title: Effects of lorglumide on growth and invasion of human pancreatic cancer cell line Mia PaCa-2 in vitro through the cholecystokinin-cholecystokinin-1 receptor pathway.
abstract: BACKGROUND
  Cholecystokinin (CCK) has been found to be a growth stimulant through its special receptor pathway, especially for gastrointestinal malignancies. Although the CCK-1 receptor has been shown to be highly expressed in resected human pancreatic cancer samples, its role is less clear.
  
  
  OBJECTIVE
  The aim of this in vitro study was to investigate the CCK-1 receptor expression and the function of the CCK-CCK-1 receptor pathway in the human pancreatic adenocarcinoma cell line, Mia PaCa-2.
  
  
  METHODS
  The expression of the CCK-1 receptor in Mia PaCa-2 cells was detected by reverse-transcriptase polymerase chain reaction and flow cytometry. CCK-1 receptor agonist CCK-8S (the major transmitter form of CCK) and antagonist lorglumide were cultured respectively with Mia PaCa-2. Three groups were created for this study: CCK-8S group (Mia PaCa-2 cells treated with CCK-8S), lorglumide group (Mia PaCa-2 cells treated with lorglumide), and the control group (Mia PaCa-2 cells alone). Investigators were blinded to group designation. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry were used to detect the cell growth, cell cycle, and apoptosis. Apoptosis index rate was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling. Cell invasion ability was observed by invasion assay. Expression of matrix metalloproteinase-2 (MMP-2) was measured by Western blotting.
  
  
  RESULTS
  Mia PaCa-2 cells were found to express the CCK-1 receptor. Compared with the control group (70.2% [1.5%]), CCK-8S was associated with significant mean (SD) cell proliferation (85.1% [1.7%]; P = 0.039), and the ratio in the S stage of the cell cycle increased significantly (50.5% [1.7%] vs 42.2% [1.4%]; P = 0.021). CCK-8S was also associated with increased Mia PaCa-2 cell invasion ability (123.8 [1.7] vs 102.1 [5.8]; P = 0.005 vs control). Compared with the control group, lorglumide was associated with significantly inhibited cell growth (52.1% [1.8%]; P = 0.002) and cell invasion (77.6% [1.2%]; P = 0.003). Lorglumide also induced G0/G1 cell cycle arrest and apoptosis (27.1% [3-5%] vs 3-7% [0.6%]; P = 0.003 vs control). The change of invasion ability appeared to be mediated by MMP-2 expression, which was upregulated by CCK-8S and downregulated by lorglumide.
  
  
  CONCLUSIONS
  The findings of this in vitro study suggest that CCK may exert a trophic action on the Mia PaCa-2 cell line, while lorglumide inhibited the cell growth and invasion.
authors.affiliation: General Surgery Department, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhou
authors.affiliation: General Surgery Department, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Zi-Xiang
authors.initials: ZX
authors.lastname: Zhang
authors.affiliation: General Surgery Department, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: De-Chun
authors.initials: DC
authors.lastname: Li
keywords: CCK-1 receptor; MMP-2; apoptosis; cholecystokinin; pancreatic cancer