In Vitro Assays Predictive of Telomerase Inhibitory Effect of G‑Quadruplex Ligands in Cell Nuclei

• Published in: The journal of physical chemistry. B Vol. 118; no. 10; pp. 2605 - 2614
• Main Authors: Yaku, Hidenobu, Murashima, Takashi, Miyoshi, Daisuke, Sugimoto, Naoki
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 13-03-2014
• Subjects: Antiproliferatives; Cationic; Cell Nucleus - metabolism; Cell Proliferation - drug effects; Copper; Deoxyribonucleic acid; Dilution; DNA - metabolism; Enzyme Inhibitors - pharmacology; G-Quadruplexes; HeLa Cells; Humans; Indoles - pharmacology; Ligands; Mitosis Modulators - pharmacology; Models, Biological; Organometallic Compounds - pharmacology; Polyethylene Glycols - metabolism; Porphyrins - metabolism; Side effects; Static Electricity; Telomerase; Telomerase - antagonists & inhibitors; Telomerase - metabolism; Telomere - metabolism
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp410669t

G-quadruplex-binding and telomerase-inhibiting capacities of G-quadruplex ligands were examined under a cell nuclei-mimicking condition including excess double-stranded DNA (λ DNA) and molecular crowding cosolute (PEG 200). Under the cell nuclei-mimicking condition, a cationic porphyrin (TMPyP4) did not bind to the G-quadruplex despite the high affinity (K a = 3.6 × 106 M–1) under a diluted condition without λ DNA and PEG 200. Correspondingly, TMPyP4 inhibited telomerase activity under the diluted condition (IC50 = 1.6 μM) but not under the cell nuclei-mimicking condition. In contrast, the K a and IC50 values of an anionic copper phthalocyanine (Cu-APC) under the diluted (2.8 × 104 M–1 and 0.86 μM) and the cell nuclei-mimicking (2.8 × 104 M–1 and 2.1 μM) conditions were similar. In accordance with these results, 10 μM TMPyP4 did not affect the proliferation of HeLa cells, while Cu-APC efficiently inhibited the proliferation (IC50 = 1.4 μM). These results show that the cell nuclei-mimicking condition is effective to predict capacities of G-quadruplex ligands in the cell. In addition, the antiproliferative effect of Cu-APC on normal cells was smaller than that on HeLa cells, indicating that the cell nuclei-mimicking condition is also useful to predict side effects of ligands.