Saraggi Deborah, Galuppini Francesca, Fanelli Giuseppe N, Remo Andrea, Urso Emanuele D L, Bao Ricardo Q, Bacchin Deborah, Guzzardo Vincenza, Luchini Claudio, Braconi Chiara, Farinati Fabio, Rugge Massimo, Fassan Matteo
Department of Medicine (DIMED), University of Padua, Padua, PD, Italy.
Department of Pathology, "Mater Salutis" Hospital - ULSS9, 37045, Legnago, VR, Italy.
Pathol Res Pract. 2018 Jun;214(6):835-839. doi: 10.1016/j.prp.2018.04.018. Epub 2018 May 1.
Poor information is available on the molecular landscape characterizing the carcinogenetic process leading to ampullary carcinoma. MiR-21 is one of the most frequently up-regulated miRNAs in pancreatic adenocarcinoma, a tumor sharing similar molecular features with ampullary adenocarcinomas (AVCs), above all with the pancreatic-biliary type. We profiled, by in situ hybridization (ISH), miR-21 expression in a series of 26 AVCs, 50 ampullary dysplastic lesions (35 low-grade [LG-IEN] and 15 high-grade [HG-IEN]) and 10 normal duodenal mucosa samples. The same series was investigated by immunohistochemistry for β-catenin, p53 and HER2 expression. HER2 gene amplification was evaluated by chromogenic in situ hybridization. To validate miR-21 ISH results we performed miR-21 qRT-PCR analysis in a series of 10 AVCs and their matched normal samples. All the normal control samples showed a negative or faint miR-21 expression, whereas a significant miR-21 up-regulation was observed during the carcinogenetic cascade (p < 0.001), with 21/26 (80.8%) of cancer samples showing a miR-21 overexpression. In comparison to control samples, a significant overexpression was found in samples of LG-IEN (p = .0003), HG-IEN (p = .0001), and AVCs (p < 0.0001). No significant difference in miR-21 overexpression was observed between LG-IEN, HG-IEN and AVCs. By qRT-PCR analysis, AVCs showed a 1.7-fold increase over the controls (p = .003). P53 was frequently dysregulated in both dysplastic and carcinoma samples (44 out of 76; 57.9%). A 20% (10/50) of dysplastic lesions and 11% (3/26) of carcinomas were characterized by a nuclear localization of β-catenin. Only 2 AVCs (7.7%; both intestinal-type) showed a HER2 overexpression (both 2+), which corresponded to a HER2 gene amplification at CISH analysis. This is the first study demonstrating a miRNA dysregulation in the whole spectrum of ampullary carcinogenesis. MiR-21 overexpression is an early molecular event during ampullary carcinogenesis and its levels increase with the neoplastic progression.
关于导致壶腹癌的致癌过程的分子图景，目前可获得的信息较少。MiR-21是胰腺腺癌中最常上调的miRNA之一，胰腺腺癌是一种与壶腹腺癌（AVC）具有相似分子特征的肿瘤，尤其是与胰胆管型相似。我们通过原位杂交（ISH）分析了26例AVC、50例壶腹发育异常病变（35例低级别[LG-IEN]和15例高级别[HG-IEN]）以及10例正常十二指肠黏膜样本中miR-21的表达情况。对同一组样本进行免疫组织化学检测，分析β-连环蛋白、p53和HER2的表达情况。通过显色原位杂交评估HER2基因扩增情况。为验证miR-21 ISH结果，我们对10例AVC及其匹配的正常样本进行了miR-21 qRT-PCR分析。所有正常对照样本均显示miR-21表达为阴性或弱阳性，而在致癌级联反应过程中观察到miR-21显著上调（p<0.001），26例癌症样本中有21例（80.8%）显示miR-21过表达。与对照样本相比，LG-IEN样本（p = 0.0003）、HG-IEN样本（p = 0.0001）和AVC样本（p<0.0001）中均发现有显著过表达。LG-IEN、HG-IEN和AVC之间在miR-21过表达方面未观察到显著差异。通过qRT-PCR分析，AVC样本相对于对照样本增加了1.7倍（p = 0.003）。p53在发育异常和癌组织样本中经常失调（76例中有44例；57.9%）。20%（10/50）的发育异常病变和11%（3/26）的癌组织表现为β-连环蛋白核定位。只有2例AVC（7.7%；均为肠型）显示HER2过表达（均为2+），在CISH分析中对应HER2基因扩增。这是第一项证明miRNA在壶腹癌发生全过程中失调的研究。MiR-21过表达是壶腹癌发生过程中的早期分子事件，其水平随肿瘤进展而增加。
