Cancer 9/29

Question 1

What is the term used to describe variation in cell size and shape?

Answer 1

Pleomorphism

Question 2

What is anaplasia?

Answer 2

Lack of differentiation in tumor cells (bad)

Question 3

What is a reversible conversion of one differentiated cell type to another?

Answer 3

Metaplasia

Ex: columnar epithelium replaced by squamous epithelium in respiratory tract of smokers

Question 4

What is the term for a disordered growth and maturation of cells and a disturbance of growth regulation?

Answer 4

Dysplasia

Question 5

3 factors used to grade a tumor:

Answer 5

Size (T)

Lymph node involvement (N)

Metastasis (M)

Question 6

What is a bio marker expressed in 75% of breast cancers? How is it treated when positive?

Answer 6

ER+

Endocrine therapy- TAMOXIFEN

Question 7

What is the target therapy when the HER-2 receptor is expressed in Brest cancer?

Answer 7

Trastuzumab (herceptin)

Question 8

How is familial breast cancer inherited?

Answer 8

Germ line mutations

Autosomal dominant mutations of BRCA1 or BRCA2

Question 9

Molecular classification of breast cancer: high expression of cytokeratins 5/6 and 17 and proliferation markers

Answer 9

1. Triple negative or basal-like

Question 10

Molecular classification of breast cancer: keratins (-)

Answer 10

2. HER2 (+)

Question 11

Molecular classification of breast cancer:

ER + high expression

E cadherin +

Answer 11

3. Luminal-A

Question 12

Molecular classification of breast cancer:

ER + lower expression

E cadherin -

Answer 12

4. Luminal-B

Question 13

Molecular classification of breast cancer:

ER+

Answer 13

5. Normal breast like

Question 14

What are the 4 gene mutations that serve as the basis for colon cancer?

Answer 14

1. Loss of APC tumor suppressor gene
2. Activation of K-ras oncogene
3. Loss of DCC tumor suppressor
4. Loss of p53 tumor suppressor

Question 15

What are normal cellular genes that encode proteins involved in cell growth and proliferation?

Answer 15

Proto-oncogenes

Question 16

what are cancer producing genes derived from Proto-oncogenes?

Answer 16

Oncogenes

Question 17

7 types of proteins participating in cell growth:

Answer 17

1. Growth factors
2. GFRs
3. Intercellular cell growth signal transducers
4. Transcription factors
5. Pro or anti-apoptosis proteins
6. Cell-cycle control proteins
7. DNA repair proteins

Question 18

What are 2 proto oncogenes that encode cell surface receptors (receptors for gf)?

Answer 18

1. Her2
2. EGF

Both receptor tyrosine kinases

Question 19

What is the HER2 mutation that causes cancer?

Answer 19

Val -> Gla

Her2 receptor gene is mutated to NEU gene.

Treat w herceptin

Question 20

What is the EGF mutation that causes cancer?

Answer 20

Deletion.

Involved in lung cancers.

Question 21

Are RTK mutations oncogenes or tumor suppressor genes?

Answer 21

Oncogenes.

TKIs target RTK mutated receptors.

Question 22

What is one of the most frequently mutated proto oncogenes in cancer and an example of a growth signal transducer?

Answer 22

Ras mutations.

Mutation occurs as aa position 12 or 61 -> constitutively active.

Question 23

What are two important transcription factors that cause cancer when mutated?

Answer 23

1. C-Fos
2. C-myc

Constitutively active

Question 24

4 ways the proto-oncogene can be mutated to become an oncogene?

Answer 24

1. Promotor mutation
2. Coding sequence mutation
3. Chromosomal translocation
4. Gene amplification

Question 25

What is the product of a chromosome translocation called? Translocation of what chromosomes causes this?

Answer 25

Philadelphia chromosome Translocation of Ch 9 & 22 Fusion of bcr and abl

Question 26

What kind of gene is the Rb gene?

Answer 26

Tumor supressor

Question 27

What is the two-hit origin of cancer hypothesis?

Answer 27

Some forms of hereditary cancer might be initiated when a person heterozygous for a germ line mutation undergoes a SECOND, SOMATIC MUTATION in the OTHER ALLELE OF THE SAME GENE, rendering the cell homozygous for loss of function. Only in TS GENES

Question 28

What is p53?

Answer 28

Tumor supressor, transcription factor. Involved in DNA damage repair, cell cycle control, apoptosis.

Question 29

What checkpoint in the cell cycle do Rb and p53 regulate?

Answer 29

G1/S checkpoint

Question 30

Telomeres are a region of repetitive DNA at the end of a chromosome. What do they do?

Answer 30

Protect end of chromosomes. Shortened during cell divisions, replenished by Telomerase. As they grow shorter, cells reach end of replicative ability and progress into senescence.

Question 31

Compared to normal cells, cancer cells' telomerase activity is (higher/lower) and telomeres are (longer/shorter)

Answer 31

Higher activity Longer telomeres

Question 32

True or false: both RNA and DNA viruses can carry oncogenes.

Answer 32

True.

Question 33

Do RNA or DNA viruses carry oncogenes that function in the cell replication cycle?

Answer 33

DNA viruses do participate in replication cycle. RNA viruses do not.

Question 34

Retroviruses that cause cancer can be fast or slow tumor forming. Which contains an oncogene?

Answer 34

Fast retroviruses contain oncogene.

Question 35

How do slow acting retroviruses cause cancer?

Answer 35

Retroviral promoter and enhancer insertions activates c-Myc proto oncogene

Question 36

How does hpv cause cancer?

Answer 36

Over expression of proteins E6 and E7 E6 inhibits p53 E7 inhibits Rb