Aetiology of Cancer and Neoplasms II Flashcards
What are selfish cells?
Cancer cells with selective advantage over normal regulated cells
What is difference with cancer cells to normal?
Large no. dividing Large nuclei variable Small cytoplasmic volume Variation in cell size and shape Loss of specialised cell features Disorganised arrangements Poorly defined boundary
What are doublings?
tumour cell mass doubling in size
What is Carcinogenesis?
Process of inducing cancer
What is a change to DNA called?
Mutation
What are 6 hallmarks?
Resisting cell death sustain proliferative signalling Evading growth surpressors Activate invasion and metastis Enable replicative immortality Induce angiogenesis
How do cancer cells sustain proliferative signalling?
Acquire mutations short circuit leading to unregulated growth
What is an e.g of sustaining proliferative signalling?
Mutation in Ras oncoprotein disrupts normal negative feedback
How do cancer cells evade growth suppressors?
Acquired mutations interfere with inhibitory pathways
What is an e.g of growth suppressor?
P53 inactivated
How do cancer cells resist cell death?
Evade apoptotic signals
What is an e.g of resisting cell death?
Dysregulation of anti-apoptotic BCL-2 family
How do cancer cells enable replicative immortality?
Cancer cells maintain the length of their telomeres
what is an e.g of replicative immortality?
Overexpression of telomerase
How do cancer cells induce Angiogenesis?
Growth of new blood vessels need for tumour survival and expansion
How do Cancer cells activate invasion and metastasis?
Move to other parts of body and start secondary tumours
How does cancer grow and spread?
Duplicate and invade surrounding tissue, produces TAFs and competes with normal tissue killing it for space some cells detach to create secondary tumour
What are the 4 metastatic steps?
Motility and invasion from primary site
Embolism and circulation in blood or lymph system
Arrest in a distant capillary
Extravasation into target organ
What external stimulus do tumour cells use to metastasize?
Tumour associated macrophages TAMS that supply cancer with EGF epidermal growth factor and CSF-1
What are 4 Enabling hallmarks?
Deregulating cellular energetics
Avoiding immune destruction
Genome instability and mutation
Tumour promoting inflammation
How does genome instability and mutation work?
Several chromosomal abnormalities drive tumour progression
What is an eg of genome instability?
defects in BRCA 1/2 in breast cancer
How does tumour promoting inflammation work?
Inflammatory cytokines promote tumour growth
What is an eg of tumour promoting inflammation?
Promotes angiogenesis
