title: Human colon adenocarcinoma HT-29 cell: electrochemistry and nicotine stimulation.
abstract: Recently, it was demonstrated that colorectal cancer HT-29 cells can secrete epinephrine (adrenaline) in an autocrine manner to auto-stimulate cellular growth by adrenoreceptors activation, and that this secretion is enhanced by nicotine, showing an indirect relation between colorectal cancer and tobacco. The electrochemical behaviour of human colon adenocarcinoma HT-29 cells from a colorectal adenocarcinoma cell line, the hormone and neurotransmitter epinephrine, and nicotine, were investigated by cyclic voltammetry, using indium tin oxide (ITO), glassy carbon (GC) and screen printed carbon (SPC) electrodes. The oxidation of the HT-29 cells, previously grown onto ITO or SPC surfaces, followed an irreversible oxidation process that involved the formation of a main oxidation product that undergoes irreversible reduction, as in the epinephrine oxidation mechanism. The effect of nicotine stimulation of the HT-29 cells was also investigated. Nicotine, at different concentration levels 1, 2 and 15 mM, was introduced in the culture medium and an increase with incubation time, 0 to 3h and 30 min, of the HT-29 cells oxidation and reduction peaks was observed. The interaction of nicotine with the HT-29 cells stimulated the epinephrine secretion causing an increase in epinephrine release concentration, and enabling the conclusion that epinephrine and nicotine play an important role in the colorectal tumour growth.
authors.affiliation: Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal.
authors.forename: S C B
authors.initials: SC
authors.lastname: Oliveira
authors.forename: I B
authors.initials: IB
authors.lastname: Santarino
authors.forename: T A
authors.initials: TA
authors.lastname: Enache
authors.forename: C
authors.initials: C
authors.lastname: Nunes
authors.forename: J
authors.initials: J
authors.lastname: Laranjinha
authors.forename: R M
authors.initials: RM
authors.lastname: Barbosa
authors.forename: A M
authors.initials: AM
authors.lastname: Oliveira-Brett
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry* / Q000473:pathology; D002244:Carbon / Q000737:chemistry; D049109:Cell Proliferation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000737:chemistry* / Q000473:pathology; D004563:Electrochemistry; D004566:Electrodes; D004837:Epinephrine / Q000494:pharmacology*; D019073:HT29 Cells; D006801:Humans; D009538:Nicotine / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D017971:Tin Compounds / Q000737:chemistry / Q000627:therapeutic use
chemical_list: D017971:Tin Compounds; D009538:Nicotine; C109984:indium tin oxide; D002244:Carbon; D004837:Epinephrine
keywords: Carbon electrodes; Colon cancer HT-29 cells; Epinephrine; ITO electrodes; Nicotine