Inhibition of pancreatic stellate cell activation by halofuginone prevents pancreatic xenograft tumor development.
OBJECTIVE
Most solid tumors consist of neoplastic and nonneoplastic cells and extracellular matrix components. In the pancreas, activated stellate cells (PSCs) are the source of the extracellular matrix proteins. We evaluated the significance of PSC activation in tumor establishment and development in mouse xenografts.


METHODS
Xenografts were established by implanting human pancreatic cancer cells (MiaPaca-2) subcutaneously or orthotopically by injecting them into the spleen. Fibrosis was induced by cerulein. Collagen level was evaluated by Sirius red staining. Prolyl 4-hydroxylase β and stellate cell activation-associated protein (Cygb/STAP) were determined by immunohistochemistry.


RESULTS
Halofuginone inhibited subcutaneous tumor development implanted with Matrigel and reduced collagen and prolyl 4-hydroxylase β levels. Few tumors, which developed slowly, were observed after MiaPaca-2 implantation without Matrigel. Increase in tumor number and rate of development were observed with addition of PSCs from control pancreas, and further increase was observed when the PSCs were from cerulein-treated mice. Preincubation of the PSCs with halofuginone elicited Cygb/STAP level reduction and tumor growth inhibition. More tumors developed orthotopically in cerulein-treated mice than in controls; this was prevented by halofuginone.


CONCLUSIONS
Extracellular matrix production by activated PSCs is essential for tumor establishment and growth. Thus, inhibition of PSC activation is a viable means of reducing pancreatic tumor development.
Spector
Itai
I
Institute of Animal Sciences, Volcani Center, Bet Dagan, Israel.
Honig
Hen
H
Kawada
Norifumi
N
Nagler
Arnon
A
Genin
Olga
O
Pines
Mark
M
D000818:Animals; D045744:Cell Line, Tumor; D005109:Extracellular Matrix / Q000502:physiology; D005355:Fibrosis; D006801:Humans; D008297:Male; D051379:Mice; D009368:Neoplasm Transplantation; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000517:prevention & control*; D058954:Pancreatic Stellate Cells / Q000187:drug effects* / Q000502:physiology; D010880:Piperidines / Q000494:pharmacology*; D052999:Quinazolinones / Q000494:pharmacology*; D014183:Transplantation, Heterologous
D010880:Piperidines; D052999:Quinazolinones; C010176:halofuginone