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

• Benigna. Loss of inhibitors to prevent

overcrowding in tissuesb. Cell population increases at high

densities…… tumorc. 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 smokingradiationbarbecue 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