Download What causes the change in a normal cell to make it

I. Cancer
Cancer cells evolve and accumulate traits that
distinguish them from normal cells causing them
to form tumors
normal cell
cancer cell
Matthew Saelzler
Graduate 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 in
cells do?
DNA
mRNA
Protein
mutant
DNA
mutant
mRNA
mutant
Protein
The change into a cancer cell is not in one step.
normal cell
cancer cell
There are several changes to become a cancer cell
normal
cancer cell
Each box represents a mutation
in the DNA of the cell.
= normal cell
= cancer 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
What do these changes in the normal
cell do?
What does the mutation cause the normal cell to do?
The first mutation induces the cell to divide.
What happens next?
What does the second mutation do to the cell?
The second mutation blocks
the cell from stopping division.
activate
What happens next?
inhibit
What does the third most likely do to the cell?
Normal Cell
Cancer Cell
Uncontrolled Growth
Cancer cells can evade
cell death (apoptosis).
Normal Cell Dies
Cancer Cell Lives
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.
The fourth mutation causes the cell to be
immortal.
Scientists have shown
cells only divide a certain number
of times. Once this is reached,
they stop growing.
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.
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 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 site
2. The cells breakthrough and invade nearby tissue
3. The cells move into the bloodstream
4. 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
What Makes a Cell a Cancer Cell?
1. Self-sufficiency in growth signals
2. Insensitivity to anti-growth signals
3. Evading Apoptosis
3. It evades cell death
4. Limitless replicative potential
4. It becomes immortal
5. Sustained Angiogenesis
5. It causes blood vessel formation
6. Invasion and Metastasis
6. It can spread to other parts of the body
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 normal
cell do?