NCIt definition : An orally bioavailable, lipophilic, copper-binding, halogenated 8-hydroxyquinoline
with antifungal, antiparasitic and potential antitumor activities. Clioquinol forms
a stable chelate with copper (copper (II) ions), which inhibits the chymotrypsin-like
activity of the proteasome; consequently, ubiquitinated proteins may accumulate in
tumor cells, followed by tumor cell apoptosis and the inhibition of tumor angiogenesis.
In addition, the clioquinol-copper complex appears to decrease the expression of androgen
receptors (AR) in human copper-enriched prostate cancer cells. Serum levels of copper
are often elevated in patients with cancer; copper chelation may inhibit copper-dependent
endothelial cell proliferation and tumor secretion of angiogenic factors.;