Presentation on theme: "Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!"— Presentation transcript:
1 Mitosis & Cancer: When Making New Cells Goes Terribly Wrong!
2 If we want to cure cancer… We must understand what causes it. This means understanding the cell cycle.
3 When is mitosis a good thing? 1) When you have to add or replace cellsgrowth & developmentrepairreplacement
4 Checkpoints2) There are strict checkpoints in the cell cycle to ensure that each stage does not start before the last one finishedCheckpoint in Interphase: S phase to make sure that DNA was replicated correctly
5 When is mitosis a BAD thing 3) When cells reproduce & they are not neededthese cells take over organs, but don’t do the right jobthey just keep making copiescancerdamages organs
6 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
7 How do the cells turn bad? The timing of the cell cycle is regulated by cyclins (proteins)Cyclins trigger cell divisionFor example: p53 gene regulates the process that leads the cell into mitosisConditions have to be right for the cell to divide5) Gene proto-oncogenes encourage cell division in normal healthy cells6) Tumor suppressor genes inhibit cell division
8 Why would cells just make copies? 7) If DNA gets damaged, cells stop listening to correct instructionsmutationsCauses of mutations:UV radiationchemical exposureradiation exposureheatcigarette smokepollutionagegenetics
9 8) Cells gone bad…If the proto-oncogene is damaged then cells can either never divide or divide uncontrollably creating a tumorIf 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
10 Tumors9) Benign tumorabnormal cells remain at original site as a lumpmost do not cause serious problems & can be removed by surgery
11 Tumors 10) Malignant tumor cells leave original site carried by blood system to other tissuesstart more tumorsdamage functions of organs throughout body
12 Treatments for cancers side effectsTreatments for cancers11) Treatments kill rapidly dividing cellschemotherapypoisonous drugs that kill rapidly dividing cellsradiationhigh energy beam kills rapidly dividing cells