A fluorescent guanosine dinucleoside as a selective switch-on sensor for c-myc G-quadruplex DNA with potent anticancer activities.

Like likes like! A novel fluorescent C2 -symmetric guanosine-based dinucleoside has been engineered by chemical ligation of two guanosine units with a biocompatible dansyl tag. The nucleoside exhibits high selectivity for c-myc G-quadruplex DNA through fluorescence enhancement over duplex DNA and other promoter G-quadruplexes (see scheme). It stains the nucleus preferentially, arrests the cell cycle at the G2/M phase, inhibits cell growth, and induces apoptosis in A375 cancer cells.