Overexpression of AMP-metabolizing enzymes controls adenine nucleotide levels and AMPK activation in HEK293T cells.

We investigated whether overexpression of AMP-metabolizing enzymes in intact cells would modulate oligomycin-induced AMPK activation. Human embryonic kidney (HEK) 293T cells were transiently transfected with increasing amounts of plasmid vectors to obtain a graded increase in overexpression of AMP-deaminase (AMPD) 1, AMPD2, and soluble 5'-nucleotidase IA (cN-IA) for measurements of AMPK activation and total intracellular adenine nucleotide levels induced by oligomycin treatment. Overexpression of AMPD1 and AMPD2 slightly decreased AMP levels and oligomycin-induced AMPK activation.

Nucleoside analogs induce proteasomal down-regulation of p21 in chronic lymphocytic leukemia cell lines.

Nucleoside analogs (NAs) represent an important class of anticancer agents that induce cell death after conversion to triphosphate derivatives. One of their most important mechanisms of action is the activation of p53, leading to apoptosis through the intrinsic pathway. Classically, the activation of p53 also induces p21 accumulation, which leads to cell cycle arrest at the G1/S transition.

Mechanisms of cell death induced by 2-chloroadenosine in leukemic B-cells.

2-chloroadenosine (2-CAdo) is an adenosine deaminase-resistant analogue of adenosine, widely used as an adenosine receptor agonist. This compound has been shown to induce apoptosis in several cell types either via activation of adenosine receptors or via intracellular metabolism. However, the molecular mechanisms of 2-CAdo-induced apoptosis are unclear.