Lec 45

Question 1

Why do cells become cancerous

cancer critical genes

Answer 1

Encode proteins involved in the cell cycle

Question 2

Tumor suppressor gene

Answer 2

Inhibit cell cycle

mutation can happen to this to cause cancer

Question 3

Proto-oncogenes

Answer 3

Promote cell cycle

mutation can occur to this
to cause cancer

Question 4

Why cancer happens

New (somatic) mutations

Answer 4

Mutation happens within the person which alters the protein amount and activity

Question 5

Why cancer happens

inherited mutation

Answer 5

Mutation is inherited from a parent

Alters protein amount and activity

Question 6

Why cancer happens

viral infection

Answer 6

Some viruses deliberately cause cancer to facilitate their own reproduction

Question 7

how much of cancer is caused by viral infection

Answer 7

more than 10 percent

Question 8

Initiation can occur by either

Answer 8

Unregulated cell reproduction due to loss of tumor suppressor genes

Question 9

Normal function of tumor suppressor genes

Answer 9

Inhibit cell proliferation

Causes cancer when non-functional

Question 10

Rb stops cell cycle at

Answer 10

g1 checkpoint

Question 11

Nonfunctional Rb cell can cause cancer

Answer 11

Initiation

Question 12

Unregulated cell reproduction due to proto-oncogene turning into an

Answer 12

oncogene

Question 13

Proto-oncogene normal function

Answer 13

Stimulate cell cycle

Can cause cancer if it becomes an overactive oncogene

Question 14

HER2 example

Answer 14

Receiving too much of a GF/mitogen signal leads to over reproduction (initiation)

Question 15

Progression

Genetic instability

Answer 15

Cancer cells acquire new mutations at more than the spontaneous rate because of a damaged p53 not patching up DNA damage

Question 16

p53 is a

Answer 16

Tumor suppressor gene

Question 17

PUMA is a

Answer 17

tumor suppressor gene because too few PUMA is dangerous

Question 18

BCL2 is a

Answer 18

proto-oncogene because too many BCL2 proteins is dangerous

Question 19

What proportion of human cancers have mutations in the TP53 gene

Answer 19

More than half

Question 20

Properties that lead to metastasis/spread

Induce angiogenesis

Answer 20

Tumors can not grow without recruiting blood vessels because they need glucose and oxygen which comes from blood vessels

Question 21

VEGF

Answer 21

positive mitogen/growth factor

harmful cells perform angiogenesis by releasing VEGF which recruit blood vessels which allow the cells to spread

Question 22

Properties that lead to metastasis/spread

Invade neighboring tissue

Answer 22

Cancer cells spread if some of them dismantle the collagen (as if they were fibroblasts)

basically cancer cells pretend to be fibroblasts to breakdown collagen to move into new locations

Question 23

Collagen

Answer 23

Contain cells

Question 24

Fibroblasts

Answer 24

Normally move around by going through collagen

Question 25

How many cells survive to reach new sites

Answer 25

0.1%

so many cells are in the new site though so it does not matter - they will be able to spread.