Hypoxia induces transcription of a DNA methyltransferase, DNMT1. What does this suggest about the relationship between hypoxia and regulation of gene expression

Hypoxia is defined as an inherent condition of tumors that causes cancer development.

Hypoxia induces transcription of DNA methyltransferase, DNMT1 which suggest that hypoxia and regulation of gene expression have epigenetic relationship that refers to inheritable mechanisms responsible for regulating gene expression without altering the sequence of DNA bases.

DNA methylation is main epigenetic mechanism of Hypoxia.

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?