Neoplasia and Genetics

Question 1

Cancers arise from least to most from:

• Familial Cancer
• Sporadic Cancer
• Hereditary Cancer Syndrome

Answer 1

Sporadic Cancer = 75%
Familial cancer = 20%… History of cancer in family, Not to sure what caused it.. could be environment or genes!
Hereditary Cancer Syndrom = 10%… it is for sure caused by genes themselves

Question 2

Understand the terms oncogene and tumour suppressor and the link between mutations in those genes and their impact on cellular functions, such as signaling pathways.

Answer 2

• Oncogene: Ex. Growth factors, Signalling, Transcription. You upregulate these to increase cell growth! Always on, Gain of Function, Methylation Decrease
• Tumor Suppressor: Ex. Signal Regulator, Cell Cycle Regulator. You down regulate these to increase cell growth! Loss of function, knocked out, methylation increased (increase methylation = decrease cell expression)
• These lead to accelerated cell growth, reduced apoptosis, mitosis before DNA damage corrected, Reduced/Abnormal DNA repair, and Abnormal gene expression.
• Note that oncogenes and tumor suppressor genes ARE NOT just for fancer!

Question 3

KRAS Oncogene

Answer 3

• essential for normal cell growth.
• Causes deletion or point mutation, regulatory mutation, gene amplification, and chromosome rearrangement.
• Wild-type KRAS = Can use drugs to stop growth!
• Mutated KRAS = Even if you use drugs it will continue to grow!

Question 4

BRCA2 Tumor Suppressor

Answer 4

BRCA2 Tumor Suppressor: Higher risk of cancer! Especially Ovarian and Breast Cancer

Question 5

Knutson Two-Hit Model

Answer 5

• Born normal, One hit… and there is one mutation in one gene. Then Second hit and you now have two mutations… one in each gene. You then get cancer!

Question 6

Next Generation Sequencing

Answer 6

• Can scan genes and pinpoint tumour type

- Much cheaper!