Targeting SALL4 by Entinostat Inhibits the Malignant Phenotype of Gastric Cancer Cells by Reducing EMT Signaling

Abstract

Background/Aim: Spalt-like transcription factor 4 (SALL4), as a proto-oncogene, is expressed in various tumors and correlates with poor prognosis of patients. Entinostat, a histone deacetylase (HDAC) inhibitor, has emerged as a potentially promising anti-cancer drug. This study aims to explore the biological role and underlying mechanism of SALL4 targeting by entinostat in gastric cancer. Materials and Methods: Online databases were used to exam the link between SALL4 and prognosis. We tested the biological roles of SALL4 in gastric cancer cells. Cell viability and growth were analyzed using the Cell Counting Kit-8 (CCK-8) assay and clone formation assay. Cell migration was assessed using the wound healing assay. The effects of entinostat on gastric cancer cell lines were measured by the CCK-8 assay, clone formation assay, wound healing assay and transwell assay. Epithelial-mesenchymal transition (EMT) signaling pathways were detected by western blot. Results: SALL4 expression was upregulated in gastric cancer tissues and positively correlated with tumor stage and prognosis of patients by TCGA dataset analysis. Knockdown of SALL4 by siRNA inhibited the proliferation and migration of gastric cancer cells. In contrast, SALL4 overexpression by stably transfecting a SALL4-expressing plasmid promoted the proliferation and invasiveness of gastric cancer cells in vitro through alteration of EMT-related genes. In addition, entinostat, a HDAC inhibitor targeting SALL4, could suppress the proliferation, migration, and invasion of gastric cancer cells via regulating expression of EMT-associated proteins. Conclusion: SALL4 may be a new therapeutic target for the treatment of gastric cancer, and entinostat is a potential novel agent for the treatment of gastric cancer partially by targeting SALL4.