Astaxanthin inhibits integrin α5 expression by suppressing activation of JAK1/STAT3 in Helicobacter pylori‑stimulated gastric epithelial cells

Integrins act as cell-matrix adhesion molecules involved in cell attachment to the extracellular matrix and generate signals that respond to cancer metastasis. Integrin α5β1 is a heterodimer with α5 and β1 subunits and mediates cell adhesion and migration of cancer cells. Integrins are transcriptionally regulated by the Janus kinase (JAK)/STAT signaling pathways. Our previous study revealed that Helicobacter pylori increased the levels of reactive oxygen species (ROS), which activate JAK1/STAT3 in gastric cancer AGS cells in vitro. Astaxanthin (ASX) has been reported to be an effective antioxidant and anticancer nutrient. The present study investigated whether ASX suppresses H. pylori-induced integrin α5 expression, cell adhesion and migration and whether ASX reduces ROS levels and suppresses phosphorylation of JAK1/STAT3 in gastric cancer AGS cells stimulated with H. pylori. The effect of ASX was determined using a dichlorofluorescein fluorescence assay, western blot analysis, adhesion assay and wound-healing assay in AGS cells stimulated with H. pylori. The results demonstrated that H. pylori increased the expression levels of integrin α5, without affecting integrin β1, and increased cell adhesion and migration of AGS cells. ASX reduced ROS levels and suppressed JAK1/STAT3 activation, integrin α5 expression, cell adhesion and migration of H. pylori-stimulated AGS cells. In addition, both a JAK/STAT inhibitor, AG490, and an integrin α5β1 antagonist, K34C, suppressed cell adhesion and migration in H. pylori-stimulated AGS cells. AG490 inhibited integrin α5 expression in AGS cells stimulated with H. pylori. In conclusion, ASX inhibited H. pylori-induced integrin α5-mediated cell adhesion and migration by decreasing the levels of ROS and suppressing JAK1/STAT3 activation in gastric epithelial cells.