I. Cancer

Cancer cells evolve and accumulate traits that distinguish them from normal cells causing them to form tumors

cancer cellnormal cell

Matthew SaelzlerGraduate Student

MIT

What is Cancer?

How does cancer evolve from a normal cell?

1. What causes the change in a normal cell to make it into a cancer cell?

2. How many changes does it take to make a cancer cell?

What do these changes incells do?

DNA

mRNA

Protein

mutantDNA

mutantmRNA

mutantProtein

The change into a cancer cell is not in one step.

There are several changes to become a cancer cell

normal

cancer cellnormal cell

cancer cell

Each box represents a mutation in the DNA of the cell.

= normal cell

= cancer cell

Main Concepts

A. Cancer is caused by mutations in DNA.

B.The change from a normal to a cancer cell is the result of several mutations.

C.6 mutations give cancer cells abilities that normal cells lack

Normal Cell Cancer Cell

What do these changes in the normalcell do?

What does the mutation cause the normal cell to do?

What happens next?

The first mutation induces the cell to divide.

What does the second mutation do to the cell?

activate inhibit

What happens next?

The second mutation blocks the cell from stopping division.

What does the third most likely do to the cell?

Normal Cell

Normal Cell Dies

Cancer Cell

Cancer Cell Lives

Uncontrolled Growth

Cancer cells can evade cell death (apoptosis).

This mutation allows cells to inhibit apoptosis

What Makes a Cell a Cancer Cell?

1. Grow and divide without being told to do so.

2. Won’t stop growing and dividing when it should

3. It evades planned cell death

What happens next?

What does the fourth mutation do to the cell?

The cells must become immortal to form a tumor.

Scientists have shown cells only divide a certain number of times. Once this is reached, they stop growing.The fourth mutation causes the cell to be

immortal.

Angiogenesis -formation of new blood vessels

-the tumor releases molecules that recruit cells that form the blood vessel

-the recruited cells then form new blood vessels

VEGF is a molecule released by tumor cells to recruit endothelial cells

What is the fifth mutation required for a normal cell to progress to a cancer cell?

Tumors need oxygen and nutrients to survive, therefore they must have the ability to recruit blood vessels.

What Makes a Cell a Cancer Cell?

1. Grow and divide without being told to do so

2. Won’t stop growing and dividing when it should

3. It evades cell death

4. It becomes immortal

5. It causes blood vessel formation

What is next in the evolution of a tumor?

Metastasis -tumor cells move (spread) from one area of the body to another

1.Tumor cells grow at the primary site2.The cells breakthrough and invade nearby tissue3.The cells move into the bloodstream4.The cells move from bloodstream somewhere else.5.Tumor cells grow here into a tumor

Metastasis

What Makes a Cell a Cancer Cell?

1. Grow and divide without being told to do so

2. Won’t stop growing and dividing when it should

3. It evades cell death

4. It becomes immortal

5. It causes blood vessel formation

6. It can spread to other parts of the body

What Makes a Cell a Cancer Cell?

1. Self-sufficiency in growth signals

2. Insensitivity to anti-growth signals

3. Evading Apoptosis

4. Limitless replicative potential 5. Sustained Angiogenesis

6. Invasion and Metastasis

Summary

A. Cancer is caused by mutations in DNA.

B.The change from a normal to a cancer cell is the result of several mutations.

C.Mutations give cancer cells abilities that normal cells lack

What do these changes in the normalcell do?