What controls cell growth

Objective: To study limits on cell growth and why cancer occurs in

cells

What controls cell growth?

Cells will typically divide until they are touching

When your skin is torn the cells will divide until they are touching again

healing

What tells cells to divide

Cyclin- protein that regulates timing of cell cycle (in eukaryotes)

Internal Regulators- proteins that respond to an event inside the cell

What tells cells to divide cont.

External Regulators- Proteins that respond to an event outside the cell

Growth Factors- important during embryonic development and wound healing

Also helps prevent excessive growing

Uncontrolled cell growth

Uncontrolled cell growth- cancer

Cancer cells do not respond to signals that regulate normal cell growth

Cancer cell- form tumors- cancer cells break loose from tumor and spread throughout the body

Uncontrolled cell growth

Some cancers are due to a problem with internal or external regulators

Most cancer cells have a defect in the P53 gene

Causes cell to lose info needed to respond to signals that would normally control growth.

Cancer Stats.

Most common cancer in US

Skin cancer

Cancer that kills most people in US

Lung cancer

Both are preventable in most cases

1/3 people are likely to get cancer