Cell experiment:

The cell proliferation reagent WST-1 assay is performed. In brief, cells are seeded at various densities, depending on cell type (0.25-4 × 103 cells/well in 100 μL complete medium), in 96-well culture plates and treated with various concentrations (0.1-20 μM) of 360A or the corresponding concentrations of DMSO (control wells) for 3 or 7 days at 37℃ in an atmosphere containing 5% CO2. For 7-day assays, the medium is changed on day 3. Experiments are performed in triplicate[1].

360A is a 2,6-pyridine-dicarboxamide derivative displaying strong affinity and selectivity for G-quadruplex structures and selective telomerase inhibition in vitro assays. 360A is a G-quadruplex ligand, which can influence the consequence of G-quadruplex formation and/or stabilization. in vitro: We found a S-phase accumulation in ATM-proficient, but not in ATM-deficient EBV-lymphocytes treated with 360A before induction of cell death. However, ATM status did not modify cell cycle distribution in 360A-treated SV40-fibroblasts and HeLa cells compared to DMSO treated controls [1]. DNA-PKcs-dependent NHEJ was responsible for sister telomere fusions as a direct consequence of G-quadruplex formation and/or stabilization induced by 360A on parental telomere G strands. NHEJ and HR activation at telomeres altered mitotic progression in treated cells [2]. This compound was shown to display a potent affinity and selectivity for telomeric G-quadruplex DNA over duplex DNA and to induce delayed growth inhibition in HT1080 tumor cell line [3]