Transcript Understanding SNPs and Cancer

Understanding Cancer and Related Topics
Understanding Cancer
Developed by:
Lewis J. Kleinsmith, Ph.D.
Donna Kerrigan, M.S.
Jeanne Kelly
Brian Hollen
Discusses and illustrates what cancer is,
explains the link between genes and
cancer, and discusses what is known
about the causes, detection, and
diagnosis of the disease.
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What Is Cancer?
Different Kinds of Cancer
Some common
carcinomas:
Lung
Leukemias:
Bloodstream
Lymphomas:
Lymph nodes
Breast (women)
Colon
Bladder
Prostate (men)
Some common
sarcomas:
Fat
Bone
Muscle
Naming Cancers
Cancer Prefixes Point to Location
Prefix
Meaning
adeno-
gland
chondro-
cartilage
erythro-
red blood cell
hemangio- blood vessels
hepato-
liver
lipo-
fat
lympho-
lymphocyte
melano-
pigment cell
myelo-
bone marrow
myo-
muscle
osteo-
bone
Loss of Normal Growth Control
Normal
cell division
Cell Suicide or Apoptosis
Cell damage—
no repair
Cancer
cell division
First
mutation
Second
mutation
Third
Fourth or
mutation later mutation
Uncontrolled growth
Example of Normal Growth
Dead cells
shed from
outer surface
Epidermis
Dividing cells
in basal layer
Cell migration
Dermis
The Beginning of Cancerous Growth
Underlying tissue
Tumors (Neoplasms)
Underlying tissue
Invasion and Metastasis
1
Cancer cells invade
surrounding tissues
and blood vessels
2
Cancer cells are
transported by the
circulatory system
to distant sites
3
Cancer cells
reinvade and grow
at new location
Malignant versus Benign Tumors
Benign (not cancer)
tumor cells grow
only locally and cannot
spread by invasion or
metastasis
Time
Malignant (cancer)
cells invade
neighboring tissues,
enter blood vessels,
and metastasize to
different sites
Why Cancer Is Potentially Dangerous
Brain
Melanoma
cells travel
through
bloodstream
Liver
Melanoma
(initial tumor)
Genes and Cancer
Viruses
Chemicals
Radiation
Heredity
Chromosomes
are DNA
molecules
DNA Structure
Chemical
bases
A
C
DNA molecule
T
G
DNA Mutation
DNA
CA AG C T A A C T
Normal gene
CA AG C G A A C T
Single base change
CA A G G CG C T A A C T
Additions
C
T
CA A G A A C T
Deletions
Oncogenes
Normal cell
Cancer cell
Mutated/damaged oncogene
Normal
genes
regulate
cell growth
Oncogenes
accelerate
cell growth
and division
Proto-Oncogenes and Normal Cell Growth
Normal Growth-Control Pathway
Growth factor
Receptor
Signaling enzymes
Transcription
factors
Cell nucleus
DNA
Cell proliferation
Oncogenes are
Mutant Forms of Proto-Oncogenes
Inactive growth factor receptor
Inactive intracellular
signaling protein
Signaling protein from active oncogene
Activated gene
regulatory protein
Transcription
Cell proliferation driven by
internal oncogene signaling
Tumor Suppressor Genes
Normal
genes
prevent
cancer
Normal cell
Remove or inactivate
tumor suppressor genes
Cancer cell
Damage to
both genes
leads to
cancer
Mutated/inactivated
tumor suppressor genes
Tumor Suppressor Genes
Act Like a Brake Pedal
Tumor Suppressor
Gene Proteins
Growth factor
Receptor
Signaling
enzymes
Cell nucleus
Transcription
factors
DNA
Cell proliferation
p53 Tumor Suppressor Protein
Triggers Cell Suicide
p53 protein
Normal cell
Excessive DNA damage
Cell suicide
(Apoptosis)
DNA Repair Genes
Normal DNA repair
T C GA C
Base pair
mismatch
No cancer
TC T AC
AG C T G
TC TAC
TCT AC
AG C T G
Cancer
AG
TG
AG A T G
No DNA repair
Cancer Tends to Involve Multiple Mutations
Benign tumor cells
grow only locally and
cannot spread by
invasion or metastasis
Malignant cells invade
neighboring tissues, enter
blood vessels, and
metastasize to different sites
Time
Mutation
Cells
inactivates proliferate
suppressor
gene
Mutations
inactivate
DNA repair
genes
Proto-oncogenes
mutate to
oncogenes
More mutations,
more genetic
instability,
metastatic
disease
Mutations and Cancer
Genes Implicated in Cancer
Cancer Tends to
Corrupt Surrounding Environment
Growth factors = proliferation
Invasive
Matrix
Proteases
Fibroblasts,
adipocytes
Blood vessel
Cytokines, proteases = migration & invasion
Cytokines
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