3.8.2.3 Gene Expression and Cancer Flashcards
What is cancer?
Uncontrolled cell division
Which genes are responsible for controlling the rate of cell division?
Oncogenes and tumour-suppressor genes
Where do oncogenes come from?
They normally derive from proto-oncogenes
What is the purpose of proto-oncogenes?
They normally code for proteins that regulate cell growth by providing protein signals that cause cell division or by regulating cell apoptosis (cell death)
What types of proteins does proto-oncogene involvement occur in?
All kinds
How is a proto-oncogene turned into an oncogene?
A mutation
What is the role of tumour-suppressor genes?
They produce proteins that slow down cell division
What occurs when a mutation occurs in a tumour-suppressor gene?
It stops proteins that slow down division from being formed
This is called silenced
What genes are affected by epigenetics?
Tumour-suppressor genes
Which hormone falls after menopause?
Oestrogen
How is Oestrogen and breast cancer linked?
By positive feedback
In breast tissue, fat cells produce more Oestrogen
Breast cancer tumours produce more Oestrogen
What is the process of Oestrogen affecting DNA synthesis?
Oestrogen diffuses across the cell membrane (lipid soluble)
Oestrogen binds to a complimentary transcriptional factor
The transcriptional factor is caused to change shape
The DNA binding site can now bind to DNA (activated)
Transcriptional factor moves through a nuclear pore to bind to DNA bases
This stimulates the transcription of a gene