Neoplasia 2

Question 1

Two enabling factors of malignancy

Answer 1

Tumor promoting inflammation and genomic instability (mutator phenotype)

Question 2

Examples of tumor suppressor genes

Answer 2

Rb, p52, TGF β, APC

These send proliferating cells to enter G0

Question 3

How do tumors evade apoptosis?

Answer 3

Usually by the lost of p53 function that cause over expression of MDM2 which is a p53 inhibitor

Question 4

What is BCL2?

Answer 4

Anti-apoptotic member

Question 5

Explain the mechanism of how tumor cells have limitless replciative potential (telomeres)

Answer 5

Tumor cells deactivate telomerase and thus telomeres do not shorten after replication and thus allowing for limitless replicative potential

Question 6

Metabolism of cancer cells

Answer 6

Warburg metabolism where they favor glycolysis over oxidative phosphorylation

Question 7

Some ocoproteins (products of mutated oncogenes) causes formation of high levels of abonromal metabolites that leads to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_? 
Give an example of a metabolite

Answer 7

Epigenetic changes and oncogenic gene expression

Ex. Mutated isocitrate dehydrogenase (IDH)

Question 8

Tumor cells can activate and influence stromal cells.

How are stromal cells changed to allow for tumor cell invasion and metastasis?

Answer 8

Proteases remodel the ECM and TGF β promotes epithelial mesenchymal transition (EMT)

Question 9

Genetic component of HNPCC

Answer 9

Micro satellite instability characterized by changes in length of short tandem repeating sequences

Question 10

Xeroderma pigmentosum have a defect in ____________ (genetics)

Answer 10

Nucleotide excision repair pathway

Question 11

Tumors with high/low growth fractions are susceptible to chemotherapy

Answer 11

High;

Growth fraction: # of cycling cells / # of total cells

Question 12

In tumor cells there is more cells in the proliferative/nonproliferative pool in the cell cycle

Answer 12

Proliferative;

Normal cells you will see more of them in the non proliferative pool

Question 13

Sub populations of tumors may vary in:

Answer 13

Antigenicity, invasiveness, metastatic potential, and growth factor requirement

Question 14

Phases of metastasis

Answer 14

1. Invasion of ECM
2. Spread into the interstitial tissue
3. Hematogenous spread and tumor homing

Question 15

How do tumor cells detach and degrade ECM proteins

Answer 15

Detach Bria ↓ Catherine’s

Degrade via colagenase and Cathepsin B

Question 16

The homing (metastatic site) of tumors is related to:

Answer 16

• presence of absence of specific molecules
• chemokines
• unfavorable environment like the muscle

Question 17

Examples of tumor antigens for tumor immunity

Answer 17

• Products of mutated oncogenes and tumor suppressor genes such as RAS, BCR-ABL
• overexpressed cellular proteins such as PSA
• antigens produced by viruses
• oncofetal antigens such as CEA
• ## altered cell surface protein CA125, CA19.0

Question 18

Tumors with high/low infiltrating lymphotes (CTL and TH1 cells) have a better prognosis

Answer 18

High

Question 19

How do tumor cells breakdown the immulogical barrier?

Answer 19

Production of proteins that inhibit CTL’s, antigenic modulation and outgrowth of antigen negative clones

Question 20

Therapy involving CLTA4

Answer 20

Using an inhibitor antibody for CLTA4 allows CD8 T cells to engage B7 coreceptors and thus activate T cells

Question 21

Immunotherapy involving program cell death ligand

Answer 21

Using an anti-PD1 ligand can lead to activation of CTL which kill the tumor cells

Question 22

Describe grade of a tumor

Answer 22

Level of differentiation and is particular tot he tumor

Based on differentiation, mitosis and necrosis

Question 23

What is the stage of a tumor

Answer 23

Extent of spread

Usually more important than grade

Question 24

Explain the TNM categories in staging a tumor

Answer 24

T: size of tumor
N: extent of spread to regional lymph nodes
M: metastases (presence or absence)