Drugs targeting Hormone-Dependent Tumors
Hormone-based therapies are
used for cancers which are
hormone dependent.
ER-positive: Cancers that have
estrogen receptors are called ERpositive (or ER+) cancers.
PR-positive: Cancers with
progesterone receptors are called
PR-positive (or PR+) cancers.
Anti-estrogen
Tamoxifen
v Chemically a triphenylethylene
v Mechanism of action: competitive binding
to the estrogen receptor resulting in
reduction of transcription of estrogen
regulated genes.
v Dimethylaminoethoxy side chain and the
trans configuration are crucial for the
antiestrogenic activity of tamoxifen.
v Block in the G1 phase of the cell cycle
and a slowing of cell proliferation.
v Tamoxifen is thus, a cytostatic drug.
Anti-androgens
inhibits CYP17A1 (one kind of P450)