Cell Growth: Cancer Flashcards Preview

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Flashcards in Cell Growth: Cancer Deck (11)
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1
Q

G1 Cdk

A

Cdk that promotes cell division
Drives G1 / S Cdk to proceed through START
Promoted by mitogens
Called: Cyclin D / cdk4 and Cyclin D / cdk6

2
Q

Mitogens

A

Can be peptides or lipids
Peptides: PDGF, EGF, FGF
Lipids: LPA, S1P

3
Q

Role of G1 Cdk (Cyclin D / Cdk 4 & Cyclin D / Cdk 6)

A

G1 Cdk phosphorylates Rb protein
Phosphorylated Rb protein releases E2F in the nucleus
E2F can then transcribe genes coding for G1/S Cdk to go through START

4
Q

How do mitogens activate G1 Cdk?

A

Signal through Ras and PI3K
Ras leads to Cyclin D expression
PI3K activates PKB (AKT), which inactivates transport of G1-Cdk (cyclin D / Cdc 4) out of the nucleus

5
Q

p27

A

When bound to G1-Cdk active
When bound to G1/S Cdk inactive
Helps ensure G1-Cdk has produced enough products before going through START

6
Q

Guardian of the Genome

A

p53
Transcription factor that promotes transcription of cell cycle inhibitiors i.e. CKI p21
p21 binds to G1 -cdk and does not allow for progression through START

7
Q

T of F p53 is short lived?

A

True p53 is associated with Mdm 2 which is a ubiquitination ligase

8
Q

Too much Mitogens signals?

A

Alternative pathway through MAPK that inhibits MDM2 and allows p53 to inhibit G1 -Cdk expression via p21 and stimulate apoptosis

9
Q

Tumor Cells/ Tissue Have

A

Loss of mitogen dependence
Loss of contact inhibition
Loss of anchorage dependence
Cell shape changes due to changes in adhesion and motility

10
Q

Oncogenes act

A

Dominantly

Only need to mutate one gene

11
Q

Tumor Suprressor Genes act

A

Recessively

Need to loose both functional genes