Cadmium Promotes Cancer by Inhibiting DNA Repair

Researchers have found that cadmium promotes the development of cancer by inhibiting the ability of cells to repair routine errors made when the DNA is copied to make new cells.

Cadmium is a naturally occurring element, found in all soils and rocks, including coal and fertilizers. It is used in metal coatings and plastics and batteries, partly because it does not corrode easily. People are exposed to cadmium from breathing cigarette smoke, drinking contaminated water, or eating foods that contain it.

Investigators at the National Institute of Environmental Health Sciences (NIEHS, Research Triangle Park, NC, USA) working with a yeast model found that cadmium reduced the capacity for post-replication mismatch repair (MMR) of small misalignments and base-base mismatches. In extracts of human cells, cadmium inhibited at least one step leading to mismatch removal. Inactivation of DNA repair mechanisms causes hypermutability, a condition that encourages uncontrolled cell growth. These findings were published June 8, 2003, in the online edition of Nature Genetics.

Senior author Dr. Dmitry A. Gordenin, a NIEHS researcher, explained, "Unless cadmium is unique in its mechanism, it would seem that environmental factors may cause genetic defects and cancer not only by attacking our DNA directly but also by undermining the mechanisms by which faulty DNA replication is repaired.”





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The National Institute of Environmental Health Sciences