Cancer Flashcards
1
Q
3 assumptions about carcinogenesis
A
- Malignant transformation of a single cell is sufficient to give rise to a tumour
- Any cell in a tissue is likely to be transformed as another of the same type
- Once a malignant cell is generated the mean time to tumour detection is generally constant.
2
Q
Ataxia telangiectasia
Gene mutation
Cancer predisposition
A
Neuromotor dysfunction, dilation of blood vessels.
- Mutation in ATM gene – codes serine/threonine kinase
- Recruited and activated by dsDNA breaks causing cell cycle arrest, DNA repair and apoptosis
- Cancer predisposition – lymphoma, leukaemia and breast cancer
3
Q
Bloom syndrome
Gene mutation
Cancer predisposition
A
short stature, <5 ft tall, rash develops after exposure to sun
- Mutation in BLM gene – instructions coding a member of RecQ helicase family – help maintain structure and integrity of DNA
- Cancer predisposition – skin cancer, basal cell carcinoma and squamous cell carcinoma
4
Q
Lynch syndrome
Gene mutation
Cancer predisposition
A
1st sign = symptoms of bowel and womb cancer develop.
- Mutations in DNA mismatch repair genes – MLH1, MSH2, MSH6 and PMS2
- Cancer predisposition – colorectal cancer
5
Q
Properties required for tumorigenic viruses
A
- Stable association with cells – integrates with chromosome, or episome
- Must not kill cells – suppress viral lytic cycle, viral release by budding, non-permissive host
- Must evade immune surveillance of infected cells – immune suppression, viral antigens not expressed at surface
6
Q
Somatic mutation theory
A
- ) Cancer derived from a single somatic cell – accumulated multiple DNA mutations
- ) Mutations damage genes which control cell proliferation and cell cycle
7
Q
Tissue organisation field theory
A
1.) Carcinogenic agents destroy normal tissue architecture –> disrupt cell to cell signalling and compromise genomic integrity
2.) DNA mutations are random and the effect – not cause if events
Carcinogenesis = deterioration of tissue microenvironment due to extracellular causes
