Transport and Responsiveness to Treatment

Analysis of the Role of NTs in Sensitivity to Nucleoside Anticancer Drugs in Cultured Cell Models 

Biochemistry, Physiology, and Pharmacology of Nucleoside and Nucleobase Transporters 

The pharmacological blockade of ENT-type transport activities might increase sensitivity to nucleoside derived presumably by inhibiting efflux path ways [114—116]. Actually, sensitivity is promoted when drugs reach cells prior to the inhibition ofthe transporter function, whereas treatment of cells after exposure to NBTI results in resistance [117]. Consistent with this, in human tumoral cell lines, sequential treatment with the ENT blocker dipyridamole 2 h after their initial exposure to cytarabine increased the cytotoxicity of this nucleoside analogue and resulted in an increase in the cellular pools of cytarabine and its metabolites [118]. 

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