Cancer 2 Flashcards Preview

Extra Y2 > Cancer 2 > Flashcards

Flashcards in Cancer 2 Deck (18)
Loading flashcards...
1
Q

Cells need to be attached to ECM and they need a certain degree of spreading to be able to respond to soluble growth factors. What is the term given to the requirement of ECM binding for growth?

A

Anchorage dependence

2
Q

integrins structure

A

heterodimers consisting of alpha and beta subunits

main role is to allow cell to interact with ECM

3
Q

what do integrins bind to on the cytoplasmic side

A

actin

exception- a6b4 integrin complex found in epithelial hemidesmosomes, are linked to the cytokeratin in the cytoplasm

4
Q

2 types of cell cell junctions

A

Zonulae (belts)

Maculae (spots)

5
Q

What effect does low calcium levels have on an epithelium?

A

Many cell-cell junctions are calcium dependent
In the absence of calcium/low calcium, the junctions will break down, leading to:
- Increased MAPK activation (pro-proliferation)
- Decrease activity of p27KIP1 (its a Cdk inhibitor)
- INCREASED PROLIFERATION
When calcium returned to normal and the junctions are reformed:
- Decreased MAPK activation
- Increased activity of p27KIP1 (Cdk inhibitor)
- DECREASED PROLIFERATION

6
Q

what is contact inhibition of proliferation

A

When bound to cadherin at the plasma membrane, beta-catenin is NOT available to bind to LEF-1 and cause nuclear effects
Cytoplasmic levels of beta-catenin can rise if there is:
- Inhibition of degradation of b catenin
- Loss of cadherin-mediated adhesion
This can lead to the formation of beta-catenin/LEF-1 complexes that promote proliferation

7
Q

What 2 types of dependences are needed for cells to proliferate

A
anchorage dependence (ECM interaction with cell promotes proliferation)
density dependence (density of cells affects how much growth factors can interact with cells. growth factors will then lead to proliferation) 
slide 51
8
Q

What are the counter-part oncogenes of the proto-oncogenes c-Raf and c-Jun?

A

v-raf and v-jun

9
Q

Types of cytotoxic chemotherapies

A
Alkylating agents 
Pseudoalkylating agents 
Antimetabolites 
Anthracyclines 
Vinca alkaloids and taxanes 
Topoisomerase inhibitors
10
Q

give 3 receptors overexpressed in cancers

A

PDGFR (platelet derived growth factor) (glioma/brain cancer)
EGFR (breast + colorectal)
HER2 (breast)

11
Q

Give 2 examples of constitutive activation of tyrosine kinase receptors in cancers

A

EGFR – lung cancer

FGFR – head and neck cancers, myeloma

12
Q

Give an example of of overexpression of ligand in cancer

A

VEGF (the ligand) – prostate cancer, kidney cancer, breast cancer

13
Q

which caspases are effector caspases

A

3, 6 and 7

14
Q

which caspases are initiator caspases?

A

2 8 9 10

15
Q

name an alkylating agent (a subtype of cytotoxcic chemotherapies)

A

chlorambucil

16
Q

Define necrosis

A

Unregulated cell death associated with trauma, cellular disruption and an INFLAMMATORY response

17
Q

define apoptosis

A

controlled cell death, with controlled cell disassembly, no inflammation

18
Q

Caspase stands for what

A

Cysteine-dependent aspartate-directed proteases