Microplastics can alter structural configurations of human non-canonical G-quadruplex DNA.

Microplastics (MP) with a diameter of less than 150 μm can enter the lymph and bloodstream systems, induce cellular toxicity and damage DNA. G-quadruplexes (GQs) are tetraplex DNA secondary structures found in the human genomes that play important roles in replication, transcription and genomic integrity. Comprehending the biological and molecular processes underlying the activities of MPs could aid in estimating potential hazards to humans. In this investigation, polystyrene microplastics (PS-MPs) and polyethylene microplastics (PE-MPs) have been selected because these two MPs are environmentally most prevalent and they are of different sizes. Several biophysical strategies were employed to identify that PS-MPs are the most potent MPs that bind to CMYC GQ DNA (present in the promoter of CMYC gene, important for cellular growth and proliferation) and may alter their structure. This study helps to understand the potential threat MPs possesses by interacting with key DNA structures.