Though
copper is elevated in the
tumor tissue and
plasma of patients with various malignancies, the
molecular targets for
copper binding agents in
angiogenesis and
tumor progression remain poorly understood. It is disclosed that one anti-angiogenic target for the
copper binding agent tetrathiomolybdate is
intracellular CuZn-
superoxide dismutase (SOD1). A second generation tetrathiomolybdate analog, ATN-224, inhibits endothelial
cell (EC) proliferation
in vitro, binds to SOD1 and inhibits its activity without displacing
bound copper ATN-224 can accumulate in ECs and inhibit CuZnSOD activity with an IC50 similar to the IC50 for EC proliferation, resulting in increased generation of
intracellular reactive oxygen species. Inhibition of EC proliferation by ATN-224
in vitro is substantially reversed by a synthetic
porphyrin SOD mimetic. Similar results were observed
in vivo, where inhibition of
angiogenesis by ATN-224 in a
Matrigel plug model was also reversed by MnTBAP. Thus, a distinct molecular target for copper depletion therapy has been identified and SOD1 is now validated as a target for anti-
angiogenesis. Methods for screening, or designing, such SOD1 inhibitors for use as angiogenesis inhibitors and anti-
cancer agents are disclosed.