Restoring Tumour Selectivity of the Bioreductive Prodrug PR-104 by Developing an Analogue Resistant to Aerobic Metabolism by Human Aldo-Keto Reductase 1C3.

PR-104 is a phosphate ester pre-prodrug that is converted in vivo to its cognate alcohol, PR-104A, a latent alkylator which forms potent cytotoxins upon bioreduction. Hypoxia selectivity results from one-electron nitro reduction of PR-104A, in which cytochrome P450 oxidoreductase (POR) plays an important role. However, PR-104A also undergoes 'off-target' two-electron reduction by human aldo-keto reductase 1C3 (AKR1C3), resulting in activation in oxygenated tissues.

Identification of one-electron reductases that activate both the hypoxia prodrug SN30000 and diagnostic probe EF5.

SN30000 is a second-generation benzotriazine-N-oxide hypoxia-activated prodrug scheduled for clinical trial. Previously we showed that covalent binding of the hypoxia probe EF5 predicts metabolic activation of SN30000 in a panel of cancer cell lines under anoxia, suggesting that they are activated by the same reductases. However the identity of these reductases is unknown.

Diflavin oxidoreductases activate the bioreductive prodrug PR-104A under hypoxia.

The clinical agent PR-104 is converted systemically to PR-104A, a nitrogen mustard prodrug designed to target tumor hypoxia. Reductive activation of PR-104A is initiated by one-electron oxidoreductases in a process reversed by oxygen. The identity of these oxidoreductases is unknown, with the exception of cytochrome P450 reductase (POR).

Dermatofibrosarcoma protuberans: report of a case with a variant ring chromosome and metastases following pregnancy.

Background: The most frequent molecular abnormality observed in dermatofibrosarcoma protuberans (DFSP) is the formation of a supernumerary ring chromosome or translocation resulting in fusion of the gene encoding the alpha-chain of type 1 collagen, COL1A1 from 17q22, to the platelet-derived growth factor beta-chain, PDGFB gene from 22q13. Rare cases documenting variant ring or marker chromosomes involving regions other than 17q22 and 22q13 have been reported. Further analysis in three of these cases demonstrated the presence of the COL1A1 and PDGFB genes.

Inflammatory myofibroblastic tumor of the left ventricle in an older adult.

We report an unusual study of a 72-year-old woman who presented with a symptomatic space-occupying lesion in the left ventricle. The lesion was surgically excised with a good long-term result. It was histologicaly diagnosed as an inflammatory myofibroblastic tumor.