G-quadruplex (G-四联体)

G-Quadruplex nucleic acids or G-quadruplexes (G4s) are four-stranded DNA or RNA secondary structures that are formed in guanine-rich sequences. They are widely distributed in functional regions of the human genome, such as telomeres, ribosomal DNA (rDNA), transcription start sites, promoter regions and untranslated regions of mRNA, suggesting that G-quadruplex structures may play a pivotal role in the control of a variety of cellular processes. In addition, G4s are enriched and conserved in the regulatory regions of microbes, including bacteria, fungi, and viruses.

The irregular formation of G4s on some genes might cause neurodegenerative diseases and cancers. Therefore, G4s in the genome are the therapeutic targets of these diseases. Small molecules, from naturally occurring to synthetic, are exploited to specifically target G-quadruplexes and have proven to be a new class of anticancer agents.