[The role of p38 MAPK in gastrin-induced u-PA expression in human colon cancer cells].
OBJECTIVE
To study the effect of gastrin on the mRNA and protein expression of urokinase-type plasminogen activator (u-PA) in human colon cancer cells and detect the role of p38 MAPK in this process.


METHODS
Lipofectin method was used to transfect pCR3. 1/CCK2R vector expressing gastrin receptor into a colon cancer cell line colo320. Gastrin and gastrin antagonist were used to up-regulate and down-regulate the signaling pathway, respectively. Human colon cancer colo320 cells and colo320/ CCK2,R cells were cultured and then stimulated with gastrin for different time; SB203580 was added into culture medium to prevent p38 kinase pathway before incubating with gastrin; Western blot and RT-PCR were used to examine the u-PA expression. Western blot was employed to detect p38 kinase phosphorylation.


RESULTS
Gastrin increased evidently the mRNA and protein expressions of u-PA and induced p38 kinase phosphorylation in colo320/CCK,R cells time-dependently. However, the extent of enhancement of u-PA and p38 MAPK expression in colo320 cells was much less than that in colo320/CCK2R cells. The gastrin antagonist L-365, 260 showed an effect of competitive inhibition on gastrin-induced u-PA expression and p38 kinase phosphorylation. The inhibitor SB203580 could sufficiently suppress gastrin-induced p38 kinase phosphorylation and significantly attenuate gastrin-induced u-PA mRNA and protein expressions in colo320/ CCK2 R cells in a dose-dependent manner.


CONCLUSIONS
Gastrin-gastrin receptor signal transduction pathway can obviously induce u-PA expression in human colon cancer cells via activating the phosphorylation of p38 kinase.
Ming
Mei
M
Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
Yu
Jie-ping
JP
Zhou
Yan-hong
YH
Cao
Jun
J
Song
Wen-chong
WC
Yu
Hong-gang
HG
Luo
He-sheng
HS
D001570:Benzodiazepinones / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005755:Gastrins / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005822:Genetic Vectors; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D010671:Phenylurea Compounds / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D043887:Receptor, Cholecystokinin B / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics* / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D001570:Benzodiazepinones; D005755:Gastrins; D007093:Imidazoles; D010671:Phenylurea Compounds; D011725:Pyridines; D012333:RNA, Messenger; D043887:Receptor, Cholecystokinin B; C058121:L 365260; D048051:p38 Mitogen-Activated Protein Kinases; D014568:Urokinase-Type Plasminogen Activator; C093642:SB 203580