LSD1 deletion represses gastric cancer migration by upregulating a novel miR-142-5p target protein CD9.

•LSD1 is a promoter in gastric cancer migration.•LSD1 deletion suppresses gastric cancer migration by decreasing intracellular miR-142−5p.•Migration suppressor CD9 is a new target of miR-142−5p.•Secretion of miR-142−5p using sEVs as vehicles contributes to decreased amount of intracellular miR-142−5p.