Cell Cycle and Cancer
Date: January 2004
How do cancer cells differ from "normal" cells in
relation to the cell cycle?
Cancer cells have mutations in the genes that control the cell cycle. Some of these
genes tell the cell cycle to proceed, in other words they are "go" genes like the
accelerator in your car. These are called proto-oncogenes. Some of these genes
tell the cell cycle to stop when the cell is done dividing and no more cells are
needed. These are called tumor suppressor genes. They are like the brake on your
car. If either of these are mutated, it causes the cell cycle to go too fast, like
having your accelerator stuck to the floor or losing your brakes. So the cancer cells
divide too fast and pile up in one area, this is called a tumor.
This is an extremely complex issue. Essentially cell cycle is everything
when it comes to control of growth in cells and that is just what cancer
is...a loss in the control of cell growth. There are many known and
probably far too many more unknown control points in the cell cycle that
normal cells lose when the become cancerous. These can be in any of the
stages, G1, G2, or even S. There are a number of genes which exert control
in the cell cycle, on eof the best known is P53 which is implicated in over
50% of human cancers.
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Update: June 2012