41. THE HER2 ONCOGENE Flashcards
1
Q
- What does the HER2 gene encode for?
A
- it encodes for part of the human epidermal growth
factor receptor
2
Q
- What is HER2 binded to?
A
- this is binded to the EGFR
- it is binded by growth factors
- this alters the structure of the receptors that became
active
3
Q
- What does HER2 need to function?
A
- receptor dimerisation
4
Q
- Where is HER2 amplified?
A
- it is amplified in invasive breast cancers
- it is amplified by roughly 20%
5
Q
- What is a therapy that targets HER2?
A
- Trastuzumab (Herceptin)
- it is a monoclonal antibody
6
Q
- What is the third way in which proto-oncogenes can be converted to oncogenes?
A
- mutations in the Proto-oncogenes
- mutations in the control elements
- these are known as gain-of-function mutations
- the increase the gene expression of the proto-
oncogene
7
Q
- What mutation is common in human cancers?
A
- mutations in the Ras proto-oncogene
- this leads to a hyperactive Ras protein
- leads to increased cell division
- leads to cancer
8
Q
- What happens tumour suppressor genes are inactivated?
A
- cancers can form
9
Q
- How can Tumour suppressor genes be inactivated?
A
- Loss of function mutations
- Insertional Mutagenesis
10
Q
- What are Loss of function Mutations?
A
- they are inactivating mutations
- they happen within the tumour suppressor genes
- they inactivate the tumour suppressor genes
- they inactivate the proteins
- cancer development follows
11
Q
- What is Insertional Mutagenesis?
A
- this is the insertion of the viral genome
- this viral genome is inserted into the host cell’s DNA
- inactivates the tumour suppressor genes
- inactivates proteins
- allows for cancer development
12
Q
- What are the 3 roles of the Tumour Suppressor proteins?
A
- THEY INHIBIT CELL SIGNALLING PATHWAYS
- they inhibit the cell cycle
- they induce apoptosis
- (Rb and p53 tumour suppressor proteins)
- THEY REPAIR DAMAGED DNA
- using the BRCA 1
- THEY CONTROL CELL ADHESION
13
Q
- Why is p53 very important?
A
- it is known as the gatekeeper of the genome
- it is a major tumour suppressor protein
- it causes cell cycle arrest at the G1 phase
- it prevents the DNA damaged cell from passing
mutations to its daughter cells through replication
14
Q
- What do mutations in the p53 gene result in?
A
- they prevent necessary cell cycle arrest
- they lead to prolific damaged cell growth
- they lead to cancer
15
Q
- Where is DNA damage detected at?
A
- it is detected at the checkpoints
- this gives the cell the opportunity to repair this damage
- the cell will commit apoptosis if the damage cannot be
repaired - this is when the cell commits programmed death
