?-Conotoxins Enhance both the In Vivo Suppression of Ehrlich carcinoma Growth and In Vitro Reduction in Cell Viability Elicited by Cyclooxygenase and Lipoxygenase Inhibitors.
Ontology highlight
ABSTRACT: Several biochemical mechanisms, including the arachidonic acid cascade and activation of nicotinic acetylcholine receptors (nAChRs), are involved in increased tumor survival. Combined application of inhibitors acting on these two pathways may result in a more pronounced antitumor effect. Here, we show that baicalein (selective 12-lipoxygenase inhibitor), nordihydroguaiaretic acid (non-selective lipoxygenase inhibitor), and indomethacin (non-selective cyclooxygenase inhibitor) are cytotoxic to Ehrlich carcinoma cells in vitro. Marine snail ?-conotoxins PnIA, RgIA and ArIB11L16D, blockers of ?3?2/?6?2, ?9?10 and ?7 nAChR subtypes, respectively, as well as ?-cobratoxin, a blocker of ?7 and muscle subtype nAChRs, exhibit low cytotoxicity, but enhance the antitumor effect of baicalein 1.4-fold after 24 h and that of nordihydroguaiaretic acid 1.8-3.9-fold after 48 h of cell cultivation. ?-Conotoxin MII, a blocker of ?6-containing and ?3?2 nAChR subtypes, increases the cytotoxic effect of indomethacin 1.9-fold after 48 h of cultivation. In vivo, baicalein, ?-conotoxins MII and PnIA inhibit Ehrlich carcinoma growth and increase mouse survival; these effects are greatly enhanced by the combined application of ?-conotoxin MII with indomethacin or conotoxin PnIA with baicalein. Thus, we show, for the first time, antitumor synergism of ?-conotoxins and arachidonic acid cascade inhibitors.
SUBMITTER: Osipov AV
PROVIDER: S-EPMC7230841 | biostudies-literature | 2020 Apr
REPOSITORIES: biostudies-literature
ACCESS DATA