Molecular mechanisms of micronucleus, nucleoplasmic bridge and nuclear bud formation in mammalian and human cells

Area of Science:

• Genetics
• Molecular Biology
• Cell Biology

Background:

• Micronuclei (MN), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) are nuclear anomalies indicating genotoxic events and chromosomal instability.
• These biomarkers are crucial for assessing genome damage, which is linked to cancer and other diseases.
• The cytokinesis-block micronucleus cytome (CBMNcyt) assay allows simultaneous measurement of these anomalies.

Purpose of the Study:

• To review and summarize current knowledge on the molecular mechanisms behind the formation of MN, NPBs, and NBUDs.
• To elucidate how these nuclear anomalies arise from specific genotoxic events and cellular processes.
• To highlight the significance of these biomarkers in the context of cancer and disease risk.

Main Methods:

• Review of existing literature over the past two decades.
• Analysis of molecular probes and genetically engineered cell data.
• Synthesis of findings related to DNA damage, chromosome segregation, and nuclear anomalies.

Main Results:

• Micronuclei formation is linked to lagging chromosome/chromatid fragments or whole chromosome missegregation.
• Nucleoplasmic bridges arise from dicentric chromosomes or defective sister chromatid separation.
• Nuclear buds are associated with the elimination of amplified DNA or excess chromosomes.

Conclusions:

• The formation of MN, NPBs, and NBUDs involves complex molecular mechanisms related to DNA damage and chromosome dynamics.
• These nuclear anomalies serve as critical indicators of genome instability and potential disease risk.
• Continued research into these mechanisms aids in understanding cancer development and other degenerative diseases.