Glucose regulates cellular uptake of boric acid and substituted boric acid

Boron neutron capture therapy (BNCT) is a binary radiotherapeutic modality based on nuclear capture and fission reactions that occur when the stable isotope boron-10 is irradiated with neutrons to produce high energy α particles．For this to be successful, about 20 μg·g⁻¹ of ¹⁰B (per weight of tumor) must be selectively delivered to tumor cells (≈ 10⁹ atoms·cell⁻¹), and enough neutrons must be absorbed to sustain a lethal ¹⁰B(n, α)⁷Li capture reaction．Therefore the key to enhance effectiveness of BNCT is for ¹⁰B to be targeted to tumor cells efficiently and selectively．Carbohydrates are known to accumulate in tumor cells．Increased boron uptake in tumor cells is expected after introducing carbohydrates in the form of covalently-bonded complexes of boric acid or derivatives．It was found that the uptake of boric acid and derivatives by tumor cells increased with increasing concentrations of glucose, but glucose uptake by normal cells did not increase markedly．Glucose had no effect on cellular persistence of boron compounds．