<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A substance being studied in the treatment of cancer. PR-104 becomes active when cancer cells don't receive enough oxygen. It may kill cancer cells by damaging their DNA.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A non-toxic, small-molecule, hypoxia-activated, 3,5-dinitrobenzamide nitrogen mustard pre-prodrug with potential antitumor activity. Upon intravenous administration, PR-104 is converted by systemic phosphatases to the alcohol intermediate PR-104A, which is reduced to form the active DNA-crosslinking mustard species hydroxylamine PR-104H intracellularly under hypoxic conditions. PR-104H specifically crosslinks hypoxic tumor cell DNA, resulting in the inhibition of DNA repair and synthesis, cell-cycle arrest, and apoptosis in susceptible hypoxic tumor cell populations while sparing normoxic tissues.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>