Brainscape's Knowledge GenomeTM

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


See full index

EMS > Lecture 37: Carcinogenesis: causes of cancer > Flashcards

Lecture 37: Carcinogenesis: causes of cancer Flashcards

1
Q

What are Heterocyclic aromatic amines (HAAs)?

A

HAAs are heat-induced mutagenic agent present in some food products. These can cause single stranded DNA breaks, chromosomal aberrations and DNA adducts in guanine-rich regions.

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

What are Polycyclic aromatic hydrocarbons (PAHs)?

A

Combustion of organic matter results in the generation of PAHs resulting in the development of breast, skin or lung cancer. Bioactivation of PAHs results in carcinogenesis mediated by cytochrome P450 enzymes

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

What is ultraviolet (UV)?

A

This agent is implicated in the causation of skin tumours by targeting pyrimidine bases.

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

What is ionizing radiation?

A

Exposure to ionising radiation induces DNA damage. The carcinogenesis effect promotes the production of reactive oxygenation species resulting in oxidative damage, which can result in single stranded breaks. Direct interaction of electrons with DNA resulting in molecular distortion and double stranded breaks.

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

What is asbestos?

A

Asbestos is found in industry and household applications. Damage occurs through oxidative stress, fibrosis and interaction with the mitotic apparatus of dividing cells.

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

What do carcinogens do?

A

Carcinogens work by interacting with a cell’s DNA and inducing genetic mutations. A carcinogen is a specific chemical or physical agent that has the ability to cause cancer in individuals exposed to that agent.

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

What is a carciongen?

A

an external agent associated with causing cancer

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

Which organisation classified agents into carcinogen related categories from 1-4?

A

The International Agency for Research on Cancer (IARC)

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

What does category 1 of the IARC carcinogen list mean?

A

carcinogenic to humans

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

What does category 2a of the IARC carcinogen list mean?

A

probably carcinogenic to humans

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

What does category 2b of the IARC carcinogen list mean?

A

possible carcinogenic to humans

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

What does category 3 of the IARC carcinogen list mean?

A

carcinogenicity not classifiable

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

What does category 4 of the IARC carcinogen list mean?

A

probably not carcinogenic

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

Give 3 examples of category 1 carcinogens:

A

1) tobacco

2) UV light

3) processed meats

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

Give 2 examples of category 2a carcinogens:

A

1) red meat

2) working night shifts

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

Give 2 examples of category 2b carcinogens:

A

1) radio frequency

2) gasoline

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

Give 3 examples of category 3 agents listed in the IARC carcinogen list:

A

1) caffeine

2) cholesterol

3) fluorescent light

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

What is the main general mechanism of carinogenesis?

A

DNA damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are heterocyclic aromatic amines?

A

heat-induced mutagenic agents present in some food products

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

Give 3 ways in which heterocyclic aromatic amines cause DNA damage:

A

1) single stranded DNA breaks

2) chromosomal aberrations

3) DNA adducts

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

What are DNA adducts?

A

covalent modifications to DNA due to carcinogens

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

What process generates polycyclic aromatic hydrocarbons?

A

the combustion of organic matter

23
Q

What enzyme mediates polycyclic aromatic hydrocarbon carcinogenesis?

A

cytochrome p450

24
Q

What bases does ultraviolet radiation target?

A

pyrimidine bases (C, T and U)

25
Q

Give 2 ways in which ionising radiation can damage DNA:

A

1) it promotes free radical production, resulting in oxidative damage, causing single stranded breaks in DNA

2) direct interaction of electrons with DNA results in molecular distortion and double stranded breaks

26
Q

Give 3 ways in which asbestos causes DNA damage:

A

1) oxidative stress

2) fibrosis

3) negative interactions with the mitotic apparatus of dividing cells

27
Q

Give 6 examples of viral carcinogens:

A

1) epstien-barr virus

2) hepatitis B and C

3) kaposi sarcoma herpes virus

4) HIV type 1

5) human papillomavirus type 16

6) human T cell lymphotropic virus type 1

28
Q

What cancers is epstein-barr virus associated with? (2)

A

1) nasopharyngeal carcinomas

2) lymphomas

29
Q

What cancer is hepatitis B and C associated with?

A

Hepatocellular carcinoma

30
Q

What cancer is kaposi sarcoma herpes virus associated with?

A

kaposi sarcoma

31
Q

What cancers is HIV type 1 associated with? (3)

A

1) kaposi sarcoma

2) carcinoma of the conjunctiva, anus and cervix

3) lymphomas

32
Q

What cancers is human papilloma virus (HPV) type 16 associated with?

A

carcinoma of the cervix, vulva, vagina, penis, anus, oral cavity, oropharynx and tonsil

33
Q

What cancers is human T cell lymphotropic virus type 1 associated with? (2)

A

1) adult T cell leukaemia

2) lymphoma

34
Q

Give three examples of carnicogenic protozoa:

A

1) Clonorchis sinensis

2) Opisthorchis viverrine

3) Schistosoma haematobium

35
Q

What cancer is Helicobacter pylori associated with?

A

non-cardia gastric carcinoma

36
Q

What cancer is Clonorchis sinensis associated with?

A

cholangiocarcinoma

37
Q

What is cholangiocarcinoma?

A

Cancer of biliary tract epithelium

38
Q

What cancer is Opisthorchis viverrine associated with?

A

cholangiocarcinoma

39
Q

What cancer is Schistosoma haematobium associated with?

A

urinary bladder cancer

40
Q

Describe the initiation process of carcinogenesis:

A

the carcinogen reaches a cell activating proto-oncogenes, inactivating onco-suppressor genes and anti-metastatic genes

41
Q

Describe the promotion process of carcinogenesis:

A

the initiated cell develops defects in growth control and programmed cell death as well as a resistance to cytotoxicity allowing for selective clonal expansion, forming a pool of preneoplastic cells

42
Q

Describe the progression process of carcinogenesis:

A

further genetic changes allow for the preneoplastic cells to become malignant tumours and eventually a cancer invasion

43
Q

What cell cycle proteins drive progression and act as check points?

A

cyclins

44
Q

What enzyme phosphorylates protein substrates by forming complexes with their relevant cyclins?

A

cyclin dependent kinases

45
Q

What 2 amino acids do cyclin dependent kinases phosphorylate?

A

1) serine

2) threonine

46
Q

In which two stages of the cell cycle can cells be halted and removed?

A

1) between G1 and S

2) between G2 and M

47
Q

What is biotransformation in relation to carcinogenesis?

A

the deactivation or activation of a carcinogen absorbed and distributed by a tissue

48
Q

Give two examples of geneotoxic carcinogen mechanisms:

A

1) DNA adductions

2) chromosomal breakages, fusion, deletion, mis-segregation and non-disjunction

49
Q

Give six examples of non-genotoxic carcinogen mechanisms:

A

1) inflammation

2) immunosuppression

3) reactive oxygen species

4) reactive nitrogen species

5) receptor activation

6) epigenetic silencing

50
Q

Give three methods of epigenetic silencing:

A

1) DNA methylation

2) histone methylation

3) histone acetylation

51
Q

Give 4 genes associated with breast cancer in women:

A

1) BRCA1

2) BRCA2

3) ATM

4) BARD1

52
Q

Give 4 genes associated with colorectal cancer, gastric cancer and endometrial cancer:

A

1) EPCAM

2) MSH2

3 MSH6

4) MLH1

53
Q

Give 2 genes associated with melanoma:

A

1) BAP1

2) BRCA2

54
Q

Give 6 genes associated with pancreatic and prostate cancer:

A

1) BRCA1

2) BRCA2

3) ATM

4) MSH2

5) MSH6

6) MLH1

EMS (54 decks)

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