<p>(A) Protein expression of IK1 is shown in six melanoma cell lines. Negative control: mock-transfected HEK-293; positive control: IK1-transfected HEK-293 cells. Equal protein loading (30 µg per lane) is proven by GAPDH. (B) Expression of IK1 mRNA in melanoma cell lines was determined by real-time PCR. The threshold of negative HEK-293 is indicated. Values were normalized to β-actin. (A, B) Each two independent experiments revealed comparable results. (C) Voltage-dependent potassium currents were recorded in TRAM-34-treated A-375, as compared to non-treated controls. The voltage range, used for subsequent time course, is indicated. (D) Time course of potassium currents in A-375 after addition of TRAM-34 (t = 0) is shown. Short arrowheads indicate the time interval for determination of the current/voltage dependency. (E) Cell cycle analysis of TRAM-34-treated A-375 as compared to DMSO-treated controls. (F) Decreased proliferation in response to increasing concentrations of TRAM-34 is shown for Mel-HO, as determined by WST-1 assay. Means and SDs are shown of three independent experiments, each one consisting of triplicates. Statistical significance is indicated (*; p<0.005), when comparing TRAM-34-treated cells with DMSO-treated controls. (G, H) Real-time growth curves of TRAM-34-treated A-375 and Mel-HO are compared to DMSO-treated controls. Cell indices were normalized at t = 0.</p
