Cancer 1

Question 1

What is cancer?

Answer 1

disease in which an individual mutant clone of cells begin by prospering at the expense of its neighbor cells

Question 2

What are some properties of cancer cells?

Answer 2

cells growing out of control
do not need signals to grow
release autocrine growth factor
ignore apoptosis signals

Question 3

What are two heritable properties of cancer cells?

Answer 3

1. reproduce in defiance of normal restraints on cell division and cell growth
2. invade area normally reserved for other cells

Question 4

How do cancer cells kill?

Answer 4

as a tumor grows and spreads, it squeezes or destroys blood vessels, nerves until an organ can no longer do its job

Question 5

What are carcinomas?

Answer 5

from epithelial cells

Question 6

What are sarcomas?

Answer 6

from connective tissue and muscle tissue

Question 7

What are leukemias and lymphomas?

Answer 7

from white blood cells and their precursors

Question 8

What are benign tumors?

Answer 8

adenoma- benign epithelial tumor with glandular organization

Question 9

A malignant tumor of same type is _______

Answer 9

adenocarcinoma

Question 10

What is basal cell carcinoma?

Answer 10

keratinocyte stem cell in skin

Question 11

What is melanoma?

Answer 11

pigment cells in skin

Question 12

What is the difference between basal cell carcinoma and melanoma?

Answer 12

basal cell carcinoma rarely metastasize whereas malignant melanomas metastasize widely

Question 13

what mutation occurs to cause colon cancer?

Answer 13

mutation in APC gene (which is a tumor suppressor)

Question 14

Most cancer derive from ______

Answer 14

single abnormal cell

Question 15

What is the evidence that cancer comes from a single cell?

Answer 15

The Philadelphia chromosome
translocation with Chr 9 and 22
all cancer cells have same chromosomal aberration

Question 16

What are the two types of carcinogens?

Answer 16

chemical and radiation

Question 17

What is the best weapon against cancer?

Answer 17

early detection

Question 18

How can obesity be related to more incidence of cancer?

Answer 18

more cells/ more chance of mutation

Question 19

What is angiogenesis

Answer 19

formation of new blood vessels from pre existing blood vessels

Question 20

What is neovascularization?

Answer 20

formation of new blood vessels from scratch

Question 21

what does the Ames test do?

Answer 21

bacteria needs histidine, and salmonella will not grow without it
if cells are mutagenic, they can produce colonies of bacteria that grow without histidine

Question 22

______ is the most important environmental cause of cancer

Answer 22

tobacco

Question 23

What are the two genetic causes of cancers?

Answer 23

tumor supressor genes

oncogenes

Question 24

What happens in a tumor suppressor gene mutation?

Answer 24

under activity mutation–loss of function

tumors can no longer be suppressed

Question 25

What happens in a oncogene mutation?

Answer 25

overactivity mutation-gain of function

involves single mutation event and activation of gene causing proliferation

Question 26

What are DNA maintenance genes?

Answer 26

subset of tumor suppressor genes, mutations involve inactivation of caretaker genes that create genomic stability

Question 27

What was the first human oncogene?

Answer 27

Ras

Question 28

What is Ras?

Answer 28

monomeric GTPase for signal transduction

Question 29

Ras oncogenes _____ shut off by hydrolyzing GTP to GDP

Answer 29

cannot

Question 30

What are the four mechanisms of oncogene activation?

Answer 30

1. Deletion or point mutation
2. regulatory mutation
3. gene amplification
4. chromosomal rearrangement

Question 31

Describe deletion or point mutation for mechanism of oncogene

Answer 31

makes hyperactive protein

can keep protein in active state

Question 32

Describe regulatory mutation for mechanism of oncogene

Answer 32

produce more normal protein-promotor mutation

Question 33

Describe gene amplification for mechanism of oncogene

Answer 33

several copies instead of 1 copy-normal protein overproduced

Question 34

Describe chromosomal rearrangement for mechanism of oncogene

Answer 34

brings new regulatory sequence that causes overproduction OR creates overreaction fusion protein

Question 35

How can ligands cause cancer?

Answer 35

if ligands produced constitutively they cause proliferation and growth all the time (cancer cells produce own ligand–autocrine signaling)

Question 36

How can receptors cause cancer?

Answer 36

tyrosine kinase receptors–when RTKs constitutively produced don’t even need a ligand

Question 37

What does Bcl2 do?

Answer 37

promotes cell survival despite DNA damage