Intracellular macromolecules in hypoxic cells after nitroreductase-mediated reduction

This target refers to the collective pool of intracellular proteins, DNA, and RNA that become covalently modified by reactive intermediates generated from the reduction of nitro-containing compounds. This process is specifically mediated by nitroreductase enzymes, such as cytochrome P450 oxidoreductase or NQO1, in environments with low oxygen tension (hypoxia) [1][2]. In the absence of oxygen, which would normally reverse the initial one-electron reduction step, these compounds undergo further reduction to form highly reactive species like hydroxylamines or nitrenium ions. These species then form stable adducts with cellular macromolecules, effectively trapping the molecule within the hypoxic cell [2][3]. This mechanism is widely exploited in oncology for both the imaging of tumor hypoxia and the delivery of hypoxia-activated prodrugs (HAPs) [1]. By targeting the unique metabolic state of hypoxic tumor regions, these drugs aim to overcome the treatment resistance typically associated with low-oxygen environments in solid tumors [4]. Sources: [1] Brown JM, Wilson WR. Nat Rev Cancer (2004); [2] Wilson WR, Hay MP. Nat Rev Cancer (2011); [3] Raleigh JA, et al. Br J Cancer (1998); [4] Hunter FW, et al. Expert Rev Mol Med (2016).

Other names

Hypoxic cell adductsNitroreductase-activated macromolecular targetsHypoxia-induced covalent adductsNitroimidazole-derived macromolecular adducts

Reductive activation of nitro-containing prodrugs by intracellular nitroreductases under hypoxic conditions, leading to the formation of reactive intermediates that covalently bind to cellular macromolecules.