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Cancer Biology > Introduction > Flashcards

Flashcards in Introduction Deck (28)
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1
Q

Definition

A

heterogeneous group of diseases where single cells acquire ability to proliferate abnormally - accumulation of progeny
tumours acquired ability to invade surrounding tissues

2
Q

Carcinoma

A

epithelial

3
Q

Sarcoma

A

mesoderm

4
Q

leukaemia/lymphoma

A

blood cell precursor

5
Q

benign

A

localised, non-invasive

6
Q

malignant

A

invasion and metastasis

7
Q

benign —> malignant

A

progression

8
Q

Angiogenesis

A

formation of new blood vessels

9
Q

Rate limiting step in growth

A

every cancer cell needs to be within 1mm of blood supply

10
Q

Metastasis

A

leave initial site and transit to distant sites via blood/lymph and body cavities

11
Q

Malignant melanoma can travel to

A

brain and liver

12
Q

intravasation

A

into vessel

13
Q

Mutation

A

stably inherited change in genetic material

14
Q

Evidence for genetic basis

A

inheritance
sporadic mutations are transforming
chromosomal changes common - particular to cancer
agents damage DNA —> increase cancer risk
diseases from DNA defects —> increase cancer
infection certain viruses —> development cancer

15
Q

Tobacco smoke responsible for

A

20-30% cancers

16
Q

Types mutation

A

Chromosome number change - ploidy change
translocations
amplifications
interstitial gains and losses
small deletions/insertions and single base pair muatations
exogenous sequences - viruses in cervical cancer HPV, burkitts lymphoma EBV, hepatocellular carcinoma hepatitis, kaposi’s sarcoma HIV
epigenetic mechanisms - promoter hypermethylation, inherited as cells divide

17
Q

Cancer is rare at cell level due to

A

DNA repair mechanisms (highly evolved)
apoptotic mechanisms
mutations usually not affect growth
most DNA not code protein
rapidly dividing cells (skin) lost so not matter if mutations
many cells lose potential to divide after differentiation
single mutation not escape defences

18
Q

Mutation increase growth, division, survivial

A

expand population for subsequent mutations (bigger target)

19
Q

mutation alter genomic stability

A

increase mutation rate and susceptibility to further mutations, 2nd mutation not repaired

20
Q

oncogenes normal role (proto-oncogene)

A

promote proliferation, growth, invasion

21
Q

oncogene gain of function

A

1 allele - excessive/inappropriate activity

22
Q

Tumour suppressor normal

A

inhibit events leading to cancer, inhibit and slow growth

23
Q

tumour suppressor loss of function

A

2 alleles - inactivation and cancer development

24
Q

Gatekeeper

A

control proliferation

25
Q

caretaker

A

control rate of mutation

26
Q

adenoma

A

benign tumour

27
Q

Feature of cancer development

A

order mutations important

28
Q

Hanahan and Weinberg principles

A
Independence of external growth signals
insensitivity to external anti-growth signals
avoid apoptosis
indefinite replication
angiogenesis
metastatsis/invasion