Synthesis and biological activity of 2-fluoro adenine and 6-methyl purine nucleoside analogs as prodrugs for suicide gene therapy of cancer

A novel series of 6-methylpurine nucleoside derivatives with substitutions at 5-position have been synthesised These compounds bear a 5'-heterocycle such as triazole or a imidazole with a two carbon chain, and an ether, thio ether or amine. To extend the SAR study of 2-fluoroadenine and 6-methyl purine nucleosides, their corresponding alpha-linker nucleosides with L-xylose and L-lyxose were also synthesized. All of these compounds have been evaluated for their substrate activity with E. coli PNP.

Gene therapy of cancer: activation of nucleoside prodrugs with E. coli purine nucleoside phosphorylase

During the last few years, many gene therapy strategies have been developed for various disease targets. The development of anticancer gene therapy strategies to selectively generate cytotoxic nucleoside or nucleotide analogs is an attractive goal. One such approach involves the delivery of herpes simplex virus thymidine kinase followed by the acyclic nucleoside analog ganciclovir. We have developed another gene therapy methodology for the treatment of cancer that has several significant attributes. Specifically, our approach involves the delivery of E. coli purine nucleoside phosphorylase, followed by treatment with a relatively non-toxic nucleoside prodrug that is cleaved by the enzyme to a toxic compound. This presentation describes the concept, details our search for suitable prodrugs, and summarizes the current biological data.