An in-vitro assessment of the genotoxic impacts of Acid Mine Drainage in the human MCF7 cell line

Abstract

Chemical compounds and heavy metals can damage the DNA of living cells. If not repaired these DNA aberrations can initiate a cascade of biological consequences at the cellular, organ, whole animal; ultimately affecting the community and population level. Bio-assays evaluating short-term impacts of heavy metal contamination found in Acid Mine Drainage (AMD) have proven useful to screen the toxic potential within the environment. However, a more complete validation of the use of assays such as the Alkaline Comet Assay for the assessment of genotoxicity of AMD in humans is yet to be established. The single-cell gel electrophoresis assay (Comet Assay) was developed to measure both single and double stranded DNA breaks in mammalian cells. The advantages of this technique are the small sample size required, its rapidity and the possibility to discriminate between cell types regarding the degree of DNA damage or DNA repair level. The progression of cell death can be further elucidated with the detection of small fragmented DNA particles viewed as an apoptotic laddering pattern. Laddering of highly damaged cell types gives insight into the type of programmed cell death initiated and clearly establishes when degradation occurs. This study proposes the use of the above described tools as reliable detection mechanisms of genomic impairment and damage in human cell types exposed to AMD. Furthermore this study presents a novel opportunity as a first report in South Africa, to establish an eco-genotoxic profile of a human cell line exposed to both Raw and pH Neutralised AMD arising from gold and coal mining areas in South Africa.