DNA methylation alterations induced by transient exposure of MCF-7 cells to maghemite nanoparticles.

AIM: To evaluate the DNA methylation profile of MCF-7 cells during and after the treatment with maghemite nanoparticles (MNP-CIT).

MATERIALS & METHODS: Noncytotoxic MNP-CIT concentrations and cell morphology were evaluated by standard methods. DNA methylation was assessed by whole genome bisulfite sequencing. DNA methyltransferase (DNMT) genes expression was analyzed by qRT-PCR.

RESULTS: A total of 30 and 60 µgFeml-1 MNP-CIT accumulated in cytoplasm but did not present cytotoxic effects. The overall percentage of DNA methylation was not affected, but 58 gene-associated regions underwent DNA methylation reprogramming, including genes related to cancer onset. DNMT transcript levels were also modulated.

CONCLUSION: Transient exposure to MNP-CIT promoted epigenomic changes and altered the DNMT genes regulation in MCF-7 cells. These events should be considered for biomedical applications.