Exam 3 pt 4

Question 1

contact inhibition

Answer 1

normal cells stop moving when reach contact each other, cancer cells dont do this and keep growing
* cancer cells dont need survival factors/signals
* selective advantage because proliferate when normal cells would stop

Question 2

cancer cells alterred sugar metabolism

Answer 2

• tumor cells have increased rate of glucose uptake
• small amount of oxidative phosphorylation
• cancer cells instead form lactate at high levels, promoting cell growth

Question 3

tumors grow within

Answer 3

a framework of supporting connective tissue stroma

Question 4

metastasis

Answer 4

• EMT for carcinomas allows decreased adhesion and escape from parent tissue
• enter blood through aid of angiogenesis

Question 4

metastasis

Answer 4

• EMT for carcinomas allows decreased adhesion and escape from parent tissue
• enter blood through aid of angiogenesis

Question 5

cancer critical gene

Answer 5

genes whose alteration frequenctly contributes to the causation of cancer

Question 6

oncogenes

Answer 6

• gain of function mutations
• dominant
• non mutated forms are called proto oncogenes

Question 7

tumor supressor genes

Answer 7

• loss of function mutations
• often recessive
• cant add to tester strain to find

Question 8

_ can act as vectors for oncogenes

Answer 8

retroviruses

Question 9

Ras oncogene

Answer 9

First identified and one of the most important cancer critical genes, it codes for a monomeric GTPase involved in control of cell proliferation

Question 10

chromosomal rearrangements

Answer 10

The breaking and rejoining of DNA segments which can lead to the expression of a hyperactive or overexpressed fusion protein

Question 11

EGF receptor in cancer

Answer 11

deltion that deletes extracellular domain of EGF receptor, causing it to always stay active and promote growth

Question 12

excessive quantities of myc protein

Answer 12

causes cells to proliferate when they usually would not

Question 13

Burkitt’s lymphoma

Answer 13

Type of lymphoma in which a translocation brings the Myc gene under the control of regulatory sequences which normally control the production of antibodies in B lymphocytes

Question 14

individuals with heriditary form of retinoblastoma

Answer 14

have a deletion in one copy of the Rb gene in every somatic cell
* retinal cells become transformed when an event eliminates the good copy of a gene

Question 15

loss of Rb gene

Answer 15

allows cells to enter the cell cycle when they otherwise would not

Question 16

Rb gene

Answer 16

A universal regulator of the cell cycle in almost all cells in the body, its loss allows cells to enter the cell cycle when they otherwise would not

Question 17

_ of tumor supressor genes causes cancer

Answer 17

inactivation

Question 18

ways to see tumor supressor genes

Answer 18

• sequencing of cancer cell genomes
• analysis of methylation patterns
• karyotype analysis

Question 19

drivers of cancer

Answer 19

Group of mutations present in a tumor that play a role in the development of the cancer

Question 20

drivers of cancer

Answer 20

Group of mutations present in a tumor that play a role in the development of the cancer

Question 21

passenger mutations

Answer 21

Group of mutations present in a tumor that arise due to the genetic instability of the cancer, but are irrelevant to the development of the disease

Question 22

mutations found at _ are candidates for drivers

Answer 22

high frequencies

Question 23

uncontrolled proliferation of cancer cells requires the loss of restraints on

Answer 23

cell cycle progression and also regulate cell growth

Question 24

Warburg effect

Answer 24

The excessive rate of glycolysis that is observed in tumor cells
* result of PI3/AKt/mTOR pathway being activated abnormally

Question 25

loss of p53 promotes cancer in four ways

Answer 25

• allows DNA damage to continue throughout cell cycle
• allows damaged cells to escape apoptosis
• allows continues division of damages cells
• cells become relatively resistant to anticancer drugs

Question 26

_ copy/s of p53 has to be mutated

Answer 26

one copy only

Question 27

cancer stem cells

Answer 27

Small subset of tumor cells which maintain the tumor cell population and are less sensitive to many types of anti-cancer therapies; they undergo self-renew without limit and give rise to transit amplifying cancer cells

Question 28

carcinogens

Answer 28

Any agent (i.e. chemicals or radiation) that causes increased cancer rates

Question 29

Ames test

Answer 29

A quick and accurate test for mutagenicity using bacteria defective in histidine synthesis and DNA repair
* if colony grow, then mutation has corrected his synthe
* means it is a mutagen

Question 30

the most potent carcinogens are intially

Answer 30

initally chemically inert and only become damaging when altered by ctochrome p-450 oxidases in the liver

Question 31

Hep A and B causes

Answer 31

liver cancer

Question 32

HPV

Answer 32

Virus which causes warts, and is implicated in most cases of cervical cancer

Question 33

products of viral oncogenes bind

Answer 33

Rb and p53

Question 34

binding of Rb by _ allows _

Answer 34

E7 and E3 allows incontrolled entry into S phase

Question 35

binding of p53 by _ allows _

Answer 35

E6 allows continued proliferation of abnormal cells

Question 36

Brca 1 and 2 are

Answer 36

needed for homologous recombination, repair double stranded breaks

Question 37

PARP

Answer 37

repairs single stranded breaks

Question 38

Brac1 and 2 tumor supressor genes

Answer 38

Mutations in these tumor suppressor genes predispose humans to breast and ovarian cancers

Question 39

drugs that block PARP

Answer 39

kill cells that dnt have Brac but spare normal cells
* good treatment

Question 40

philadelphia translocation results in

Answer 40

formation of a hyperactive tyrosine kinase

Question 41

imatinib (gleeve)

Answer 41

• binds and inhibits the activity of Bcr-Abl protein
• cells with philadelphia chromosome are yeeted
• relapse when cancer cells develop resistance to the drug

Question 42

The process by which an initial mildly disordered cell behavior gradually accumulates more mutations and evolves into a full-blown cancer.

Answer 42

tumor progression

Question 43

Human cancer cells display _____________________ which causes them to accumulate genetic changes at an abnormally rapid rate.

Answer 43

genetic instability

Question 44

Loss-of-function mutations in these genes can promote the formation of cancer

Answer 44

tumor suppressor genes

Question 45

A cancer arising from connective tissue or muscle cells.

Answer 45

sarcoma

Question 46

Tumors whose cells have acquired the ability to invade other tissues are referred to as ______________________

Answer 46

malignant

Question 47

Hepatitis-B and C cause

Answer 47

chronic inflammation of the liver (hepatitis) and are implicated in the development of liver cancer.

Question 48

T or F: Oncogenes directly promote cancer by causing unregulated cell proliferation, while tumor suppressor mutations only promote cancer indirectly by causing genetic instability.

Answer 48

False

Question 49

Most carcinogens are also .

Answer 49

mutagens

Question 50

The activity of cytochrome P-450 oxidases in the liver may

Answer 50

sometimes convert chemically inert substances into potent carcinogens.