Targeting G-quadruplexes in gene promoters: a novel anticancer strategy?

G-quadruplexes are four-stranded DNA structures that appear to be over-represented in the promoter region of various genes, including oncogenes such asMYC and KRAS. This article discusses evidence indicating the possibility of therapeutically modulating the transcription of such genes through the targeting of G-quadruplexes with small molecules, and considers challenges and opportunities for the development of such molecules as anticancer drugs. G-quadruplexes are four-stranded DNA structures that are over-represented in gene promoter regions and are viewed as emerging therapeutic targets in oncology, as transcriptional repression of oncogenes through stabilization of these structures could be a novel anticancer strategy. Many gene promoter G-quadruplexes have physicochemical properties and structural characteristics that might make them druggable, and their structural diversity suggests that a high degree of selectivity might be possible. Here, we describe the evidence for G-quadruplexes in gene promoters and discuss their potential as therapeutic targets, as well as progress in the development of strategies to harness this potential through intervention with small-molecule ligands.