XRCC3 THR241MET polymorphism influence on nuclear buds frequency in exposed to formaldehyde

Formaldehyde (FA), also known as formalin, formal and methyl aldehydes, is a colorless, flammable, strong-smelling gas. It has an important application in embalming tissues and that result in exposures for workers in the pathology anatomy laboratories and mortuaries. Occupational exposure to FA has been shown to induce nasopharyngeal cancer and has been classified as carcinogenic to humans (group 1) on the basis of sufficient evidence in humans and sufficient evidence in experimental animals. Manifold in vitro studies clearly indicated that FA is genotoxic. FA induced various genotoxic effects in proliferating cultured mammalian cells. The cytokinesis-block micronucleus (CBMN) assay was originally developped as an ideal system form easuring micronucleus (MN), however it can also be used to measure nucleoplasmic bridges (NBP) and nuclear buds (NBUD). Over the past decade another unique mechanism of micronucleus formation, known as nuclear budding has emerged. NBUDS is considered as a marker of gene amplification and/or altered gene dosage because the nuclear budding process is the mechanism by which cells removed amplified and/excess DNA.

Genotoxicity biomarkers micronucleus, nucleoplasmic bridges and nuclear buds

The increase of mortality from cancer brought urgency in identification and validation of predictive markers of risk and therefore early diagnosis. There is evidence that cytogenetic biomarkers are positively correlated with risk of cancer, and this is validated by studies of cohort and case-control. Cytokinesis-blocked micronucleus (CBMN) assay is used extensively in molecular epidemiology, and can be considered as a “cytome” assay covering cell proliferation, apoptosis, necrosis and chromosomal changes. The chromosomal alterations most reported and studied by the CBMN are: micronucleus (MN), nucleoplasmic bridges (NPB) and nuclear buds (NBUDS). The use of the MN assay in biomonitoring studies had a large increase in the last 15 years and international projects such as the HUMN have helped to increase the applicability and reliability of these tests.