N6-Isopentenyladenosine: A potential therapeutic agent for a variety of epithelial cancers

Abstract

Isopentenyladenosine (i6A) is a product of isopentenyltransferases and, in mammals, occurs either bound to tRNA or as a free nucleoside. Sporadic reports have suggested an anticancer effect of i 6A, mostly on leukemia cells. The present analysis of 9 human epithelial cancer cell lines derived from different types of malignant tissue revealed complete suppression of clonogenic activity in 8 of the lines after exposure to i6A at a concentration of 10 μM. Mechanistic studies showed that i6A tumor suppressor activity is associated with inhibition of cell proliferation, a block in DNA synthesis and morphological changes. These results point to i6A and to its possible derivatives as a new potential class of wide-spectrum anticancer agents. © 2007 Wiley-Liss, Inc.