Protease-activated receptor-2 expression and the role of trypsin in cell proliferation in human pancreatic cancers.
Protease-activated receptor (PAR)-2 is a G protein-coupled receptor that is activated by trypsin. The purpose of this study was to examine PAR-2 expression and the role of trypsin in cell proliferation in human pancreatic cancer cells. All four pancreatic cancer cell lines studied, from well to undifferentiated types, AsPC-1, BxPC-3, Panc-1, and MIAPaCa-2, had significant levels of PAR-2 mRNA detected by reverse transcription-polymerase chain reaction, and showed a band of about 55 kDa corresponding to the known molecular weight of PAR-2: AsPC-1, BxPC-3 and Panc-1 showed a strong band, and MIAPaCa-2 showed a weak one. Immunocytochemically, AsPC-1, BxPC-3, and Panc-1 showed intense immunostaining for PAR-2, predominantly in the plasma membrane, while in MIAPaCa-2, immunostaining was weak. Proliferative activity of AsPC-1 cells was increased by concentrations of trypsin as low as 10 nM, and activity peaked at a concentration of 100 nM, representing almost 60% of that induced by 10% fetal bovine serum. In contrast, trypsin had no significant effect on proliferation of MIAPaCa-2 cells. These findings suggest that trypsin plays a role in the growth of PAR-2-positive pancreatic cancer cells and serves as a potent mitogen in vitro, functioning as a growth factor.
Ohta
Tetsuo
T
Department of Gastroenterologic Surgery, Kanazawa University Hospital, Takara-machi 13-1, Kanazawa 920-0934, Japan. ohtat@surg2.m.kanazawa-u.ac.jp
Shimizu
Koichi
K
Yi
Shuangqin
S
Takamura
Hiroyuki
H
Amaya
Kohji
K
Kitagawa
Hirohisa
H
Kayahara
Masato
M
Ninomiya
Itasu
I
Fushida
Sachio
S
Fujimura
Takashi
T
Nishimura
Gen-Ichi
G
Miwa
Koichi
K
D015153:Blotting, Western; D002455:Cell Division; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008934:Mitogens / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D044464:Receptor, PAR-2 / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014357:Trypsin / Q000502:physiology*
D006133:Growth Substances; D008934:Mitogens; D012333:RNA, Messenger; D044464:Receptor, PAR-2; D014357:Trypsin