Abnormal methylation of cancer-related genes can cause tumour growth

Methylation means adding a methyl group onto something.
Methylation of DNA is an important method of regulating gene expression - it can control whether or not a gene is transcribed and translated.
When methylation is happening normally, it plays a key role in many processes in the body. It's only when it happens too much (hypermethylation) or too little (hypomethylation) that it becomes a problem.
The growth of tumours can be caused by abnormal methylation of certain cancer related genes:

When tumour suppressor genes are hypermethylated, the genes are not transcribed - so the proteins they produce to slow cell division aren't made. This means that cells are able to divide uncontrollably and tumours can develop.

Hypomethylation of proto-oncogenes causes them to act as oncogenes - increasing the production of the proteins that encourage cell division. This stimulates cells to divide uncontrollably, which causes the formation of tumours.

	Criado por Lucy Nove quase 10 anos atrás

A2 Biology (Mutations and Gene Expression) Notas sobre Cancer, criado por Lucy Nove em 29-01-2017.