Download Cancer_Genomics_BIOL_312

Cancer: The Role of
the Cell Cycle &
Genomics
Genes & Evolution Recap
 Review of Evolutionary Processes:
http://ed.ted.com/lessons/myths-and-misconceptionsabout-evolution-alex-gendler
 Genetic Mutations and Disease
 http://ed.ted.com/lessons/what-happens-when-yourdna-is-damaged-monica-menesini
Proliferation vs. Differentiation
Differentiation
Proliferation
Stem Cell Types
http://learn.genetics.utah.edu/content/stemcells/scintro/
Somatic Stem Cells
 http://learn.genetics.utah.edu/content/stemcells/sctypes/
Proto-oncogenes
 = normal genes that code for normal proteins used in
cell division
 Growth factors
 Growth factor receptors
 G proteins
 Enzymes that produce second messengers
 Genes that turn production of these proteins on & off
Oncogenes
 Oncogenes = mutated proto-oncogenes  still code
for proteins needed for cell division
 But they might produce
 Too much of the protein
 An abnormal protein
 Protein that turns on all by itself
 Protein that is made when it is not needed
 Protein that cannot turn cell division off
 Protein that should be made by a different cell
Tumor Suppressor Genes
= a gene that protects a cell from one step on the
path to cancer. When this gene mutates to cause
a loss or reduction in its function, the cell can
progress to cancer, usually in combination with
other genetic changes.
Video: http://ed.ted.com/lessons/the-cancer-gene-we-allhave-michael-windelspecht
THINK/PAIR/SHARE – 10 minutes
 What is the cell cycle?
 Can you list the steps?
 How is it related to cancer?
Cell Cycle Activity
 http://www.hhmi.org/biointeractive/eukaryotic-cellcycle-and-cancer
Cancer & the Cell Cycle
 The eukaryotic cell cycle is a sequence of events that
culminate in cell division.
 The cell cycle events are regulated by various
checkpoint proteins, which either stimulate or inhibit
cell division until conditions are right to proceed to the
next phase.
 When a cell specializes (or differentiates), it generally
stops dividing and "exits" the cell cycle. Once
differentiated, some cells can divide again.
 Cancer is the uncontrolled division of cells, which
results from an improperly regulated cell cycle.
Cancer as a Genetic
Disease
 http://www.hhmi.org/biointeractive/cancer-geneticdisease-video-highlights
What is cancer?
 Neoplasm= new abnormal growth = tumor  due to aberrant cell
growth
 Do not wait for signals that new tissue is needed
 Ignore signals to stop dividing
 Often do not differentiate
 Loss of apoptosis
 Carcinogenesis = production or origination of cancer cells
Summary Videos
 How do cancer cells act differently:
http://ed.ted.com/lessons/how-do-cancer-cellsbehave-differently-from-healthy-ones-george-zaidan
Steps of Oncogenesis
1.
2.
3.
Metastasis
 Cells in a primary tumor
develop ability to escape
& enter bloodstream
 Imagine you were a
cancer cell. What abilities
would you need to survive
in the tumor?
 What abilities would you
need to metastasize?
 Relationship to dysplasia?

Video: How Does Cancer Spread?:
http://ed.ted.com/lessons/how-doescancer-spread-through-the-bodyivan-seah-yu-jun
Tumor Classification
 Benign
 Malignant
 Similar to cell of origin
 look like normal tissue cells




 May perform normal function
(like secreting hormones) 
oversecretion
Do not usually metastasize
 usually encapsulated
Compress locally
Slow growth rate
Seldom reoccur after removal
 Dissimilar to cell of original
○ Undifferentiated cells that
divide rapidly
○ Cells mutate faster & can
change type
○ Do not have clear
boundaries  sends “legs”
out into surrounding tissue
○ Do not perform normal
functions
○ May secrete hormones
associated with other tissues
 Necrosis & ulceration common
 Seldom encapsulated
○ Metastastic
The Nature of Cancer
 http://media.hhmi.org/hl/03Lect1.html?_ga=1.18733113.10548086
74.1468863809
Carcinogens
 = substances that induce neoplastic growth
 3 types
 Chemicals  tobacco smoke, automobile exhaust, insecticides,
drugs/therapeutic agents (dosage-dependent)
 Physical  ionizing radiation (sun, x-rays, radioactive elements)
 Viral  viruses alter genome
 Some are oncogenic  Epstein-Barr & HPV
 Also consider role played by lifestyle
Risk Factors
 Air pollution
 Tobacco & alcohol
 Occupation
 Radiation
 Sexual practices
 Diet
 Age
 Genetics
Cancer Treatment
 Surgery
 Radiation Therapy
 Chemotherapy
 Hormone & Antihormone Therapy
 Biotherapy
Diagnostic Tests
 MRI, PET, or CT scans
 Screening tests
 Endoscopy
 Ultrasonography
Clinical Manifestations of Cancer
 Cancer anorexia-cachexia syndrome
Nomenclature of Neoplams
1.
Based on its behavior & growth
•
Benign  add “oma” at end for connective tissue
origin
•
Malignant 
2.
•
add “sarcoma” for connective tissue origin
•
Add “adenosarcoma” for glandular origin
Based on cell of origin
•
Prefix  cell of origin
•
Suffice  denotes whether benign or malignant
Nomenclature Examples
Cells of origin
Behavior of growth
Benign
Malignant
Adipose
lipoma
liposarcoma
Bone cells
osteoma
osteosarcoma
Blood vessels
hemangioma hemangiosarcoma
Fibrous tissues
fibroma
fibrosarcoma