20 - Carcinogenesis

Question 1

Aflatoxin affects the

Answer 1

Liver

Question 2

Alcohol affects the

Answer 2

pharynx, larynx, oesophagus, liver

Question 3

Asbestos affects the

Answer 3

lung pleura

Question 4

X rays affect

Answer 4

Bone marrow - leukaemia

Question 5

Oestrogen affects

Answer 5

breast

Question 6

tobacco smoke affects

Answer 6

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

Question 7

HBV affects the

Answer 7

liver (hepatitis B virus)

Question 8

HPV affects the

Answer 8

cervix (human papilloma virus)

Question 9

initiator carcinogen

Answer 9

chemically modifies DNA

Question 10

promoter carcinogen

Answer 10

induce proliferation and DNA replication

Question 11

complete carcinogen

Answer 11

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

Question 12

CpG methylation is only effective at turning gene expression off when

Answer 12

the CpG islands occurs within the promoter sequence of the gene

Question 13

TSG stands for

Answer 13

tumour suppressor gene

Question 14

direct acting metabolic activation

Answer 14

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

Question 15

Procarcinogens are

Answer 15

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

Question 16

what is benzopyrene?

Answer 16

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

involved with the TP53 gene.

Question 17

defects in the ATM gene lead to what

Answer 17

ATM gene responsible for recombinational repair

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

Question 18

Lynch syndrome aka

Answer 18

Hereditary non-polyposis colorectal cancer (HNPCC)

Question 19

Defence against carcinogenesis

Answer 19

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

Question 20

An e.g. of PAH

Answer 20

(Polycyclic aromatic hydrocarbons)

e.g. benzopyrene

Question 21

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

Answer 21

acetaldehyde

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

Question 22

why does chronic inflammation cause cancer?

Answer 22

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

Growth factor induced cell division to repair tissue damage.