Benzo( a)pyrene, but not 2,3,7,8-tetrachlorodibenzo- p-dioxin, alters cell adhesion proteins in human uterine RL95-2 cells

• Published in: Biochemical and biophysical research communications 2002-05, Vol.294 (1), p.101-107
• Main Authors: McGarry, Michelle A, Charles, Grantley D, Medrano, Theresa, Bubb, Michael R, Grant, Maria B, Campbell-Thompson, Martha, Shiverick, Kathleen T
• Format: Article
• Language: English
• Subjects: Actins - drug effects; Actins - metabolism; Adhesion; Attachment; BaP; Benzo(a)pyrene - pharmacology; beta Catenin; Blotting, Western; Cadherin; Cadherins - metabolism; Cell Adhesion - drug effects; Cell Adhesion Molecules - drug effects; Cell Adhesion Molecules - metabolism; Cell Line; Cell Membrane - drug effects; Cell Membrane - metabolism; Cytoskeletal Proteins - metabolism; Cytoskeleton; Dimethyl Sulfoxide - pharmacology; EGF-R; Endometrium - drug effects; Endometrium - metabolism; Female; Human uterine endometrium; Humans; Phalloidine - metabolism; Polychlorinated Dibenzodioxins - pharmacology; Receptor, Epidermal Growth Factor - metabolism; Receptors, Aryl Hydrocarbon - agonists; TCDD; Trans-Activators; Uterus - drug effects; Uterus - metabolism; Vinculin - metabolism; β-catenin
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(02)00437-0

This study compared the effects of benzo( a)pyrene (BaP) and 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD), two aryl hydrocarbon receptor agonists, on cell attachment and adherens junction proteins in RL95-2 human uterine endometrial cells. Exposure to 10 μ M BaP significantly decreased cell attachment to Matrigel, whereas 10 nM TCDD had no effect. Immunocytochemistry and Western immunoblot analysis showed that BaP, but not TCDD, produced a marked loss of plasma membrane epidermal growth factor receptor (EGF-R) localized along intercellular boundaries. BaP-treated cells exhibited significant decreases in β-catenin and cadherin protein levels, while vinculin levels remained unchanged relative to control. In contrast, TCDD treatment had no effect on the levels of β-catenin, cadherin, or vinculin. Further studies using the fluorescein labeled peptide phalloidin showed the presence of continuous subcortical actin filaments in control cells, whereas BaP-treated cells had subcortical actin aggregates. Thus, in contrast to TCDD, BaP produces a loss of cell attachment involving decreased localization of molecules important for cell–cell interactions in RL95-2 cells.