HUMAN astrocytoma cells were studied using whole-cell patch-clamp reco
rding. Voltage-dependent outwardly-rectifying anion currents were iden
tified in primary cultures of six freshly resected human brain tumors
and in seven established anaplastic astrocytoma/glioblastoma cell line
s (U251MG, CH235MG, U373MG, U105MG, D54MG, SK-MG-1, and STTG1). Anion
currents were not observed in normal, non-neoplastic glial cells, nor
in human tumor-derived cells of non-glial origin (melanoma, breast can
cer, neuroblastoma, rhabdomyosarcoma). Currents activated at potential
s >50 mV and showed large transients upon termination of voltage steps
. Currents reversed at the predicted equilibrium potential for chlorid
e ions and could also be recorded when Cl- was replaced by F-, Br- or
I-. Currents were inhibited by the Cl- channel blockers chlorotoxin, D
IDS, and DNDS. These Cl- currents may play a role in the growth contro
l of astrocytoma cells.