title: Effects of adrenaline in human colon adenocarcinoma HT-29 cells.
abstract: OBJECTIVE
  Stress has been implicated in the development of cancers. Adrenaline levels are increased in response to stress. The effects of adrenaline on colon cancer are largely unknown. The aims of the study are to determine the effects of adrenaline in human colon adenocarcinoma HT-29 cells and the possible underlying mechanisms involved.
  
  
  METHODS
  The effect of adrenaline on HT-29 cell proliferation was determined by [(3)H] thymidine incorporation assay. Expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) were detected by Western blot. Matrix metalloproteinase-9 (MMP-9) activity and prostaglandin E(2) (PGE(2)) release were determined by zymography and enzyme immunoassay, respectively.
  
  
  RESULTS
  Adrenaline stimulated HT-29 cell proliferation. This was accompanied by the enhanced expression of COX-2 and VEGF in HT-29 cells. Adrenaline also upregulated MMP-9 activity and PGE(2) release. Adrenaline stimulated HT-29 cell proliferation which was reversed by COX-2 inhibitor sc-236. COX-2 inhibitor also reverted the action of adrenaline on VEGF expression and MMP-9 activity. Further study was performed to determine the involvement of β-adrenoceptors. The stimulatory action of adrenaline on colon cancer growth was blocked by atenolol and ICI 118,551, a β(1)- and β(2)-selective antagonist, respectively. This signified the role of β-adrenoceptors in this process. In addition, both antagonists also abrogated the stimulating actions of adrenaline on COX-2, VEGF expression, MMP-9 activity and PGE(2) release in HT-29 cells.
  
  
  CONCLUSIONS
  These results suggest that adrenaline stimulates cell proliferation of HT-29 cells via both β(1)- and β(2)-adrenoceptors by a COX-2 dependent pathway.
authors.affiliation: Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China.
authors.forename: Helen P S
authors.initials: HP
authors.lastname: Wong
authors.forename: Judy W C
authors.initials: JW
authors.lastname: Ho
authors.forename: Marcel W L
authors.initials: MW
authors.lastname: Koo
authors.forename: Le
authors.initials: L
authors.lastname: Yu
authors.forename: William K K
authors.initials: WK
authors.lastname: Wu
authors.forename: Emily K Y
authors.initials: EK
authors.lastname: Lam
authors.forename: Emily K K
authors.initials: EK
authors.lastname: Tai
authors.forename: Joshua K S
authors.initials: JK
authors.lastname: Ko
authors.forename: Vivian Y
authors.initials: VY
authors.lastname: Shin
authors.forename: Kent Man
authors.initials: KM
authors.lastname: Chu
authors.forename: Chi Hin
authors.initials: CH
authors.lastname: Cho
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000201:enzymology / Q000209:etiology / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000378:metabolism / Q000494:pharmacology*; D019073:HT29 Cells; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism; D013315:Stress, Psychological / Q000150:complications / Q000201:enzymology / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis
chemical_list: D000319:Adrenergic beta-Antagonists; D052246:Cyclooxygenase 2 Inhibitors; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D051546:Cyclooxygenase 2; D020780:Matrix Metalloproteinase 9; D015232:Dinoprostone; D004837:Epinephrine