Carcinogenesis : Causes of Cancer Flashcards Preview

EMS - Mechanisms Of Disease > Carcinogenesis : Causes of Cancer > Flashcards

Flashcards in Carcinogenesis : Causes of Cancer Deck (28):
1

What is the strongest association with eating red meat?

Colorectal cancer

2

The categories of human carcinogens are as follows. Give an example for each.
Chemicals
Infectious Agents
Radiation
Minerals
Physiological
Chronic Inflammation

1) Chemicals:
- PAHs (Polycyclic aromatic hydrocarbons)
-nitrosamines

2) Infectious agents
-human papilloma virus
-Helicobacter Pylori

3) Radiation
-UV light
-Radon

4)Minerals
-asbestos
-heavy metals

5)Physiological
-oestrogen
-androgens

6)Chronic Inflammation
-free radicals
-growth factors

3

PAHs are chemical carcinogens. What does it stand for?

Polycyclic aromatic hydrocarbons

4

Aflatoxin is associated with

Liver

5

Alcohol is associated with

Pharynx, Larynx, oesophagus, liver

6

Asbestos is associated with

Lung pleura

7

Xrays are associated with

bone marrow (leukaemia0

8

UV-Light is associated with

skin

9

Oestrogen is associated with

breast

10

Tobacco smoke is associated with

mouth, lung, oesophagus, pancreas, kidney, bladder

11

Hepatitis B virus is associated with

Liver

12

Human papilloma virus is associated with

cervix

13

What are initiators?

carcinogens that are genotoxic that can modify or damage DNA

14

What are promoters

carcinogens that induce proliferation and DNA replication.

15

What are complete carcinogens

They can both initiate (modify DNA) and promote (induce proliferation) e.g. UV light

16

What makes a carcinogen a good promoter?

1) can stimulate 2 rounds of DNA replication requires for mutation fixing
2) can stimulate clonal expansion of mutated cells

17

What are the common genetic abnormalities? (there are 7)

1) Base pair Substitution
2) Frameshift
3) Deletion
4) Gene amplification
5) Chromosomal translocation
6) Chromosomal inversion
7) aneuploidy

18

The term given to "the smallest change in the DNA sequence that can give rise to a change in gene function. They can result in an amino acid substitution (missense) or can introduce a stop condon into the coding sequence of a gene resulting in a truncated protein product"

Point mutation (or base pair substitution)

19

What is a frameshift mutation?

Gain or loss of one to several base pairs that results in a shift in the reading frame of a gene transcript

20

What does aberrent methylation of gene promoters leads to ........

inactivation of Tumour Suppressor Genes (TSGs)

21

How are Tumour Suppressor Genes most commonly inactivated?

Methylation of gene promotors causes inactivation of TSGs

22

What are oncogenes?

oncogene is a gene that has the potential to cause cancer. In tumor cells, they are often mutated or expressed at high levels.

23

Mutuations in which genes lead to a GAIN of function

Oncogenes

(oncogenes have a potential to cause cancer. If there is a mutation in the gene it becomes overactive >>>cancer)

24

Mutations found in XXX lead to a LOSS of function

Tumour suppressor genes

(if there is a mutation in TSGs then it can't work properly >>>cancer)

25

what are procarcinogens?

Pro-carcinogens require enzymatic (metabolic) activation before they react with DNA. e.g. PAHs (polycyclic aromatic hydrocarbons)

26

What are direct carcinogens?

Direct carcinogens interact directly with DNA e.g oxygen radicals, UV light

27

What is benzopyrene?

Benzopyrene is a PAH that can be generated through the combustion of most organic material such as meat, tobacco and fuel.
It is a PRO CARCINOGEN.

28

What is also known as Lynch Syndrome?

HNPCC (Hereditary non-polyposis colorectal cancer).

It is an autosomal dominant disorder.