G-quadruplex (G4)-targeting telomerase inhibitor with anti-cancer efficacy in cultures and in vivo.
RHPS4 is a pentacyclic acridine compound that exerts telomerase inhibitory activity (IC50 = 330 nM by TRAP assay) via targeting telomeric DNA G-quadruplex (G4) structure, causing alteration in the telomeric architecture and telomere dysfunction. RHPS4 induces cell cycle arrest and growth inhibition in cancer cultures in vitro(% GI/culture/time = 93%/21NT/15 days, 67%/A431/12 days, 91%/GM847/15 days; 200 nM replenish twice weekly) and exhibits anti-tumor efficacy in mice in vivo (10-15 mg/kg/d iv.). RHPS4 is also reproted to target mitochondrial DNA (mtDNA) G4 structures, perturbing mitochondrial genome replication, transcription processivity, and respiratory function.
Clinical cancer research : an official journal of the American Association for Cancer Research, 14(22), 7284-7291 (2008-11-18)
The formation of G-quadruplex structures at telomeric DNA sequences blocks telomerase activity, offering an original strategy to design and develop new antitumor agents. The pentacyclic acridinium salt RHPS4 is one of the most effective and selective G4 ligands able to
This study had two goals: 1) to evaluate the biological effect of the novel pentacyclic acridine 3,11-difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium methosulfate (RHPS4) on human melanoma lines possessing long telomeres, and 2) to elucidate the relationship between G-quadruplex-based telomerase inhibitor-induced cellular effects and telomere
The Journal of clinical investigation, 117(11), 3236-3247 (2007-10-13)
Functional telomeres are required for the replicability of cancer cells. The G-rich strand of telomeric DNA can fold into a 4-stranded structure known as the G-quadruplex (G4), whose stabilization alters telomere function limiting cancer cell growth. Therefore, the G4 ligand
British journal of cancer, 96(8), 1223-1233 (2007-04-05)
The pentacyclic acridinium methosulfate salt RHPS4 induces the 3'single-stranded guanine-rich telomeric overhang to fold into a G-quadruplex structure. Stabilisation of the latter is incompatible with an attachment of telomerase to the telomere and thus G-quadruplex ligands can effectively inhibit both
The pentacyclic acridine RHPS4 is a highly potent and specific G-quadruplex (G4) ligand, which binds and stabilizes telomeric G4 leading to the block of the replication forks at telomeres and consequently to telomere dysfunctionalization. In turn, the cell recognizes unprotected