Topic 25 - Cancer

Question 1

Cancer can result from

Answer 1

A transformation of a single cell in any tissue of the body

Question 2

A family of diseases characterized by uncontrolled cell proliferation (growth or division)

Answer 2

Cancer

Question 3

If the tumor stays confined it is considered

Answer 3

Benign

Question 4

Cancer cells may ___________ by leaving their original location to colonize other areas of the body

Answer 4

Metastasize

Question 5

Metastasizing is dependent on

Answer 5

The actin cytoskeleton

Question 6

Cells normally stop dividing when they contact neighboring cells

Answer 6

Contact inhibition

Question 7

Transformed cells lose

Answer 7

Contact inhibition

Question 8

Metastasizing cancer cells secrete

Answer 8

Matrix Metalloproteases

Question 9

Special enzymes that digest the extracellular matrix components promoting migration through tissues

Answer 9

Matrix Metalloproteases

Question 10

Activation of matrix metalloproteases and loss of contact inhibition alls tumor cells to

Answer 10

Colonize other tissues

Question 11

Involved in the ability of cancer cells to metastasize

Answer 11

Actin Cytoskeleton
Matrix Metalloproteases
Loss of Contact inhibition

Question 12

Six cellular properties of deadly cancers

Answer 12

Self-sufficiency in growth signals
Insensitivity to antigrowth signals
Evasion of Apoptosis
Limited replicative potential
Tissue Invasion and Metastasis
Sustained Angiogenesis

Question 13

Cancer is a progressive disease cause by

Answer 13

An accumulation of mutations

Question 14

Genes that promote cell survival and cell proliferation

Answer 14

Proto-oncogenes

Question 15

Mutation of proto-oncogenes results in

Answer 15

Gain of function mutations

Question 16

Encode proteins with unregulated permanently activated activity

Answer 16

Gain of Function mutations

Question 17

Gain of function mutated genes are called

Answer 17

oncogenes

Question 18

_________________ are genes that promote cell proliferation and when mutated with a “gain of function” mutation can result in cancer

Answer 18

Proto-oncogenes

Question 19

Three main ways that pro to-oncogenes are turned into oncogenes

Answer 19

1. Mutation in coding sequence
2. Gene amplification
3. Chromosome Rearrangement

Question 20

Tyrosine Receptor Kinase (Trk)

Answer 20

Proto-oncogene

Question 21

Activates cell division in response to extracellular growth factors

Answer 21

Trk

Question 22

A chromosomal rearrangement with _____________ makes a chimeric protein

Answer 22

Tropomyosin

Question 23

Permanent receptor dimerization and cell proliferation even in the absence of a signal

Answer 23

Chimeric protein made by Tropomyosin-Trk

Question 24

Gene whose normal function is to stimulate the cell to divide

Answer 24

Proto-oncogene

Question 25

Mutation of a proto-oncogene to an oncogene results in

Answer 25

“Gain of Function” = unregulated cell proliferation

Question 26

Normally inhibit events in the cell cycle until feedback control stimulates passage through a cell cycle checkpoint

Answer 26

Tumor Suppressor genes

Question 27

In tumore suppressor genes, inactivates this activity which leads to cancer formation

Answer 27

“Loss of function” mutation

Question 28

Typically a “recessive” mutation because both alleles need to be lost

Answer 28

Loss of Function

Question 29

“Loss of Function” mutations of ______________ can result in cancer formation

Answer 29

Tummor Suppressors

Question 30

“Loss of function” mutations in p53 would result in

Answer 30

The inability to halt the cell cycle in the presence of damaged DNA

Question 31

Replication of damaged DNA can lead to

Answer 31

Mutations that lead to cancer

Question 32

Gene that inhibits cell proliferation

Answer 32

Retinoblastoma (Rb)

Can be hereditary and usually forms as a child

Question 33

Rb mutation of both genes - adult onset

Answer 33

Sporadic Tumor Formation

Question 34

When the cell is not proliferating active Rb proteins binds to and inhibits transcriptional activator

Answer 34

E2F

Question 35

In response to mitogen (growth factor):

Answer 35

1. G1-Cdk and G1/S-Cdk are activated
2. G1-Cdk and G1/S-Cdk phosphorylate Rb and inactivate it
   This frees E2F to activate genes for cell proliferation

Question 36

Loss of function mutation of Rb results in

Answer 36

The inability to inhibit E2F

Question 37

Two proto-oncogenes

Answer 37

Myc (transcriptional factor)

Ras (major growth facto signal pathway component)

Question 38

Gain of function mutations of Myc and Ras are

Answer 38

More tumorigenic than either alone