【Abstract】 Objective To investigate the effect of verapamil on apoptosis, calcium and expressions of bcl-2 and c-myc of pancreatic cells in ischemia-reperfusion rat model. Methods Wistar rats were randomly divided into three groups: control group （n=10）; ischemia-reperfusion group （n=10）; verapamil treatment group （n=10）. The anterior mesenteric artery and the celiac artery of rats in both ischemia-reperfusion group and verapamil treatment group were occluded for 15 min followed by 12-hour reperfusion. Verapamil （1 mg／kg） was injected via caudal vein to the rats in verapamil treatment group 15 min before occlusion and 1 hour after the initiation of reperfusion, respectively; and ischemia-reperfusion group was given the same volume of salient twice intravenously. Pancreatic tissues were collected from the dead rats after twelve hours since the reperfusion. The pathologic characters of pancreatic tissue were observed under light microscope; The level of calcium in the tissue was measured by atomic absorption spectrometer; TUNEL was used to detect apoptosis of pancreatic cells; and the expressions of c-myc and bcl-2 in the cells were also analyzed by immunohistochemistry technique and flow cytometry. Results The pathologic change in verapamil treatment group was less conspicuous than that of ischemia-reperfusion group. Both the calcium level and the number of apoptotic cells in verapamil treatment group were less than those of ischemia-reperfusion group 〔（411.1±55.8） μg/g dry weight vs （470.9±31.9） μg/g dry weight, P＜0.05 and （9.5±2.9）% vs （18.4±3.1）% 〕, P＜0.05. After taking verapamil, the number of apoptotic cells decreased, whereas the expressions of bcl-2 and c-myc increased. The fluorescent indexes of bcl-2 and c-myc in verapamil treatment group were significantly higher than those of ischemia-reperfusion group (1.72±0.11 vs 1.41±0.07, P＜0.05; 1.76±0.19 vs 1.55±0.13, P＜0.05. Conclusion Ischemia-reperfusion injury can induce apoptosis of pancreatic cells. Verapamil could protect the injured pancreatic tissue by reducing the level of calcium, stimulating the expressions of bcl-2 and c-myc and inhibiting apoptosis of pancreatic cells.
Objective To investigate the mechanism of gastrointestinal motility disorder of severe acute pancreatitis （SAP） in rats. Methods SD rats were randomly divided into 2 groups：sham operation （SO） group （n=16） and SAP group （n=16）. The gastric antrum interdigestive myoelectric complex （IMC） of rat was recorded by using bipolar silver electrode recording， the concentration of serum motilin （MTL） and vasoactive intestinal peptide （VIP） were detected by enzyme-linked immunosorbent assay （ELISA） method， and determined the pancreatic pathology score. Results Compared with SO group， the concentration of serum MTL obvious decreased and the concentration of VIP obvious rised in SAP group （P＜0.01）. Compared with SO group， the time of IMC cycle， andⅠand Ⅱ phase were extended， and time of Ⅲ phase was shortened， also the amplitude and frequency of peak electric of Ⅲ phase were declined in SAP group （P＜0.01）. And the concentration of MTL in SAP group showed positive correlation with the time of Ⅲ phase of IMC （r=0.967， P＜0.01）， the concentration of VIP in SAP group showed negative correlation with the time of Ⅲ phase of IMC （r=-0.592， P＜0.05）. The pancreatic organization pathological score in SAP group was higher than that in SO group （P＜0.01）. Conclusion There is gastrointestinal motility disorder in SAP rats， furthermore， it may induce gastrointestinal motility disorder through effecting the gastrointestinal smooth muscle electrical activity.
【 Abstract 】 Objective Overexpressions of epidermal growth factor (EGF) and EGF receptor have been associated with progression and invasive phenotype of pancreatic cancer. However, the underlying molecular mechanism by which EGF worked in pancreatic cancer cells has not been completely understood. In this study, effect of EGF on the invasion and metastasis of pancreatic cancer cells and its regulatory mechanism were investigated. Methods The effects of EGF on the proliferation, adhesion and invasion of pancreatic cancer cells were detected by WST-1 proliferation assay, adhesion assay and invasive assay, respectively. The activity and expression of MMP-2 and MMP-9 were examined by zymography, Western blot and RT-PCR, respectively. The activity of NF- κ B was examined by EMSA. Results EGF could significantly promote the invasiveness of pancreatic cancer cells but did not affect cell proliferation or adhesion. The expressions of NF- κ B and MMP-9 were significantly increased by EGF, but EGF did not affect the activity and expression of MMP-2. Furthermore, EGF stimulated the NF- κ B binding activity. Pretreatment with NF- κ B inhibitors, pyrrolidine dithiocarbamate (PDTC), could significantly inhibit the activity of NF- κ B induced by EGF. Meanwhile, the EGF-induced expression and activity of MMP-9, as well as cell invasiveness were also inhibited by NF- κ B inhibitor. Conclusion EGF could increase the expression and promote the invasiveness of MMP-9 via the activation of NF- κ B in pancreatic cancer cells, which implies that NF- κ B inhibitant, such as PDTC, may diminish the invasiveness of pancreatic cancer cells.
ObjectiveTo investigate the influence of heat shock protein A2 (HSPA2) on the biological behavior of pancreatic adenocarcinoma cells and its mechanism. MethodsThe expressions of HSPA2 were determined in the human pancreatic adenocarcinoma cell lines (PANC-1, BxPC-3, and AsPC-1) using the Western blot. Subsequently, the cells with the lowest and highest HSPA2 expressions among these three lines were selected for conducting overexpression and knockdown experiments targeting HSPA2, respectively. The cellular proliferation, cell clonogenesis, migration, and invasion capabilities were assessed using MTT, clonogenic assay, and Transwell assay, respectively. Additionally, the impact of HSPA2 on the expression of key markers of epithelial-mesenchymal transition (EMT) was examined using the Western blot. The potential target molecules of HSPA2 were identified through immunoprecipitation assay and mass spectrometry. The rescue experiments further explored the regulatory relation between the HSPA2 and its target molecules. The influence of HSPA2 on pancreatic adenocarcinoma growth was investigated through establishment of xenograft tumor model in nude mice. ResultsThe HSPA2 exhibited the lowest expression in the PANC-1 cells and the highest expression in the AsPC-1 cells among the three cell lines. Subsequent functional studies demonstrated that the overexpression of HSPA2 in the PANC-1 cells markedly promoted proliferation, cell clonogenesis, migration, and invasion, while the knockdown of HSPA2 expression in the AsPC-1 cells markedly inhibited these processes. The Western blot analysis further showed that the HSPA2 overexpression downregulated E-cadherin expression and upregulated N-cadherin and Vimentin expressiones, whereas the HSPA2 knockdown produced opposite effects. The rescue experiments indicated that the HSPA2 promoted the EMT in pancreatic adenocarcinoma cells by upregulating Yes associated protein (YAP). The subcutaneous xenograft tumor experiments in the nude mice showed that the HSPA2 knockdown inhibited tumor growth. ConclusionThe results of this study suggest that HSPA2 promotes EMT via upregulating YAP, which facilitates proliferation, migration, and invasion of pancreatic adenocarcinoma cells.
ObjectiveTo evaluate the quality of pancreatic cancer guidelines using evidence-based methods based on the global burden of pancreatic cancer, so as to explore its status, region distribution, characteristics of coverage themes, and difference of therapies recommended by the guidelines of various quality, and to provide references for clinical decisionmaking. MethodsPubMed, The Cochrane Library (Issue 11, 2013), CBM, CNKI, and VIP, as well as the website of National Guidelines Clearinghouse (NGC), Guidelines International Network (GIN), and National Institute for Clinical Excellence (NICE) were systematically searched for pancreatic cancer treatment guidelines. The Appraisal of Guidelines for Research and Evaluation (AGREE Ⅲ) was applied to assess methodological quality of included guidelines. ResultsA total of 14 relevant guidelines (including five evidence-based guidelines) were included involving seven countries of four continents (Asia, Europe, North America and Oceania) and four international academic organizations. There were only two domains, namely "scope and purpose" and "clarity of presentations" which got high average scores (more than 60%) among all 14 guidelines. The mean AGREE domain scores in guidelines varied with areas, and the quality of five evidence-based guidelines was superior to that established by consensus. According to the outcomes of AGREE Ⅲ, 11 guidelines were weakly recommended, while 3 were not recommended due to poor methodological quality. The subjects of 14 guidelines covered six treatment categories, including chemotherapy, surgery, radiotherapy, support therapy, radiotherapy, and interventional therapy. ConclusionThe overall methodological quality of pancreatic cancer guidelines is not high among different countries or regions. The quality of evidence-based guidelines is superior to that established by consensus. Chemotherapy, surgery, radiotherapy and support therapy were reccommended as predominant choice by these guidelines.
Autoimmune pancreatitis (AIP) is a unique subtype of chronic pancreatitis, which shares many clinical presentations with pancreatic ductal adenocarcinoma (PDA). The misdiagnosis of AIP often leads to unnecessary pancreatic resection. 18F-FDG positron emission tomography/ computed tomography (PET/CT) could provide comprehensive information on the morphology, density, and functional metabolism of the pancreas at the same time. It has been proved to be a promising modality for noninvasive differentiation between AIP and PDA. However, there is a lack of clinical analysis of PET/CT image texture features. Difficulty still remains in differentiating AIP and PDA based on commonly used diagnostic methods. Therefore, this paper studied the differentiation of AIP and PDA based on multi-modality texture features. We utilized multiple feature extraction algorithms to extract the texture features from CT and PET images at first. Then, the Fisher criterion and sequence forward floating selection algorithm (SFFS) combined with support vector machine (SVM) was employed to select the optimal multi-modality feature subset. Finally, the SVM classifier was used to differentiate AIP from PDA. The results prove that texture analysis of lesions helps to achieve accurate differentiation of AIP and PDA.
ObjectiveTo investigate the relationship between insulin-like growth factor binding protein (IGFBP) gene with pancreatic cancer. MethodsThe relevant literatures at home and abroad in recent years were reviewed. From the pancreatic cancer related genes, IGFBP related tumors and the correlation between IGFBP and pancreatic cancer research and other aspects of the previous research results were summaried. ResultsMost of the studies suggested that IGFBP could inhibit the function of tumor cells through the IGF dependent pathway, but the deletion or mutation of IGFBP gene and its regulation mechanism are still unclear. ConclusionIGFBP is closely related to the tumor, but its specific effects and mechanism of pancreatic cancer has not been settled. In order to affect the degree of cell differentiation, regulation of tumor growth and metastasis probability through the change of endogenous IGFBP gene level, the further studie is needed.