Ductal Adenocarcinoma Of Pancreas Research Articles

The heparin-binding protein interactome in pancreatic diseases

BackgroundThe cellular microenvironment plays an important role in the regulation of homoeostasis and is a source of potential biomarkers and drug targets. In a genome-wide analysis the extracellular proteins that bind to heparin (HBPs) have been shown to form highly modular and interconnected extracellular protein regulatory networks. Using a systems biology approach, we have investigated the role of HBP networks in the normal pancreas and pancreatic digestive diseases. MethodsLists of mRNAs encoding for HBPs associated with the normal pancreas (NP), acute pancreatitis (AP), chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) were obtained using public databases and publications. Networks of the putative protein interactomes derived from mRNA expression data of HBPs were built and analysed using cluster analysis, gene ontology term enrichment and canonical pathways analysis. ResultsThe extracellular heparin-binding putative protein interactomes in the pancreas were better connected than their non heparin-binding counterparts, having higher clustering coefficients in the normal pancreas (0.273), acute pancreatitis (0.457), chronic pancreatitis (0.329) and pancreatic ductal adenocarcinoma (0.269). ‘Hepatic Fibrosis/Hepatic Stellate Cell Activation’ appears to be a significant canonical pathway in pancreatic homoeostasis in health and disease with a large number of important HBPs. ConclusionsOur analyses clearly demonstrate that HBPs form disease-specific and highly connected networks that can be explored for potential biomarkers and as collective drug targets via the modification of heparin binding properties.

Pancreatic Ductal Adenocarcinoma: Implications of Epigenetic Role Related the Src Pathway

Epigenetic has become, in recent years, in a very important process in the control of several pathologies, including cancer. DNA methylation has been described in numerous studies as crucial for differentiation control, cell proliferation and invasion in cancer. Pancreas ductal adenocarcinoma is one of the most deadly diseases of our society; its complexity and variability have become one of the medical challenges of this decade. Combining the potential of epigenetic with the high mortality and the limited knowledge of pancreatic ductal adenocarcinoma origin, may result in new approaches for diagnosis, treatment and monitoring, crucial in this pathology. For this purpose, we analyzed genes involved in different cellular processes (GSTP1, p16, RASFF1A, RARβ2, CyclinD2, HIN-1, SOCS1, TIMP3, DAPK and TWIST1) in 61 cases of pancreatic ductal adenocarcinoma. A first approach led us to analyze the Src pathway, never studied in this sense, as crucial in the development of this pathology. Clusters for clinicopathological characteristics and epigenetic profiles were obtained. The high degree of methylation of these adenocarcinomas, and the statistical relationship between Src pathway methylation and clinicopathological profile, has been postulated, for the first time. These results show the importance of this pathway in pancreatic disease, opening a new challenge for research and therapy.

Abstract 4277: Comparative gene expression analysis of proliferating stromal cells from pancreatic ductal adenocarcinoma, pancreatitis and normal pancreas

Abstract Introduction: Stromal cells associated with cancer cells are considered an important component of tumor microenvironment of pancreatic cancer. The intratumoral desmoplasia characteristic of pancreatic cancer is a result of growing carcinoma paracrine action on surrounding normal tissue cells. Selective targeting of tumor stroma cells can markedly increase the effectiveness of currently used chemotherapeutic agents against pancreatic cancer. Therefore, a search for new targets in stromal cells is an important part of developing new combined therapies of this disease. Our work was aimed at comparative studying of gene expression in stromal cells of normal pancreas, pancreatitis and pancreatic ductal adenocarcinoma tissues. Methods: Cultured stromal cells were obtained from samples of normal pancreatic (n=3), pancreatitis (n=3) and ductal adenocarcinoma tissues (n=4). The cell cultures obtained were preliminary characterized by immunofluorescence, RT-PCR and western blotting. A full genome gene expression analysis was performed using a modified SAGE technique. Expression of selected dysregulated genes was analyzed by quantitative PCR. Results: Morphological and immunofluorescent analyses of the obtained primary stromal cultures indicated that they could be assigned to pancreatic stellate cells (PSC). The SAGE analysis allowed to quantitatively estimate expression of 9860 genes in normal PSC, 8744 PSC genes in pancreatitis, and 9311 genes in tumor PSC. A comparison of normal and tumor PSC revealed statistically significant (P<0.001) differences in expression of 270 genes. Of them, 146 genes were upregulated and 124 genes downregulated in tumor PSC as compared to normal PSC. An expression analysis of selected dysregulated genes by RT-PCR detected changes in the activity of some genes involved in tumor progression of pancreatic cancer. In particular, the genes of two chemokines (CXCL12 and CX3CL1) and the JAG1 Notch ligand were upregulated in tumor PSC. A similar comparison of tumor PSC and PSC from pancreatitis tissue detected 68 differentially expressed genes (P<0.001), 40 of which were upregulated and 28 downregulated in tumor PSC as compared to pancreatitis PSC. Expression of 23 genes was upregulated in tumor PSC as compared with PSC both from pancreas and pancreatitis. On the whole, the expression profile of tumor PSC was markedly more similar to that of PSC from pancreatitis tissues than from normal PSC. Conclusions: The results obtained in our work revealed statistically significant changes in the expression of some PSC genes in stroma of ductal pancreatic adenocarcinoma as compared to normal PSC. The similarity of tumor and pancreatitis PSC expression profiles may suggest mutual mechanisms of forming the fibrous tissue of pancreatitis and tumor stroma of pancreatic carcinomas. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4277. doi:1538-7445.AM2012-4277

Comparative evaluation of cancer stem cell markers in normal pancreas and pancreatic ductal adenocarcinoma

Chemoresistance and self-renewal of cancer stem cells (CSC), found in many tumors including pancreatic ductal adenocarcinoma (PDAC), are believed to underlie tumor mass regrowth. The distribution of cells carrying the putative stem-cell markers CD133, Nestin, Notch1-4, Jagged1 and 2, ABCG2 and aldehyde dehydrogenase (ALDH1) was assessed immunohistochemically using PDAC and normal pancreas tissue microarrays. The immunoreactivity was semi-quantitatively graded against the normal pancreas and was correlated with the differentiation grade and disease stage. No statistical significant differences were found between normal pancreas and PDAC in the expression of Nestin, Notch1, 3 and 4, ABCG2 or ALDH1. Notch2 and Jagged1 and 2 expression were increased in PDAC. CD133-positive cells were above-normal in PDAC, but the difference was not statistically significant. Nestin, Notch1-4, Jagged1, ABCG2 and ALDH1 immunostaining scores were not correlated with tumor grade or disease stage. CD133 and Notch2 expression was significantly inversely correlated with tumor grade, but not disease stage. Notch3 immunostaining positively correlated with tumor stage, but not with differentiation grade. Jagged2 protein expression correlated inversely with disease stage, but not with tumor grade. From the clinical standpoint, improved delineation of the tumor CSC signature, putatively responsible for tumor initiation and recurrence after initial response to chemotherapy, may offer novel therapeutic targets for this highly lethal cancer.

Identification of Novel Accessible Proteins Bearing Diagnostic and Therapeutic Potential in Human Pancreatic Ductal Adenocarcinoma

Pancreas ductal adenocarcinoma (PDAC) remains a deadly malignancy with poor early diagnostic and no effective therapy. Although several proteomic studies have performed comparative analysis between normal and malignant tissues, there is a lack of clear characterization of proteins that could be of clinical value. Systemically reachable ("potentially accessible") proteins, suitable for imaging technologies and targeted therapies represent a major group of interest. The current study explores potentially accessible proteins overexpressed in PDAC, employing innovative proteomics technologies. In the discovery phase, potentially accessible proteins from fresh human normal and PDAC tissues were ex vivo biotinylated, isolated and identified using 2D-nano-HPLC-MS/MS method. The analysis revealed 422 up-regulated proteins in the tumor, of which 83 (including protein isoforms) were evaluated as potentially accessible. Eleven selected candidates were further confirmed as up-regulated using Western blot and multiple reaction monitoring protein quantification. Of these, transforming growth factor beta-induced (TGFBI), latent transforming growth factor beta binding 2 (LTBP2), and asporin (ASPN) were further investigated by employing large scale immunohistochemistry-based validations. They were found to be significantly expressed in a large group of clinical PDAC samples compared to corresponding normal and inflammatory tissues. In conclusion, TGFBI, LTBP2, and ASPN are novel, overexpressed, and potentially accessible proteins in human PDAC. They bear the potential to be of clinical value for diagnostic and therapeutic applications and merit further studies using in vivo models.

Synchronous Epithelial and Neuroendocrine Cancers of the Pancreas: Case Series of a Rare Occurrence

The presence of neuroendocrine cells in adenocarcinomas is not an unusual finding and is well described in gastrointestinal tract cancers, eg, colorectal cancer and gastric cancer. Genetic analysis of such tumors has suggested a common multipotent progenitor stem cell origin. The prognostic significance of neuroendocrine cells in adenocarcinoma cells is unclear. There is a scant literature on synchronous pancreas ductal adenocarcinoma and pancreas neuroendocrine tumors. We report 2 cases with a purpose of discussing management strategies, prognosis, and potential etiologies of this rare presentation.

Visualization of CD44 and CD133 in Normal Pancreas and Pancreatic Ductal Adenocarcinomas

Tumor-initiating cells of pancreatic ductal adenocarcinoma (PDAC) have been isolated based on expression of either CD133 or CD44. The authors aimed to visualize pancreatic cells simultaneously expressing both these cell surface markers by employing the same antibodies commonly used in cell-sorting studies. Normal and diseased pancreatic tissue, including 51 PDAC cases, were analyzed. CD44 and CD133 expression was determined by immunohistochemical double staining on formalin-fixed material and subcellular protein distribution evaluated by immunofluorescence/confocal microscopy. In the normal pancreas, CD44 and CD133 were coexpressed in the centroacinar regions but in non-overlapping subcellular compartments. As expected, CD44 was found mainly basolaterally, whereas CD133 was present on the apical/endoluminal membrane. This was also the case in chronically inflamed/atrophic pancreatic tissue and in PDAC. In some malignant ducts, CD44 was found at the apical cell membrane adjacent to but never overlapping with CD133 expression. CD44 level was significantly associated with the patient's lymph node status. In conclusion, a CD44+/CD133+ cell population does exist in the normal and neoplastic pancreas. The preferentially centroacinar localization of the doubly positive cells in the normal parenchyma suggests that this population could be of particular interest in attempts to identify tumor-initiating cells in PDAC.

Hypoxia inducible BHLHB2 is a novel and independent prognostic marker in pancreatic ductal adenocarcinoma

Aims The cyclic adenosine monophosphate-inducible basic helix–loop–helix (bHLH) domain containing class-B2 transcriptional factor BHLHB2 is differentially expressed in a number of human malignancies. In the present study, the expression, regulation, functions and prognostic impact of BHLHB2 in pancreatic cancer were investigated. Methods Expression analyses were carried out in tissues of the normal pancreas ( n = 10) and pancreatic ductal adenocarcinoma ( n = 77) as well as in eight pancreatic cancer cell lines using quantitative RT-PCR, semiquantitative immunohistochemistry, and immunoblot analyses. In vitro functional experiments were conducted using siRNA transfection, hypoxia, serum starvation, apoptosis induction with gemcitabine and actinomycin-D, and invasion assays. Survival analysis was performed using the Kaplan–Meier method. Prognostic factors were determined in a multivariable analysis using a Cox proportional hazards model. Results BHLHB2 mRNA and protein expressions were strongly induced by hypoxia and by serum starvation in pancreatic cancer cell lines. BHLHB2 silencing with RNAi had no significant effects on growth and invasion but increased apoptosis resistance against gemcitabine by reducing caspace-3 cleavage. In BHLHB2 silenced cells the ED50 of gemcitabine increased from 13.95 ± 1.353 to 38.70 ± 5.262 nM ( p < 0.05). Ex vivo, the weak/absent nuclear staining in normal pancreatic ducts and acinar cells was replaced by moderate to strong nuclear/cytoplasmic staining in PanIN lesions and pancreatic cancer cells. Patients with weak/absent nuclear BHLHB2 staining had significantly worse median survival compared to those with strong staining (13 months vs. 27 months, p = 0.03). In a multivariable analysis, BHLHB2 staining was an independent prognostic factor (Hazard-Ratio = 2.348, 95% CI = 1.250–4.411, p = 0.008). Conclusions Hypoxia-inducible BHLHB2 expression is a novel independent prognostic marker in pancreatic cancer patients and indicates increased chemosensitivity towards gemcitabine.

Solitary concomitant endocrine tumor and ductal adenocarcinoma of pancreas

Pancreatic tumors with combined exocrine and endocrine features are rare. Most reported cases are classified as mixed exocrine and endocrine carcinoma of the pancreas. We report the first case of solitary concomitant endocrine tumor and ductal adenocarcinoma of the pancreas. A 58-year-old patient was admitted for uncontrolled diabetes mellitus and body weight loss. The tumor was fortuitously discovered in the pancreatic tail after a tumor survey panel. Grossly, the solitary tumor had a central fibrous band that clearly divided it into two parts. On microscopic examination, the tumor contained both endocrine and exocrine components distinctly separated by the central fibrous band. The exocrine part showed a poorly-differentiated adenocarcinoma. The endocrine part was strongly immunoreactive to chromogranin, synaptophysin and glucagon. We reviewed the literature on pancreatic tumors with combined exocrine and endocrine features. A simple classification for this group of neoplasms is suggested, including five types: amphicrine, mixed, collision, solitary concomitant and multiple concomitant.

Silencing of GRP94 expression promotes apoptosis in pancreatic cancer cells

As a molecular chaperone, GRP94 is the most abundant glycoprotein in the endoplasmic reticulum, playing an important role in maintaining cellular homeostasis. Here, we investigated the expression and the role of GRP94 in regulating cell growth and apoptosis in pancreatic cancer cells. GRP94 mRNA levels were analyzed by QRT-PCR. Immunohistochemistry was performed to localize GRP94 in tissues of the normal pancreas (n=20), chronic pancreatitis (n=20) and pancreatic ductal adenocarcinoma (n=44). Silencing of GRP94 expression was carried out by transfection with specific siRNA oligonucleotides. Apoptosis was induced by treatment with actinomycin D. Compared to normal pancreatic tissues, median mRNA levels of GRP94 were 1.5- and 3.7-fold (p<0.05) lower in chronic pancreatitis and pancreatic cancer tissues, respectively. GRP94 protein was strongly expressed in normal acinar cells and moderately expressed in normal ductal cells. GRP94 expression was lost in 48% of the cancer cases. Moderate or strong staining in cancer cells was observed in 32 and 20% of pancreatic cancer tissues, respectively. Silencing GRP94 by siRNA increased apoptosis of pancreatic cancer cells in vitro. Patients with higher than the median expression have a tendency for a worsened survival. When the small number of patients with the highest expression (n=3) were compared with the rest of the group (n=41), the survival difference was significantly worse (5 vs. 18 months, respectively, p=0.006). Down-regulation of GRP94 decreases apoptosis resistance in pancreatic cancer cells. Clinically, patients with high GRP94 expression show a tendency for a worsened survival.

Invasive intraductal papillary‐mucinous neoplasm of the pancreas: Comparison with pancreatic ductal adenocarcinoma

The aim of this study was to clarify the clinicopathological differences between patients with invasive intraductal papillary-mucinous neoplasm (IPMN) of the pancreas and pancreatic ductal adenocarcinoma. The medical records of 16 patients with invasive IPMN and 106 patients with pancreatic ductal adenocarcinoma, who underwent surgical resection, were retrospectively reviewed, and the clinicopathological factors and survival were compared between the two groups. The presence of retroperitoneal tissue invasion, portal or splenic vein invasion, nodal involvement, and positive surgical margins were significantly lower in patients with invasive IPMN than in those with ductal adenocarcinoma (P < 0.05). The actuarial 5-year overall survival rates in patients with invasive IPMN and ductal carcinoma were 40% and 18%, respectively (P = 0.008). However, the actuarial 5-year survival rate of patients with invasive IPMN was only 27% for UICC stage II disease, although this was significantly higher than that of patients with UICC stage II ductal adenocarcinoma (P = 0.049). Invasive IPMN has a favorable prognosis compared with pancreatic ductal adenocarcinoma that is likely due to the less aggressive nature of the disease. However, the prognosis for cases of advanced invasive IPMN is not always favorable despite complete tumor resection.

Induction of osteopontin expression by nicotine and cigarette smoke in the pancreas and pancreatic ductal adenocarcinoma cells.

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease with etiological association with cigarette smoking. Nicotine, an important component of cigarettes, exists at high concentrations in the bloodstream of smokers. Osteopontin (OPN) is a secreted phosphoprotein that confers on cancer cells a migratory phenotype and activates signaling pathways that induce cell survival, proliferation, invasion, and metastasis. Here, we investigated the potential molecular basis of nicotine's role in PDA through studying its effect on OPN. Nicotine significantly (p < 0.02) increased OPN mRNA and protein secretion in PDA cells through activation of the OPN gene promoter. The OPN mRNA induction was inhibited by the nicotinic acetylcholine receptor antagonist, mechamylamine. Further, the tyrosine kinase inhibitor genistein inhibited the nicotine-mediated induction of OPN, suggesting that mitogen activated protein kinase signaling mechanism is involved. Nicotine activated the phosphorylation of ERK1/2, but not p38 or c-Jun NH2-terminal MAP kinases. Inhibition of ERK1/2 activation reduced the nicotine-induced OPN synthesis. Rats exposed to cigarette smoke showed a dose-dependent increase in pancreatic OPN that paralleled the rise of pancreatic and plasma nicotine levels. Analysis of cancer tissue from invasive PDA patients, the majority of whom were smokers, showed the presence of significant amounts of OPN in the malignant ducts and the surrounding pancreatic acini. Our data suggest that nicotine may contribute to PDA pathogenesis through upregulation of OPN. They provide the first insight into a nicotine-initiated signal transduction pathway that regulates OPN as a possible tumorigenic mechanism in PDA.

Pancreatic Islet and Stellate Cells Are the Main Sources of Endocrine Gland-Derived Vascular Endothelial Growth Factor/Prokineticin-1 in Pancreatic Cancer

Aims: Endocrine gland-derived vascular endothelial growth factor (EG-VEGF)/prokineticins have been identified as tissue-specific angiogenic factors. This study investigates the expression and localization of EG-VEGF and its receptors in pancreatic tissues and pancreatic stellate cells (PSCs). Methods: mRNA levels of EG-VEGF/prokineticin 1 (PK1), prokineticin 2 (PK2) and their receptors 1 (PKR1) and 2 (PKR2) were measured in pancreatic tissues, pancreatic cancer cell lines and PSCs by quantitative reverse-transcriptase polymerase chain reaction (QRT-PCR). Protein expression of PKI, PKR1 and PKR2 was assessed in pancreatic tissues by immunohistochemistry. Growth factor-induced secretion of EG-VEGF was measured by ELISA. Results: QRT-PCR analysis in bulk tissues of normal pancreas, chronic pancreatitis and pancreatic ductal adenocarcinoma showed no significant difference of PK1 mRNA levels, whereas PK2 mRNA was barely detectable. High PK1 mRNA levels were observed only in cultured PSCs and microdissected islet cells, but not in cancer cells, and PK1 protein was localized mainly in islets and cancer-associated stromal cells. PKR1 and PKR2 proteins were present in endothelial cells of small blood vessels. TGF-β1 and PDGF-BB specifically stimulated PK1 secretion in PSCs. Conclusions: Islet and/or PSC-derived PK1 might act through its receptors on endothelial cells to increase angiogenesis in pancreatic diseases.

Genomic alterations link Rho family of GTPases to the highly invasive phenotype of pancreas cancer.

Pancreas ductal adenocarcinoma (PDAC) is a highly lethal cancer that typically presents as advanced, unresectable disease. This invasive tendency, coupled with intrinsic resistance to standard therapies and genome instability, are major contributors to poor long-term survival. The genetic elements governing the invasive propensity of PDAC have not been well elucidated. Here, in the course of validating resident genes in highly recurrent and focal amplifications in PDAC, we have identified Rio Kinase 3 (RIOK3) as an amplified gene that alters cytoskeletal architecture as well as promotes pancreatic ductal cell migration and invasion. We determined that RIOK3 promotes its invasive activities through activation of the small G protein, Rac. This genomic and functional link to Rac signaling prompted a genome wide survey of other components of the Rho family network, revealing p21 Activated Kinase 4 (PAK4) as another amplified gene in PDAC tumors and cell lines. Like RIOK3, PAK4 promotes pancreas ductal cell motility and invasion. Together, the genomic and functional profiles establish the Rho family GTP-binding proteins as integral to the hallmark invasive nature of this lethal disease.

Expression of the "stem cell marker" CD133 in pancreas and pancreatic ductal adenocarcinomas

BackgroundIt has been suggested that a small population of cells with unique self-renewal properties and malignant potential exists in solid tumors. Such "cancer stem cells" have been isolated by flow cytometry, followed by xenograft studies of their tumor-initiating properties. A frequently used sorting marker in these experiments is the cell surface protein CD133 (prominin-1). The aim of this work was to examine the distribution of CD133 in pancreatic exocrine cancer.MethodsFifty-one cases of pancreatic ductal adenocarcinomas were clinically and histopathologically evaluated, and immunohistochemically investigated for expression of CD133, cytokeratin 19 and chromogranin A. The results were interpreted on the background of CD133 expression in normal pancreas and other normal and malignant human tissues.ResultsCD133 positivity could not be related to a specific embryonic layer of organ origin and was seen mainly at the apical/endoluminal surface of non-squamous, glandular epithelia and of malignant cells in ductal arrangement. Cytoplasmic CD133 staining was observed in some non-epithelial malignancies. In the pancreas, we found CD133 expressed on the apical membrane of ductal cells. In a small subset of ductal cells and in cells in centroacinar position, we also observed expression in the cytoplasm. Pancreatic ductal adenocarcinomas showed a varying degree of apical cell surface CD133 expression, and cytoplasmic staining in a few tumor cells was noted. There was no correlation between the level of CD133 expression and patient survival.ConclusionNeither in the pancreas nor in the other investigated organs can CD133 membrane expression alone be a criterion for "stemness". However, there was an interesting difference in subcellular localization with a minor cell population in normal and malignant pancreatic tissue showing cytoplasmic expression. Moreover, since CD133 was expressed in shed ductal cells of pancreatic tumors and was found on the surface of tumor cells in vessels, this molecule may have a potential as clinical marker in patients suffering from pancreatic cancer.

BGLAP is expressed in pancreatic cancer cells and increases their growth and invasion

BackgroundBone gamma-carboxyglutamate protein (BGLAP; osteocalcin) is a small, highly conserved molecule first identified in the mineralized matrix of bone. It has been implicated in the pathophysiology of various malignancies. In this study, we analyzed the expression and role of BGLAP in the normal human pancreas, chronic pancreatitis (CP), and pancreatic ductal adenocarcinoma (PDAC) using quantitative RT-PCR, immunohistochemistry, immunocytochemistry and enzyme immunoassays, as well as cell proliferation and invasion assays. Gene silencing was carried out using specific siRNA molecules.ResultsCompared to the normal pancreas, BGLAP mRNA and protein levels were not significantly different in CP and PDAC tissues. BGLAP was faintly present in the cytoplasm of normal acinar cells but was strongly expressed in the cytoplasm and nuclei of tubular complexes and PanIN lesions of CP and PDAC tissues. Furthermore, BGLAP expression was found in the cancer cells in PDAC tissues as well as in 4 cultured pancreatic cancer cell lines. TNFalpha reduced BGLAP mRNA and protein expression levels in pancreatic cancer cell lines. In addition, BGLAP silencing led to reduction of both cell growth and invasion in those cells.ConclusionBGLAP is expressed in pancreatic cancer cells, where it potentially increases pancreatic cancer cell growth and invasion through autocrine and/or paracrine mechanisms.

Distribution of somatostatin in pancreatic ductal adenocarcinoma remodels the normal pattern of the protein during foetal pancreatic development: an immunohistochemical analysis

To determine the immunoreactivity of somatostatin during the development of the human fetal pancreas and pancreatic ductal adenocarcinoma, given that, somatostatin-positive cells were demonstrated either into its embryonic anlage or into pancreatic cancer. Tissue sections from 15 pancreatic fetal specimens, and an equal number of ductal adenocarcinoma specimens were assessed. The density of positive cells in the primitive exocrine ductal epithelium and endocrine epithelium was significantly different from the relevant density in the neoplastic pancreatic tissue of mixed (ductal-endocrine) and pure ductal type (P1=0.021 P2=0.001, P3<0.0001, P4=0.003 respectively). The above values were estimated from the 8th to 10th week. There was no significant difference in the density of positive cells in the mantle zone of the islets from the 13th to the 24th week, and the neoplastic tissue of mixed (P5=0.16) and pure ductal type (P6=0.65). The immunostaining for somatostatin identifies a subgroup of pancreatic ductal adenocarcinomas with a neuroendocrine component, (initially considered as pure ductal tumors), and mixed ductal and neuroendocrine tumors. This pattern of expression in neoplasms recapitulates the normal pattern during the embryonal development of the organ, raising the question of therapeutic efficacy of somatostatin and analogues as monotherapy in pancreatic cancer management.

Mucinous noncystic (colloid) adenocarcinoma of the pancreas

To determine the clinicopathologic characteristics and the relationship between related gene expression and pathobiologic behavior of pancreatic mucinous noncystic adenocarcinoma. Among the 249 pancreatic carcinoma cases from the department files, 6 tumors were identified to meet the pathologic criteria of colloid carcinoma. Envision immunohistochemical staining technique was used to detect expression of p21(ras), p21(WAF1), p16, p33(ING1), p53, ATM, MDM2, PCNA, Cyclins (D1, D3, A, B and E). Intra- and extra- cellular mucin production were determined by AB-PAS staining. Clinically, all of 6 cases were followed to June, 2003. In all 6 cases, the tumors were located in the head of the pancreas and all displayed similar microscopic findings. Duodenal invasion was seen in 4 cases and perineural invasion was seen in 1 case. Tumor metastasis in the liver was seen in 2 cases and in the regional lymph nodes in 2 cases. Positive immunostaining was seen in 5 cases with p21(ras), 3 cases with p21(WAF1), 1 case with p16, 4 cases with p33(ING1), 2 cases with p53, 3 cases with ATM, 3 cases with MDM2, 6 cases with PCNA, 3 cases with cyclinA, 3 cases with cyclinD1, 4 cases with cyclinD3, 4 cases with cyclinB and 6 cases with cyclinE. Both extracellular and intracellular mucin was strongly positive for AB-PAS staining. Clinical follow-up found that 2 patients died of their tumors at 14 and 20 months. Three patients were alive after 28, 49 and 87 months of follow-up. One case were lost contact. Pancreatic mucinous noncystic adenocarcinoma has distinct morphologic features and biologic behavior. Multiple gene products including many cyclins may be involved in the pathogenesis of pancreatic colloid carcinoma. The tumor has an aggressive behavior with a high frequency of invasion and metastases, though the prognosis could be better than that of ordinary ductal adenocarcinoma of pancreas.

Immunohistochemical characterization of human fetal pancreas and pancreatic ductal adenocarcinoma: a study of somatostatin antibody NCL-SOMATOp

• Purpose: Somatostatin is a gastrointestinal peptide hormone that inhibits growth of pancreatic cancer as reported by an increasing body of evidence. Yet this is not always the case. To clarify the controversy we aimed to identify the expression of somatostatin in developing human embryonic pancreatic tissue and pancreatic adenocarcinoma given that somatostatin positive cells were shown either into primitive pancreatic ductal epithelium or into pancreatic carcinoma. • Methods: Tissue sections representing pancreatic fetal specimens (n=15) and ductal pancreatic adenocarcinoma specimens (n=15) were assessed using immunohistochemical methods for somatostatin expression. • Results: Normal primitive exocrine ductal epithelium and endocrine epithelium showed a definite, statistically significant, higher expression of somatostatin over neoplastic pancreatic tissue of mixed (ductalendocrine) and pure ductal type (p1=0.021, p2=0.001, p3<0.0001, and p4=0.003 respectively) during the 8th to the 10th week. No statistically significant differential expression of somatostatin in the mantle zone of the islets over neoplastic tissue of mixed (p5=0.16) and pure ductal type (p6=0.65), from the 13th to the 24th week was demonstrated. • Conclusion: Pancreatic cancer cells can express somatostatin in a model that reproduces the normal expression of the peptide by δ-cells during embryonal organogenesis. Therapy aimed at pancreatic cancer must be targeted to somatostatin and analogues as potential adjuvant novel option.

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in some endocrine organs and their tumors

Matrix metalloproteinases (MMPs) are single-chain zinc-containing metalloenzymes. The MMP gene family currently includes more than 19 endopeptidases. Both MMP-2 and 9 are widely expressed by many stromal and endothelial cells. Tissue inhibitors of metalloproteinases (TIMPs) form complexes with MMPs, which in turn inhibit active MMPs. MMP and TIMP homeostasis has been implicated in many aspects of both physiological and pathological processes. The latter include tumor invasion and metastasis. Although ductal adenocarcinomas of pancreas were immunocytochemically faintly stained for MMPs and TIMPs, normal pancreatic islets in the normal adjacent pancreas were found to be strongly stained for MMPs and TIMPs. Five kinds of islet cell tumors, including insulinomas, gastrinomas, glucagonomas, pancreatic polypeptide- (PP) omas, and nonfunctioning islet cell tumor, were stained for MMPs and TIMPs. The tumor cells were relatively weakly stained for MMPs and TIMPs compared to normal islets. Similarly, weaker staining for MMPs and TIME’s was noted for medullary thyroid carcinomas (MTCs) and pituitary adenomas. There was no correlation between immunostaining intensity of protein hormones and MMPs and TIMPs. However parathyroid hyperplasia, adenoma, and carcinoma that stained for MMPs and TIMPs were weaker, which paralleled the weaker immunostaining for parathyroid hormone and chromogranin. This weaker staining for MMPs and TIMPs in endocrine tumors may imply a less significant role of tumor invasion and metastasis by MMP and TIMP homeostasis. At present, immunocytochemical staining for MMPs and TIMPs may well be used as new markers for neuroendocrine cells and their tumors.