Exogenous H₂S promotes cancer progression by activating JAK2/STAT3 signaling pathway in esophageal EC109 cells

Hydrogen sulfide (H₂S) plays an important role in diverse physiological and pathophysiological processes in cancer cells both in vitro and in vivo. We have previously shown that exogenous H₂S exerts its biological effects on hepatoma, glioma, and esophageal cancer cells through the activation of NF-κB, p38-MAPK/ERK1/2-COX-2, and HSP90 pathways. However, the role of H₂S and the underlying mechanism in esophageal squamous cell carcinoma remain unclear. Here we investigated whether exogenous H₂S contributes to the biological behavior of esophageal squamous cancer cell line EC109, through the activation of JAK2/STAT3 signaling pathway. EC109 cells were treated with NaHS (a donor of H₂S) and AG490 (a specific inhibitor of JAK2/STAT3 signaling pathway). The expression levels of p-JAK2, p-STAT3, caspase-3/9/12, Bax, Bcl-2, MMP-2/9, and VEGFR were measured by western blot analysis. Cell viability was detected by CCK-8 and quantified by direct counting of cells under a microscope. Cell migration was analyzed by the scratch-wound assay, while the level of VEGF was measured by ELISA. Cells treated with NaHS for 24 h showed significant upregulation of p-JAK2, and p-STAT3 expression, as well as increased cell viability when compared to the control cells. The expression levels of caspase-3/9/12 and Bax decreased, while those of Bcl-2, MMP-2/9, VEGFR, and VEGF increased. NaHS induced the migration of EC109 cells. However, co-treatment with NaHS and AG490 significantly inhibited these effects. Thus, JAK2/STAT3 signaling pathway may contribute to H₂S-induced cell proliferation, anti-apoptosis, migration, and angiogenesis in EC109 cells.