Neoplasia (Henry)

Question 1

a genetic disease, involving mutations and epigenetic alterations, primarily of somatic cells

Answer 1

cancer

Question 2

what two heritable properties define cancer cells?

Answer 2

1. they reproduce in defiance of normal restraints of cell division
2. they invade and colonize other tissues

Question 3

Which of these is a characteristic of malignant tumor cells?
A. slow growing
B. homogenous
C. aneuploidy
D. mitotic bodies are present
E. high cytoplasmic to nucleus ratio

Answer 3

D

Question 4

Which of these is not a risk factor for cancer?
A. Low BMI
B. Bad luck
C. Age
D. Environmental exposures
E. Genetics

Answer 4

A

Question 5

____ lesions irreversibly affect DNA sequence and karyotype.

Answer 5

genetic

Question 6

____ changes affect gene expression and may be reversible

Answer 6

epigenetic

Question 7

two inactivating mutations functionally eliminate these genes, promoting cell transformation

Answer 7

tumor suppressor genes

Question 8

gene that may become active after only a single mutation event, leading to either gain or loss of function in the protein

Answer 8

oncogene

Question 9

why is there a high level of variation in melanoma?

Answer 9

uv exposure causes pyrimidine dimers in DNA that are not repaired

Question 10

activated fibroblasts, macrophages, and endothelial cells all contribute to the ____ microenvironment

Answer 10

tumor

Question 11

Loss of CDK inhibitors, overexpression of Cyclin D1/CDK4 and constitutively active Ras are all ways that a cancer cell may exhibit which 'hallmark of cancer'?
A. Limitless replicative potential
B. Evading apoptosis
C. Insensitivity to anti-growth signals
D. Self-suficiency in growth signals
E. Sustained angiogenesis

Answer 11

D

Question 12

a classical tumor suppressor gene that, when hypophosphorylated, controls entry into the cell cycle via its regulation of the E2F transcription factor; it is inactivated in many tumor types

Answer 12

Rb

Question 13

what does it mean that retinoblastoma follows a 2-hit model?

Answer 13

it takes the knockout of both Rb genes for a tumor to form.

Question 14

the ‘guardian of the genome’ that induces cell cycle arrest to allow for DNA repair and is involved in Li-Fraumeni syndrome

Answer 14

P53

Question 15

The Rb and P53 pathways are targets for what type of oncoproteins?

Answer 15

viral (HPV, Epstein Barr)

Question 16

Which of these is a way that cancer cells evade death?

A. Upregulatation of CD95
B. Upregulation of Bax
C. Decreased expression of APAF-1
D. Downregulation of Bcl-2
E. Downregulation of inhibitors of apoptosis

Answer 16

C. APAF-1 (stands for apoptotic protease activating factor 1)

Bax is a pro-apoptotic protein and Bcl-2 is anti-apoptotic. CD95 is the Fas receptor and is important for death receptor signalling.

Question 17

enzyme that is often overexpressed in cancer cells that gives the cell limitless replicative potential

Answer 17

telomerase

Question 18

why do cancers cause bleeding?

Answer 18

tumor blood vessels are poorly formed and leaky compared to normal blood vessels

Question 19

when a tumor cell gets too far away from a blood source, upregulation of ____ is triggered, which drives the expression of ____, which causes endothelial cells to proliferate that will later become new blood vessels

Answer 19

HIF1α (hypoxia inducing factor); VEGF

Question 20

____ metastasis occurs when cancer cells travel to other parts of the body via the blood vessels

Answer 20

hematogenous

Question 21

loss of this protein in tumor cells is one factor that gives them an ability to invade and metastasize

Answer 21

e-cadherin

Question 22

enzymes that degrade the basement membrane/ECM of cells, facilitating tumor cell invasion

Answer 22

matrix metalloproteases

Question 23

cancer cells avoid ____, which is an induction of death for a cell that becomes detached from the matrix

Answer 23

anoikis

Question 24

what is meant by the term “metastatic inefficiency”?

Answer 24

only a small fraction of the tumor cells shed into circulation produce a clinically detectable metastasis. this is because cells are subject to immune system exposure, anoikis and hemodynamic stress.

Question 25

cancer cells exhibit altered energy metabolism compared to normal cells, often manifested as increaed aerobic glycolysis. this is known as what?

Answer 25

Warburg Effect - this is the basis of PET imgaing

Question 26

Name 3 ways that tumors may avoid the immune system in immunocompetent patients

Answer 26

1. secrete factors like TGF-β to dampen immune response
2. engagement of the T-cell inhibitory receptor CTLA-4
3. activation of immune-suppressive regulatory T-cells
4. selective outgrowth of antigen-negative variants
5. reduced expression of histocompatibility antigens

Question 27

_____ may be a response to tumor growth or it may occur as a result of a chronic inflammatory condition (e.g. Crohn’s disease) or associated with infectious agents (e.g. Helicobacter pylori).

Answer 27

inflammation

Question 28

drug used for treatment of melanoma that targets the cell proliferation-causing BRAF mutation

Answer 28

vemurafenib

Question 29

A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process and may be used to see how well the body responds to a treatment for a disease or condition

Answer 29

biomarker