IQUIFIB   02644
INSTITUTO DE QUIMICA Y FISICOQUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Thallium alters cyclins expression in rat pheochromocytoma (PC12) cells. Modulatory effects of EGF.
Autor/es:
PINO, M. T. L.; VERSTRAETEN, S. V.
Lugar:
Puerto Madryn, Chubut
Reunión:
Congreso; XLVI Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2010
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.
Resumen:
The mechanisms underlying the toxicity of the heavy metal thallium (Tl) are not elucidated yet. Previously, we demonstrated that Tl(I) and Tl(III) (5-100 uM) altered cell cycle progression inPC12 cells, effect that was modulated by the epidermal growth factor (EGF). We next investigated in synchronized PC12 cells, the effects of Tl(I) and Tl(III) on the expression of the major cyclinsthat regulate cell cycle. All the experiments were performed after 24 h of reentering into cell cycle (when cells were mostly in S phase) with or without Tl and/or EGF. EGF did not prevent thedecrease in cell viability due to Tl. In the absence of EGF, Tl(I) increased cyclin D1 content, without affecting cyclins A or B1. Tl(III) increased cyclin B1 expression, and did not affect cyclins A and D1. On the other hand, in the presence of EGF, Tl(I) slightly increased cyclins D1 and B1 contents, while Tl(III) markedly increased cyclins D1, decreased cyclin A, and did not affect cyclinB1. Interestingly, only in the presence of EGF both Tl(I) and Tl(III) increased H2O2 production that also could affect cell cycle progression. Together the experimental evidence suggest that both Tl(I) and Tl(III) affect cell cycle progression, effect that could partially account for the cytotoxic effects of these cations. Supported by grants of UBA (B086), CONICET (PIP 112-200801-01977), and ANPCyT (PICT 32273), Argentina.