20 - Carcinogenesis Flashcards Preview

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Flashcards in 20 - Carcinogenesis Deck (22):
1

Aflatoxin affects the

Liver

2

Alcohol affects the

pharynx, larynx, oesophagus, liver

3

Asbestos affects the

lung pleura

4

X rays affect

Bone marrow - leukaemia

5

Oestrogen affects

breast

6

tobacco smoke affects

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

7

HBV affects the

liver (hepatitis B virus)

8

HPV affects the

cervix (human papilloma virus)

9

initiator carcinogen

chemically modifies DNA

10

promoter carcinogen

induce proliferation and DNA replication

11

complete carcinogen

both a promoter and an initiator e.g. UV light

12

CpG methylation is only effective at turning gene expression off when

the CpG islands occurs within the promoter sequence of the gene

13

TSG stands for

tumour suppressor gene

14

direct acting metabolic activation

interact directly with DNA e.g. oxygen radicals, nitrosomines, UV light, ionising radiation

15

Procarcinogens are

require enzymatic activation before they react with DNA e.g. aromatic amines, polycyclic aromatic hydrocarbons (PAHs)

16

what is benzopyrene?

generated through combustion of most organic material e.g. meat, tobacco, fuel requires metabolic activation.

involved with the TP53 gene.

17

defects in the ATM gene lead to what

ATM gene responsible for recombinational repair

gives rise to ataxia telangiectasis (A-T). AR disorder. 100-fold increase in cancer.

18

Lynch syndrome aka

Hereditary non-polyposis colorectal cancer (HNPCC)

19

Defence against carcinogenesis

Exposure to myriad carcinogenic agents
Many defences
Dietary antioxidants
Detox mechanisms
DNA repair enzymes
Apoptotic response to unrepaired genetic damage
Immune response to infection and abnormal cells

20

An e.g. of PAH

(Polycyclic aromatic hydrocarbons)

e.g. benzopyrene

21

what is alcohol converted to to make it do DNA damage?

acetaldehyde

also more oestrogen and testosterone, increases carcinogenic uptake in upper GI, reduce levels of folate and kills surface epithelium.

22

why does chronic inflammation cause cancer?

inflam response causes DNA damage from release of free radicals by immune cells (initiation).

Growth factor induced cell division to repair tissue damage.