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Flashcards in MOD - carcinogenesis + behaviours of tumours Deck (108)
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what two types of meat can cause colorectal cancer?

- red meat
- processed meat


what carcinogens are workers exposed to in aluminium production, coal gasification, coke production, iron and steel industries?

heavy metals

eg cadmium and nickel


mining of hematite and uranium exposes miners to what carcinogen?



what sort of cancers have been reported among woodworkers\?

cancers of the sinonasal cavities and paranasal sinuses


what industry exposes workers to the carcinogens B-napthylamine and 4-aminobiphenyl?

rubber industry


what type of cancer is seen in workers in boot/shoe manufacture and repair?

nasal adenocarcinoma


what is EPIC?

The European Prospective Investigation into Cancer and Nutrition (EPIC) study is one of the largest cohort studies in the world, with more than half a million (521 000) participants recruited across 10 European countries and followed for almost 15 years. EPIC was designed to investigate the relationships between diet, nutritional status, lifestyle and environmental factors, and the incidence of cancer and other chronic diseases.


what are the 6 categories of human carcinogens?

Chemicals e.g. PAHs, nitrosamines

Infectious agents e.g. human papilloma virus, Helicobacter pylori

Radiation e.g. UV light, radon

Minerals e.g. asbestos, heavy metals
Like cadmium and nickel

Physiological e.g. oestrogen, androgens

Chronic inflammation – free radicals and growth factors


what are PAHs

Polycyclic aromatic hydrocarbons (PAHs) are a group of more than 100 different chemicals that are released from burning coal, oil, gasoline, trash, tobacco, wood, or other organic substances such as charcoal-broiled meat

they are carcinogens


what type of cancer does exposure to aflatoxin cause? and what is it?

liver cancer

a mold found on food products such as corn and peanuts, peanut butter


what 4 types of cancer does alcohol cause?

pharynx, larynx, oesophageal, liver


what type of cancer does asbestos cause?


(ie of the lung pleura)


what type of cancer do x-rays cause?

leukaemia (bone marrow)


what kind of cancer does oestrogen cause?

breast cancer


what 6 types of cancer does smoking cause?

lung, mouth, oesophagus, pancreas, kidney, bladder

and others!!


what kind of cancer does HPV (human papilloma virus) cause?



what is a carcinogen?

any agent that significantly increases the risk of developing cancer


what are the 3 types of carcinogen?

- modify or damage dna (genotoxic)

- induce proliferation and DNA replication (non-genotoxic)

complete carcinogens
- initiate and promote
- eg UV light


what 2 steps does initiation of cancer (mutation induction) require?

- chemical modification of DNA
- replication of modified DNA and mis-incorporation by DNA polymerase


what are the two ways in which promoters contribute to carcinogenesis?

- by stimulating the 2 rounds of DNA replication required for mutation fixation

- by stimulating clonal expansion of mutated cells, which enables the accumulation of further mutations


what are the 3 stages of carcinogenesis?

- initiation
- promotion
- progression


why are you a lot more likely to get a basal cell carcinoma than a melanoma?

because cancer is directly related to levels of cell division

Basal cells and maelanocytes (produce melanin) are exposed to the same amount of uv light but, because basal cells replicate more in normal physiology, you are 10 fold more likely to get a basal cells carcinoma than a melanoma

This would support a hypothesis that cell division, and by inference DNA replication, is a significant risk factor for the development of cancer


what genetic change is associated with chronic myeloid leukaemia?

translocation on chromosome 22 (Philadelphia translocation)


what is aneuploidy?

Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46.


mutations which result in an over-activation in which genes can cause cancer?

activation of proto-oncogenes


mutations which result in an inactivation in which genes can cause cancer?

inactivation of tumour suppressor genes (TSGs)


what is a colloquial name for a common type of promoter sequence?

CpG islands


what does methylation of promotor sequences result in?

loss of gene expression of said gene


what are the two 'umbrella' ways that carcinogens can induce cancer?

+ examples?

direct acting
- interact directly with DNA
(eg oxygen radicals, UV light, ionising radiation, nitrogen mustard)

- require enzymatic (metabolic) activation before they react with DNA
(eg polycyclic aromatic hydrocarbons - PAH, found in burnt organic products)


what is benzopyrene? what is it an example of? and what happens to it in the body?

a type of PAH

can be generated through combustion of most organic material (eg meat, tobacco, fuel)

example of a procarcinogen
- requires activation to convert it to BPDE (= ultimate carcinogen)

however genetic variation in enzymes between individuals determines how much bpde you produce from a set amount of benzopyrene

so same level of exposure but different likelihood of developing cancer