Cancer
Lecture 1
- Very old disease found 2 million years ago it was found in a mummy (prostate
cancer) and a European princess had breast cancer
- Carcinogen – chemical agents that cause cancer
- X ray and UV, tar from cigarette (over 100)
- Virus infection – papilloma virus can be responsible for cervical cancer
- Hereditary – more susceptible to getting certain cancer
Geographical variation
- Australian have melanoma (Skin cancer), prostate cancer common in UK and US,
liver cancer in china, penis cancer in brazil and low in Israel where there is religion,
- But some can be lower reporting of cancer
- Lung cancer kills more people in eastern people,
- Alcohol is not a carcinogen but as a result of metabolism can lead to many
carcinogen – can lead to many cancer
- Alcohol can degrade good genes, direct cell damage, increase damage from tobacco,
affect hormones linked to breast cancer – so can cause 7 types of cancer
- Tobacco can cause 14 types of cancer –
Chemical carcinogen
- Classified as direct and indirect
- Direct include – UV light
- Indirect- they don’t do damage but as a result of metabolis can cause cancer
- Hydrocarbons that can cause cancer include benzo pyrene (found in smoke),
estrone,
Direct – can modify the DNA directly and introduce mutations by changing the N and O in
DNA bases. (ethylmethane sulfonate dimethyl sulfonate, nitrogen mustards)
Indirect – unreactive, water insoluble, but P-450 enzymes in cells add hydroxyl group to
solubilise them and can turn them into carcinogen. Eg: BENZOL PYRENE – it can be
converted to a harmful chemical, guanine normally pairs up with cytosine, but now it pases
up with GC into an AT basepair which is a mutation.
HOW TO IDENTIFY CARCINOGEN ? – AMES TEST
- One common feature is that they damage the DNA
- Anything that can cause a mutation is a potential carcinogen
- He took two separate test tube with liver extract from rats (rich source for any
bacterium to grow) and then he adds a special culture of salmonella bacteria that are
his negative – cannot synthesis histidine on its own but they still have the histidine
synthesising gene
- now in one test tube add a potential mutagen – as a result of mutation the deflect
may be reversed and may allow histidine biosynthesis to happen. Centrifuge them
Lecture 1
- Very old disease found 2 million years ago it was found in a mummy (prostate
cancer) and a European princess had breast cancer
- Carcinogen – chemical agents that cause cancer
- X ray and UV, tar from cigarette (over 100)
- Virus infection – papilloma virus can be responsible for cervical cancer
- Hereditary – more susceptible to getting certain cancer
Geographical variation
- Australian have melanoma (Skin cancer), prostate cancer common in UK and US,
liver cancer in china, penis cancer in brazil and low in Israel where there is religion,
- But some can be lower reporting of cancer
- Lung cancer kills more people in eastern people,
- Alcohol is not a carcinogen but as a result of metabolism can lead to many
carcinogen – can lead to many cancer
- Alcohol can degrade good genes, direct cell damage, increase damage from tobacco,
affect hormones linked to breast cancer – so can cause 7 types of cancer
- Tobacco can cause 14 types of cancer –
Chemical carcinogen
- Classified as direct and indirect
- Direct include – UV light
- Indirect- they don’t do damage but as a result of metabolis can cause cancer
- Hydrocarbons that can cause cancer include benzo pyrene (found in smoke),
estrone,
Direct – can modify the DNA directly and introduce mutations by changing the N and O in
DNA bases. (ethylmethane sulfonate dimethyl sulfonate, nitrogen mustards)
Indirect – unreactive, water insoluble, but P-450 enzymes in cells add hydroxyl group to
solubilise them and can turn them into carcinogen. Eg: BENZOL PYRENE – it can be
converted to a harmful chemical, guanine normally pairs up with cytosine, but now it pases
up with GC into an AT basepair which is a mutation.
HOW TO IDENTIFY CARCINOGEN ? – AMES TEST
- One common feature is that they damage the DNA
- Anything that can cause a mutation is a potential carcinogen
- He took two separate test tube with liver extract from rats (rich source for any
bacterium to grow) and then he adds a special culture of salmonella bacteria that are
his negative – cannot synthesis histidine on its own but they still have the histidine
synthesising gene
- now in one test tube add a potential mutagen – as a result of mutation the deflect
may be reversed and may allow histidine biosynthesis to happen. Centrifuge them
