Transcript cancer

CANCER
A. THE NATURE OF
CANCER
def - sudden uncontrolled
growth of cells
1. FEEDS ON THE BODY’S
NUTRIENTS
RESULTS FROM
ANGIOGENESIS FORMATION OF NEW
BLOOD VESSELS
2. DEPLETES BODY’S
SUPPLY OF NUTRIENTS
AMINO
ACIDS, GLUCOSE,
FATTY ACIDS
3. BLOCKS PASSAGEWAY FOR
MATERIAL FLOW
4. DISRUPTS, OR PREVENTS
PROTEIN SYNTHESIS
5. SECRETE PROTEASES
LEADS
TO METASTASIS
6. BLOCKS
DIFFERENTIATION
CELLS
PRODUCED LACK
SPECIALIZATION, THEIR
FUNCTION IS THEREFORE
INHIBITED
7. NO CONTACT INHIBITION
LEADS
TO METASTASIS
CELLS MOVE OVER UNDER
AND THROUGH
NEIGHBORING CELLS
8. LACK ANCHORAGE
DEPENDENCY
CELLS
FLOAT FREELY
CELLS DO NOT REMAIN AT
ORIGINAL SITE
LEADS TO METASTASIS
9. GENETIC INSTABILITY
HIGH
MUTATION RATE
LEADS TO DRUG
RESISTANCE
CONTAIN GENETIC
ABBERRATIONS
10. GROWTH FACTOR
REQUIREMENTS ARE LOW
RECEPTORS
TO REGULATE
GROWTH MALFUNCTION
IT DOESN’T REQUIRE MUCH
TO INITIATE GROWTH
B. POSSIBLE CONTRIBUTING
FACTORS
1.
GENETIC PREDISPOSITION
2. CARCINOGENS
3. DIET
 4. RADIATION
 5. VIRUSES
C. MOLECULAR LEVEL
ONCOGENES – GENES THAT
TRIGGER RAPID CELL DIVISION
 (GAS PEDAL)
 FORM WHEN PROTO-ONCOGENES
MUTATE TO FORM ONCOGENES
 1.
discovery
discovered
because of a viral link
to some cancers and also from the
ability to transfer genes from
cancer cells to normal cells
resulting in cancerous growth in
the previously normal cells. THIS
IS KNOWN AS
TRANSFORMATION
2. TUMOR SUPPRESSOR
GENES
GENES
THAT SUPPRESS CELL
GROWTH, KEEP IT IN CHECK
discovery from
the fusion of a normal cell
with a cancer cell resulting in no
cancer activity
ex. - retinoblastoma - arises from a
deletion of a gene on chromosome
#13
p53 gene
tumor
suppressor gene
found on chromosome #17
plays a role in lung, breast,
colon/rectal cancers some
leukemias and lymphomas - about
1 out of 3 cancers
3. DNA REPAIR GENES
 OVER
130 HAVE BEEN IDENTIFIED
 MAY BE INVOLVED IN MANY KINDS
 OF CANCERS
 XERODERMA PIGMENTOSUM
E. RESULTS
1.
GROWTH SURROUNDED BY
A MEMBRANE
2. ANGIOGENESIS
3. ENZYMES RELEASED BY
CANCER CELLS DISSOLVE
THE MEMBRANE
4. CANCER METASTASIZES
5.
CANCEROUS GROWTHS
SPRING UP ELSEWHERE
F. HOW CANCER ELUDES
THE IMMUNE SYSTEM
1.
CANCER CELLS ARE SELF
CELLS, SOMETIMES THE
CHANGE IN SURFACE
PROTEINS IS SO SLIGHT THAT
IT GOES UNNOTICED
2.
THEY CAN EMIT DECOY
ANTIGENS INTO THE
BLOODSTREAM IN HIGH
NUMBERS, AS ANTIBODY
BINDS TO DECOYS, TUMOR
GOES UNNOTICED
3.
NON COMPLEMENT
BINDING ANTIBODIES
SURROUND BUT DO NOT
HARM THE TUMOR
4.
PIECE OF TUMOR BREAKS
OFF - CLUMP IS DESTROYED,
IMMUNE SYSTEM’s
RESPONSE FOCUSED ON THE
CLUMP, TUMOR REMAINS - A
STATE OF SUPPRESSION
OCCURS
5.
ANTI-ANTIBODIES SHUT
DOWN AN ATTACK, ALONG
WITH T SUPPRESSOR CELLS
G. PREVENTION
1.
HABITS
smoking
excessive alcohol consumption
excessive exposure to the sun
diet (low fat, high fiber, low in
pickled, smoked, cured foods
2. POSSIBLE POSITIVE
ACTIONS
intake
of vitamins A, C, D,E
beta carotene
calcium
avoid exposure to carcinogens,
radiation, sunlight
H. WARNING SIGNS
CHANGE
IN
BOWEL/BLADDER HABITS
A SORE THAT DOES NOT
HEAL
UNUSUAL BLEEDING OR
DISCHARGE
Thickening
or lump in breast or
elsewhere
Indigestion or difficulty in
swallowing
Obvious change in wart or mole
Nagging cough or hoarseness
I. EARLY
DETECTION/SCREENING
PAP
SMEAR - cervical carcinoma
Breast/testicular self exam
Prostate/ colon-rectal exams
Mammography
Annual exams
Ames Test – for carcinogenicity
SOME
CANCERS CANNOT
BE OR ARE NOW
DIFFICULT TO DETECT AT
EARLY STAGES –
ESPECIALLY LUNG
CANCERS
J. TREATMENTS
1.
SURGERY
2. RADIATION
3. CHEMOTHERAPY
4. IMMUNOTHERAPY-active – ex
cancer vaccines and passive -ex
monoclonal antibodies
PROTON THERAPIES – easier
to aim, cancer cells poor at repair
6. ANGIOSTATIC DRUGS
7. GENE THERAPY
8. BONE MARROW
TRANSPLANTATION
9. HORMONE THERAPY –
tamoxifen to block estrogen
receptors in breast cancer
5.
10.
COMBINATION THERAPIES
11. HIGH INTENSITY
THERAPIES
12. PHOTODYNAMIC
THERAPY – photosensitizing
agent injected, remains in cancer cells
longer, 2-3 d later exposed to light
13. TARGETED THERAPIES
- Enzyme inhibitors
- Apoptosis inducing drugs
- gleevec
FUTURE?
GENE
THERAPY? PROBLEM OF
DELIVERY
MORE TARGETED
APPROACHES
CLASSIFY CANCER
ACCORDING TO THE
MUTATION, NOT THE
LOCATION
Go to the following web site:
 www.goorulearning.org
 Look
up cancer – diagnosis and treatment