The Cell Cycle and Cancer

The Stages of the Cell Cycle

1. Click on picture for cell cycle animation –will go to www.cancerquest.org)

2. Use alt-tab keys to go between websiteand power point presentation.

3. Click on blank space to proceed to next slide.)

There are several factors that regulate the cell cycle and assure a cell divides correctly.

1.Before a cell divides, the DNA is checked to make sure it has replicated . (If DNA does not copy itself correctly, a gene mutation occurs.

DNA replication animation:click on DNA picture

2. Chemical Signals tell a cell when to

(Target cells animation: click on go sign)

Neighboring cells communicate with dividing cells to regulate their growth also.

(Normal contact inhibition animation: click on petri dish)

Cancer is a disease of the . Some of the body’s cells divide and tumors form.

Tumors in LiverTumor in Colon

DNA mutations disrupt the cell cycle.

Mutations may be caused by:

1. 2. 3. 4. 5.

While normal cells will stop dividing if there is a mutation in the DNA, cancer cells

Sometimes cells do respond normally to the body’s control mechanisms and

• cells are an example of cells that do not heed the normal signals which shut down the cell division process.

•They continue to divide even when they are very packed and/or there is no growth factor present.

•Cancer begins when a single cell is transformed into a cancer cell, one that does not heed the

– a feature of healthy organisms– caused by a cell’s production of

enzymeswebbed fingers

• Apoptosis is programmed cell death.

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Cell division is uncontrolled in cancer.

• Cancer cells form disorganized clumps called .

cancer cellbloodstream

normal cell

– tumors remain clustered and can be removed.– tumors break away, and can form more tumors.

Due to DNA mutations, cancer cells the chemical signals that start and stop the cell cycle.

2 animations of cancer cells dividing: click on picture

Due to DNA mutations, cancer cells communicate with neighboring cells. Cells

continue to grow and form tumors.

(cancer cells dividing: click on picture.)

Skin cancer

SUMMARYNormal Cell Division

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Cancer Cells

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