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CANCER: CHAPTER 18
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DNA TECHNOLOGY & GENETIC
ENGINEERING: CHAPTER
20
What is Cancer??
1. Unregulated mitotic division of cells
Cellular division does NOT stop
2. Faulty Differentiation of cells into tissues in a
way that effects mitotic division
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Types of Tumors
I. Benign
• Remain in one location
• Single, well defined mass
• May be surrounded by connective tissue
II. Cancerous
• Abnormal cell structure, may appear
undifferentiated
• May spread
• Edge of tumor not clearly defined
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Cancerous Cells: Lose Control Over Cell
Functions
1. Dysplasia: abnormal change in cell structure
2. In Situ Cancer: malignant tumor in only one
place
3. Matastases: secondary tumors at other
locations throughout body
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
How Cancer Develops
I. Mutated or damaged genes
1. Proto-oncogenes: normal regulatory genes
•
Oncogenes: mutated or damaged protooncogenes
2. Tumor Suppressor genes: regulatory genes
repress cell growth, cell division, differentiation,
adhesion
•
These TS genes may be turned off,
damaged or mutated in cancers
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Advances in Diagnosis:
Early Detection!!!
• Tumor imaging:
• X-rays - physical view
• PET = positron-emission tomography
[physiology/metabolism of tissues]
• MRI = magnetic resonance imaging
[x-sectional chemical composition]
• Genetic testing: identify mutated genes [privacy
and treatment issues]
• Enzyme tests for cancer markers: screening
large numbers of people
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Cancer Treatments
• Conventional treatments: surgery, radiation, &
chemotherapy
• Immunotherapy: promotes immune response
• Starving cancers: inhibits angiogenesis [reduces
blood supply to tumor]
• Molecular treatments: target oncogenes
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
1. Skin cancer:
Most Common Cancers
•
Basal cell - common, basal cells divide
abnormally
•
Squamous cell- arises from epithelial cells
made by basal cells
•
Melanoma - deadly, abnormal malanocytes
2. Breast cancer: almost exclusively in women
3. Prostate cancer: most common after age 50 in
males
4. Lung cancer: smoking is the leading risk factor
5. Cancers of colon & rectum: early detection
has increased survival rates to 62%
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Most Common Cancers
(cont.)
6. Lymphoma: related to altered immune function
7. Urinary bladder cancer: surgery needed early
8. Cancer of the uterus: includes cervical cancer
& cancer of the endometrium
9. Leukemia: cancer of blood forming organs.
chemotherapy often effective
10. Cancers of mouth & pharynx: tobacco major
risk
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Most Cancers are Preventable
• Know family history
• Get regular medical screenings
• Learn self-examination techniques
• Avoid direct sunlight 10 AM to 4 PM, avoid
sunlamps and tanning salons
• Watch diet & weight
• Don’t smoke
• Drink in moderation, if at all
• Be informed
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
DNA TECHNOLOGY AND GENETIC
ENGINEERING: CHAPTER 20
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
DNA Sequencing
Figure 20.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Gel Electrophoresis
Figure 20.2
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Recombinant DNA Technique
Figure 20.3
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Laboratory Modified DNA
• Recombinant DNA: Cutting, Splicing, Copying
DNA
• Restriction Enzymes
• DNA Ligases
• Plasmids
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Polymerase Chain Reaction (PCR)
Figure 20.4
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Genetic Engineering: Transgenic
Organisms
• Transgenic Bacterial Uses
• Insulin
• Human Growth Hormone
• Vaccines
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Genetic Engineering: Transgenic
Organisms
• Transgenic Plants
• Increased resistance to freezing
• Longer shelf life
• Increased Vitamin A
• Edible Vaccines
• Human Proteins, i.e., albumin
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Transgenic Plants
• Concerns
• “Frankenfoods”
• Plant disease susceptibility
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Transgenic Animals
• Bigger challenges
• No plasmid use
• Cloning more difficult
• Successes
• Bovine growth hormone for faster animal growth
• “gene farming”
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Vectors Transfer Genes to Human
Cells
Gene Therapy
Figure 20.11
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.