Fiche publication
Date publication
décembre 1998
Journal
Cell biology and toxicology
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BARBERI-HEYOB Muriel
,
Pr MERLIN Jean-Louis
Tous les auteurs :
Bachmann N, Barberi-Heyob M, Bour C, Parache RM, Guillemin F, Batt AM, Merlin JL
Lien Pubmed
Résumé
A tamoxifen-resistant cell line (MCF7TAM) was established from tamoxifen-sensitive MCF-7 human breast cancer cells expressing estrogen receptors. Though the resistant cell line grows in the presence of tamoxifen, estrogen receptors continue to be expressed at similar levels as in the parental cell line. However, estrogen receptors appeared to be altered in the resistant cell line since important discrepancies are observed between results obtained with ligand binding assays and immunoenzymatic assays, tending to show modifications of estrogen receptor ligand binding capacity. The intracellular distribution of tamoxifen in sensitive and resistant cell lines was investigated using fluorescence of eosin-tamoxifen ionic association. Fluorescence emission spectra of eosin, tamoxifen and eosin-tamoxifen complex (lambda(ex)=480 nm) were analyzed and the maximal fluorescence intensity found for the complex (lambda(em)=540 nm) was four times higher than that of eosin alone, while tamoxifen alone did not emit any fluorescence in this spectral range. In MCF-7 cells, tamoxifen was found to be mainly located surrounding the nucleus, although nuclear fluorescence intensity was significantly lower. No highly fluorescent granules were observed in the resistant cell lines as opposed to sensitive cells. Improvement of this fluorescence microscopy methodology could appear of interest, taking into account the complexity of tamoxifen resistance molecular pathways.
Mots clés
Adenocarcinoma, metabolism, Antineoplastic Agents, Phytogenic, chemistry, Breast Neoplasms, metabolism, Drug Resistance, Neoplasm, Eosine Yellowish-(YS), chemistry, Humans, Microscopy, Fluorescence, Spectrometry, Fluorescence, Tamoxifen, chemistry, Tumor Cells, Cultured
Référence
Cell Biol. Toxicol.. 1998 Dec;14(6):429-35
