mitosis & cancer: when making new cells goes terribly wrong!

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Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

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Page 1: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

Mitosis & Cancer:When Making New Cells

Goes Terribly Wrong!

Page 2: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

If we want to cure cancer… We must understand what causes it.

This means understanding the cell cycle.

Page 3: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

When is mitosis a good thing?1) When you have to add or replace cells

growth & development repair replacement

Page 4: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

Checkpoints2) There are strict checkpoints in the cell cycle to ensure that each stage does not start before the last one finished

Checkpoint in Interphase: S phase to make sure that DNA was replicated correctly

Page 5: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

When is mitosis a BAD thing3) When cells reproduce & they are not needed

these cells take over organs, but don’t do the right job

they just keep making copies cancer

damages organs

Page 6: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

What is cancer4) Cancer is a disorder in which some of the body’s own cells lose the ability to control growthCancer cells do not respond to the signals that regulate the growth of most cells

Page 7: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

How do the cells turn bad? The timing of the cell cycle is regulated by

cyclins (proteins) Cyclins trigger cell division

For example: p53 gene regulates the process that leads the cell into mitosis

Conditions have to be right for the cell to divide

5) Gene proto-oncogenes encourage cell division in normal healthy cells

6) Tumor suppressor genes inhibit cell division

Page 8: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

Why would cells just make copies?

7) If DNA gets damaged, cells stop listening to correct instructions

mutations

Causes of mutations: UV radiation chemical exposure radiation exposure heat

cigarette smoke pollution age genetics

Page 9: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

8) Cells gone bad… If the proto-oncogene is damaged then

cells can either never divide or divide uncontrollably creating a tumor

If the tumor-suppressor gene gets damage it may never tell the cell to stop dividing and the cell will divide and divide creating a tumor

Page 10: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

Tumors9) Benign tumor

abnormal cells remain at original site as a lump

most do not cause serious problems &can be removed by surgery

Page 11: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

Tumors10) Malignant tumor

cells leave original site carried by blood system to other tissues start more tumors

damage functions of organs throughout body

Page 12: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

Treatments for cancers11) Treatments kill rapidly dividing cells

chemotherapy poisonous drugs that kill rapidly dividing cells

radiation high energy beam kills rapidly dividing cells

side effects

Page 13: Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!

2009-2010

Any Questions??

Any Questions??