The Cancer cell Flashcards
How many genes are usually mutated in cancer?
5-7
What are the hallmarks of cancer?
Sustained angiogenesis Evades apoptosis Limitless replication Evades immune system Growth factor independant Invasion and metastases
When is the cell cycle halted by mutated DNA?
G1 checkpoint
How are proto-oncogenes activated in cancer?
Substitutions (hyperactive mutants)
Deletions (truncations/hyperactive mutants)
Amplification (overexpression)
Chromosome translocations
What do proto-oncogenes encode?
TFs
Growth factors
Receptors for growth factors
Signal cascade proteins
Which viruses target proto-oncogenes?
Reteroviruses
Papovavirus
Herpes
Hepadnavirus
How does HPV16 cause cancer?
E6 for disruption of p53 and telomerase
E7 for disruption of Rb
Produces benign growths but integration produces malignancy
How does helicobacter pylori cause cancer?
Damages gut epithelium by inflammation causing excessive proliferation
What is Retinoblastoma?
Mutation of both alleles of Rb tumour suppressor by sporadic or inherited predisposition
How many people are affected by sporadic retinoblastoma?
1/30,000 people have a benign tumour in 1 eye
How do epigenetic factors cause cancer?
Inactivation of MLH1 and MSH2 DNAmismatch repair genes
How do cancer cells grow in culture?
Serum free No adhesion No contact inhibition Rounded Disorganised Actin cytoskeleton Immortal
What are the 2 types of colon cancer?
Hereditary Non-Polyposis Colon Cancer
Familial Adenomatous Polyposis/ Adenomatous Polyposis Coli
What causes HNPCC?
Absence of MLH1 and MSH2
What percentage of colon cancers are inherited?
10-15%
