title: PD2/Paf1 depletion in pancreatic acinar cells promotes acinar-to-ductal metaplasia.
abstract: Pancreatic differentiation 2 (PD2), a PAF (RNA Polymerase II Associated Factor) complex subunit, is overexpressed in pancreatic cancer cells and has demonstrated potential oncogenic property. Here, we report that PD2/Paf1 expression was restricted to acinar cells in the normal murine pancreas, but its expression increased in the ductal cells of KrasG12D/Pdx1Cre (KC) mouse model of pancreatic cancer with increasing age, showing highest expression in neoplastic ductal cells of 50 weeks old mice. PD2/Paf1 was specifically expressed in amylase and CK19 double positive metaplastic ducts, representing intermediate structures during pancreatic acinar-to-ductal metaplasia (ADM). Similar PD2/Paf1 expression was observed in murine pancreas that exhibited ADM-like histology upon cerulein challenge. In normal mice, cerulein-mediated inflammation induced a decrease in PD2/Paf1 expression, which was later restored upon recovery of the pancreatic parenchyma. In KC mice, however, PD2/Paf1 mRNA level continued to decrease with progressive dysplasia and subsequent neoplastic transformation. Additionally, knockdown of PD2/Paf1 in pancreatic acinar cells resulted in the abrogation of Amylase, Elastase and Lipase (acinar marker) mRNA levels with simultaneous increase in CK19 and CAII (ductal marker) transcripts. In conclusion, our studies indicate loss of PD2/Paf1 expression during acinar transdifferentiation in pancreatic cancer initiation and PD2/Paf1 mediated regulation of lineage specific markers.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, U.S.A.
authors.forename: Parama
authors.initials: P
authors.lastname: Dey
authors.forename: Satyanarayana
authors.initials: S
authors.lastname: Rachagani
authors.forename: Arokia P
authors.initials: AP
authors.lastname: Vaz
authors.forename: Moorthy P
authors.initials: MP
authors.lastname: Ponnusamy
authors.forename: Surinder K
authors.initials: SK
authors.lastname: Batra
mesh_terms: D061354:Acinar Cells / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D008679:Metaplasia; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D010165:Palladium / Q000032:analysis / Q000378:metabolism*; D010183:Pancreatic Ducts / Q000166:cytology* / Q000378:metabolism; D014157:Transcription Factors; D014162:Transfection
chemical_list: D009687:Nuclear Proteins; C501972:PAF1 protein, human; D014157:Transcription Factors; D010165:Palladium