title: MicroRNA-21 in pancreatic cancer: correlation with clinical outcome and pharmacologic aspects underlying its role in the modulation of gemcitabine activity.
abstract: MicroRNA-21 (miR-21) was reported to be overexpressed and contributes to invasion and gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to evaluate whether miR-21 expression was associated with the overall survival (OS) of PDAC patients treated with gemcitabine and to provide mechanistic insights for new therapeutic targets. miR-21 expression was evaluated in cells (including 7 PDAC cell lines, 7 primary cultures, fibroblasts, and a normal pancreatic ductal cell line) and tissues (neoplastic specimens from 81 PDAC patients and normal ductal samples) isolated by laser microdissection. The role of miR-21 on the pharmacologic effects of gemcitabine was studied with a specific miR-21 precursor (pre-miR-21). Patients with high miR-21 expression had a significantly shorter OS both in the metastatic and in the adjuvant setting. Multivariate analysis confirmed the prognostic significance of miR-21. miR-21 expression in primary cultures correlated with expression in their respective tissues and with gemcitabine resistance. Pre-miR-21 transfection significantly decreased antiproliferative effects and apoptosis induction by gemcitabine, whereas matrix metalloproteinase (MMP)-2/MMP-9 and vascular endothelial growth factor expression were upregulated. Addition of inhibitors of phosphoinositide 3-kinase and mammalian target of rapamycin resulted in decrease of phospho-Akt and prevented pre-miR-21-induced resistance to the proapoptotic effects of gemcitabine. miR-21 expression correlated with outcome in PDAC patients treated with gemcitabine. Modulation of apoptosis, Akt phosphorylation, and expression of genes involved in invasive behavior may contribute to the role of miR-21 in gemcitabine chemoresistance and to the rational development of new targeted combinations.
authors.affiliation: VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Elisa
authors.initials: E
authors.lastname: Giovannetti
authors.forename: Niccola
authors.initials: N
authors.lastname: Funel
authors.forename: Godefridus J
authors.initials: GJ
authors.lastname: Peters
authors.forename: Marco
authors.initials: M
authors.lastname: Del Chiaro
authors.forename: Leyla A
authors.initials: LA
authors.lastname: Erozenci
authors.forename: Enrico
authors.initials: E
authors.lastname: Vasile
authors.forename: Leticia G
authors.initials: LG
authors.lastname: Leon
authors.forename: Luca E
authors.initials: LE
authors.lastname: Pollina
authors.forename: Annemieke
authors.initials: A
authors.lastname: Groen
authors.forename: Alfredo
authors.initials: A
authors.lastname: Falcone
authors.forename: Romano
authors.initials: R
authors.lastname: Danesi
authors.forename: Daniela
authors.initials: D
authors.lastname: Campani
authors.forename: Henk M
authors.initials: HM
authors.lastname: Verheul
authors.forename: Ugo
authors.initials: U
authors.lastname: Boggi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D021441:Carcinoma, Pancreatic Ductal / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000235:genetics; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000096:biosynthesis / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012189:Retrospective Studies; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D003841:Deoxycytidine; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D000093542:Gemcitabine