Biological Hallmarks of Cancer Flashcards
How many hallmarks of cancer are there?
10 in total. There are 6 main, 2 emerging and 2 enabling
What are the 6 main hallmarks?
- Sustaining proliferative signalling
- Evading growth supressors
- Enabling replicative immortality
- Activating invasion and metastasis
- Inducing angiogenesis
- Resisting cell death
What are the 2 emerging hallmarks?
- Deregulating cellular energetics
- Evading immune destruction
What are the 2 enabling hallmarks?
- Tumour promoting inflammation
- Genome instability and mutation
What are 4 major functional changes in cancer?
- Increased growth due to loss of growth regulation
- Failure to undergo apoptosis or senescence
- Loss of differentiation
- Failure to repair DNA damage
What are 3 ways in which tumours sustained proliferative signalling?
- Autocrine signalling where the cells produce their own signals
- Negative feedback through destroying off switches that prevent excess growth
- Growth being deregulated due to the proteins that control this being altered
How do cancer cells evade growth supressors?
Through the mutations of oncogenes (gain of function) and tumour suppressor genes (loss of function) which affects multiple pathways
How do cancer cells avoid immune destruction?
Tumours shield themselves from immune attacks through cancer immunoediting
What is immunoediting?
The immune system attempting to control cancer contested with the ability of some tumours still arising from cancer cells that have evaded the immune system
How do cancer cells enable replicative immortality?
In normal cells, replication is limited and ends with apoptosis. They do this through telomeres (ends of chromosomes) which consist of multiple repeats of TTAGGG. After each cell division, the repeats shorten and eventually there are no more which leads to the end of the cycle. Cancer cells are able to use enzyme telomerase to add telomeric repeats, allowing replication to continue to no limit
How do tumours promote inflammation?
Cause cancer related inflammation (CRI) which includes infiltration of white blood cells, especially tumour-associated macrophages (TAMs)
How do cancer cells activate invasion and metastasis
- Initial local invasion (loss of cell-cell adhesion)
- Intravasation (traffic into blood vessels)
- Life in transit
- Cell adhesion in vasculature/extravasation
- Survival and colonisation at a distant site
How do cancer cells induce angiogenesis?
It is the formation of new blood vessels from pre-existing vessels. Cancer cells are able to amplify angiogenesis resulting in excessive vessel growth
How do cancer cells cause genome instability and mutation?
Genomic instability is the result of either temporary and permanent unscheduled alterations within a genome. Most cancers have chromosomal instability (CIN) where chromosome structure and number changes over time. There is also microsatellite instability (MIN)
How do cancer cells resist cell death?
They defect apoptotic pathways by altering proteins, resulting in no cell death and resistance to therapy
