What is cancer
Definition of cancer? L01
Uncontrolled growth of abnormal cells in a tissue, invasive and metastasising
What is cancer
What is a carcinoma? L01
Cancer of epithelial cells
What is cancer
What is an adenocarcinoma? L01
A carcinoma featuring microscopic glandular-related tissue cytology, tissue architecture, and/or gland-related molecular products
What is cancer
What is a squamous cell carcinoma? L01
Refers to a carcinoma with observable features and characteristics indicative of squamous differentiation (intercellular bridges, keratinisation, squamous pearls)
What is cancer
List the three most common sites of adenocarcinoma? L01
Lung
Colon
Breast
What is cancer
List the three most common sites of squamous cell carcinoma? L01
Skin
Nasal cavity
Oropharynx
What is cancer
What is a sarcoma? L01
Cancer of cells of mesenchymal origin e.g. osteosarcoma (osteoblasts), fibrosarcoma (fibroblasts), chondrosarcoma (chondroblasts)
What is cancer
What is a leukaemia? L01
Cancer of leukocytes that usually begins in bone marrow
What is cancer
What is a lymphoma? L01
Cancer of lymphocytes
What is cancer
What is a cancer of the plasma cells called? L01
Myeloma
What is cancer
What are four types of leukaemia? L01
Acute lymphocytic
Acute myelogenous
Chronic lymphocytic
Chronic myelogenous
What is cancer
What is a cancer of the central and peripheral nervous system called? L01
Neuroectodermal tumours
What is cancer
What is a glioblastoma multiforme? L01
A highly progressed cancer of the astrocytes
What is cancer
What is an ependymoma? L01
Cancer of cells lining the ventricles of the brain
What is cancer
What are the types of gene that normally initiate cancer? L01
Genes that control:
- growth
- the cell cycle
- stem cells
- integrity of genome + repair
What is cancer
How do mutations arise? L01
Copying errors during DNA replication
Spontaneous depurination
Exposure to different agents e.g. UV light, tobacco, background ionising radiation
What is cancer
Of what clonal growth is cancer? L01
Monoclonal
What is cancer
What is a tumour suppressor gene’s function? L01
Negative regulator of cell growth (prevents growth), even when one allele is mutated. Need to lose both alleles to lose suppressor effect
What is cancer
What is the function of an oncogene? L01
Positive regulator of cell growth, makes cells grow, even when one allele is mutated
What is cancer
What are the six hallmarks of cancer? L01
Resisting cell death Sustaining proliferative signalling Evading growth suppressors Activating invasion and metastasis Inducing angiogenesis Enabling replicative immortality
What is cancer
Explain how cancer cells are self-sufficient in growth signals. L01
Ligand independent firing; they can signal without extracellular factors
Autocrine signalling; they secrete their own GFs
What is cancer
What is the function of Ras protein? L01
It controls intracellular signalling pathways including proliferation, differentiation, cell adhesion, apoptosis and cell migration
What is cancer
What is the significance of Ras protein in cancers? L01
Ras and Ras-related proteins are often deregulated in cancers, leading to invasion and metastasis, and decreased apoptosis
What is cancer
How are cancer cells insensitive to anti-growth signals? L01
Disruption of pRB pathway. pRB controls the restriction point in the cell cycle from G0 to S stages. It is normally determined by tumour suppressor genes but cancer cells evade this mechanism.
What is cancer
How do cancer cells evade apoptosis? L01
They increase anti-apoptotic regulators e.g. P13K
They decrease pro-apoptotic regulators e.g. cytochrome C, p53, through loss or mutations
What is cancer
What is the function of p53? L01
p53 causes cell cycle arrest, DNA repair, angiogenesis block, and apoptosis. It is a pro-apoptotic regulator
What is cancer
How do cancer cells create a limitless replicative potential? L01
They escape crisis by adding telomeres to the ends of DNA. They bypass senescence.
What is cancer
How do cancer cells sustain angiogenesis? L01
Control the transcription of angiogenic activators and down-regulate angiogenic inhibitors
What is cancer
Example of angiogenic activators? L01
VEGF-A, -B, -C
FGF1, FGF2
What is cancer
Example of angiogenic inhibitors? L01
Thrombospondin-1, -2 INFalpha and beta Angiostatin Endostatin Collagen IV fragments
What is cancer
Define metastasis. L01
Multistep process leading to the spread of cancer to distant organs
What is cancer
What are the two emerging hallmarks of cancer? L01
Deregulating cellular energetics (glycolytic switch)
Avoiding immune destruction (secrete immunosuppressive factor)
What is cancer
What are the two enabling characteristics of cancer? L01
Genome instability and mutation
Tumour-promoting inflammation
What is cancer
How does growth occur in cancerous cells? L01
Selective clonal selection
