ATP Stimulates the PI3K/Akt Signaling Pathway in Osteoblastic and Breast Cancer Cells

SCODELARO BILBAO, PAOLA GABRIELA; KATZ SEBASTIÁN,; BOLAND, RICARDO; SANTILLÁN, GRACIELA

Villa Carlos Paz, Córdoba, Argentina

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2008

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

It is well established that extracellular nucleotides, acting through P2 receptors, elicit a wide range of responses in many cell types. In the present work we studied the effect of ATP on the PI3K/Akt signaling pathway in rat osteosarcoma ROS-A 17/2.8 osteoblasts and human breast cancer MCF-7 cells. Western blot analysis showed that ATP rapidly (5 min) stimulated the phosphorylation of the serine/threonine kinase Akt in a dose- and time-dependent manner. Moreover, the use of ATPgS, UTP, ADP and ADPbS and RT-PCR studies suggested the involvement of the P2Y2 receptor subtype in the phosphorylation of Akt. In both systems, the use of Ly294002, a PI3K inhibitor, suppressed the phosphorylation of Akt at Ser 473 in response to ATP. We established that ATP stimulated the phosphorylation of Src at Tyr 416 in ROS-A 17/2.8 osteoblast-like and MCF-7 breast cancer cells. Immunocytochemistry studies showed that ATP induced the translocation of Src from cytoplasm to nucleus. In addition, the use of PP1/PP2, Src inhibitors, suppressed the effect of ATP on Akt phosphorylation. The results obtained suggest that ATP leads to the phosphorylation of Akt in a PI3K- and Src- dependent manner through P2Y2 receptors in both cell lines. These data may underly mechanisms involved in the regulation of proliferation and apoptosis in cancer cells by extracellular ATP.