What is Cancer? Flashcards
Cancer occurs as a result of?
Unregulated cell growth
Name the three type of cancer cells.
Epithelial cells
Mesoderm cells
Glandular cells
Describe epithelial cells.
Squamous (flat)
- Cuboidal
- Columnar
- 85% of cancers
What do mesoderm cells form?
Blood vessels and connective tissue.
Describe glandular cells.
-Organised secretory epithelial cells
Which group of cells are carcinomas?
Epithelial cells.
Which group of cells are adenicarcomas?
Glandular cells.
Which group of cells are sarcomas?
Mesoderm cells.
Where do you find epithelial cells?
They line body surfaces
Where do you find mesoderm cells?
Sandwiched between the ectoderm and endoderm cells.
Name the two type of glandular cells.
Exocrine
Endocrine
Describe exocrine glandular cells.
Form ducts like sweat glands or breast tissue
Describe endocrine glandular cells.
Do not have ducts.
How do endocrine glands secrete substances?
Released direcetly into the bloodstream.
How do endocrine glands secrete substances?
Released directly into the bloodstream.
Give examples of endocrine glandular cells.
Ovary, testes, pancreas.
What is sustaining proliferative signalling/ growth signal autonomy?
Lack of regulation of growth factor signalling.
What do normal cells require in order to divide?
External growth signal.
What do cancer cells bypass which ultimately leads to this unregulated growth?
Bypass normal growth factor pathways.
How does unregulated cell growth occur?
Due to a mutation which allows the self production of growth factors.
What do inhibitory growth signals do?
Maintain homeostasis within the tissue
-This means cells do not continuously divide.
Define gene silencing
Interruption or suppression of gene expression at the trancriptional or tranlastonal level.
How do cancer cells evade inhibitory growth signals?
They ignore them because of acquired mutation and gene silencing.
Which system and recognise and remove cancer cells?
The immune system.
How do cancer cells avoid detection?
They adapt there mechanisms and don’t initiate a cell response.
This is done by hijacking immune checkpoints and modulate their immune response via STING.
What is STING?
Stimulator and interferon genes,
->signalling molecule which controls transcription.
Define immune checkpoint.
Built in control mechanisms that maintain self tolerance during an immune response.
What are telomeres?
Counting device which monitor and adjust the number of cells doubling.
What does unlimited replication potential mean?
Cancer cells maintain their telomere length which means replication overdrive begins.
What happens to chromosomes after every round of DNA replication?
How is this different to cancer cells?
Chromosome shortens.
->Cancer cells maintain their telomere length.
What do inflammatory cells provide?
Growth factors which promote angiogenesis and invasion.
Define angiogenesis.
The development of new blood vessels.
What are the blood vessels used for by cancer cells?
Used to provide for the growing cancer,
Cell death by what gives rise to inflammation#?
Cell death by necrosis.
What do necrotic cells release?
Regulatory factors IL-1
What can in inflammatory cells release?
Radical oxygen species which give rise to mutations.
Name one ability cancer cells have.
The ability to migrate to other parts of the body.
What is a major cause of death in cancer?
Formation of metastasis
What may mutations within the genome effect?
The enzymes involved in cell-cell adhesion.
What do blood vessels provide cancer cells with?
Supply of oxygen and nurtients
Why do blood vessels let tumour cells escape?
They are more friable (Said of tissue that readily tears, fragments, or bleeds when gently palpated or manipulated) than other cells.
What can lead to genomic instability?
Alterations in DNA
What may contribute to the development of DNA mutations?
Faulty DNA repair pathways
Hereditary predisposition (increased likelihood of developing a particular disease based on a person’s genetic makeup)
What abnormalities may a cancer cell have?
Single point mutations to large chromosomal abnormalities, like deletion or translocation.
Why is cancer more prominent in the ageing population?
Accumulation of mutations over a period of time.
What may trigger cell death in normal cells?
Environmental factors or physical damage.
How do cancer cells evade cell death?
As a result of mutations within the apoptosis pathway.
Name two physical conditions in which cell death can occur.
Menstruation, embryogenesis.
Name one pathological condition in which cell death can occur.
DNA damage.
Mutations in whcih family allow cancer cells to go through the body unchecked?
A mutation in the caspase family as they usually cause DNA damage so do not need checked.
What does deregulating cell energetics mean?
Reprogramming energy metabolism.
How is aerobic glycolysis used by cancer cells?
To redirect energy allowing the cancer cells to grow and fuel cell division.
What is PET scanning?
The tracking of cancer cells within the body using FDG (glucose analogue).
What mutations are common and become required?
Somatic mutaions.
Which mutations are hereditary?>
Germline mutations
What is an oncogene?
Mutated gene which gives rise to the formation of a tumour in a dominant fashion.
What is a tumour suppression gene>?
Gene which inhibits tumour formation.
Can mutations occur within tumour suppression egens?
Yes- they are often recessive.
For the cell cycle-
Define G0
Resting phase
For the cell cycle-
Define G1
Cells grow larger and copy organelles.
For the cell cycle-
Define S
Cells make a complete copy of DNA
For the cell cycle-
Define G2
Further cell growth
What is cancerFor the cell cycle-
Define M
Four stages of mitosis
