Pathology - Tumour Lectures

Question 1

What is the hallmark of cancer?

Answer 1

10 capabilities which are acquired during the multi-step nature of tumour development

Question 2

What is a carcinoma? What is its prevalence?

Answer 2

85% of all cancers. Malignant cancer of epithelial cells

Question 3

What are sarcomas?

Answer 3

Malignant tumour of the mesoderm - connective tissue, bone, muscle, blood

Question 4

What is an adenocarcioma and some examples?

Answer 4

Malignant cancer of glandular epithelial cells of organs.

Breast, Oesophagus, Lung, Stomach

Question 5

What is the name of the mechanism of cancer spread?

Answer 5

Metastasis

Question 6

What is the main route of cancer spread? What is the prevelance?

Answer 6

En-route theory - via the blood. 2/3 of all metastasis

Question 7

How do tumour cells spread from the primary tumour and in which format?

Answer 7

Spread as subclonal, meaning identical genome, just with added mutations.

Monoclonal or polyclonal routes, and either linear or branched mechanism

Question 8

What must tumour cells go through to become motile?

Answer 8

Epithelial Mesenchymal Transmission (EMT)

Question 9

What occurs during EMT?

Answer 9

Down-regulation of E-Cadherins to stop cell-cell adhesion. Upregulation of N-Cadherins which split cells, changing the shape of the cells

Question 10

What are the 5 steps that tumour cells must go through as part of epithelial mesenchymal transition (EMT)?

Answer 10

Invasion, Intravasation, Transport, Extravasaton, Colonisation

Question 11

What is necessary for invasion of a tumour cell?

Answer 11

Cadherins to break cell-cell adhesion
Integrins ensemble tumour cell to break free
Protease form a pathway through ECM to endothelial cells of blood vessel

Question 12

What is necessary for intravasation of a tumour cell?

Answer 12

Tumour cell attaches to basement membrane of vessel and destroys it. Passes through endothelium into blood stream

Question 13

What occurs during transport of a tumour cell?

Answer 13

Tumour can transport solo or in clumps

Extravasation occurs for some cancers in the first organ en-route after entry. E.G. entering the lungs from the breast

Question 14

What occurs during extravasation of a cancer cell?

Answer 14

E-selectin allows tumour to adhere to inner endothelium and exit

Question 15

What occurs during colonisation and what conditions must be present?

Answer 15

Tumour site of metastasis depends on the site of extravasation, and also on the ability of the tumour to carry out angiogenesis in the specific location

Question 16

What is a pro-angiogenic factor?

Answer 16

Vascular endothelial growth factors (VEGF) promotes angiogenesis once its receptors are phosphorylated

Tumours tell nearby cells to produce VEGF too

Question 17

What are 2 angiogeneic inhibitors?

Answer 17

Plasminogen can be converted to angiostatin, which inhibits angiogenesis

Endostatin blocks MAPK pathway which inhibits gene expression

Question 18

Why is angiogenesis necassary for tumours?

Answer 18

To receive the nutrients and o2 they need to grow and divide. Inhibiting angiogenesis may prevent tumour growth and survival