Lecture 1: Cancer

Question 1

Cancer facts

Answer 1

r facts
Majority of cancer(men) prostate, (women) breast followed by LUNG and BRONCHUS
Can develop in any body tissue
Both hereditary and environmental factors
Cancer always named from where it originated(metastasis)

Develop due to the loss of growth control in cells
Point mutation
Gene amplification
Chromosomal translocation

Question 2

Mutations

Answer 2

Hereditary(inherited mutations: gene changes that come from a parent and therefore exist in all cells of the body-germ-line mutations(5% to 10% of cancers)

Acquired mutations: environmental influences such as exposure to radiation or toxins-not passed on to offspring-AKA sporadic or somatic mutations

Question 3

Multiple-Hit Hypothesis:

Answer 3

two or more mutations-can be both hereditary and acquired

Question 4

Oncogenes

Answer 4

Mutated form of genes(proto-oncogenes) that cause normal cell to grow out of control.
proto-oncogenes normally control how often a cell divides and the degree in which differentiates(specializes).
When a proto-oncogene mutates into an oncogene, it becomes permanently turned on or activated when it is not supposed to be.

Question 5

5 major classes of Oncogenes

Answer 5

Growth factor: sis. - overproduction platelet-derived growth factor
Growth factor receptors: HER2/neu amplification in breast cancer-herceptin
Signal transducers: abl in chronic myelocytic leukemia- imatinib/gleevec
Transcription factor/nuclear transducers: myc
Programmed cell death regulators : bcl-2-inhibits apoptosis

Question 6

Tumor Suppressor Genes

Answer 6

Genes that slow down cell division, repair DNA mistakes and tells cell when to die
When they dont work, cell can grow out of control=cancer
About 30 TSG have been identified including: p53, BCRA1, BCRA2, APC and RB1

Question 7

3 types of TSG

Answer 7

Genes that control cell division(RB1-retinoblastoma gene)
Genes that repair DNA(HNPCC-hereditary nonpolyposis colon cancer)
Cell “suicide” genes(p53 gene)

Question 8

4 Stages of Cancer Development

Answer 8

Uncontrolled proliferation
Dedifferentiation and loss of function-abnormal cells
Invasiveness
Metastasis

Question 9

Invasive cancer

Answer 9

Mutations include:
Production of metalloproteinases-break down extracellular matrix
Telomerase expression: enzyme that maintains and stabilized telomeres
Factor leading to growth of local blood vessels: angiogenesis