cancer Flashcards
(25 cards)
what is cancer a result of ?
- mutations in genes that regulate mitosis
what happens if the genes that regulate mitosis have a mutation ?
- non-functioning proteins are made
- mitosis is not regulated
- results in uncontrollable cell division and the creation of a tumour
what are the 2 types of tumours ?
- benign
- malignant
features of benign tumours ?
- grow very large but at a slow rate
- non-cancerous tumours
- often surrounded by a membrane so remain compact and cannot break off and invade surrounding tissues
- can be removed by surgery and rarely return
why are benign tumours non-cancerous tumours ?
- they produce adhesion molecules sticking them together and to a particular tissue (1 location in the body)
how do we describe the impact of a benign tumour ?
- the impact is localised and often non-life threatening, depending on the location of the tumour
features of malignant tumours ?
- cancerous
- grow very large very rapidly
- cell nucleus becomes large and the cell can become unspecialised again
- so not produce the adhesive
- instead metastasis occurs
- not contained by a cell membrane so can grow projections into surrounding tissues and develop its own blood supply
what is meant by metastasis occurring in malignant tumours ?
- the tumour breaks off and spreads to other parts of the body in the bloodstream
- resulting in secondary tumours
what is the impact of a malignant tumour ?
- can be life threatening
- removal of the tumour needs supplementary treatment
- recurrence is more likely
what are examples of supplementary treatments for malignant tumours ?
- chemotherapy
- radiotherapy
how do tumours develop ?
- due to a gene mutation in either:
- the tumour suppressor gene and/or oncogene
- abnormal methylation of tumour suppressor genes and oncogenes
- increased oestrogen concentrations
what are oncogenes ? and what do they create ?
- the mutated versions of a proto-oncogene
what is the function of a proto-oncogene ?
- creates a protein involved in the initiation of DNA replication and mitosis cell division when the body needs new cells
what can oncogene mutations result in ?
- the process of DNA replication and mitosis being permanently activated to make cells divide continually
what is the function of tumour suppressor genes ?
- genes that produce proteins to slow down cell division and to cause cell death if DNA copying errors are detected
what occurs when there is a mutation in the tumour suppressor gene ?
- it does not produce the proteins that slow down cell division
- so cell division could continue
- mutated cells would not be identified and destroyed
what are the 2 known mutated tumour suppressor genes that are linked to breast cancer ?
- BRCA1
-BRCA2
what type of methylation do tumour suppressor genes show and what does this result in ?
- hypermethylation
- results in the gene being inactivated and becomes turned off
what type of methylation do oncogenes show and what does this result in ?
- hyomethylation
- results in the gene being permanently switched on
where is oestrogen produced ?
- produced by the ovaries
why is oestrogen produced by the ovaries ?
- to regulate the menstrual cycle
when does oestrogen production stop ?
after menopause
what happens instead of the ovaries producing oestrogen after menopause ?
- fate cells in breast tissues can produce oestrogen and this has been linked with causing breast cancer in women post-menopause
what kind of effect does the beast cancer tumour have and why ?
- knock on effect
- tumour results in even more oestrogen production which increases the tumour size and attracts white blood cells which can increase the tumour size futher
