Adenosine stimulation of the proliferation of colorectal carcinoma cell lines. Roles of cell density and adenosine metabolism.

摘要: Adenosine is a purine nucleoside which present at micromolar concentrations in the extracellular fluid of solid cancers as result tissue hypoxia. acts to promote tumor survival by inhibiting cell-mediated anti-tumor immune response. However, its role modulating proliferation cell population unclear. Differing results have been obtained using adenosine analogues or interfering with metabolism. We examined effect itself on DNA synthesis and growth six different human mouse colorectal carcinoma lines, from sites stages differentiation. given single dose consistently stimulated all lines tested, an EC(50) 3.8-30 microM maximum stimulation being reached 10-100 microM. AMP ATP also similar doses. The varied depending upon culture density, greatest mitogenic subconfluent densities. was metabolized cellular deaminase kinase. half-life (t(1/2)) for decline concentration medium following addition between 40 min 3 hr line conditions. rate production endogenous low under normoxic Continuous dosing cultures provide steady-state showed that could be adenosine. conclude stimulatory cells within environment.