Several N-3 substituted carboranyl Thd analogs were synthesized. These agen
ts as well as some non-boronated nucleosides were evaluated in, phosphoryl
transfer assays with recombinant human TK1 and TK2. For some carboranyl thy
midine analogs, TK1 phosphorylation rates approached 38% that of thymidine.
Their in vitro cytotoxicty appeared to correlate with the TK1 levels in th
e tested cells. In some cases increased uptake in tumor cell nuclei compare
d with the surrounding cytoplasm was detected in vitro.