8- Cancer Biology

Question 1

Why do cancerous cells stain yellow with FDG (flourdeoxyglucose)?

Answer 1

Cancerous cells exhibit increased glucose uptake. Usually get energy from glycolysis because they are in anaerobic conditions

Tumors will be yellow in the scan

Question 2

What is the carcinogen Vinyl Chloride associated?

Answer 2

liver angiosarcoma

Question 3

What is the carcinogen Benzene associated with?

Answer 3

leukemia

Question 4

What is the carcinogen Arsenic associated with?

Answer 4

Skin and bladder cancer

Question 5

What is the carcinogen Asbestos associated with?

Answer 5

mesotheliema

Question 6

What is the carcinogen radium associated with?

Answer 6

osteosarcoma

Question 7

What does cytochrome P 450s role in cancer?

Answer 7

Can activate some carcinogens (indirect acting agents)

Question 8

What is the doubling time for breast cancer?

Answer 8

100 days

Question 9

the Philadelphia chromosome is related to chronic myelogenous leukemia (CML) , what is this mutation?

Answer 9

Philadelphia chromosome (the small abnormally paired chromosome) is translocation between chromosomes 9 and 22.

Forms oncogene, BCRADL –> associated with proliferation.

Question 10

What is the ‘proof’ that all cancer arrives from one cell?

Answer 10

The inactive X is the same inactive X in all of the tumor.

Question 11

Cancer progresses through different stages. Example of uteran cancer. What defines low grade intraepithelial neoplasia, high grade intraepithelial neoplasia, and invasive carcinoma?

Answer 11

low grade: dividing cells invade lower 1/3 of epithelium.

High grade: cells in all of epithelium are proliferating

Invasive (malignant): cells move through or destroy basal lamina.

Question 12

Clonal evolution *****

Answer 12

cells around each other have the initial mutation. One might get new mutation (cell prolif or decrease cell death) and will try to out compete surrounding cells for malignancy.

Harbor different mix of mutations and competing to be dominant clone in the tumor.

Question 13

What can cancer stem cells do that is bad?

Answer 13

Give rise to all types of cells within the microenvironment of the tumor.

Question 14

Two ways that tumors can break off and spread to others.

Answer 14

1. cross into blood stream

2. cross into lymphatic system.

Question 15

Why is it important to know that a tumor is a microenvironment?

Answer 15

It might be beneficial to target all the types of cells in the tumor. Example fight off angiogenesis.

Question 16

How are cancers and viruses related to cancer?

Simple broad explanation

Answer 16

They damage the cell and can induce mutations.

Question 17

What cancer is related to the Hrpsevirus family and Epstein- Barr virus

Answer 17

Burkitt’s lymphoma ( B lymphocyte cancer)

Nasopharyngeal carcinoma

Question 18

What cancer is HIV related to?

HTLV1?

Answer 18

HIV= Kaposi’s sarcoma

HTLV1= Adult T-cell leukemia/ lymphoma
– (Human Tcell Leukemia Virus-1)

Question 19

How can viruses produce cancer?

What two proteins work in HPV?

Answer 19

1. SRC integrate oncogene into DNA
2. E6 and E7- Cell proliferation AND lose of suppressant function
   - - E6 inhibits p53
   - - E7 bind Rb and prevents binding to EIIF
3. Also HPV- plasmid chromosome entered into cell, accidentally incorporated into the human chromosome. Upregulation of certain viral proteins interferes with the control of cell division in basal cells

Question 20

Proto oncogene

Answer 20

Normal gene that could become an oncogene by over expression

Question 21

Overactivity (proliferation, oncogene) and tummor suppressants are needed to, what types of mutations are they?

Answer 21

oncogene (gain of function) = dominant

tummor suppresant (loss of function) = recessive

Question 22

Mechanism of retinoblastoma?

Answer 22

p16 (Cdk inhibitor) > cyclin DCdk complex > Rb > E2F > transcription of target genes to control s phase entry

Question 23

Non hereditary vs hereditary retinoblastoma

Answer 23

Non-hereditary= mutates both alleles (recessive) then goes on to tumors

Hereditary= acquire copy of bad allele, second allele mutation acquired. Leads to multiple tumors in both eyes

Question 24

how to convert proto oncogene into an oncogene?

Answer 24

Point mutation or deletion- leads to overactive gene

Mutation in regulatory gene= overactive gene

Gene amplification= too much normal protein

Chromosomal rearrangement

Question 25

How does microarray help with cancers?

Answer 25

You can analyze gene expression to see what has changed from the normal cell. Binds PROTEINS

Question 26

p16s role in cancer?

Answer 26

Mutated/inactive form does not bind to Cdk4 and can’t inhibit it.

Question 27

How are growth factors related to cancer?

How about metabolism and what does mTOR do?

Answer 27

Growth factor is unregulated.

Glucose inport will increase to meet the demand of the higher metabolic activity.

mTOR leads to increased protein synthesis, increased glycolysis and glucose uptake.

Question 28

Colon cancer pathway

Answer 28

normal epithelium > loss of Apc > early adenoma > activation of K-ras (protooncogene) > intermediate adenoma > loss of Smad4 and other tumor suppressors > late adenoma > loss of p53 > carcinoma > other unknown alterations > invasions and metastasis

1. lose Apc
2. activate K-ras
3. loss of Smad4 and other tumor suppressors
4. loss of p53