targeted chemotherapy Flashcards
what does SERM stand for?
selective oestrogen receptor modulator.
what does the SERM (ie tamoxifen) do?
it is given after surgery/treatment to stop the oestrogen stimulating the increasing cell proliferation.
what is a positive side effect of tamoxifen?
it prevents osteoporosis, via oestrogen effects.
osteoporosis is a feature of menopause.
what is a modulator and how is it different to an antagonist?
interacts with the modulator to stop it being stimulated. not as clear cut as competing with the oestrogen instead it seems to turn the receipt off.
what do aromatase inhibitors do?
alternative to tamoxifen.
in post menopausal female, they have male androgens.
these are metabolised to oestrogens by the enzyme aromatase.
aromatase inhibitors inhibit this and prevent oestrogens.
why do some people need alternatives of tamoxifen?
can’t activate tamoxifen
what is the function of HER2 (human epidermal growth factor receptor 2)?
it is a protein on surface of cells, which has tyrosine kinase activity.
the TK will go through autophosphorylation and the DNA will start translating VEGF this starts angiogenesis, and COX2 and cyclins which are cell cycle regulators.
if you have overexpression of the HER2 there will be disregulation of the cell cycle.
why is the HER2 over expressed in some cancer patients?
oncogene B2 switched on causes this.
the amount of oncogene B2 increases with age.
so an older patient is more likely to be HER2 positive.
Herceptin (trastuzumab) works how?
slows down cell replication.
by SERM
what is the small molecule approach ?
attacking the second messenger system.
EGF receptors need to phosphorylase the TK to have its effects. (angiogenesis, apoptosis, proliferation)
the small molecule target s the receptor and stops the phosphorylation of the tyrosine kinase.
what is the philadelphia chromosome?
90% of chronic myeloid leukaemia are because of the Philadelphia chromosome.
produces the abl-bcl chromsome coding zone.
this is the Philadelphia chromosome
imatinib (a small molecule selective for Philadelphia chromosome) does what for chronic myeloid leukaemia?
it inhibits the TK activity.
what does the PARP inhibitor do?
PARP is involved with DNA repair.
what does a positive test result of the BRCA gene test?
it means that person has a harmful mutation in the BRCA1 gene which is responsible for the tumour suppressor.
