title: Small heat shock protein hsp27 as a possible mediator of intercellular adhesion-induced drug resistance in human larynx carcinoma HEp-2 cells.
abstract: The confluence-dependent resistance of human larynx carcinoma HEp-2 cells to hydrogen peroxide and a new antitumor drug based on the combination of vitamins C and B12b was studied. It was found that this resistance in growing cells is suppressed by the disruption of intercellular contacts by EGTA and is related neither to the activity of P-glycoprotein nor to the content of intracellular glutathione and the activities of glutathione S-transferases, glutathione peroxidase and glutathionine reductase. Here we showed that the level of expression of the small heat shock protein hsp27, which is known to protect cells from a variety of stresses associated with apoptosis, in growing confluent cells both in the presence and absence of the vitamins B12b and C is much higher (about 20-25 times) than in non-confluent cells. Taken together, the results suggest that the confluence-dependent resistance of cells to the combination of vitamins C and B12b and to hydrogen peroxide is mediated by hsp27 overexpression, which is activated via cell-cell adhesion.
authors.affiliation: Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Mazurov
authors.forename: Marina E
authors.initials: ME
authors.lastname: Solovieva
authors.forename: Violetta V
authors.initials: VV
authors.lastname: Leshchenko
authors.forename: Alexey G
authors.initials: AG
authors.lastname: Kruglov
authors.forename: Eveline F
authors.initials: EF
authors.lastname: Edelweiss
authors.forename: Raisa I
authors.initials: RI
authors.lastname: Yakubovskaya
authors.forename: Vladimir S
authors.initials: VS
authors.lastname: Akatov
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D002277:Carcinoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006879:Hydroxocobalamin / Q000494:pharmacology; D007822:Laryngeal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000502:physiology*; D014407:Tumor Cells, Cultured
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D004533:Egtazic Acid; D006861:Hydrogen Peroxide; D005978:Glutathione; D001205:Ascorbic Acid; D006879:Hydroxocobalamin