neoplasia 2 Flashcards
miRNAs
micro RNAs - dont produce proteins, loss of these genes sees increased carcinogenesis
oncogenes
‘accelerators’
produce oncoproteins
proto-oncogenes
normal genes involved in regulating cell division
mutations to these genes sees them then being called oncogenes
What might an oncogene cause (mutation to proto-oncogene)
production increase - e.g growth factor production increased
excess copies of gene - e.g excess growth factor
tumour suppressor genes
‘brakes’
act to inhibit cell division and suppress growth, produce growth suppressor factors
retinoblastoma gene
tumour suppressor
how many alleles must be mutated in proto-oncogenes and tumour suppressors for them to mutate
proto-oncogenes - 1
tumour suppressors - 2
p53
‘police’
acts just before restriction points in cell cycle to check for DNA damage
either DNA repaired or p53 activated and apoptosis induced
when is p53 often inactive
in patients with cancer either due to mutations or viral proteins form viruses inactivating it
what abilities must cancer cells have
- ability to rapidly divide
- ability to detach from surrounding cells
- ability to evade immune system
- ability to produce own growth signals
how do carcinomas spread
first to lymphatic system them later in the disease they spread by blood
how do sarcomas spread
blood (lymphatic spread is rare)
grade of tumour
biological nature (histopathology)
stage of tumour
extent of spread (clinical)
when grading a tumour what is looked at
histopathology
is there invasion to surrounding tissue ?
do cells resemble origin ?
nuclei staining?
