Cancer-stellate cell interactions perpetuate the hypoxia-fibrosis cycle in pancreatic ductal adenocarcinoma.
OBJECTIVE
Although both cancer and stellate cells (PSCs) secrete proangiogenic factors, pancreatic cancer is a scirrhous and hypoxic tumor. The impact of cancer-PSCs interactions on angiogenesis was analyzed.


METHODS
Expression of periostin, CD31, and alpha-smooth muscle actin was assessed by immunohistochemistry. Human PSCs and cancer cells were cultivated under normoxia and hypoxia alone, or in coculture, to analyze the changes in their angiogenic and fibrogenic attributes, using enzyme-linked immunosorbent assay, immunoblot, and quantitative polymerase chain reaction analyses and growth of cultured endothelial cells in vitro.


RESULTS
On the invasive front of the activated stroma, PSCs deposited a periostin-rich matrix around the capillaries in the periacinar spaces. Compared with the normal pancreas, there was a significant reduction in the microvessel density in chronic pancreatitis (five-fold, P < .001) and pancreatic cancer (four-fold, P < .01) tissues. In vitro, hypoxia increased PSCs' activity and doubled the secretion of periostin, type I collagen, fibronectin, and vascular endothelial growth factor (VEGF). Cancer cells induced VEGF secretion of PSCs (390 +/- 60%, P < .001), whereas PSCs increased the endostatin production of cancer cells (210 +/- 14%, P < .001) by matrix metalloproteinase-dependent cleavage. In vitro, PSCs increased the endothelial cell growth, whereas cancer cells alone, or their coculture with PSCs, suppressed it.


CONCLUSIONS
Although PSCs are the dominant producers of VEGF and increase endothelial cell growth in vitro, in the peritumoral stroma, they contribute to the fibrotic/hypoxic milieu through abnormal extracellular matrix deposition and by amplifying endostatin production of cancer cells.
Erkan
Mert
M
Department of General Surgery, Technische Universität München, Munich, Germany.
Reiser-Erkan
Carolin
C
Michalski
Christoph W
CW
Deucker
Stefanie
S
Sauliunaite
Danguole
D
Streit
Sylvia
S
Esposito
Irene
I
Friess
Helmut
H
Kleeff
Jörg
J
D000199:Actins; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002450:Cell Communication / Q000502:physiology*; D015687:Cell Hypoxia / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000378:metabolism* / Q000473:pathology; D005355:Fibrosis / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000378:metabolism*
D000199:Actins; D015815:Cell Adhesion Molecules; C512835:POSTN protein, human; D019408:Platelet Endothelial Cell Adhesion Molecule-1