, GSK-3, and PKB in response to glucose and IGF-1 was more prolonged (>24 h) and, though not as robust as TGF-alpha/EGF, did increase beta-cell proliferation. Phosphorylation of p70(S6K) was also increased by IGF-1/glucose, but not by TGF-alpha/EGF, despite upstream PKB activation. It was found that IGF-1 induced phosphatidylinositol 3-kinase (PI3K) association with insulin receptor substrate (IRS)-1 and -2 in a glucose-dependent manner, whereas TGF-alpha/EGF did not. The importance of specific IRS-2-mediated signaling events was emphasized in that adenoviral-mediated overexpression of IRS-2 further increased glucose/IGF-1-induced beta-cell proliferation (more than twofold; P < 0.05) compared with control or adenoviral-mediated IRS-1 overexpressing INS-1 cells. Neither IRS-1 nor IRS-2 overexpression induced a beta-cell proliferative response to TGF-alpha/EGF. Thus, a prolonged activation of Erk1/2 and PI3K signaling pathways is important in committing a beta-cell to a mitogenic event, and it is likely that this sustained activation is instigated by signal transduction occurring specifically through IRS-2.

Influences of the lysosomal associated membrane proteins (Lamp-1, Lamp-2) and Mac-2 binding protein (Mac-2-BP) on the prognosis of pancreatic carcinoma

BACKGROUND

Lamps and Mac-2-BP are ligands of galectin-3, and they were suggested to influence tumor proliferation and metastasis formation. The authors studied the expression of Lamp-1, Lamp-2, and Mac-2-BP in pancreatic carcinoma and evaluated their influence on patient prognosis.

METHODS

Northern blot analysis, in situ hybridization, and immunohistochemistry were performed in 12 normal and 28 pancreatic carcinoma tissue samples and in pancreatic carcinoma cell lines. The molecular findings in the tumor samples were correlated with the prognosis and histopathologic tumor characteristics. In addition, in Lamp-1 transfected CAPAN-1 pancreatic carcinoma cells, cell proliferation was analyzed.

RESULTS

Lamp-1, Lamp-2, and Mac-2-BP were overexpressed in 61% (1.6-fold increase, not significant), 71% (3.0-fold increase, P < 0.01), and 93% (5.6-fold increase, P < 0.01) of the pancreatic carcinoma samples. Lamp-1 and Lamp-2 immunoreactivity was present at the luminal side of the ductal carcinoma cells whereas Mac-2-BP immunoreactivity was diffusely spread over the whole cytoplasm and the nucleolus of ductal carcinoma cells. Correlation of the molecular data with clinical patient parameters revealed that patients whose tumors exhibited high Lamp-1 mRNA expression lived significantly longer (median, 17 months) after tumor resection than patients whose tumors exhibited low to moderate Lamp-1 mRNA levels (median, 8 months; P < 0.02). No relation between Lamp-2 and Mac-2-BP mRNA expression and any of the histopathologic parameters was found. Lamp-1 transfected CAPAN-1 cells showed decreased cell growth compared with the nontransfected cells.

CONCLUSIONS

Lamp-1 might influence local tumor progression rather than the formation of tumor metastasis in pancreatic carcinoma, whereas Mac-2-BP and Lamp-2 seem to have little influence on these parameters in pancreatic carcinoma.