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Background/objectives: Pancreatic ductal adenocarcinoma (PDAC) is characterized by excessive desmoplasia and autophagy-dependent tumorigenic growth. Pancreatic stellate cells (PSCs) as a predominant stromal cell type play a critical role in PDAC biology. We have previously reported that autophagy facilitates PSC activation, however, the mechanism remains unknown. We investigated the mechanism of autophagy in PSC activation., Methods: We compared gene expression profiles between patient-derived PSCs from pancreatic cancer and chronic pancreatitis using a microarray. The stromal expression of target gene in specimen of PDAC patients (n = 63) was analyzed. The effect of target gene on autophagy and activation of PSCs was investigated by small interfering RNAs transfection, and the relationship between autophagy and ER stress was investigated. We analyzed the growth and fibrosis of xenografted tumor by orthotopic models., Results: In analysis of gene expression microarray, endoplasmic reticulum aminopeptidase 2 (ERAP2) upregulated in cancer-associated PSCs was identified as the target gene. High stromal ERAP2 expression is associated with a poor prognosis of PDAC patients. Knockdown of ERAP2 inhibited unfolded protein response mediated autophagy, and led to inactivation of PSCs, thereby attenuating tumor-stromal interactions by inhibiting production of IL-6 and fibronectin. In vivo, the promoting effect of PSCs on xenografted tumor growth and fibrosis was inhibited by ERAP2 knockdown., Conclusions: Our findings demonstrate a novel mechanism of PSCs activation regulated by autophagy. ERAP2 as a promising therapeutic target may provide a novel strategy for the treatment of PDAC., Competing Interests: Declaration of competing interest The authors have no conflict of interest., (Copyright © 2021 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Objectives: CD105 expression correlates with prognosis for several cancers. However, its significance in pancreatic cancer is unclear., Methods: We analyzed CD105 expression in resected pancreatic cancer tissue and pancreatic cancer cell lines, compared the properties of CD105(+) and CD105(-) cells using quantitative RT-PCR and migration assays, and evaluated the relationship between CD105(+) cells and pancreatic stellate cells (PSCs)., Results: Immunohistochemistry showed that the frequency of CD105 expression was higher in pancreatic cancer than that in normal tissue(8% vs 0%, respectively). In flow cytometry, CD105 was expressed in pancreatic cancer cells, whereas weak CD105 expression was detected in normal pancreatic ductal epithelial cells. Quantitative RT-PCR showed that E-cadherin mRNA expression was suppressed and vimentin mRNA was overexpressed in CD105(+) cells (P < 0.05). Migration of CD105(+) cancer cells was strongly enhanced (more than that of CD105(+) cells) in coculture with PSCs (P < 0.05). CD105 expression did not correlate to clinicopathologic characteristics or the Kaplan-Meier survival analysis., Conclusions: Suppression of an epithelial marker and over expression of a mesenchymal marker suggest that epithelial-mesenchymal transition is induced in CD105(+) pancreatic cancer cells. CD105(+) pancreatic cancer cell migration is strongly enhanced by PSCs, suggesting that these cells play a role in the pancreatic cancer microenvironment.

Background: Pancreatic cancer (PC), a hypovascular tumor, thrives under hypoxic conditions. Pancreatic stellate cells (PSCs) promote PC progression by secreting soluble factors, but their functions in hypoxia are poorly understood. This study aimed to clarify the effects of hypoxic conditions on the interaction between PC cells and PSCs., Methods: We isolated human PSCs from fresh pancreatic ductal adenocarcinomas and analyzed functional differences in PSCs between normoxia (21% O2) and hypoxia (1% O2), including expression of various factors related to tumor-stromal interactions. We particularly analyzed effects on PC invasiveness of an overexpressed molecule-connective tissue growth factor (CTGF)-in PSCs under hypoxic conditions, using RNA interference techniques., Results: Conditioned media from hypoxic PSCs enhanced PC cell invasiveness more intensely than that from normoxic PSCs (P < 0.01). When co-cultured with PSCs, PC cell invasion was more enhanced under hypoxia than under normoxia (P < 0.05). Among various soluble factors, which were related to invasiveness, CTGF was one of the overexpressed molecules in hypoxic PSCs. A higher level of CTGF expression was also found in supernatant of hypoxic PSCs than in supernatant of normoxic PSCs. PC cell invasiveness was reduced by CTGF knockdown in hypoxic PSCs co-cultured with PC cells (P < 0.05)., Conclusion: Hypoxia induces PSCs' secretion of CTGF, leading to enhancement of PC invasiveness. CTGF derived from hypoxia-stimulated PSCs may be a new therapeutic target for pancreatic cancer., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Pancreatic stellate cells (PSC), which are implicated in desmoplasia in pancreatic cancer, enhance the malignancy of cancer cells and confer resistance to established treatments. We investigated whether the antifibrotic agent pirfenidone can suppress desmoplasia and exert antitumor effects against pancreatic cancer. Primary PSCs were established from pancreatic cancer tissue obtained during surgery. In vitro, pirfenidone inhibited the proliferation, invasiveness, and migration of PSCs in a dose-dependent manner. Although supernatants of untreated PSCs increased the proliferation, invasiveness, and migration of pancreatic cancer cells (PCC), supernatants of pirfenidone-treated PSCs decreased these effects. Exposure to PCC supernatant increased the production of platelet-derived growth factor-A, hepatic growth factor, collagen type I, fibronectin, and periostin in PSCs, which was significantly reduced by pirfenidone. Mice were subcutaneously implanted with PCCs (SUIT-2 cells) and PSCs into the right flank and PCCs alone into the left flank. Oral administration of pirfenidone to these mice significantly reduced tumor growth of co-implanted PCCs and PSCs, but not of PCCs alone. Pirfenidone also decreased the proliferation of PSCs and the deposition of collagen type I and periostin in tumors. In mice with orthotopic tumors consisting of PCCs co-implanted with PSCs, pirfenidone suppressed tumor growth, reduced the number of peritoneal disseminated nodules, and reduced the incidence of liver metastasis. Pirfenidone in combination with gemcitabine more effectively suppressed orthotopic tumor growth compared with pirfenidone or gemcitabine alone. In conclusion, our findings indicate that pirfenidone is a promising antitumor agent for pancreatic cancer, owing to its suppression of desmoplasia through regulating PSCs., (©2013 AACR.)

Pancreatic stellate cells (PSCs) play a crucial role in the aggressive behavior of pancreatic cancer. Although heterogeneity of PSCs has been identified, the functional differences remain unclear. We characterized CD271⁺ PSCs in human pancreatic cancer. Immunohistochemistry for CD271 was performed for 31 normal pancreatic tissues and 105 pancreatic ductal adenocarcinomas (PDACs). We performed flow cytometry and quantitative RT-PCR, and assessed CD271 expression in PSCs isolated from pancreatic tissues and the changes in CD271 expression in PSCs cocultured with cancer cells. We also investigated the pattern of CD271 expression in a SCID mouse xenograft model. In the immunohistochemical analyses, the CD271-high staining rates in pancreatic stroma in normal pancreatic tissues and PDACs were 2/31 (6.5%) and 29/105 (27.6%), respectively (p = 0.0069). In PDACs, CD271⁺ stromal cells were frequently observed on the edge rather than the center of the tumors. Stromal CD271 high expression was associated with a good prognosis (p = 0.0040). Flow cytometric analyses demonstrated CD271-positive rates in PSCs were 0-2.1%. Quantitative RT-PCR analyses revealed that CD271 mRNA expression was increased in PSCs after coculture with pancreatic cancer cells. However, the level of CD271 mRNA expression subsequently decreased after the transient increase. Furthermore, CD271 mRNA expression was decreased in PSCs migrating toward pancreatic cancer cells through Matrigel. In the xenograft model, CD271⁺ PSCs were present at tumor margins/periphery and were absent in the tumor core. In conclusion, CD271 was expressed in PSCs around pancreatic tumors, but not in the center of the tumors, and expression decreased after long coculture with pancreatic cancer cells or after movement toward pancreatic cancer cells. These findings suggest that CD271⁺ PSCs appear at the early stage of pancreatic carcinogenesis and that CD271 expression is significantly correlated with a better prognosis in patients with PDAC.

Pancreatic cancer cells (PCCs) are surrounded by an abundant stroma, which is produced by pancreatic stellate cells (PSCs). PSCs promote tumor cell proliferation and invasion. The objective of the current study was to identify compounds that suppress PSC activation. Gene expression profiles of cancer-derived fibroblasts and normal fibroblasts were used, and the pathway analysis suggested altered pathways that were chosen for validation. It was found that the 'neuroactive ligand-receptor interaction' pathway from the Kyoto Encyclopedia of Genes and Genomes pathway analysis was one of the altered pathways. Several compounds related with this pathway were chosen, and changes in PSC activity were investigated using fluorescence staining of lipid droplets, reverse transcription-quantitative PCR, western blotting, and invasion and migration assays. Among these candidates, duloxetine, a serotonin-noradrenaline reuptake inhibitor, was found to suppress PSC activation and disrupt tumor-stromal interaction. Thus, duloxetine may be a potential drug for suppressing PSC activation and pancreatic cancer growth. [ABSTRACT FROM AUTHOR]

Background & Aims: Pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer by producing extracellular matrix and soluble factors. However, the functional heterogeneity of PSCs has not been identified until now. Detailed characterization of the PSCs in human pancreatic cancer would provide a set of potential targets for stroma-directed therapy. Methods: We isolated PSCs from fresh pancreatic ductal adenocarcinoma tissue and sorted them by flow cytometry according to cell surface expression of CD10, which is a stromal prognostic marker for various tumors. We analyzed the functional differences between CD10+ PSCs and CD10− PSCs. Results: Immunohistochemical analysis showed that the frequency of CD10 expression by PSCs was markedly higher in tumor tissue than in normal tissue (33.7% vs 0%, respectively, P = .028). In pancreatic ductal adenocarcinoma, CD10 expression by PSCs was associated with positive nodal metastases (P = .011) and a shorter survival time (P < .001). In vitro coculture experiments showed that CD10+ PSCs promoted the invasiveness of pancreatic cancer cell lines, SUIT-2 and Panc-1 cells more intensively than CD10− PSCs. CD10+ PSCs significantly increased the tumor growth and invasiveness of SUIT-2 cells in a murine cotransplantation model. CD10+ PSCs secreted higher levels of matrix metalloproteinase 3 than CD10− PSCs, and knockdown of matrix metalloproteinase 3 in cocultured PSCs reduced the invasion of SUIT-2 and Panc-1 cells. Conclusions: CD10+ PSCs enhance the progression of pancreatic cancer cells. CD10+ PSCs may be a candidate for selective therapeutic targeting in the treatment of pancreatic cancer. [Copyright &y& Elsevier]