Stem cells, organogenesis and cancer

Question 1

What are the three classes of genes often causing cancer?

Answer 1

Proto-oncogenes (promote cell survival or proliferation)
Tumor-suppressor genes (inhibit cell survival or proliferation)
Care taker genes (repair or prevent DNA damage)

Question 2

What is the function of tumor suppressor genes?

Answer 2

To inhibit cells survival or proliferation

Question 3

What developmental process, is similar to metastasis?

Answer 3

The epithelial-mesenchymal transition

Question 4

What is required for cancer cells to metastasize?

Answer 4

They must degrade the basement membranes of connective tissue, underlying epithelial cells and the surrounding endothelial cells of blood

Question 5

What are carcinomas?

Answer 5

Tumors derived from the endoderm or ectoderm

Question 6

How can cancer be hereditary?

Answer 6

If you have a mutation in a cancer-risk gene, on one allele, there is a higher risk of you becoming homozygous for it

Question 7

What is the multi-hit model for cancer causation?

Answer 7

The more mutations a cells has, the more likely it is to become cancerous

Question 8

What are the similarities between cancer and organogenesis

Answer 8

Sustaining proliferation
Evading growth suppressors
Metastasis/migration
Replicative immortality
Angiogenesis - ensuring nutrient supply
Resisting cell death
Unlocking phenotypic plasticity

Question 9

Examples of cancers, where the embryonic program is deregulated

Answer 9

Wilms tumors
Familial Adenomatous polyposis (Colorectal cancer)

Question 10

How is development deregulated in hereditary colorectal cancer (CRC)?

Answer 10

Wnt signal is not inhibited, which causes uncontrolled cell proliferation