Assessment of the Mutation of Pig-A Gene as Biomarker of Genotoxic Exposure in Humans

The evaluation of the impact of environment on the incidence of cancer is a major public health issue. Increased knowledge in this area is necessary for the implementation of primary prevention means with appropriate preventive measures but also to the implementation of secondary prevention measures with targeted screening actions.

Among the environmental exposures that may lead to cancer, mutagenic environments are of major importance, and the causal link between environmental genotoxicity and cancer has been established for a long time. It is also well established that susceptibility to mutation is highly variable among individuals. This is explained by genetic polymorphisms of genes involved in metabolism and in genome stability.

The identification of biomarkers of exposure to mutagenic environments is necessary for assessing the impact of an environment in humans. Some studies in animals have shown that the PIG-A gene may be a biomarker of exposure to a mutagenic environment. In particular, a significant increase in erythrocyte PIG-A mutants has been demonstrated in rats after a genotoxic exposure to cisplatin, but it has so far not been evaluated in humans. One study of healthy volunteers shows that the frequency of PIG-A mutated cells in humans can be estimated efficiently and reliably.

The PIG-A gene meets all the necessary criteria for a sentinel gene for tracking of spontaneous somatic mutation frequency or induced a mutagenic environment: ubiquitous expression, phenotypic change linked to a mono-allelic mutation viability of mutated cells , spectrum off inactivating mutations (deletions, substitutions, chromosomal rearrangements). Finally, the detection of the disappearance of glycosylphosphatidylinositol on the plasma membrane is easily achievable by flow cytometry.