title: Autocrine extra-pancreatic trypsin 3 secretion promotes cell proliferation and survival in esophageal adenocarcinoma.
abstract: Trypsin or Tumor associated trypsin (TAT) activation of Protease-activated receptor 2 (PAR-2) promotes tumor cell proliferation in gastrointestinal cancers. The role of the trypsin/PAR-2 network in esophageal adenocarcinoma (EA) development has not yet been investigated. The aim of this study is to investigate the role of trypsin/PAR-2 activation in EA tumorogenesis and therapy. We found that esophageal adenocarcinoma cells (EACs) and Barrett's Metaplasia (BART) expressed high levels of type 3 extra-pancreatic trypsinogen (PRSS3), a novel type of TAT. Activity of secreted trypsin was detected in cultured media from EA OE19 and OE33 cultures but not from BART culture. Surface PAR-2 expression in BART and EACs was confirmed by both flow cytometry and immunofluorescence. Trypsin induced cell proliferation (~ 2 fold; P<0.01) in all tested cell lines at a concentration of 10 nM. Inhibition of PAR-2 activity in EACs via the PAR-2 antagonist ENMD (500 µM), anti-PAR2 antibody SAM-11 (2 µg/ml), or siRNA PAR-2 knockdown, reduced cell proliferation and increased apoptosis by up to 4 fold (P<0.01). Trypsin stimulation led to phosphorylation of ERK1/2, suggesting involvement of MAPK pathway in PAR-2 signal transduction. Inhibition of PAR-2 activation or siRNA PAR-2 knockdown in EACs prior to treatment with 5 FU reduced cell viability of EACs by an additional 30% (P<0.01) compared to chemotherapy alone. Our data suggest that extra-pancreatic trypsinogen 3 is produced by EACs and activates PAR-2 in an autocrine manner. PAR-2 activation increases cancer cell proliferation, and promotes cancer cell survival. Targeting the trypsin activated PAR-2 pathway in conjunction with current chemotherapeutic agents may be a viable therapeutic strategy in EA.
authors.affiliation: Department of Surgery, University of Florida College of Medicine, Gainesville, Florida, United States of America.
authors.forename: Song
authors.initials: S
authors.lastname: Han
authors.forename: Constance W
authors.initials: CW
authors.lastname: Lee
authors.forename: Jose G
authors.initials: JG
authors.lastname: Trevino
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Hughes
authors.forename: George A
authors.initials: GA
authors.lastname: Sarosi
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D017209:Apoptosis / Q000187:drug effects; D019898:Autocrine Communication / Q000187:drug effects; D001471:Barrett Esophagus / Q000473:pathology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D004938:Esophageal Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D010179:Pancreas / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D044464:Receptor, PAR-2 / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism*
chemical_list: D044464:Receptor, PAR-2; D048049:Extracellular Signal-Regulated MAP Kinases; C040749:PRSS3 protein, human; D014357:Trypsin; D005472:Fluorouracil