49. TUMOUR SUPPRESSOR GENES Flashcards
1
Q
- What do the Tumour Suppressor Genes control?
A
- the Cell Cycle
2
Q
- What inhibits Cell Division?
A
- the protein products of the Tumour Suppressor
Genes - they prevent the uncontrolled Growth that
contributes to cancer
3
Q
- What are two very important Tumour Suppressor Genes?
A
- RB1
- TP53
- these produce Rb and p53 proteins
4
Q
- What is p53 the Gate Keeper of?
A
- the CDK Inhibitor
5
Q
- What is Rb?
A
- this is the Retinblastoma Protein
- it is a tumour suppressor gene
- it codes for the tumour suppressor protein
- it inhibits the cell cycle progression
6
Q
- What does Rb inhibit?
A
- E2F activation during G1
- it does this by first isolating E2F
7
Q
- How is Rb regulated during the G1 Phase?
A
- Rb is dephosphorylated by the PP-1 protein
- the Protein Phosphatase 1
8
Q
- At the end of the G1 Phase, how is Rb regulated?
A
- the Cyc-cdks phosphorylate Rb
9
Q
- What kind of Rb cannot isolate E2F?
A
- Phosphorylated Rb
- this means that E2F is released
- E2F is activated
- the cell then enters the S Phase
10
Q
- What is Retinoblastoma?
A
- it is a malignant tumour
- it can occur in one eye (Unilateral)
- it can occur in both eyes (Bilateral)
- it typically occurs in children that are less than 5
years old
11
Q
- Where does Retinablastoma originate from?
A
- the Retina
- this is the sensitive lining of the eye
12
Q
- How many children World Wide develop Retinablastoma?
A
- about 6000 children
13
Q
- How many births are affected by Retinoblastoma?
A
- 1 out of 15 000
14
Q
- What are the two forms of Retinoblastoma?
A
- Familial (Heritable) Retinoblastoma
- Sporadic (Non-Heritable) Retinoblastoma
15
Q
- What causes Retinoblastoma?
A
- the mutation in the Tumour Suppressor Gene
RB1 - this encodes for the Rb protein