Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Principles of Physiopathology > Molecular Biology of Neoplasias > Flashcards

Molecular Biology of Neoplasias Flashcards

(57 cards)

Start Studying
1
Q

There is a strong rationale for the implications of ___ in the evolution of cancers

A

genetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the molecular etiology of neoplasia/root of all cancers?

A

Genetic mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a mutation?

A

Alterations in nuclear DNA sequences (genes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens to most mutations?

A

They are repaired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which non-repaired genes will give rise to neoplasia?

A

Those that control cell growth, division, and differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some types of DNA mutations?

A
  • DNA point mutations
  • Chromosomal translocation
  • Gene amplification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Deletions can occur in…

A
  • entire chromosomes
  • parts of chromosomes
  • specific genes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some examples of additions?

A
  • Aberrant chromosome replication: trisomy and aneuploidy
  • Amplifications and repeats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What causes genetic mutation?

A
  • Environmental agents
  • Mutations arising during normal cell metabolism
  • Spontaneous errors in DNA replication and repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some examples of environmental agents/mutagens causing genetic mutation?

A
  • Chemical carcinogens
  • Radiation
  • Dietary carcinogens
  • Tobacco smokes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an example of a mutation arising during normal cell metabolism?

A

Free radical-induced mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A genetic characteristic of all neoplasms is that it’s a result of ___ genetic damage (acquired or inherited)

A

non-lethal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the normal regulatory genes that are principal targets of genetic damage?

A
  • Proto-oncogenes
  • Oncogenes
  • Tumor suppressor genes
  • Genes that regulate DNA repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Neoplasia is a ___ process

A

multi-step

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How many mutations are required to generate cancer?

A

6-12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the one-hit hypothesis?

A

One mutation can spoil the whole bunch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When proto-oncogenes are mutated, what can they become?

A

Oncogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are three examples of receptor mutations leading to neoplasia?

A
  • ret: stuck in ON position
  • erb: overexpression mutation
  • Her2/neu: 2 copies of human epidermal receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The receptor mutation, Her2/neu is important in what cancer?

A

Breast cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is an example of a G protein mutation leading to neoplasia?

A

ras mutation leaves G protein stuck in ON position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are some examples of nuclear regulatory protein mutations leading to neoplasia?

A

myc, jun, fos genes when activated, turn on last set of genes which turn on cell division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Oncogenes encode proteins called…

A

onco-proteins (which resemble normal products of proto-oncogenes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are proto-oncogenes?

Study These Flashcards
A

Cellular genes that promote normal growth and differentiation

24
Q

Proto-oncogenes may become oncogenic by…

Study These Flashcards
A

viral or other exogenous influences

25
Oncogenes are genes which promote...
neoplastic growth
26
Oncogenes are mutations of naturally occurring...
proto-oncogenes
27
Oncoproteins do not have...
important regulatory functions
28
Oncoprotein production in the transformed cell does not depend on...
growth factors or other external signals
29
What are the four classes of oncogenes?
1. Growth factors 2. Growth factor receptors 3. Membrane associated signal transduction proteins 4. Nuclear regulatory proteins
30
Sis encodes for...
Platelet Derived Growth Factor
31
Polypeptide growth factors normally stimulate...
proliferation of cells
32
Mutations of genes that encode growth factors render protein products oncogenic either by ___ or ___
overexpression or increased binding capacity
33
Normal receptor binding by growth factor results in...
transient activation of tyrosine kinase activity --> transient second messenger activity
34
How do oncogenic receptors differ from normal growth factor receptors?
They are either over-expressed or demonstrate persistent activation of enzyme activity --> continuous mitogenic signals to the cell
35
What is an example of continuous activation mutation of an oncogenic growth factor receptor?
ret continuous activation
36
What is an example of overexpression mutation of an oncogenic growth factor receptor?
erb overexpression
37
What class of oncogene is the Her2/neu gene leading to breast cancer?
Growth factor receptor mutation
38
Ras protein (G protein family) is the most well-studied...
membrane associated signal transduction protein
39
10-20% of all human cancers contain ___ mutations
ras
40
Ras mutation that contributes to neoplasia is a mutation that...
maintains ras protein in an activated state
41
What are nuclear regulatory proteins?
Proteins which are localized in the nucleus and which bind to DNA and activate transcription of proto-oncogenes
42
What are three nuclear regulatory proteins that may become oncogenes?
* myc * jun * fos
43
Tumor suppressor genes are involved in...
regulation of cell growth via inhibition
44
Inactivation of tumor suppressor genes that leads to neoplasia involves mutations of...
both alleles aka "two-hit" hypothesis ie. recessive genes
45
Name seven common tumor suppressor genes
* RB * P53 (guardian of genome) * BRCA1/BRCA2 * NFx * WTx * DCC * APC
46
Li Fraumeni syndrome is a mutation of which tumor suppressor gene?
P53
47
Breast carcinoma is caused by mutation of which tumor suppressor gene?
BRCA1/BRCA2
48
What mutation in DCC will cause colon carcinoma?
Deletion of DCC in colon carcinoma
49
P53 links cell damage with...
DNA repair, cell-cycle arrest, and apoptosis
50
P53 assists in DNA repair by causing... and inducing...
causing G1 arrest and inducing DNA repair genes
51
What happens with homozygous loss of p53?
DNA damage goes un-repaired
52
What percent of all cancers have p53 gene mutation?
75%
53
What type of gene is bcl-2? Overexpression of bcl-2 is found where?
bcl-2 is an anti-apoptotic gene Overexpression found in malignant lymphoma
54
What type of gene is bax? Deletion of bax can lead to what?
bax is a pro-apoptotic gene Deletion of bax can lead to malignancy
55
Programmed cell death is dictated by interaction/balance of...
anti- and pro-apoptotic gene products
56
What is telemorase? What happens when somatic cells lack telemorase?
Enzyme which prevents chromosome shortening (by adding nucleotides) Somatic cells lacking telemorase will eventually die
57
Do cancer cells "reactivate" telemorase?
Yes

Principles of Physiopathology (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions