Biology of Neoplasia II

Question 1

Normal proliferation restricted to the ___ layer orderly differentiation

Answer 1

basal

Question 2

growth promotion

Answer 2

oncoproteins (oncogenes)

Question 3

growth inhibition

Answer 3

tumor suppressors

Question 4

cell free extract injected into chickens caused sarcomas which lead to findings of retrovirus

Answer 4

Rous sarcoma virus

Question 5

Retrovirus (RSV) contains ____

Answer 5

viral oncogene

Question 6

Virus detection uses

Answer 6

fibroblast assays

Question 7

Flat, contact inhibited

Answer 7

non-transformed fibroblasts

Question 8

If fibroblasts start pilling up

Answer 8

transformed

Question 9

• single mutation gives growth advantage
• additional mutations increase this
• further mutations activate other cellular properties

Answer 9

Cancer is a result of multiple genetic events

Question 10

Cells in a tumor should _____ some genetic alterations

Answer 10

share

Question 11

Combined oncogenes ____ change

Answer 11

increases

Question 12

Salivary gland metastasis can be caused by ____ loss which is a _____ inhibitor

Answer 12

p16, CDK4

Question 13

Oncogene activation

Answer 13

1) proliferation
2) survival
3) motility
4) angiogenesis

Question 14

Mechanisms of oncogene activation

Answer 14

1) point mutation
2) chromosomal translocation
3) gene amplification

Question 15

Deletion can lead to deregulation making gene always

Answer 15

on

Question 16

gp55 mimics binding of

Answer 16

erythropoietin (viral oncoprotein)

Question 17

The ___ pathway is a key target during tumor development

Answer 17

Ras

Question 18

___ factors can induce transformation

Answer 18

Nuclear

Question 19

____ is deregulated in Burkitt’s Lymphoma

Answer 19

myc (8+14 translocation)

Question 20

Some viral oncogenes have

Answer 20

cellular counterparts

Question 21

Tumor supressor genes leads to aberrant proliferation, survival, and motility due to

Answer 21

loss of function

Question 22

Loss of ____ is indicative of a tumor suppressor locus

Answer 22

heterozygosity

Question 23

___ is a key mediator of epithelial homeostasis, negative regulator of cell cycle progression

Answer 23

TGFbeta

Question 24

___ is a tumor suppressor gene that is inactivated in many human cancers

Answer 24

p53

Question 25

p53 can turn on

Answer 25

1) apoptosis
2) sustained G1 and G2 arrest
3) DNA repair

Question 26

Oncogenes can have gain-of-function by

Answer 26

point mutation, translocation, amplification, overexpression

Question 27

Tumor suppressor genes can have loss of function by

Answer 27

point mutation, chromosomal loss, deletion, and gene silencing

Question 28

Have “proofreading” activity

Answer 28

DNA polymerase

Question 29

Disease that have squamous cell carcinoma susceptability

Answer 29

Fanconi sarcoma

Question 30

Base excision repair completed by

Answer 30

DNA Pol beta and brought together by DNA ligase

Question 31

Mismatch repair proteins that are important

Answer 31

MSH2, 6, MLH1

Question 32

Unwinds DNA

Answer 32

DNA helicase

Question 33

Removes affected strands

Answer 33

DNA exonuclease

Question 34

____ can cause intrastrand T-T crosslinks (dimer formation)

Answer 34

UV radiation

Question 35

Double strand break

Answer 35

break in both strands most likely due to environmental factors

Question 36

Non-homologous end joining can lead to

Answer 36

1) error

2) translocation

Question 37

tumor suppressors usually have ___ alleles inactivated

Answer 37

both

Question 38

Tumor suppressors -inherited mutations predispose to tumor development-

Answer 38

cancer syndromes

Question 39

Key targets of tumor suppressors

Answer 39

1) cell cycle regulators

2) DNA repair systems