Transcript Cancer - Siegel Science

Cancer Warriors Recap
• What does ‘angiogenesis’ mean?
• New blood vessel growth
• How did Dr. Folkman think cancerous
tumors could be stopped?
• Stop blood vessel growth (blood supply)
• Cancer cells can metastasize. What does
this mean?
• Cells can travel/spread to other parts of the
body.
Cancer Warriors Recap
• Why would a tumor cell continue to
make a blood vessel inhibitor?
• Primary tumor makes small amount of
inhibitor to prevent new blood vessel
growth to cancerous cells in other
places in the body.
• Why did they name the inhibitor
‘angiostatin’?
• Stops blood vessel growth
• *Endostatin- new inhibitor
Cancer
•Cancer begins when a single cell mutates. This
mutated cell then begins to divide out of control.
All the cells produced from
this original cell will also
divide more often than
normal cells.
Mutations
• Genetic transformation…something in the
GENE changes and this causes the cell to
function and develop differently from a normal
cell.
• Carcinogens = cancer causing agents
• Examples?
• UV light, X-rays, chemicals in cigarette smoke
• Inheritance = mutations that are passed from
parent to child
• Examples?
• Colon cancer, breast cancer, ovarian cancer
Genes that can be mutated &
trigger cancer growth
• Proto-oncogenes are genes that help cells
divide. When this gene mutates it becomes
an oncogene, which makes a cell divide too
much.
• Tumor suppressor genes are genes that
stop cells from dividing. When it mutates it
can’t stop cells from dividing when they
should stop.
• Scientific name of a cancer doctor?
• oncologist
Some Definitions
• Malignant tumor is a tumor that is invasive
and invades healthy tissue.
• Benign tumor is a non-cancerous tumor. It
does not invade healthy tissue, organs or
other parts of the body.
• Metastasis is when cancerous cells may
get into the blood stream or the lymph
system and travel to other parts of the body
where they may form other tumors.
How are cancer cells different?
1. Cancer cells have a bigger nucleus.
2. Cancer cells lack contact inhibition.
Normally when cells come in contact with
each other they stop dividing. Cancer cells
do not “obey” this signal.
3. Cancer cells have unusual numbers of
chromosomes.
4. Cancerous cells lose their attachments
to neighboring cells.
Difference in cells
Contact Inhibition
Cancer develops over a long
period of time.
• Cancer is a long and complex process
of genetic changes.
• Many mutations must develop together
in one cell. This is why the incidence of
cancer increases with age.
How does your body defend
against developing cancer?
• Proto-oncogenes and tumor suppressor genes
help cells divide normally.
• DNA repairs system - throughout your life your
genes are constantly under attack from both
carcinogens and from chemicals produced in
your cells. These cause errors in the genes or
during the DNA replication process. This system
is good at fixing mistakes which is why it takes
many years before all of the mutations required
for cancer to develop.
• Apoptosis (cell suicide) - p53 gene
“encourages” cell suicide in damaged cells.