Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MOD > Carcinogenesis > Flashcards

Carcinogenesis Flashcards

1
Q

what are the main categories of carcinogens.

A 
chemicals
infectious agents
radiation
minerals
Physiological
chronic inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the target organ for aflatoxin

A

liver

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

what are the target organs for alcohol

A

pharynx, larynx, oesophagus and liver.

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

what is the target organ for asbestos

A

lungs pleura

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

what is the target organ for X-rays

A

bone marrow (leukaemia

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

what is the target organ for UV light

A

skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the target organ for oestrogen

A

breast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the target organ for tobacco smoke

A

mouth, lung, oesophagus, pancreas, kidney and bladder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the target organ for HBV

A

liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the target organs for HPV

A

Cervix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

define carcinogen

A

any agent that significantly increases the risk of developing cancer

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

what are the 2 types of biochemical carcinogens

A

Initiators- genotoxic

promoter- non genotoxic

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

define a initiator carcinogen

A

genotoxic i.e. can chemically modify or damage DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define a promoter carcinogen

A

non-genotoxic e.g. induce proliferation and DNA replication

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

how many rounds of cell division are required to show a initiator has been successful in modifying DNA which has been fives by DNA polymerase.

A

2

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

what are the 2 methods of action by which promoters work

A

Firstly, they can stimulate the two rounds of DNA replication required for mutation fixation
Secondly, they can stimulate clonal expansion of mutated cells, which enables the accumulation of further mutations

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

how many mutations are required to drive cancer cells

A

2-8.

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

describe the full pathogenesis of initiator and promoters and how they work together to cause cancer

A
  • Genotoxic initiating agent damages DNA
  • Promoting agent fixes damage as a mutation and converts normal cell into mutant initiated cell
  • Promoting agent stimulates clonal expansion of initiated cell to produce papillomas
  • Further rounds of mutations and clonal expansion allows papilloma to progress to carcinoma
19
Q

abnormal methylation of genera promoters leads to epigenetic inactivation of which class of genes

A

tumour suppressor genes.

CpG islands in promoter sites are methylated then the gene will no longer be expressed.

20
Q

do mutations in oncogenes lead to gain or loss in function

A

gain

21
Q

do mutations in tumour suppressor genes lead to gain or loss in function

A

loss

22
Q

the metabolic activation of carcinogens can be from 2 processes, theses include

A

direct acting-interact directly with DNA.

Pro carcinogen- require enzymatic (metabolic) activation before they react with DNA,

23
Q

examples of direct acting carcinogens include

A

oxygen radicals, nitrosomines, UV light and ionising radiation

24
Q

examples of pro carcinogens

A

aromatic amines, polycyclic aromatic hydrocarbons

25
Q

are most carcinogens direct acting or pro carcinogens

A

procarcinogens

26
Q

what is the function of the enzymes that help metabolically active pro carcinogens.

A

enzymes normally function in the detoxification and excretion of toxic chemicals.

27
Q

how does the involvement of enzymes that normally function in the detoxification and excretion of toxic chemicals introduce a genetic influence on the extent to which we are sensitive to genotoxic attack by different agents

A

people who activate a particular chemical more efficiently are more likely to get cancer, while those that excrete the activated chemical less efficiently are also more likely to get cancer

28
Q

does benzopyrene need metabolic activation before it can interact with DNA

A

Yes

29
Q

where is benzopyrene obtained

A

combustion of most organic material such as meat, tobacco and fuel,

30
Q

what gene does benzopyrene cause mutations in (tumour suppressor gene) and what cancer is it associated with

A

TP53

Lung cancer.

31
Q

how do genetic polymorphisms affect susceptibility to carcinogenic exposure

A

Genetic polymorphisms in genes encoding metabolic activation, detoxifying, or DNA repair enzymes may confer greater or lesser susceptibility to the effects of carcinogenic exposure

32
Q

what are the main defences against carcinogenic agents

A 
dietary antioxidants
detoxification mechanisms
DNA repair enzymes
Apoptotic response to unprepared genetic damage.
immune response to abnormal organism
33
Q

how many identifies carcinogens are there in tobacco smoke

A 
19
polycyclic aromatic hydrocarbons
acrolein
nitrosamines
radioactive lead and polonium
heavy metal- cadmium and chromium.
34
Q

the conversion of alcohol to what molecule increases the risk of DNA damage

A

acetylaldehyde.

35
Q

what hormone levels do alcohol consumption increase which act as promoters

A

osetrogen and testosterone

36
Q

is alcohol consumption ncreases uptake of carcinogenic chemicals into cells within the upper GI
reduces levels of what needed for DNA replication

A

folate

37
Q

In breast cancer how does oestrogen act as both a promoter and initiator.

A

Oestrogen binds to transcription factors, which increase proliferation.

Oestrogen converts to estradiol, 3-4 quionne which damages DNA

38
Q

does menarche decrease or increase your risk of breast cancer

A

decrease- less and less oestrogen.

39
Q

what procedure significantly reduced the risk of breast cancer

A

Oopherectomy

40
Q

how can chronic inflammatory response result in promoters and imitators being activated

A

DNA damage from release of free radicals by immune cells - initiation
Growth factor induced cell division to repair tissue damage - promotion

41
Q

what key cell links tumour cells and inflammatory response

A

tumour-associated macrophages (TAMs)

42
Q

what activates tumour-associated macrophages (TAMs)

A

cytokines released by tumour cells

43
Q

what do tumour-associated macrophages (TAMs) produce

A

tumour necrosis factor-alpha (TNF-α), a cytokine that induces and maintains the inflammatory response.

release reactive oxygen and nitrogen species (ROS and RNS) that can act as complete carcinogens, resulting in mutation by damaging DNA and stimulating proliferative through induction of growth factors
ROS - can also induce fibroblasts to undergo autophagy, which releases important nutrients that tumour cells can “feed” on

MOD (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions