Transcript The Cell Cycle and Cancer

The Cell Cycle and Cancer
The Stages of the Cell Cycle
There are several factors that regulate the cell cycle
and assure a cell divides correctly.
1.Before a cell divides, the
DNA is checked to make
sure it has replicated
correctly. (If DNA does
not copy itself correctly,
a gene mutation occurs.
2. Chemical Signals tell a cell when to start and
stop dividing.
Neighboring cells communicate with
dividing cells to regulate their growth also.
Cancer is a disease of the cell cycle. Some of the
body’s cells divide uncontrollably and tumors
form.
Tumor in Colon
Tumors in Liver
DNA mutations disrupt the cell cycle.
Mutations may be
caused by:
1. radiation
2. smoking
3. pollutants
4. chemicals
5. viruses
While normal cells will stop dividing if there is a mutation in the
DNA, cancer cells will continue to divide with mutation.
Cell Suicide or Apoptosis
Cell damage—
no repair
First
mutation
Second
mutation
Third
mutation
Fourth or
later mutation
Uncontrolled growth
Due to DNA mutations, cancer cells ignore the
chemical signals that start and stop the cell cycle.
Due to DNA mutations, cancer cells cannot communicate
with neighboring cells. Cells continue to grow and form
tumors.
Skin cancer
ABCD of Cancer
Regions of Highest Incidence
U.K.:
UK:
Lung
Lung
cancer
cancer
Regions of Highest Incidence
JAPAN:
Stomach
cancer
CHINA:
Liver
cancer
AUSTRALIA:
Skin cancer
Cancer by State
US:
Colon
cancer
CANADA:
Leukemia
BRAZIL:
Cervical
cancer
Mitosis and Cancer
1.
Typically, cell division is controlled by genes in the cell, contact
with other cells, and available nutrients in the environment.
2. Cancer is a class of diseases characterized by uncontrolled cell
division and the ability of these cells to invade other tissues.
How Cancer Develops
Treating Cancers
Cancer treatments include surgery, chemotherapy,
radiation, or lasers.
SUMMARY
Normal Cell Division
DNA is replicated
properly.
2. Chemical signals start
and stop the cell cycle.
3. Cells communicate with
each other so they don’t
become overcrowded.
1.
Cancer Cells
Mutations occur in the
DNA when it is
replicated.
2. Chemical signals that
start and stop the cell
cycle are ignored.
3. Cells do not communicate
with each other and
tumors form.
1.
Vocabulary
 cancer: term used to indicate a disease
characterized by abnormal cell growth
 mutagen: environmental factor that causes
mutations
 carcinogen: cancer-causing agent
 tumor: mass of growing tissue
benign: does NOT invade surrounding cells
 malignant: spreads into nearby tissues

 metastasis: spread of malignant cells
 oncogene: gene that causes cancerous growth