The role of ROS toxicity in spontaneous aneuploidy in cultured cells.

It is well known that the karyotype of animal cells cultured in vitro tends to become aneuploid as the culture ages. Aneuploidy can cause genetic instability, alter the biological properties of cells, and affect their application in genetic studies and cell engineering. Understanding the causes and mechanisms of aneuploidy is primary to control its occurrence in cultured cells, and is also helpful to understand the mechanisms of tumorigenesis because aneuploidy is a hallmark of tumor cells. This review underscores the potential role of reactive oxygen species (ROS) toxicity in spontaneous aneuploidy of cultured cells. The underlying mechanisms and possible sources of ROS are also discussed.

Somatic mtDNA mutations in lung tissues of pesticide-exposed fruit growers.

Some pesticides have been considered potential chemical mutagens and their widespread use involves the assessment of their potentially hazardous effects. The mitochondrial genome is especially prone to DNA damage and thus can serve as a biomarker to monitor the genotoxicity of pesticides to human DNA. We performed a screening for somatic mutations in lung tissues from pesticide-exposed fruit growers, by direct comparing the entire mtDNA sequences of the lung tissue and the matched peripheral blood from the same individual. A phylogenetic approach and a high standard procedure were utilized to avoid potential errors in data generation and analysis. We observed a significantly increased frequency of mtDNA somatic mutations in lung tissues which had been exposed to pesticides multiple times by inhalation, and the potential biological significance of these mutations was further discussed. The samples represented in this observational study, which has multiple exposures to pesticides, experience a significant greater incidence of mtDNA mutations, suggesting that multiple exposures to pesticides could damage human mtDNA and cause somatic mutations.