Adjacent Pancreatic Tissues Research Articles

Clinicopathological significance of the expression of carbonic anhydrase II in human pancreatic invasive ductal cancer

To study the clinicopathological significance of the expression of carbonic anhydrase (CA)II protein and mRNA in primary invasive ductal cancer (IDC) of human pancreas. The expression of CAII protein in 33 paired paraffin embedded IDC specimens of the pancreas and paired adjacent non-cancerous pancreatic tissues was detected by immunohistochemistry. Western blot and reverse transcription polymerase chain reaction (RT-PCR) were used to examine the expression of CAII protein and mRNA level in 12 paired fresh IDC specimens of the pancreas and adjuvant non-cancerous pancreatic tissues. The relationship between the protein expression and clinicopathological features was analyzed. Overexpression of CAII protein was shown in 11 cases of pancreatic IDC tissues (33.3%, 11/33), which was much lower than that in paired non-cancerous pancreatic tissues (72.7%, t = 6.275, P = 0.000). The expression of CAII protein had no correlation with tumor position (χ² = 0.992, P = 0.319), differentiation (χ² = 0.866, P = 0.352), TNM stage (χ² = 1.210, P = 0.271) and Lymph node metastasis (χ² = 0.798, P = 0.372), but had bordering statistic sig with the prognosis of the patients (χ² = 3.233, P = 0.072). The median survival time in the patients with high expression of CAII protein was 540 days, while that in the patients with low expression was 320 days. The expression of CAII protein and mRNA was lower in IDC than that in paired non-cancerous pancreatic tissues detected by Western blot and RT-PCR respectively (t = 3.399, P = 0.006; t = 2.281, P = 0.043). CAII is down regulated in pancreatic IDC and might be relative with the prognosis.

Evaluation of pancreatic cancer by multiple breath-hold dynamic contrast-enhanced magnetic resonance imaging at 3.0 T

ObjectiveTo investigate the microcirculation in pancreatic cancer by pharmacokinetic analysis of multiple breath-hold dynamic contrast-enhanced magnetic resonance imaging at 3.0T. Materials and methodsMultiple breath-hold dynamic contrast-enhanced magnetic resonance imaging was performed in 40 healthy volunteers and 40 patients with pancreatic cancer proven by histopathology using an axial three-dimensions fat-saturated T1-weighted spoiled-gradient echo sequence at 3.0T. A two compartment model with T1 correction was used to quantify the transfer constant, the rate constant of backflux from the extravascular extracellular space to the plasma and the extravascular extracellular space fractional volume in pancreatic cancer, obstructive pancreatitis distal to the malignant tumor, adjacent pancreatic tissue proximal to the tumor and normal pancreas. All parameters were statistically analyzed. ResultsStatistical differences were noticed in both the transfer constant (p=0.000075) and the rate constant of backflux (p=0.006) among different tissues. Both the transfer constant and the rate constant of backflux in pancreatic cancer were statistically lower than those in normal pancreas and adjacent pancreatic tissue (p<0.05). Both the transfer constant and the rate constant of backflux in obstructive pancreatitis were statistically lower than those in normal pancreas and adjacent pancreatic tissue (p<0.05). The extravascular extracellular space fractional volume in pancreatic cancer was statistically lager than that in normal pancreas (p=0.002). ConclusionMultiple breath-hold dynamic contrast-enhanced magnetic resonance imaging offers a useful technique to evaluate the microenvironment in pancreatic cancer at 3.0T. Compared to normal pancreas, pancreatic cancer has lower transfer constant, rate constant of backflux and larger extravascular extracellular space fractional volume.

Thermal bile duct and duodenal protection during pancreatic cryoablation

AimTo examine whether thermo-perfusion of the bile duct and duodenum may protect these organs during cryoablation of adjacent pancreatic tissue. Study designCryoablation of the pancreatic tissue, adjacent to the common bile duct and duodenum was performed in two groups of pigs. In the experimental group, the bile duct and duodenum were protected during the cryo-procedure by intraluminal perfusion of warm saline. In the control group, cryoablation was performed without thermo-protection. ResultsAll three animals in the control group developed duodenal perforation and abscesses and died within a week. All the pigs in the experimental group survived and on re-operation 14days after the first procedure were found to have normal duodenum and bile duct adjacent to the cryoablated pancreatic tissue. Histological examinations confirmed these results. ConclusionThe present study confirms the feasibility and efficacy of thermo-protection of the duodenum and common bile duct during cryoablation of the head of the pancreas.

Research on perfusion weighted imaging and diffusion weighted imaging of pancreatic masses at 3.0 T MR

Objective To investigate the value of MR perfusion parameters and ADC in the diagnosis of pancreatic cancer and pancreatic mass at 3.0 T MR. Methods Twenty healthy volunteers and 25 patients with pancreatic cancers proven by pathological results underwent MR PWI at a 3.0 T scanner. A two-compartment model was used to quantify Ktrans, Kep and Ve in the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue. All parameters among different tissues were analyzed and compared with ANONA. Fifteen normal volunteers and 58 patients, including 30 patients with pancreatic cancer (proven histopathologically), 9 patients with pancreatitis pseudotumor (4 patients proven by histopathological results, 5 patients proven by follow-up after treatment), 9 patients with solid pseudopapillary tumor of pancreas (SPTP, proven histopathologically) and 10 patients with pancreatic neuroendocrine tumor (PET, proven by histopathology), underwent respiratory-triggered DWI on 3.0 T. ADC values of normal pancreas and all types of pancreatic lesions were statistically analyzed and compared with ANONA. ROC curve was used to analyze the diagnostic power of ADC value. Results Ktrans of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (1.66±1.25), (3.77±2.67),(1.16±0.94) and (2.69±1.46)/min respectively(F=8.160, P＜0.01). LSD test showed that Ktrans in the pancreatic cancer was statistically lower than that in normal pancreas (P=0.011)and adjacent pancreatic tissue(P=0.002). Kep of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (2.53±1.55), (5.64±2.64), (1.70±0.91) and (4.28±1.64)/min respectively(F=4.544, P＜0.01). LSD test revealed that Kep in pancreatic cancer was statistically lower than that in normal pancreatic tissue (P=0.035)and adjacent pancreatic tissue(P=0.041). The median of Ve among the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were 0.926, 0.839, 0.798 and 0.659 respectively (χ2=12.040,P＜0.01). Ve in pancreatic cancer was statistically higher than that in normal pancreatic tissue (P=0.002). ADC values of the pancreatic cancer, pancreatitis pseudotumor, SPTP, PET and normal pancreas were(1.57±0.26)×10-3,(1.19±0.15)×10-3,(1.05±0.35)×10-3,(1.62±0.41)×10-3 and (1.82±0.25)×10-3 mm2/s(F=21.681, P＜0.01). LSD test showed there were significant statistical differences in ADC values among pancreatic cancer, pancreatitis pseudotumor and normal pancreatic tissue (P＜0.01). ROC curve disclosed that the sensitivity, specificity, positive predictive value and negative predictive value were 86.7%, 88.9%, 96.3% and 66.7% respectively, when ADC≥1.33×10-3 mm2/s was used as a cutoff value for differential diagnosis of PDCA from MLP. The sensitivity, specificity, positive predictive value and negative predictive value were 77.8%, 100.0%, 100.0% and 83.3% respectively when ADC≤1.25×10-3 mm2/s was used as a cutoff value for differential diagnosis of SPTP from PET. Conclusion Compared to normal pancreatic tissue, pancreatic cancer usually had a lower Ktrans, Kep and larger Ve. ADC values from respiratory-triggered DWI were well related to histopathological features of pancreatic entities and may be helpful in the differential diagnosis. Key words: Pancreas neoplasm; Magnetic resonance imaging; Comparative study

Abstract 139: MicroRNA-375 and microRNA-221: Potential noncoding RNAs associated with antiproliferative activity of benzyl isothiocyanate in pancreatic cancer

Abstract Large high-throughput studies in patients with pancreatic cancer revealed that oncogenic miR-221 is commonly upregulated microRNA whereas putative tumor suppressor miR-375 is generally down modulated when compared to adjacent benign pancreatic tissue or normal pancreas. In our laboratory, we observed that deregulated expression of miR-375 and miR-221 (as noted in pancreatic cancer patients) can be recapitulated in PDX1-Cre+; KRasG12D+ pancreatic cancer mouse model. Coherent data obtained from pancreatic cancer patient samples to preneoplastic lesions developed in preclinical mouse model tempted us to postulate that aberrant expression of these miRNAs (−375 and-221) might play significant role for the development of pancreatic cancer. Interestingly, ablation of miR-221 by ectopic expression of antagomir-221 in pancreatic ductal carcinoma cells can significantly exert antiproliferative effect with increased expression of p27kip1, a target of miR-221. To the other end, premiR-375 overexpression diminished cell proliferation with downmodulation of Insulin like growth factor binding protein 5 (IGFBP5) and Caveolin-1 (CAV-1 gene), which are of particular interest because of their potential link with pancreatic cancer cell growth and diagnosis. It is quite intriguing that the levels of both CAV-1 and IGFBP5 expression were elevated when miR-375 expression wanes in KRASG12D driven PanIN lesion in compound mutant mice. Previous studies in our laboratory demonstrate that benzyl isothiocyanate (BITC), a prototypical member of the isothiocyanate (ITC) family, inhibits proliferation of human pancreatic cancer cells by causing cell cycle arrest and inducing apoptosis. Interestingly, real time qRT-PCR analysis indicates that anticancer agent BITC can diminish oncogenic miR-221 expression and elevate the level of tumor suppressor miR-375 in pancreatic cancer cells. Besides, genetic manipulation studies revealed that enforced silencing of miR-221 or overexpression of miR-375 enhances the antiproliferative effect of BITC in pancreatic ductal carcinoma cells. Next we explored the efficacy of BITC to interfere with the development of mouse PanIN lesions. Results indicate that pancreata of BITC administered compound mutant mice exhibit reduced level of IGFBP5 protein. Histopathological analysis of the extent of PanINs as well as studies on the magnitude of expression of miR-221/miR-375 and other molecular mediators in these pancreata are in progress. Explicitly, our investigation might provide new insight into nonconventional microRNA replacement therapy against pancreatic cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 139. doi:10.1158/1538-7445.AM2011-139

Transthyretin, identified by proteomics, is overabundant in pancreatic juice from pancreatic carcinoma and originates from pancreatic islets

Analyses of pancreatic juice by proteomics have identified many proteins that are overabundant in pancreatic cancer (PC) juice. The mechanism by which secretion of these proteins occur remains unclear. Pancreatic juice was collected from patients with three pancreatic diseases: PC, chronic pancreatitis (CP), and simple choledocholithiasis (CDS), and analyzed by 2-DE, MALDI-TOF/MS, and Western blot. Five PC cell lines, 30 PC tissues and their corresponding adjacent pancreatic tissues were used to validate the expression of genes which code for overabundant proteins in PC juice. The mRNA and protein levels were measured by RT-PCR and immunohistochemistry, respectively. Using proteomics, it was demonstrated that the protein transthyretin (TTR) was upregulated more than 2-fold in PC juice compared with CP and CDS, while apolipoprotein A-I, lithostathine, and regenerating islet-derived 1 beta precursor were downregulated more than 2-fold. Western blots confirmed that TTR was overabundant in the PC juice. However, TTR mRNA was not detected in any of the five PC cell lines, and was only detected in islet cells. By microscopy, it was shown that islet architecture was almost completely destroyed, and the islet's maximum diameter appeared larger in PC tissues than in normal. Some overabundant proteins in PC juice, such as TTR expressed only in islets, leak into the pancreatic ductal system due to hyperplasia and architectural damage in PC tissues. The destruction of organ and tissue architecture by tumor growth may result in novel tumor markers even if the markers are not secreted directly by tumor cells.

Nuclear Ploidy Is an Indicator of Malignancy Endocrine Pancreatic Tumor

Comparative morphometric and densitometric studies of cell nuclei in endocrine tumors of various differentiation degree and endocrinocytes of Langerhans islet in the adjacent pancreatic tissue were carried out. Index of proliferative activity, aneuploidy coefficient, and histogram of nuclear DNA content are recommended as additional criteria for the diagnosis of endocrine tumor malignancy.

Signal transducer and activator of transcription 3β in pancreatic cancer

Abstract Signal transducer and activator of transcription 3 (STAT3) has four isoforms: α, β, γ and δ. STAT3α and STAT3β are the transcriptionally active isoforms, while STAT3γ and STAT3δ are the products of STAT3 proteolytic degradation. STAT3 plays an important role in angiogenesis, cell proliferation and apoptosis. High levels of STAT3β in blood cells from acute leukaemia patients have been reported, suggesting that STAT3β may play an important role in cancerogenesis. Fourteen pancreatic cancer patients and six chronic pancreatitis patients were included in this pilot study. Levels of STAT3 isoforms from samples with pancreatic cancer and in adjacent histologically-normal pancreatic tissue were analysed. Pancreas from chronic pancreatitis patients served as a non-neoplastic tissue. Western-blot analysis of STAT3 proteins with the use of anti-STAT3 antibodies was performed. STAT3α and STAT3β isoforms in both cancerous and in adjacent normal tissues were found in 10 of 14. In chronic pancreatitis patients, only STAT3α and STAT3δ were detected. STAT3β was absent in pancreas from chronic pancreatitis patients, in contrast to pancreatic cancer patients. The presence of STAT3β in pancreatic cancer and in adjacent histologically-normal tissues, but not in inflamed tissues suggests that STAT3β may play a key role in cancer development.

Early over expression of messenger RNA for multiple genes, including insulin, in the Pancreatic Lymph Nodes of NOD mice is associated with Islet Autoimmunity

BackgroundAutoimmune diabetes (T1D) onset is preceded by a long inflammatory process directed against the insulin-secreting β cells of the pancreas. Deciphering the early autoimmune mechanisms represents a challenge due to the absence of clinical signs at early disease stages. The aim of this study was to identify genes implicated in the early steps of the autoimmune process, prior to inflammation, in T1D. We have previously established that insulin autoantibodies (E-IAA) predict early diabetes onset delineating an early phenotypic check point (window 1) in disease pathogenesis. We used this sub-phenotype and applied differential gene expression analysis in the pancreatic lymph nodes (PLN) of 5 weeks old Non Obese Diabetic (NOD) mice differing solely upon the presence or absence of E-IAA. Analysis of gene expression profiles has the potential to provide a global understanding of the disease and to generate novel hypothesis concerning the initiation of the autoimmune process.MethodsAnimals have been screened weekly for the presence of E-IAA between 3 and 5 weeks of age. E-IAA positive or negative NOD mice at least twice were selected and RNAs isolated from the PLN were used for microarray analysis. Comparison of transcriptional profiles between positive and negative animals and functional annotations of the resulting differentially expressed genes, using software together with manual literature data mining, have been performed.ResultsThe expression of 165 genes was modulated between E-IAA positive and negative PLN. In particular, genes coding for insulin and for proteins known to be implicated in tissue remodelling and Th1 immunity have been found to be highly differentially expressed. Forty one genes showed over 5 fold differences between the two sets of samples and 30 code for extracellular proteins. This class of proteins represents potential diagnostic markers and drug targets for T1D.ConclusionOur data strongly suggest that the immune related mechanisms taking place at this early age in the PLN, correlate with homeostatic changes influencing tissue integrity of the adjacent pancreatic tissue. Functional analysis of the identified genes suggested that similar mechanisms might be operating during pre-inflammatory processes deployed in tissues i) hosting parasitic microorganisms and ii) experiencing unrestricted invasion by tumour cells.

Comparative Characteristics of Nuclear Ploidy of Cells in Endocrine and Solid Pseudopapillary Tumors of the Pancreas

We carried out comparative morphometry and densitometry of cell nuclei in endocrine and solid pseudopapillary tumors and of exocrinocytes and endocrinocytes of the adjacent pancreatic tissue. The nuclear size, perimeters, and DNA content were higher in tumor cells. The index of proliferative activity, coefficient of aneuploidy, and histograms of DNA content in cell nuclei are recommended as additional criteria for differential diagnosis between endocrine and solid pseudopapillary tumors.

Proteomic Analysis of Pancreatic Ductal Adenocarcinoma Compared with Normal Adjacent Pancreatic Tissue and Pancreatic Benign Cystadenoma

Background: Dual expression of potential biomarkers in both benign and malignant pancreatic tumors was a major obstacle in the development of diagnostic biomarkers of early pancreatic cancer. Methods: To better understand the limitations of potential protein biomarkers in pancreatic cancer, we employed two-dimensional difference gel electrophoresis technology and tandem mass spectrometry to study protein expression profiles in pancreatic cancer tissues, benign pancreatic adenoma and normal adjacent pancreas. Seven differently expressed proteins were selected for validation by Western blot and/or immunohistochemistry. Results: 21 spots were overexpressed and 24 spots were downexpressed in pancreatic cancer compared with benign and normal adjacent tissues. Our study demonstrated that three candidate pancreatic ductal adenocarcinoma biomarkers identified in previous studies, fructose-bisphosphate aldolase A, α-smooth muscle actin and vimentin, were also overexpressed in pancreatic cystadenoma, which might lower their further utility as biomarkers for pancreatic cancer. Aflatoxin B1 aldehyde reductase (AKR7A2) was confirmed to be only highly expressed in pancreatic cancer, not in normal adjacent pancreas and benign tumors. Conclusions: The protein profile pattern of pancreatic cystadenoma was more similar to normal adjacent pancreas than pancreatic cancer. We identified panels of the upregulated proteins in pancreatic cancer, which have not been reported in prior proteomic studies. AKR7A2 may be a novel potential biomarker for pancreatic cancer.

IDENTIFICATION OF PROTEIN-CODING AND NONCODING GENE EXPRESSION SIGNATURES CORRELATED WITH MALIGNANT TRANSFORMATION AND METASTASES IN PANCREATIC CANCER

Aim: To investigate possible roles of noncoding RNAs in Pancreatic Adenocarcinoma (PA), and to identify candidate marker genes for early diagnosis, prognosis and treatment management. Introduction: Early detection and targeted therapy are decisive for management of PA. Several lines of evidence indicate that ncRNAs may participate in mechanisms of regulation of gene expression in normal and cancer cells. Methods: A custom spotted cDNA 3,355-element microarray enriched in ncRNA probes was used to obtain expression profiles from 38 clinical samples; PA n = 15, normal adjacent pancreatic tissue (NAPT) n = 9, chronic pancreatitis (CP) n = 8, and 6 metastases (M). Among the probes in the array, 1,079 map to intronic or intergenic ncRNAs and 2,276 are exons from protein-coding genes. Results: Statistical analysis by SAM identified 323 transcripts (204 exonic, 89 intronic and 30 intergenic) that separate the samples according to histological type. We identified a signature of 24 transcripts (19 exonic, 3 intronic, and 2 intergenic; FDR<5%) that differentiate PA from PC and NAPT eliciting for malignant markers without inflammatory influence. We also identified 361 transcripts (213 exonic, 109 intronic, and 39 inter-genic; FDR<5%) as differentially expressed between PA and M, suggesting that those transcripts are associated with invasive phenotype. Conclusion: Our findings demonstrate the ubiquitous expression of intronic ncRNA in pancreatic cancer tissues, suggesting the involvement of this class of transcripts with malignant transformation and severity. Clinically, the characterization of these protein-coding transcripts and ncRNAs have the potential to contribute for new diagnostic molecular markers and putative therapeutic targets for treatment.

Comments and Illustrations Regarding the Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) – Update 2008

The recently published EFSUMB guidelines and recommendations provide general advice for the use of ultrasound contrast agents to improve the management of patients. They are the subject of this pictorial essay, comments and analysis of the literature. CEUS has become the most important imaging method for focal liver diseases. Its uses are discussed in detail, especially the characterization of liver tumors and the monitoring of local treatment. The recommendations also deal with the uses of ultrasound contrast agents for the evaluation of the microvasculature and macrovasculature of the kidneys, including the characterization of focal renal lesions, the detection of lesions and the monitoring of local treatment. CEUS and contrast-enhanced endoscopic ultrasound can be used to characterize lesions. Ductal adenocarcinoma as the most common tumor of the pancreas is typically hypoenhanced compared to the adjacent pancreatic tissue in all phases. Neuroendocrine tumors and serous microcystic adenoma of the pancreas are characterized by hypervascularization appearing typically hyperenhanced during CEUS. This is of importance for a differential diagnosis. Vesicoureteric reflux and blunt abdominal trauma are also mentioned. Other parts or chapters of the guidelines are described in a separate paper of this supplement.

Geminin is overexpressed in human pancreatic cancer and downregulated by the bioflavanoid apigenin in pancreatic cancer cell lines

Pancreatic adeniocarcinoma is among the deadliest of human cancers. Apigenin, an antitumor flavonoid, inhibits pancreatic cancer cell proliferation in vitro. Geminin is a recently identified novel protein that plays a critical role in preventing abnormal DNA replication by binding to and inhibiting the essential replication factor Cdt1. Microarray analysis identified geminin to be downregulated in pancreatic cancer cells treated with apigenin. Therefore, we investigated the effects of apigenin on geminin expression and other proteins involved in replication (Cdc6, Cdt1, and MCM7) in pancreatic cancer cell lines CD18 and S2013. Real time RT-PCR and western blotting analysis showed that geminin expression is downregulated by apigenin at both mRNA and protein levels. Furthermore, treatment of cells with proteosome inhibitor MG132 reversed the downregulation of geminin by apigenin, supporting our hypothesis that the degradation pathway is another mechanism by which apigenin affects geminin expression. Apigenin treatment also resulted in downregulation of Cdc6 at both mRNA and protein levels. However, Cdt1 and MCM7 expression was not affected in apigenin-treated cells. The effect of apigenin treatment on geminin promoter activity was measured by transient transfection of Hela cells with a reporter gene, demonstrating that apigenin inhibited geminin promoter activity. Geminin expression was also evaluated in human pancreatic tissue (n = 15) by immunohistochemistry and showed that geminin is overexpressed in human pancreatic cancer compared to normal adjacent pancreatic tissue. In conclusion, our studies demonstrated that geminin is overexpressed in human pancreatic cancer and downregulated by apigenin which may contribute to the antitumor effect of this natural flavonoid.

Pancreatic Neuroendocrine Tumours: Established Role of Endoscopic Ultrasound in High-Risk Populations

Pancreatic neuroendocrine tumours (PNETs) are rare tumours of the pancreas that arise from cells that produce hormonally active substances. Insulin and gastrin are the most common hormone-producing tumours that are associated with symptoms. A proportion of these tumours can develop without symptoms and are incidentally found at the time of abdominal imaging, or only become symptomatic when the tumour is large. Certain genetic syndromes are associated with a high prevalence of PNETs. Multiple endocrine neoplasm type 1 (MEN1) is the most common genetic syndrome associated with PNETs. The tumours can be multifocal, ranging in size and function. Often, MEN1 patients have a high prevalence of other tumours, such as adrenal and pituitary tumours. In this issue of The Canadian Journal of Gastroenterology, Alsohaibani et al ( pages 817–820) report a retrospective study of 14 PNET patients who underwent preoperative assessment with endoscopic ultrasound (EUS). They also discuss the impact that EUS had on surgical decision-making. The initial workup for nearly all patients consisted of computed tomography (CT) scanning and EUS, while others had other preoperative workups, such as magnetic resonance imaging and octreotide scintigraphy. EUS detected PNETs in all 14 cases (100%), whereas the CT detection rate was 77%. Furthermore, among those with multifocal PNETs, the extent of pancreatic involvement was underestimated by CT imaging in three cases. As a result, the decision to undergo surgery was changed in 36% of patients and the extent of surgery required was changed in 50% of patients. There are drawbacks to the study by Alsohaibani et al. No inferences can be made about the efficacy of EUS in impacting the role of surgery because of the small numbers of patients and the retrospective, descriptive study design. However, because PNETs are rare (estimates of one per 100,000 population), to accumulate more cases would require years, during which time imaging technology and surgical techniques would most certainly change. A multicentre review would be the best way to investigate whether EUS truly impacts surgery. Although the authors state that there are drawbacks to their retrospective case series, the results speak to the detection limits of existing imaging techniques. Many PNETs are vascular lesions and often enhance to the same degree as adjacent pancreatic tissue, thereby evading detection by contrast CT. Although all PNETs have somatostatin receptors, the elusive tumours are small and there is variable binding of somatostatin in them. Therefore, current indium-based scintigraphy is unable to detect the small lesions with variable somatostatin binding due to a lack of resolution. More promising data are emerging on radiopharmaceuticals with variable affinity somatostatin receptor analogues (1). Finally, magnetic resonance imaging has a better sensitivity than CT scanning, but small lesions can also be missed by this modality. Only EUS, which has an axial resolution of 0.4 mm at 7.5 MHz, can reliably detect these small lesions and provide a cytological diagnosis by fine needle aspiration (2). Is EUS an essential modality in all PNETs, or all pancreatic masses, for that matter? Risk-stratifying patients would determine which patients would benefit the most from EUS. Patients with MEN1 are distinctly different from those who present with no such history. Indeed, in the study by Alsohaibani et al, all patients who were found to have multifocal disease had MEN1. Some authorities have suggested that asymptomatic MEN1 patients should be screened to detect multifocal disease (3). Because not all MEN1-related PNETs are functional tumours, detection before they become symptomatic is key. As for the PNETs not associated with MEN1 or other genetic syndromes, this group is usually detected as an incidental finding on cross-sectional imaging. Unless these tumours undergo cystic degeneration or cause compressive biliary symptoms, they are essentially asymptomatic. There is an increasing trend of detecting nonfunctional tumours. This group of patients will become more important in the future (4). With the current state of cross-sectional imaging, a high index of suspicion is required to make this diagnosis with EUS providing the cytological confirmation by fine needle aspiration. There is a well-established role for EUS in pancreatic masses. Cross-sectional imaging will still be the test of first contact and is needed to assess distant metastatic disease. However, the article by Alsohaibani et al has reiterated the essential role of EUS in providing a more detailed evaluation of pancreatic masses.

Cystic Dystrophy in Heterotopic Pancreas of Duodenal Wall －A Case Report－

Cystic dystrophy is an uncommon, benign poorly understood disease. It is characterized by the development of cysts in heterotopic pancreatic tissue. A 57-year-old-man was hospitalized for abdominal pain for a week. He is a heavy alcohol drinker. There was a cyst at second portion of duodenum on CT. Under the impression of peptic ulcer perforation, Whipple’s operation was performed. Grossly, a cystic space, measuring 3.0 cm in diameter, was noted within the thickened duodenal wall. Microscopically, the cyst was lined by columnar epithelium and granulation tissue and embedded in ectopic pancreatic tissue. The adjacent pancreatic tissue showed focal chronic pancreatitis.

Expression and functional consequences of oestrogen and progesterone receptors in human insulinomas

The expression of steroid receptors by tumours offers a therapeutic advantage if functionally responsive to exogenous hormones. Insulinomas represent a highly symptomatic group of pancreatic tumours and the steroid receptor status of these tumours is poorly understood. The object of the study was to characterise the sex steroid receptor status of human insulinomas and to investigate whether sex steroids alter insulin expression therein. At our tertiary referral University Hospital, archival and prospective tissues from 25 insulinoma patients collected over 14 years were analysed for oestrogen receptor-alpha (ERalpha), oestrogen receptor beta (ERbeta) and progesterone receptor (PR) expression. Tissue explants of insulinoma and control pancreatic tissue from two new insulinoma patients were cultured and treated with oestrogen and progesterone and insulin expression measured by RT-PCR and ELISA. The main outcome measures were established before data collection and included sex steroid receptor status of tumours and insulin expression in fresh tissue in response to exogenous sex steroids. PR was expressed in 24 out of 25, ERalpha in 10 out of 25 and ERbeta in 21 out of 25 insulinomas. In fresh insulinoma cultures, insulin expression was increased by oestrogen or progesterone, whereas no significant effect was observed in adjacent pancreatic tissue. This study demonstrates widespread expression of sex steroid receptors on human insulinoma tissue and provides in vitro evidence of functionality with increased expression of insulin by insulinoma explants in response to exogenous oestrogen or progesterone. Confirmation of these results may provide a therapeutic mechanism for reducing symptomatic insulin secretion by receptor blockade.

MicroRNA Expression Patterns to Differentiate Pancreatic Adenocarcinoma From Normal Pancreas and Chronic Pancreatitis

While global microRNA (miRNA) expression patterns of many embryologic, physiologic, and oncogenic processes have been described, description of the role of miRNAs in ductal adenocarcinoma of the pancreas is lacking. To define the expression pattern of miRNAs in pancreatic cancer and compare it with those of normal pancreas and chronic pancreatitis. Specimens were obtained at a National Cancer Institute-designated comprehensive cancer center from patients with ductal adenocarcinoma of the pancreas (n = 65) or chronic pancreatitis (n = 42) (January 2000-December 2005). All patients underwent curative pancreatectomy; those with pancreatic cancer were chemotherapy-naive. RNA harvested from resected pancreatic cancers and matched benign adjacent pancreatic tissue as well as from chronic pancreatitis specimens was hybridized to miRNA microarrays. Identification of differentially expressed miRNAs that could differentiate pancreatic cancer from normal pancreas, chronic pancreatitis, or both, as well as a pattern of miRNA expression predictive of long-term (>24 months) survival. Significance of Analysis of Microarrays and Prediction of Analysis of Microarrays were undertaken to identify miRNAs predictive of tissue type and prognosis. P values were calculated by t test, adjusted for multiple testing. Kaplan-Meier survival curves were constructed using mean miRNA expression (high vs low) as threshold and compared by log-rank analysis. Twenty-one miRNAs with increased expression and 4 with decreased expression were identified that correctly differentiated pancreatic cancer from benign pancreatic tissue in 90% of samples by cross validation. Fifteen overexpressed and 8 underexpressed miRNAs differentiated pancreatic cancer from chronic pancreatitis with 93% accuracy. A subgroup of 6 miRNAs was able to distinguish long-term survivors with node-positive disease from those dying within 24 months. Finally, high expression of miR-196a-2 was found to predict poor survival (median, 14.3 months [95% confidence interval, 12.4-16.2] vs 26.5 months [95% confidence interval, 23.4-29.6]; P = .009). Pancreatic cancer may have a distinct miRNA expression pattern that may differentiate it from normal pancreas and chronic pancreatitis. miRNA expression patterns may be able to distinguish between long- and short-term survivors, but these findings need to be validated in other study populations.

Topoisomerase IIalpha and HER2/neu gene alterations and their correlation in pancreatic ductal adenocarcinomas

To investigate the changes of topoisomerase IIalpha (TOP2A) and HER2/neu genes in pancreatic ductal adenocarcinomas of Chinese patients, and to determine their roles during carcinogenesis and tumor progression. Expressions of TOP2A and HER2/neu proteins were detected by using immunohistochemistry, while gene amplifications of TOP2A and HER2/neu were assessed by using multi-color fluorescence in situ hybridization (FISH). All the samples were of paraffin embedded and 10% formalin fixed tissue, including 26 cases of pancreatic ductal adenocarcinomas with adjacent non-neoplastic pancreatic tissues, 10 cases of chronic panreatitis, and 10 cases of normal pancreas. The correlation between TOP2A and HER2/neu gene status was analyzed. By immunohistochemistry, the nuclear positive index of TOP2A in pancreatic ductal adenocarcinomas varied from 0.5% to 70%, and the positive rate of HER2/neu in pancreatic ductal adenocarcinomas was 46.2% (12/26). By FISH, 9/10 TOP2A amplified adenocarcinomas showed TOP2A and HER2/neu gene coamplification, while one case with HER2/neu gene amplification adenocarcinoma showed no TOP2A amplification. No expression of TOP2A, HER2/neu proteins and no amplification of TOP2A and HER2/neu gene were detected in adjacent non-neoplastic pancreatic tissues, chronic pancreatitis tissues and normal pancreas. No relationship was found between protein expression and gene amplification of TOP2A and HER2/neu (P > 0.05). TOP2A gene amplification was significantly correlated with HER2/neu gene amplification (P < 0.01). Protein expression of TOP2A and HER2/neu are not associated with the gene amplification. There is a significant correlation between TOP2A amplification and HER2/neu gene amplification. Co-amplification of TOP2A and HER2/neu may play an important role in the carcinogenesis and progression of pancreatic carcinoma. Evaluation of the status of TOP2A and HER2/neu may be helpful to achieve target therapy of pancreatic carcinoma.

ANTISENSE INTRONIC NON-CODING RNA LEVELS IN PANCREATIC CANCER

Pancreatic adenocarcinoma (PA) is one of the most aggressive and has the worst prognosis of all solid tumors. Despite overall improvements in diagnostic imaging and molecular techniques, it is difficult to diagnose PA in the earlier stages. Surgical resection remains the only hope for cure, although only 5% to 20% of patients are candidates at the time of presentation. Early detection and targeted therapy is very important for improving a patient"s chance of survival. Monitoring of differential gene expression is an important step towards a better understanding of molecular pathogenesis of PA. Several lines of evidence indicate that non-coding RNAs may participate in control mechanisms of regulation of gene expression in normal and cancer cells. The aim of this study was to analyse the transcriptional profile of intronic messages in PA, and to identify candidate marker genes for early diagnosis and for prognosis and treatment management. Methods: To investigate a possible role of intronic ncRNAs in PA, we used a spotted cDNA 3,355-element microarray enriched in ncRNA probes constructed in our laboratory. Among these probes, there are 820 mapping to introns of RefSeq genes and 259 sequences mapping to intergenic regions. We analysed a total of 41 patient pancreatic samples: PA n = 22, normal adjacent pancreatic tissue (NAPT) n = 13, and chronic pancreatitis (CP) n = 6. Results: In an analysis by t test, we agrouped the NAPT with PA and with CP, as we identified 92 genes (74 exonic, 10 intronic, and 5 inter-genic) altered in PA and 47 genes (27 exonic, 15 intronic, and 5 inter-genic) in CP, (P < 0.02). Conclusion: Our findings show that these gene expression signatures can distinguish PA from PC and revealed several candidate genes (in special, intronic genes) in this neoplasia for further characterization.