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Flashcards in Neoplasia (Henry) Deck (29)
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1
Q

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

A

cancer

2
Q

what two heritable properties define cancer cells?

A
  1. they reproduce in defiance of normal restraints of cell division
  2. they invade and colonize other tissues
3
Q
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
A

D

4
Q
Which of these is not a risk factor for cancer?
A. Low BMI
B. Bad luck
C. Age
D. Environmental exposures
E. Genetics
A

A

5
Q

____ lesions irreversibly affect DNA sequence and karyotype.

A

genetic

6
Q

____ changes affect gene expression and may be reversible

A

epigenetic

7
Q

two inactivating mutations functionally eliminate these genes, promoting cell transformation

A

tumor suppressor genes

8
Q

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

A

oncogene

9
Q

why is there a high level of variation in melanoma?

A

uv exposure causes pyrimidine dimers in DNA that are not repaired

10
Q

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

A

tumor

11
Q
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
A

D

12
Q

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

A

Rb

13
Q

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

A

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

14
Q

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

A

P53

15
Q

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

A

viral (HPV, Epstein Barr)

16
Q

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
A

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.

17
Q

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

A

telomerase

18
Q

why do cancers cause bleeding?

A

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

19
Q

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

A

HIF1α (hypoxia inducing factor); VEGF

20
Q

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

A

hematogenous

21
Q

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

A

e-cadherin

22
Q

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

A

matrix metalloproteases

23
Q

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

A

anoikis

24
Q

what is meant by the term “metastatic inefficiency”?

A

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.

25
Q

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

A

Warburg Effect - this is the basis of PET imgaing

26
Q

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

A
  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
27
Q

_____ 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).

A

inflammation

28
Q

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

A

vemurafenib

29
Q

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

A

biomarker