L12 - Tumour Suppressor Genes & Clinical Implications

Question 1

What type of genetic change most commonly underlies thyroid cancer?

Which signalling pathway is most commonly affected in thyroid cancer?

Answer 1

• Thyroid cancer is most commonly caused by dysregulation of oncogenes rather than dysregulation of tumour suppressor genes
• Uncontrolled activation of the MAPK (ras/raf/mek/erk) pathway occurs in most thyroid cancers

Question 2

How do BRAF mutations affect thyroid cancer progression?

Answer 2

BRAF mutation has significant effect on disease progression & survival

Question 3

What are anaplastic neoplasms?

Answer 3

Malignant tumours that are so poorly differentiated that it is impossible to determine their histogenesis

Question 4

How do p53 mutations affect thyroid cancer progression?

Answer 4

• p53 rarely mutated in well differentiated thyroid cancer

- p53 mutation thought to be trigger from well to poorly differentiated thyroid cancer

Question 5

What is Cowden’s syndrome?

What causes it?

Answer 5

A multi-system disorder resulting from an AD germline mutation of PTEN

Question 6

What is familial adenomatous polyposis?

What causes it?

Answer 6

AD condition caused by germline mutations of adenomatous polyposis coli (APC) gene (chromosome 5q)

Question 7

Which cell signalling pathways are affected in melanoma?

Answer 7

• NF1/Ras pathway

- RB1/CDKN2A & MDM2/TP53 pathway