IL-27 induces TRAIL expression in human melanomas and inhibits their tumor growth partly in a TRAIL-dependent manner.

<p>(A) Human melanoma cell lines (SK-MEL-13, -28, and -37) were stimulated with IL-27 (10 ng/ml) for 0, 20, and 60 min. Cell lysate was then prepared and subjected to Western blotting with anti-pY-STAT1, anti-pY-STAT3, anti-total STAT1, and anti-total STAT3. Similar results were obtained in two independent experiments. (B) These melanoma cell lines were stimulated with increasing doses of IL-27 (0–100 ng/ml) for 72–96 h in triplicate and pulsed with ³H-thymidine for the last 24 h, and ³H-thymidine incorporation was measured. Data are shown as means ± SD. *, †, and ‡ indicate <i>p</i><0.01, <i>p</i><0.0001, and <i>p</i><0.00001, respectively, compared with 0 ng/ml IL-27. Similar results were obtained in three independent experiments. (C) These melanoma cell lines were stimulated with increasing doses of IL-27 (0–100 ng/ml) for 24 h. Total RNA was then extracted and subjected to RT-PCR analysis. Similar results were obtained in more than three independent experiments. (D) These melanoma cell lines were stimulated with IL-27 (100 ng/ml) for 48 h, and then analyzed for cell surface expression of TRAIL by FACS using PE-labeled anti-TRAIL (solid line) and its control Ab (plain line with shading). Similar results were obtained in two independent experiments. (E) These melanoma cell lines were stimulated with IL-27 (10 and 100 ng/ml) in the presence of anti-TRAIL neutralizing Ab or its control Ab (10 µg/ml) for 72–96 h in triplicate and pulsed with ³H-thymidine for the last 24 h, and ³H-thymidine incorporation was measured. Data are shown as means ± SD. * indicates <i>p</i> < 0.05, compared with control Ab. Similar results were obtained in three independent experiments.