Evaluation of eluforsen, a novel RNA oligonucleotide for restoration of CFTR function in in vitro and murine models of p.Phe508del cystic fibrosis
Fig 1
Eluforsen increases chloride efflux in CFPAC-1 cells and restores CFTR function in p.Phe508del CF HBE cells.
(A) CFPAC-1 cells transfected with CF4–CF6 duplex or CF4 alone exhibited a slightly higher increase in fluorescence compared with eluforsen-transfected cells (*p < 0.05, n = 4). Mean of values relative to eluforsen ± SEM are shown; differences between treatments were compared by one-way ANOVA with Tukey post hoc test. (B) CFPAC-1 cells transfected with eluforsen exhibited a significantly higher chloride efflux rate (as monitored by MQAE quenching) than untreated cells or negative control oligonucleotide-transfected cells (*p < 0.05, n = 10). Mean of values relative to eluforsen ± SEM are shown; differences between treatments were compared by one-way ANOVA with Tukey post hoc test. (C) Representative Isc traces of isoproterenol-stimulated HBE cultures that were untreated, treated with eluforsen, or treated with scrambled oligonucleotide. (D) CFTR-specific Isc was significantly increased upon eluforsen treatment compared with untreated HBE cultures (***p = 0.0007, n = 20 for untreated, n = 22 for eluforsen) and scrambled control-treated cultures (*p = 0.01, n = 24). Bars show mean ± SEM; differences between treatments were compared by one-way ANOVA with Tukey post hoc test. (E) Dose–response curves of HBE cells treated with eluforsen and scrambled control. The maximum effect of eluforsen is reached at a concentration of 300 nM, with an EC50 of 28 ± 2.63 nM. The scrambled control-treated cultures also showed a modest response to treatment at a significantly higher concentration (EC50 1,002 ± 1.42 nM, p < 0.01, n = 70 for eluforsen and n = 40 for scrambled control). Dots show mean ± SEM; the differences between the EC50s of the dose responses was compared by Student’s t-test.