MAP KINASES IN PROLIFERATING HUMAN COLON CANCER CaCo-2 CELLS

NATALIA BUZZI; RICARDO BOLAND; ANA RUSSO DE BOLAND

Mar del Plata

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular. SAIB

MAP KINASES IN PROLIFERATING HUMAN COLON CANCER CaCo-2 CELLS Natalia Buzzi, Ricardo Boland and Ana Russo de Boland. Departamento de Biología, Bioquímica y Farmacia. Universidad Nacional del Sur. 8000 Bahía Blanca. nbuzzi@criba.edu.ar Cells adapt to environmental changes by monitoring and reacting quickly to extracellular stimuli. The mitogen-activated protein kinase (MAPK) cascade is one of the most ubiquitous signal transduction systems and is rapidly activated by various stimuli, such as cellular stress and death. The Caco-2 cell line is an in vitro model for colon cancer studies. We investigated the activation status of the ERK1/2, p38, JNK1/2 and ERK5 kinases and their respective upstream intracellular activators in Caco-2 cells induced to proliferate by 10% fetal bovine serum (FBS). The states of phosphorylation of the above MAPKs and their upstream kinases, MEK 1/2, MKK3/6, MKK4 and MKK7, respectively, were studied by Western blot analysis. Phosphorylation was barely detectable before serum stimulation, and the stimulation of cell proliferation by the addition of FBS increased MEK1/2 and ERK1/2 phosphorylation 2- to 3-fold after 5 min. FBS stimulated p38 and MKK3/6 to the same extent within 2 min of treatment and JNK1/2 and its upstream kinases MKK4 and MKK7 5-fold (3 min). Addition of FBS also rapidly phosphorylated ERK5 (2 - 3.5-fold between 2-5 min). Studies with pharmacological inhibitors are under progress to establish interactions and the relative role of individual MAP kinases in the regulation of Caco-2 cell proliferation.