Validation of DRG-like F11 cells for evaluation of KCNQ/M-channel modulators.

F11 cells are derived from a fusion between mouse embryonic neuroblastoma and rat dorsal root ganglion (DRG) neurons. These cells have been shown to retain many features of native DRG neurons, including synthesis of neurotransmitters, expression of neuropeptide receptors, and voltage-gated calcium channels. In this study, we describe the presence of KCNQ2/3 channels in F11 cells as determined by both reverse transcription-polymerase chain reaction and functional assessment. Electrophysiological recordings in whole-cell configuration performed in F11 cells revealed the functional expression of a KCNQ/M-current with characteristic slow deactivation kinetics, similar to the KCNQ/M-current recorded from dissociated DRG neurons. Deactivation tail currents elicited by conventional M-current protocols were enhanced by a specific KCNQ/M-channel opener, WAY-1, and inhibited by the specific blocker XE991 [10,10-bis(4-pyridinylmethyl)-9(10H)- anthracenone]. Using a non-radioactive atomic absorption Rb+ efflux assay, we further validated that Rb+ efflux can be induced in differentiated F11 cells by activation of KCNQ/M-channels. These findings have led us to conclude that F11 cells can be used as a DRG cell model to evaluate effects of KCNQ/M-channel modulators.