Characteristics of Cancer Cells
- How do they
differ from
“normal” cells
Plasma Membrane Abnormalities
• Increase in transport &
permeablility
• They allow things in and
out of the cell that they
normally should not
• Surface proteins are lost
/ altered / or new
proteins appear
Changes in the Cytosol
• Cytoskeleton shrinks and
/ or becomes disorganized
• There is a shift in enzyme
activity
• Example
• Reliance on glycolysis
although oxygen is present
Abnormal Growth & Division
•
Benign
a. Loss of inhibitors to prevent overcrowding
in tissues
b. Cell population increases at high
densities…… tumor
c. Proteins form that trigger an increase in
blood capillaries that service the growing
mass
Abnormal Growth & Division
•
Malignant
a. Diminished capacity for adhesion to
substrates
- Cells aren’t anchored in parent tissue and
metasticize….. spread
Stages of Cancer
• Stage 1 – Initiation
• Early genetic changes
• Proto oncogenes –
• Genes necessary for normal cell function
are altered by structure or expression then
become……
• Oncogenes –
• Any gene having the potential to produce
cancer
• Genetic changes are causes by –
INITIATORS:
a substance that starts damage to cells that can
lead to cancer (carcinogen)
examples –
cigarette smoking
radiation
barbecue meats
Stages of Cancer
• Stage 2: Promotion
• Promoters cause change in
“normal” cells already damages by
initiators to change to cancer cells
• Examples:
• environmental pollutants
• Alcohol
• This stage can take 10-20 years
Stages of Cancer
• Stages 3 – Progression
• Growth of the cancer cells
• Metastasis – when the cell leaves its
proper space and invades other tissues