High Expression of MicroRNA-196a Indicates Poor Prognosis in Resected Pancreatic Neuroendocrine Tumor

There is limited data on miRNA expression in pancreatic neuroendocrine tumors (PanNETs). In this study, we aimed to identify miRNAs that could be potential prognostic biomarkers of PanNETs in patients who underwent curative surgery.For miRNA target screening, 2 primary PanNETs and corresponding liver metastases were screened for miRNA expression by the NanoString nCounter analysis. Candidate miRNAs were selected by ≥2-fold difference of expression between metastatic versus primary tumor. For miRNA target validation, quantitative real-time PCR was performed for candidate miRNAs on 37 PanNETs and matched nonneoplastic pancreata, and the miRNA levels were correlated with the clinicopathological features and patient survival data.Eight miRNAs (miRNA-27b, -122, -142–5p, -196a, -223, -590–5p, -630, and -944) were selected as candidate miRNAs. Only miR-196a level was significantly associated with stage, and mitotic count. When PanNETs were stratified into high (n = 10) and low (n = 27) miRNA-196a expression groups, miRNA-196a-high PanNETs were significantly associated with advanced pathologic T stage (50.0% vs 7.4%), N stage (50.0% vs 3.7%), higher mitotic counts (60.0% vs 3.7%), and higher Ki-67-labeling indices (60.0% vs 22.2%). In addition, high miRNA-196a expression was significantly associated with decreased overall survival (P = 0.046) and disease-free survival (P < 0.001) during a median follow-up of 37.9 months with the hazard ratio for recurrence of 16.267 (95% confidence interval = 1.732–153.789; P = 0.015).MiRNA-196a level may be a promising prognostic marker of recurrence in resected PanNETs, although further experimental investigation would be required.     

Pancreatic Cancer: The Role of Pancreatic Stellate Cells in Tumor Progression

Pancreatic ductal adenocarcinoma is an aggressive and highly lethal disease frequently characterized by a dense stromal or desmoplastic response. Accumulating evidence exists that tumor desmoplasia plays a central role in disease progression and that e.g. activated pancreatic stellate cells (PSCs) are responsible for the excess matrix production. The mechanisms underlying the tumor versus stroma interplay are complex. Pancreatic cancer cells release mitogenic and fibrogenic stimulants, such as transforming growth factor β₁ platelet-derived growth factor (PDGF), sonic hedgehog, galectin 3, endothelin 1 and serine protease inhibitor nexin 2, all of which may promote the activated PSC phenotype. Stellate cells in turn secrete various factors, including PDGF, stromal-derived factor 1, epidermal growth factor, insulin-like growth factor 1, fibroblast growth factor, secreted protein acidic and rich in cysteine, matrix metalloproteinases, small leucine-rich proteoglycans, periostin and collagen type I that mediate effects on tumor growth, invasion, metastasis and resistance to chemotherapy. This review intends to shed light on the mechanisms by which PSCs in the stroma influence pancreatic cancer development. The increased understanding of this interaction will be of potential value in designing new modalities of targeted therapy.     

Smad4基因沉默对胰腺上皮内瘤变细胞基因表达谱影响的初步研究

抑癌基因Smad4失活可使由Kras基因突变启动的胰腺上皮内瘤变（PanIN）细胞发生恶性转化,但其具体机制尚未阐明。目的：探讨Smad4基因沉默的PanIN细胞（PanIN—S细胞）基因表达谱的变化,分析Smad4基因沉默致PanIN细胞增殖和恶性转化的可能分子机制。方法：通过RNA干扰沉默PanIN细胞的内源性Smad4基因表达以构建PanIN—S细胞．小鼠全基因表达谱芯片筛查PanIN细胞与PanIN-S细胞的基因表达谱差异．实时荧光定量RT—PCR验证基因芯片筛选出的细胞周期相关差异表达基因。结果：基因芯片共筛选出237个差异表达基因,其中148个基因在PanIN—S细胞中表达上调,89个表达下调。差异表达基因主要涉及细胞周期、增殖、凋亡、黏附、转录活性等。实时荧光定量RT．PER验证示细胞周期相关基因p27、p19、细胞周期蛋白（cyclin）D1表达在PanIN细胞与PanIN—S细胞间存在显著差异,与基因芯片筛选结果一致。结论：PanIN-S细胞p27、p19和cyclinD1基因表达发生明显改变．可能参与了PanIN—S细胞的增殖和恶性转化。     

Expression of Fetal Antigens in Tumor Cells

The activities of sera that reacted specifically with the specific cell-surface antigens of polyoma or simian virus 40 tumors could only be inhibited by absorption of the sera with tumor cells transformed by the specific virus, and could not be removed by the absorption with cells from various fetal tissues nor with cells from other tumors. In contrasts, the antisera produced in male C3H/HeN mice by inoculation of irradiated, syngeneic fetal tissue of 1- to 2-weeks gestation, reacted with various tumor cells. The activities of these sera, when tested against cells from tumors induced by polyoma virus or simian virus 40, could also be removed by absorption with cells from tumors induced by viruses other than polyoma or simian virus 40, including leukemia cells induced by Gross virus (C58NT)D, Rauscher virus (RBL-5), and by dimethylbenzanthrene (EL. 4), and cells from mammary tumors (MM102), plasma-cell tumors (MPC-113), and fetal tissues. These results indicated that fetal antigens may be expressed in tumor cells, but they are different from tumor-specific antigens that are specific for a particular tumor or for tumors induced by a particular virus.     

棕榈酸对雨蛙肽诱导的大鼠胰腺腺泡细胞炎症早期基因表达谱的影响

背景：高三酰甘油血症是急性胰腺炎的发病原因之一。血浆中增多的游离脂肪酸（FFA）可损伤多种细胞，导致细胞功能障碍，可能在高三酰甘油血症性急性胰腺炎的发生、发展中起重要作用。目的：探讨饮食中的主要FFA棕榈酸对雨蛙肽诱导的大鼠胰腺腺泡细胞炎症早期基因表达谱的影响。方法：以胶原酶消化法分离大鼠胰腺腺泡细胞，将细胞分为3组，雨蛙肽组加入终浓度为100nmol／L的雨蛙肽，雨蛙肽＋棕榈酸组加入相同剂量的雨蛙肽和终浓度为1mmol/L的棕榈酸，正常对照组不予处理。培养3h后提取细胞总RNA，应用含15000余条大鼠基因的大鼠Affymetrix 230A基因芯片检测基因表达谱的变化。结果：雨蛙肽＋棕榈酸组较雨蛙肽组出现30条上调基因和15条下调基因，其功能涉及细胞信号转导、转录、脂质代谢、蛋白修饰等不同层次。结论：棕榈酸可能通过影响大鼠炎症胰腺腺泡细胞多种结构和功能基因的表达而加重其损伤。     

Pancreatic Stellate Cells Potentiate Proinvasive Effects of SERPINE2 Expression in Pancreatic Cancer Xenograft Tumors

We have previously reported that inducible overexpression of the serine protease inhibitor nexin 2 (SERPINE2) significantly increases local invasiveness of subclones of the pancreatic cancer cell-line SUIT-2 in nude mouse xenografts. This was associated with a striking increase of extracellular matrix deposition in the invasive tumors. Pancreatic stellate cells (PSCs) have recently been identified as the major source of fibrosis in pancreatic adenocarcinomas. Here we report that co-injection of PSCs and tumor cells dramatically enhances the invasive potential of serine protease inhibitor Nexin 2 (SERPINE2)-expressing SUIT-2 cells. 100% (24 of 24) of the SERPINE2-expressing tumors with PSCs grew aggressively invasive, as compared to 39% of SERPINE2-negative tumors with PSCs and 27% of SERPINE2-expressing tumors without PSCs. In contrast to pure cancer cell preparations, SERPINE2 overexpression in the presence of PSCs also resulted in increased tumor growth. Histological evaluation demonstrated the presence of large amounts of ECM deposits co-localizing with cells staining positive for the PSC marker α-SMA. We conclude that PSCs actively proliferate in pancreatic cancer xenograft tumors and significantly contribute to the local invasive potential of the tumors. Presence of PSCs enhances the pro-invasive effects of SERPINE2 expression, and SERPINE2 influences tumor growth (as opposed to invasiveness) only in the presence of PSCs. Our data thus suggest that SERPINE2 is an important modulator of tumor cell/host interactions in pancreatic cancer.     

胰腺癌内皮细胞的分离纯化和鉴定

背景：以正常血管内皮细胞替代肿瘤内皮细胞进行抗肿瘤血管生成研究是一种间接、模拟的研究方式。其局限性显而易见,而以肿瘤内皮细胞为研究对象可提供更为直接、有效、真实的证据。目的：建立胰腺癌内皮细胞的分离纯化、鉴定方法。方法：构建胰腺癌原位荷瘤裸鼠模型,应用免疫磁珠技术,以结合有CD31单克隆抗体的磁珠从胰腺原位移植瘤中分离纯化胰腺癌内皮细胞,通过光学显微镜观察、免疫荧光染色和乙酰化低密度脂蛋白（Ac—LDL）摄取实验从细胞形态、表面标记物和功能三个层面对所获细胞进行鉴定。结果：从裸鼠胰腺原位移植瘤中分离纯化得到的CD31阳性细胞在光学显微镜下呈典型“铺路石样”改变,CD34／VE．cadherin、CD31／VEGFR．2免疫荧光双染色均为阳性,95％以上的细胞DiI标记的Ac．LDL摄取实验结果呈阳性。结论：本研究成功建立了胰腺癌内皮细胞的分离纯化、鉴定方法,可用于胰腺癌肿瘤血管发生机制和抗肿瘤血管生成新药的研究。     

Role of p53 Tumor Suppressor Gene in Pancreatic Endocrine Tumors of Chinese Patients

Objective: The molecular genetic of pancreatic endocrine tumor (PET) has rarely been studied in depth because of its rarity. The aim of this study is to determine if there is any implication of p53 overexpression on the pathogenesis and clinicopathological parameters of PET.
Methods: This study examines the immunohistochemical expression of the p53 gene product in 52 PETs (32 insulinomas, three gastrinomas, two glucagonomas, one carcinoid, and 14 nonfunctional tumors) from Chinese patients (27 men, 25 women) collected over a 23-yr period. Of these, 21% were malignant.
Results: Irrespective of their demographic data, clinical behavior, hormonal status, or pathological features, none of the 52 PETs showed p53 overexpression.
Conclusions: This observation, together with an analysis of the literature, suggests that p53 gene aberrations may not be important in the pathogenesis of PET.     

Gli基因在胰腺癌中的表达变化及其临床意义

背景：研究发现Hedgehog信号通路的异常活化与胰腺癌发生密切相关，三种Gli核转录因子在Hedgehog信号通路中发挥不同的核转录效应。目的：探讨Gli基因在胰腺癌和正常胰腺组织中的表达水平及其临床意义。方法：收集24例胰腺癌组织和19例正常胰腺组织．以定量逆转录聚合酶链反应（qRT-PCR）检测Gli mRNA的表达量，分析其表达变化，并探讨与相关临床参数的关系。结果：与正常胰腺组织相比，胰腺癌组织的三种GE基因mRNA表达量显著升高（P〈0．05），且Glil、Gli2 mRNA 表达量与Gli3 mRNA 表达量呈正相关。Gli2 mRNA高表达与淋巴结转移相关。结论：三种Gli基因与胰腺癌发生呈一定联系，且三者之间可能存在一定相互协同作用；将三者作为一个整体进行调控可更好地控制Hedzehoz信号通路。     

Pancreatic Stellate Cells Activation and Matrix Metallopeptidase 2 Expression Correlate With Lymph Node Metastasis in Pancreatic Carcinoma

Background

This study aimed to investigate the correlation between pancreatic stellate cell activation, matrix metallopeptidase 2 (MMP2) expression and lymph node metastasis in pancreatic carcinoma.