Figure 2.

Formation of G-quadruplexes impacting physiological processes, with anticancer consequences: (A) G-quadruplexes in the telomere impose hindrance to telomerase, preventing elongation of the telomere and triggering DNA damage response signals. (B) G-quadruplex in oncogene-promoter region dislocates transcription factors and down-regulates RNA polymerase-mediated transcription of (onco)genes. (C) G-quadruplex in DNA undergoing replication stalls replication fork progression and leads to replicative stress, resulting in double strand breakpoints. (D) G-quadruplex in mRNA interferes with translation and formation of cancer proteins.