System used to induce selective apoptosis of 12B1.

(A) Transmembrane fusion protein consisting of a low-affinity nerve growth factor receptor (NGFR) accessible on the cell surface, 2 mutant FK506 binding protein (FKBP) domains, and a Fas death domain (Fas DD) intracellularly. (B) Expression of surface NGFR by stably transfected 12B1 clones. The parental line 12B1 has no expression, whereas clone 12B1-D1 has high levels of NGFR on its surface. (C) Sensitivity of transfected 12B1 clones to increasing concentrations of AP20187. Parental 12B1 cells were found to be resistant to AP20187, whereas transfected clones such as 12B1-D1 were sensitive. Evaluated by MTT assay after 24 hours.