The research effort of this project has concentrated on detailed investigations into the observed selectivity, in vitro, of several quaternized ellipticine derivatives for central nervous system (CNS) cell lines. NSC 627505, a water soluble analog, is taken up 3-12 fold more by responsive CNS tumor cell lines (U-251 glioblastoma; SNB-75 astrocytoma) than by selected refractory non-CNS cell lines (HCT-15 colon adenocarcinoma; A-498 renal cell carcinoma). The observed difference in uptake between CNS and non-CNS cell lines increases with time, suggesting the participation of a carrier-mediated drug transport process in the CNS tumor cell lines.
