Basic Research
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jun 7, 2006; 12(21): 3344-3351
Published online Jun 7, 2006. doi: 10.3748/wjg.v12.i21.3344
Identification of biomarkers of human pancreatic adenocarcinomas by expression profiling and validation with gene expression analysis in endoscopic ultrasound-guided fine needle aspiration samples
Henrik Laurell, Michèle Bouisson, Philippe Berthelémy, Philippe Rochaix, Sébastien Déjean, Philippe Besse, Christiane Susini, Lucien Pradayrol, Nicole Vaysse, Louis Buscail
Henrik Laurell, Michèle Bouisson, Christiane Susini, Lucien Pradayrol, Nicole Vaysse, Louis Buscail, INSERM U531, IFR31, Institut Louis Bugnard, BP 84225, 31432 Toulouse Cedex 4, France
Philippe Berthelémy, Service de Gastroentérologie, Centre Hospitalier de Pau, Pau, France
Philippe Rochaix, Laboratoire d’Anatomo-Pathologie, Institut Claudius Regaud, Toulouse, France
Sébastien Déjean, Philippe Besse, Laboratoire de Statistique et Probabilités, Université Paul Sabatier, Toulouse, France
Louis Buscail, Service de Gastroentérologie et de la Nutrition, CHU Rangueil, Toulouse, France
Supported by Contrat Université Paul Sabatier, Toulouse, France, ASUPS 2000 (N. Vaysse); AOL DRC Hôpitaux de Toulouse 2001, (L. Buscail); Région Midi-Pyrénées (L. Buscail). H. Laurell was supported by a grant from European Community Plan 99 ECC QLG3-CT-1999-0908 (C. Susini). The Agilent 2100 Bioanalyzer and the phosphoimager (Molecular Dynamics, Sunnyvale, CA, USA) were at the Transcriptome Platform, Toulouse Génopole, and at the molecular biology platform at the Institute Louis Bugnard, IFR31, Toulouse, France, respectively
Correspondence to: Louis Buscail, INSERM U531, IFR31, Institut Louis Bugnard, BP 84225, 31432 Toulouse Cedex 4, France. louis.buscail@toulouse.inserm.fr
Telephone: +33-5-61322404 Fax: +33-5-61322403
Received: December 14, 2005
Revised: December 28, 2005
Accepted: January 14, 2006
Published online: June 7, 2006
Abstract

AIM: To compare gene expression profiles of pancreatic adenocarcinoma tissue specimens, human pancreatic and colon adenocarcinoma and leukemia cell lines and normal pancreas samples in order to distinguish differentially expressed genes and to validate the differential expression of a subset of genes by quantitative real-time RT-PCR (RT-QPCR) in endoscopic ultrasound-guided fine needle aspiration (EUS-guided FNA) specimens.

METHODS: Commercially dedicated cancer cDNA macroarrays (Atlas Human Cancer 1.2) containing 1176 genes were used. Different statistical approaches (hierarchical clustering, principal component analysis (PCA) and SAM) were used to analyze the expression data. RT-QPCR and immunohistochemical studies were used for validation of results.

RESULTS: RT-QPCR validated the increased expression of LCN2 (lipocalin 2) and for the first time PLAT (tissue-type plasminogen activator or tPA) in malignant pancreas as compared with normal pancreas. Immunohistochemical analysis confirmed the increased expression of LCN2 protein localized in epithelial cells of ducts invaded by carcinoma. The analysis of PLAT and LCN2 transcripts in 12 samples obtained through EUS-guided FNA from patients with pancreatic adenocarcinoma showed significantly increased expression levels in comparison with those found in normal tissues, indicating that a sufficient amount of high quality RNA can be obtained with this technique.

CONCLUSION: Expression profiling is a useful method to identify biomarkers and potential target genes. Molecular analysis of EUS-guided FNA samples in pancreatic cancer appears as a valuable strategy for the diagnosis of pancreatic adenocarcinomas.

Keywords: Pancreas; Colon; Adenocarcinoma; Gene expression profiling; Endoscopic ultrasonography; Ultrasound; Fine needle aspiration