1. In vitro assays predictive of telomerase inhibitory effect of G-quadruplex ligands in cell nuclei.
- Author
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Yaku H, Murashima T, Miyoshi D, and Sugimoto N
- Subjects
- Cell Proliferation drug effects, DNA metabolism, Enzyme Inhibitors pharmacology, HeLa Cells, Humans, Indoles pharmacology, Ligands, Mitosis Modulators pharmacology, Models, Biological, Organometallic Compounds pharmacology, Polyethylene Glycols metabolism, Porphyrins metabolism, Static Electricity, Telomerase antagonists & inhibitors, Telomere metabolism, Cell Nucleus metabolism, G-Quadruplexes, Telomerase metabolism
- Abstract
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 (Ka = 3.6 × 10(6) 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 Ka and IC50 values of an anionic copper phthalocyanine (Cu-APC) under the diluted (2.8 × 10(4) M(-1) and 0.86 μM) and the cell nuclei-mimicking (2.8 × 10(4) 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.
- Published
- 2014
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