Lecture 32 - Cellular Basis of Malignancy

Question 1

Epithelial to Mesenchymal Transition (EMT)?

Answer 1

gain of migratory and invasive properties, loss of polarity and adhesion (adhering junctions of E-cadherin, beta-catenin and alpha-catenin)

Question 2

Irreversible EMT?

Answer 2

loss of E-cadherin and alpha-catenin expression due to mutation/methylation -> diffuse type cancer

Question 3

Reversible EMT?

Answer 3

HGF binding to receptor activates Ras activating ‘snail’, repress E-cadherin causing loss of adherance junctions

Question 4

Causes of HGF overactivation?

Answer 4

over-expression, gene amplification, missense point mutation, autocrine loops

Question 5

Triggers of tumor angiogenesis?

Answer 5

metabolic stress (hypoxia, pH, hypoglycaemia), inflammation, oncogen activation, TSG activation (inhibitng p53, promoting RAS)