Dihydroxyboryldeoxyuridine (DBDU); can a borated nucleoside deceive the DNA molecule

The possibility of using a boronated analog of thymidine for Neutron Capture Therapy (NCT) is intriguing, as the boron is targeted to the cell's most sensitive location. Such an analog has been synthesized in the form of dihydroxyboryldeoxyuridine (DBDU). Data are presented indicating that DBDU is indeed incorporated in the nucleus, and that significant radiosensitization is produced in cell cultures as a consequence of this uptake. The results demonstrate that cells exposed to DBDU for 1 cell cycle incorporate an amount of boron such that the resultant biological effect is equivalent to a boron concentration of 6 ..mu..g /sup 10/B/g cell. Other studies have shown that it should be possible to effect successful BNCT with a boron concentration of approx.15 ..mu..g /sup 10/B/g cell (with an epithermal neutron beam; thermal beams would require more; reference 1). Thus it would appear that DBDU is capable of delivering boron concentrations approaching that which should be useful for therapy. 7 refs.