It is known that the role of the DNA MMR system is to maintain DNA replication fidelity by repairing DNA mismatches and insertion/deletion loops acquired during DNA replication [ 19].
These enzymes maintain DNA topology, disentangling DNA that becomes knotted, under- or over-wound in the process of replication, and are required to maintain correct chromosome condensation, decondensation, and segregation.
The inability of non-recruited DNA methylases to maintain DNA methylation in cancer cells when this transcriptional mechanism has been inactivated casts doubt on the stochastic model and on DNA methylation being epigenetically inherited.
Multiple, intricate DNA methylation machineries mediate and maintain DNA methylation in plants and vertebrates, whereas DNA methylation in Drosophila melanogaster (Drosophila) appears to involve only an elementary set of factors [5], [6], [7].
In mammals, DNA methyltransferase 1 functions to maintain DNA methylation patterns that influence gene transcription [ 41] and 17-beta hydroxysteroid dehydrogenase 8 preferentially inactivates androgens and estrogens, [ 42, 43].
In cancer cells, DNMT1 is both able to maintain DNA methylation and to de novo-methylate DNA of tumour suppressor genes [ 24].
Whilst the DNMT family of enzymes establish and maintain DNA methylation, TET enzymes are implicated in DNA demethylation and epigenetic control of gene expression [ 19, 20].
In summary, the results demonstrated that Cd-tolerant Weisuobuzhi is more capable to scavenge Cd-induced ROS by increasing the activity of antioxidant enzymes, to maintain DNA structural stability and protect the normal DNA methylation, and to sequester more Cd2+ to vacuole to reduce Cd toxicity.
