c ancer and the c ell c ycle mrs. gamari. no matter how many new homes a builder builds, even if...
TRANSCRIPT
CANCER AND THE CELL CYCLEMrs. Gamari
No matter how many new homes a builder builds, even if building the same design, the builder and the crew rely on the blueprint instructions for their construction.
Similarly, cells rely on instructions for going through the cell cycle.
NORMAL CELL DIVISION
Growth should balance (apoptosis) old cell death
CHECKPOINTS
Cyclins – proteins that bind to enzymes (cyclin-dependent
kinases) in the stages of interphase and mitosis to start various activities of the cell cycle.
Different cyclin/CDK combinations control different activities Start of the cell cycle DNA replication Protein synthesis Nuclear division End of the cell cycle
CELL GROWTH
Epithelial layers of skin
Basal layer cells should balance outer surface cells
CANCER
Uncontrolled growth and division of cells Results when cell cycle checkpoints fail Cancerous cells can kill an organism by
crowding out normal cells, impairing normal tissue function.
TUMOR FORMATION
Cancer cells lack “contact-inhibition”
Basal cell layer outnumbers cells in surrounding areas.
WHY MIGHT THE CHECKPOINTS FAIL? Cells can become “abnormal” in a variety of
ways.
Carcinogens = cancer-causing substances Toxins / Chemicals UV Radiation
Could be influenced by genes OR environment Diet/Lifestyle Viruses Family history
ALL OF THESE SOMEHOW DAMAGE THE PART OF DNA THAT REGULATES CELL DIVISION
WHAT IS A MUTATION?
GENES THAT HELP REGULATE CELL DIVISION
Tumor Suppressor Genes
Proto-oncogenes
DAMAGE
DAMAGE
DIFFERENTIATION
CANCER CELL CHARACTERISTICS
Cancer cells are usually irregularly shaped.
Cancer cells are more simplistic or undifferentiated.
HEALTHY CELL FUNCTIONS Make proteins or “worker molecules” required by
the body
Communicate with other cells by sending signals and messages
Make their own energy using oxygen
Divide to make new cells
Grow in a controlled fashion and know where they belong in the body
Die after a specific number of divisions (apoptosis)
CANCER CELL FUNCTIONS (OR LACK THEREOF) Proteins can be missing, misshaped or in unnecessary
amounts
Messages or signals used for communication are missing or changed
Energy is made using sugar (usually just glycolysis- not aerobic respiration)
Growth is not regulated so the cancer cells grow out of control (dysplasia).
Cells can go places in the body where they do not belong
An “immortal” nature allows the cancer cells to live longer than normal
GOOD CELLS GONE BAD!
Each group provided with a “normal cell” and a “cancer cell”.
Examine the contents of the cells and determine what each object symbolizes.
Fill out worksheet and answer analysis questions.