Isaindigotone derivatives: a new class of highly selective ligands for telomeric G-quadruplex DNA.
Four isaindigotone derivatives (5a,b and 6a,b) designed as telomeric G-quadruplex ligands have been synthesized and characterized. The unfused aromatic rings in these compounds allow a flexible and adaptive conformation in G-quadruplex recognition. The interaction of human telomeric G-quadruplex DNA with these designed ligands was explored by means of FRET melting, fluorescence titration, CD spectroscopy, continuous variation, and molecular modeling studies. Our results showed that the adaptive scaffold might not only allow the ligands to well occupy the G-quartet but also perfectly bind to the grooves of the G-quadruplex. The synergetic effect of the multiple binding modes might be responsible for the improved binding ability and high selectivity of these ligands toward G-quadruplex over duplex DNA. Long-term exposure of HL60 and CA46 cancer cells to compound 5a showed a remarkable decrease in population growth, cellular senescence phenotype, and shortening of the telomere length, which is consistent with the behavior of an effective telomeric G-quadruplex ligand and telomerase inhibitor.
Tan
Jia-Heng
JH
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510080, China.
Ou
Tian-Miao
TM
Hou
Jin-Qiang
JQ
Lu
Yu-Jing
YJ
Huang
Shi-Liang
SL
Luo
Hai-Bin
HB
Wu
Jian-Yong
JY
Huang
Zhi-Shu
ZS
Wong
Kwok-Yin
KY
Gu
Lian-Quan
LQ
D000470:Alkaloids / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D000704:Analysis of Variance; D045744:Cell Line, Tumor; D016922:Cellular Senescence / Q000187:drug effects; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D054856:G-Quadruplexes; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D011799:Quinazolines / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D013379:Substrate Specificity; D019098:Telomerase / Q000037:antagonists & inhibitors; D016615:Telomere / Q000378:metabolism; D017186:Titrimetry; D044366:Transition Temperature
D000470:Alkaloids; D004791:Enzyme Inhibitors; D008024:Ligands; D011799:Quinazolines; C440668:isaindigotone; D004247:DNA; D019098:Telomerase