Compelling evidence suggests that formation of guanine-quadruplex (G4) can protect the
integrity of chromosome ends in eukaryotes, and regulate the activity of some gene promoters. In addition,
G4 may be a novel therapeutic target. Thus, a number of ligands have been synthesized to stabilize
G4. However, skepticism lingers over the existence of G4 in cells, as well as its biological function.
The molecule 3,6-bis(1-methyl-4-vinylpyridium) carbazole diiodide (BMVC) can be used not
only as a fluorescent probe to map endogenous and exogenous G4 in live cells, but also as therapeutic agent that arrests
cancer growth by inhibiting telomerase activity and regulating gene expression. Thus, the fluorescence of a G4 anti-cancer
agent is an invaluable tool to detect G4 in cells, investigate ligand-G4 interaction in live cells, examine the biological
function of G4, and guide the development of new fluorescent anti-cancer agents.