Neoplasia 6: Oncogenesis Flashcards
Principal traget of cancer causing mutations
- growth promoting proto-oncogenes
- growth inhibiting tumor supressor genes
- genes that regulate apoptosis (programmed cell death)
- genes involoved in DNA repair
Define Oncogenes
genes that have been mutated or over expressed
Define proto-oncogenes
normal cellular genes that encode proteins and drive cell proliferation = (normal cell division genes)
Transformation of Proto-oncogenes into oncogenes occurs by ___
- Point mutation
- Chromosomal translocation
- Gene amplification
Enumerate the 4 categories of Oncogenes
- Genes which produce growth factors
- Genes which produce receptors for growth factors: erbB2 gene —> HER2 receptor
- Genes which encodes signal transduction: RAS
- genes which encode for DNA transcription: MYC
amplification of erbB2 gene/ overexpression of HER2 receptor leads to what type of Cancer
Breast Carcionoma
breast carcinoma caused by overexpression of HER2 receptor responds to ___
target therapy via Herceptin (HER2 antibodies)
Mutation in RAS gene caused what type of cancers
- thyroid
- colon
Mutation in MYC gene causes what type of cancer
- Colon
- breast
- Lung carcinoma
- Neuroblastoma
enumerate DNA repair genes
- BRCA1
- BRCA2
Tumor supressor genes are divided into
- Governers: RB, APC
- Guardians: TP53
Function of Governors
stop cell proliferation
function of Guardians
senses genomic damage & intitiates damage control response:
* arrest or stop prolifration for DNA repair
* if damage is too great to be repaired, it causes apoptosis
effect of loss of guardian genes on cellular proliferation & apoptosis
- Has no direct effect
- But accelerated the mutations in oncogenes
over expression Anti-apoptic genes leads to what type of cancer
follicular cell lymphoma
