Outline of Cancer Process Flashcards
What are the 4 words to describe cancer?
Mass
Tumour
Growth
Neoplasm
What is the description of carcinoma?
Disorderly growth of cells (usually epithelial) which invade adjacent tissue and spread by the lymphatics and blood vessels.
What does monoclonal mean?
Arise from a single cell.
What % of cancers are lung cancer?
22
What will be seen under the microscope in cancer?
Lots of dividing cells with irregular nuclei, at different stages of mitosis.
What stages can cells go to in G1 stage?
S
G0
What are G0 cells?
Non-proliferating cells
How do you differentiate between cancer cells and normal cells?
Cancer: loss of contact, increase in growth factor, increase in oncogene, loss of tumour suppressor genes
Normal: oncogene rare, intermittent growth factors, presence of tumour suppressor genes
What is the process of preclinical cancer?
Carcinogen
Initiation
Promotion
Tumour growth
What occurs during clinical cancer?
Progression
What power of 10 is cancer detectable at?
9
What power of 10 is cancer fatal?
12
What are the 3 causes of initiation?
Chemical
Physical
Viral
What are the 2 causes of promotion?
Growth factors
Oncogenes
What is the cause of progression?
Metastasis
What 3 cancers can be caused by chemicals in alcohol and smoking?
Lung
H&N
GI
What cancer is caused by Hep B?
Liver
What do oncogenes represent?
A gain in function to transformed cells.
What are growth factors?
Polypeptide molecules
What do growth factors stimulate?
Activation of intracellular signal transduction pathways.
What are the 2 types of stimulation?
Autocrine
Paracrine
What happens during autocrine stimulation?
Cell carries receptor and secretes GF, escapes normal control.
What happens during paracrine stimulation?
GF’s acting on cell are produced locally by cell or neighbour.
What is an example of tumour suppressor genes?
P53
What is the normal function of p53?
Promotes DNA repair
Induces apoptosis
What is p53 induced by?
DNA damage
Is metastasis random?
No
What is metastasis?
Cascade of limited sequential steps.
Where does tumour invade form?
Basement membrane
What does the tumour invade after moving into ECM or connective tissue?
Blood vessels
What 3 enzymes are involved in invasion of ECM?
Matrix metalloproteinases
Plasmin
Cathepsin
What 3 enzymes are involved in invasion of cell adhesion?
Cahedrins
Integrins
CD44
Why do blood vessels need to be formed for a tumour?
To allow it to grow greater than 2mm in diameter.
What is necessary for angiogenesis?
Degradation of ECM
What does anti-VEGF antibody prevent?
Interactions with receptors
Activation of downstream signalling pathways.
Why can cancer cells hide from T-cells?
Ligand for T lymphocytes are on tumour cells and the interaction suppresses T cell action.
What side of the T-cell is PD1 on?
Inhibition
