Tumour pathology 5 Flashcards Preview

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Flashcards in Tumour pathology 5 Deck (25)
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1

types of tumour-suppressor genes

-Genes negatively regulating mitosis - Rb
-Genes regulating apoptosis
-Genes regulating DNA repair

2

factors that cause carcinogenesis

-geographic and environmental factors
-age
-heredity

3

how can pRb be altered to cause increased cell proliferation?

-mutation directly to Rb gene
- mutation to genes that control pRb phosphorylation

4

examples of mutations to genes that control Rb phosphorylation

-Mutational activation of cyclin D or CDK4
-Mutational inactivation of CDKIs also drive proliferation

5

what causes the inherited form of retinoblastoma?

-one defective inherited copy of pRb
-somatic point mutation of other copy

6

what causes the sporadic form of retinoblastoma?

both hits occur in a single cell

7

examples of inherited cancer syndromes?

-familial retinoblastoma
-familial adenomatous polyposis of colon
-multiple endocrine neoplasia
-neurofibromatosis
-Von Hippel-lindau Syndrome

8

inherited cancer syndrome characteristics

-autosomal dominant inheritance of a single mutant gene
-strong family history of uncommon site-specific cancers

9

familial cancer syndrome characteristics

-family clustering of cancers but INDIVIDUAL PREDISPOSITION UNCLEAR
-multifactorial inheritance
-early age of onset
-multiple / bilateral tumours

10

examples of familial cancers

-Some Breast cancers
-Some Ovarian cancers
-Non-FAP colon cancers

11

examples of anti-oncogenes and there function

APC- signal transduction
p53- cell cycle/apoptosis after DNA damage
Rb- cell cycle regulation
p16- inhibits CDK's
BRCA-1 and 2- DNA repair

12

cancers causes by somatic and inherited mutation of APC

somatic- gastric, colon, pancreas, melanoma
inherited mutation- FAP colon cancer

13

cancers causes by somatic and inherited mutation of p53

somatic - most cancers
inherited mutation- Li-Fraumeni syndrome

14

cancers causes by somatic and inherited mutation of Rb

somatic- retinoblastoma, colon, lung, breast carcinomas
inherited- retinoblastoma and osteosarcoma

15

cancers causes by somatic and inherited mutation of p16

somatic- pancreatic, oesophageal carcinomas
inherited- malignant melanoma

16

cancers causes by somatic and inherited mutation of BRCA1 and 2

somatic- N/A
inherited- breast and ovarian

17

what types of proteins do oncogenes code for

-growth factors
-growth factor receptors
- proteins involved in signal transduction
-nuclear regulatory proteins
-cell cycle regulators

18

how proto-oncogenes can be activated to form oncogenes

-point mutation
-chromosome rearrangements and translocations
-gene amplification
-overexpression

19

example of oncogenes that code for growth factors

sis- PDGF
overexpression causes astrocytoma and osteosarcoma

20

example of oncogenes that code for growth factor receptors

erb-B2 - EDF receptor family
amplification causes breast, ovarian, lung and stomach cancer

21

example of oncogenes that code for signal trasducers

ras-GTP
point mutation causes lung, colon, pancreas, leukaemia

22

example of oncogenes that code for nuclear regulatory proteins

myc-transcriptional activators
translocation causes Burkitt lymphoma

23

example of oncogenes that code for cell cycle regulators

-cyclin D
translocation causes mantle cell lymphoma
amplification causes breast, liver, oesophageal

-CDK4
amplification causes melanoma and sarcoma

24

how recombination produces cancer

produces chimeric proteins (two proteins joined together)

25

how viruses cause cancer

-insert an oncogene (retroviruses)
-inserts viral DNA near proto-oncogene producing an oncogene
-inserts viral promoter or other transcription regulator that cause proto-oncogene over-expression