Fig. 2

Adenosine induced cytotoxicity in ovarian cancer. Adenosine generated by the presence of ectonucleotidases CD39 and CD73 activate the adenosine receptors in tumour cells. Nucleoside transporter transports this extracellular adenosine into the cell. Inside, the cell adenosine promotes apoptosis through the caspase-3-dependent pathway. Adenosine downregulates the expression of the anti-apoptotic protein Bcl-2 and G1phase cyclin D1 and CDK4 and also, it induce the expression of pro-apoptotic Bax protein. Adenosine inhibits the cell growth by the AMPK-dependent pathway. Adenosine kinase phosphorylate the adenosine and converted into AMP results in the phosphorylation of AMPK by the upstream kinase LKB1. Activation of AMPK results in the inhibition of growth stimulatory mTOR pathway and also by decreased phosphorylation of S6K. Reduced pS6K leads to the inhibition of cell growth arrest and proliferation