Fig. 4: Sildenafil regulates the IL-6/JAK/STAT3 signalling pathway to inhibit GC cell growth.

A, B GSEA was performed on PDE5-overexpressing GC cells after treatment with sildenafil (150 μM) for 48 h, based on results from RNA-Seq data (GSEA: gene set enrichment analysis; NES: normalized enrichment score; NOM: nominal). C Western blotting analysis was conducted to evaluate the levels of pathway-associated proteins involved in the IL-6/JAK/STAT3 signaling pathway in PDE5-overexpressing GC cells following treatment with sildenafil (150 μM) for 48 h. D Cell viability of PDE5-overexpressing GC cells was evaluated after treatment with sildenafil (150 μM) and the IL-6 pathway inhibitor LMT28 (30 μM) for 48 h. Data are presented from technical replicates (n = 3). E Total apoptosis rates of the indicated cells treated with sildenafil (150 μM) and LMT28 (30 μM) for 48 h were analyzed, with data presented from technical replicates (n = 3). F Cell viability of PDE5-overexpressing GC cells was assessed after sildenafil treatment (150 μM) and recombinant human IL-6 protein (rHuIL-6) (10 ng/mL) for 48 h, with data presented from technical replicates (n = 3). G Total apoptosis rates of the indicated cells treated with sildenafil (150 μM) and rHuIL-6 (10 ng/mL) for 48 h were analyzed, with results presented as mean ± SD from three independent experiments. Statistical significance is indicated as follows: ns, P-value > 0.05; *, P-value < 0.05; **, P-value < 0.01; ***, P-value < 0.001.