Epigenetics and Cancer

Question 1

Define epigenetics.

Answer 1

The study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.

Question 2

Define promoter.

Answer 2

A promoter is a region of DNA that leads to initiation of transcription of a particular gene.

Question 3

DNA methylation

Answer 3

DNA methylation is a process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription.

Question 4

How does methylation affect the chromatin in DNA?

Answer 4

Methylation cause condensation of chromatin, making it inaccessible to transcription factors.

Question 5

How do cancer drugs target the epigenome?

Answer 5

DNA Methyltransferase inhibitors - block methylation of tumour suppressor genes.

Histone De-Acetylase inhibitors (HDACi)

Question 6

Histone De-Acetylase inhibitors (HDACi) are the to treat what?

Answer 6

Used to treat haematological malignancies.

Question 7

Epigenetic changes to what genes are most associated with causing cancer?

Answer 7

DNA repair genes - methylation of these genes inactivates them increasing risk of cancer formation.