Role of methylglyoxal protein modifications in DNA damage and chromosomal instability: Emerging molecular mechanisms

Methylglyoxal (MGO) is a highly reactive metabolite formed from glycolysis that can form advanced glycation endproducts (AGEs) on proteins and DNA. It has been well established that MGO induces DNA double strand breaks as a result of modifications on deoxyguanosine residues. However, recent studies shed new light on the genotoxic properties of MGO by its ability to cause chromosomal mis-segregation events, and other forms of chromosomal instability. These outcomes open a new avenue in which protein modifications, rather than DNA modifications, result in DNA damage. Herein, we present several hypotheses on how modification of proteins by MGO might cause these chromosome mis-segregation events based on identified protein modification sites from proteomic studies. These include various cell cycle proteins, such as those involved in sister chromatid cohesion, centrosome formation and histone proteins. Overall, recent studies implicate MGO in whole chromosome loss events, amongst other chromosomal instability events, suggesting it as a key player in cancer development and progression.