Neoplasia 2 - Molecular Aspects of Cancer and Carcinogenesis Flashcards
What are the 6 hallmarks of cancer?
- sustaining proliferative signalling
- evading growth suppressors
- activating invasion and metastasis
- enabling replicative immortality
- inducing angiogenesis (independent vasculature)
- resisting cell death
What are the 4 emerging hallmarks of cancer?
- avoiding immune destruction
- tumour promoting inflammation
- genome instability and mutation
- deregulating cellular energetics
What are the 4 classes of genes that are the principal targets of genetic damage in carcinogenesis?
- growth promoting proto-oncogenes
- growth inhibiting tumour suppressor genes
- genes that regulate programmed cell death
- genes involved in DNA repair
What are genes involved in DNA repair?
Genes which normally repair mutated DNA but if the gene is mutated will allow further mutations to develop
What is an example of genes involved in DNA repair?
BRCA1 and BRCA2
What are growth promoting proto-oncogenes?
Genes which normally regulate growth and when mutated are overly activated to cause accelerated growth
What are the different types of oncogenes?
growth factors, growth factor receptors, proteins in signal transduction, transcription factors, cell cycle regulators
What are examples of growth promoting proto-oncogenes?
Her2-neu, Ras, Mac
What happens if Ras is mutated?
It loses its ability to be dephosprylated and inactivated
What are growth inhibiting tumour suppressor genes?
Genes which normally suppress cell division and when mutated this function is inhibited and leads to continuous growth
What are the different types of tumour suppressor genes?
Either regulate cell cycle directly or inhibit oncogenic pathways
What are examples of growth inhibiting tumour suppressor genes?
P53, Rb, APC, PTEN
How many alleles need to be mutated in growth promoting proto-oncogenes?
1 allele - because that is sufficient to create accelerated growth
How many alleles need to be mutated in growth inhibiting tumour suppressor genes?
2 alleles - because if one allele is still making the product then there will be enough product to still suppress cell division - this most often occurs when 1 allele that is inherited is mutated and then another mutation develops in the other allele
What are the four types of mutations in cancer?
- errors in DNA replication not repaired
- point mutations
- amplification of oncogenes
- chromosomal rearragnement
What are the ‘hotspots’ for errors in DNA replication not being repaired?
oncogenes, tumour supressor genes and their regulatory regions