Direct evidence of mitochondrial G-quadruplex DNA by using fluorescent anti-cancer agents.
Bottom Line: In this paper, we provide the first evidence supporting the presence of G4 in the mitochondrial DNA (mtDNA) of live cells.In this study, we use fluorescence lifetime imaging microscopy to verify the existence of mtDNA G4s in live cells.Bioactivity studies indicate that interactions between these anti-cancer agents and mtDNA G4 can suppress mitochondrial gene expression.
Affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.Show MeSH
Related in: MedlinePlus
Mentions: Figure 5A presents a time-discrete FLIM image of o-BMVC-12C-P to reveal the possible existence of G4s in HeLa cancer cells and MRC-5 normal cells under the same experimental conditions. Several white spots characterized by fluorescence decay time (≥2.4 ns) were detected in the study of HeLa cancer cells (24/24), but they were not observed in MRC-5 normal cells (15/15). The absence of white spots in the normal cells can be explained by relatively far lower uptake of o-BMVC-12C-P in the mitochondria of MRC-5 normal cells. This is because the o-BMVC-12C-P localizes primarily in the lysosome of normal cells. Nevertheless, the detection of the white spots in cancer cells supports the existence of G4s in cancer cells, which is very likely contributed by mtDNA G4s.
Affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.