Enzyme inhibitor
This orally available antineoplastic agent (FW = 310.36 g/mol; CAS
297730-17-7), also known as VX-944 and (R) -1-cyanobutan-2-yl- (S) -1- (3-
(3- (3-methoxy-4- (oxazol-5-yl) phenyl) ureido) phenyl) ethyl) carbamate,
inhibits inosine 5’-monophosphate dehydrogenase (IMPDH), the enzyme
catalyzing the conversion of IMP into XMP, leading to the biosynthesis of
GMP, GDP, GTP, and ultimately dGTP. IMPDH is overexpressed in some
cancer cells, particularly in hematological malignancies, and AVN944
appears to have a selective cytotoxic effect on cancer cells. Reduction
of GTP in normal cells results in a temporary slowing of cell growth only.
AVN944 treatment results in dose-dependent cell growth inhibition in all
studied prostate cancer cells, independently of their androgen sensitivity
. AVN944 treatment arrests LNCaP cells in G1-phase and and androgen-
independent 22Rv1, DU145 and PC-3 cells in S-phase. AVN-944
treatment leads to the rapid disappearance of nucleostemin, a positive
regulator of cell proliferation that is highly expressed in a variety of stem
cells, tumors, and tumor cell lines.