Notch2-positive progenitors with the intrinsic ability to give rise to pancreatic ductal cells

Abstract

Pancreatic adenocarcinomas display foci of duct-like structures that are positive for markers of pancreatic ductal cells. The development of these tumors is promoted by conditions leading to acinar-to-ductal metaplasia, a process by which acinar cells are replaced by ductal cells. Acinar-to-ductal metaplasia has recently been shown to proceed through intermediary cells expressing Nestin. To create an in vitro system to study pancreatic adenocarcinomas, we had used an hTERT cDNA to immortalize primary cells of the human pancreas. In this report, we show that the immortalized cells, termed hTERT-HPNE cells, have the ability to differentiate to pancreatic ductal cells. Exposing hTERT-HPNE cells to sodium butyrate and 5-aza-2'-deoxycytidine lead to the formation of pancreatic ductal cells marked by the expression of MDR-1, carbonic anhydrase II, and the cytokeratins 7, 8, and 19. hTERT-HPNE cells were found to have properties of the intermediary cells formed during acinar-to-ductal metaplasia, which included their undifferentiated phenotype, expression of Nestin, evidence of active Notch signaling, and ability to differentiate to pancreatic ductal cells. These results provide further evidence for the presence in the adult pancreas of a precursor of ductal cells. hTERT-HPNE cells should provide a useful model to study acinar-to-ductal metaplasia and the role played by this process in pancreatic cancer development.

Comparative evaluation of cancer stem cell markers in normal pancreas and pancreatic ductal adenocarcinoma

“…Interestingly, though, cytoplasmic Notch2 expression was identified in approximately 50% of PDAC cells, but not in their normal counterparts, and there was a positive correlation with the grade of tumor differentiation. It has been reported that immortalized human pancreatic Nestin-expressing cells, after transfection with cDNA of the catalytic subunit of telomerase (hTERT-HPNE), have properties identical to those of the intermediary cells observed during acinar-to-ductal metaplasia (37), and that unlike their native counterparts they express Notch2 (38). By contrast, Notch3 protein was not differentially expressed in quantitative terms in PDAC vs. normal pancreas.…”

K-Ras Promotes Growth Transformation and Invasion of Immortalized Human Pancreatic Cells by Raf and Phosphatidylinositol 3-Kinase Signaling

“…Previous reports indicate that pancreatic adenocarcinoma may in some cases arise from acinar-to-ductal metaplasia (27)(28)(29) via a precursor intermediary. Our immortalized duct-derived cell line seems to represent a population of this precursor (30). Similar to other human cell types, ectopic hTERT expression and suppression of p53 and Rb function were not sufficient to render these human pancreatic cells sensitive to transformation by oncogenic K-Ras.…”

Activated Epidermal Growth Factor Receptor as a Novel Target in Pancreatic Cancer Therapy

“…HPDE was chosen as control because of concerns regarding the ductal epithelial origin of HPNE cells. 12,14 Briefly, HPDE was grown in a medium containing naturally abundant isotopic forms of amino acids with 12 C and P196 was grown in a medium containing heavy 13 C-labeled arginine and lysine. Cell lysates from HPDE and P196 were then mixed and tyrosine phosphoproteins were immunoprecipitated using phosphotyrosine specific antibodies.…”