Omipalisib Inhibits Esophageal Cancer Growth through PI3K/AKT/mTOR Signalling Pathway Disruption

Esophageal squamous cell carcinoma (OSCC) is a lethal digestive tract malignancy with limited effective interventions. This study aims to explore a new potential inhibitor on OSCC and investigate the underlying mechanisms. Based on a drug screen of an FDA-proven library consisting of 1404 compounds, we demonstrated that Omipalisib, a dual PI3K/mTOR inhibitor, markedly inhibited cell proliferation and colony formation in a panel of OSCC cell lines. Mechanistically, Omipalisib induced G0/G1 phase cell cycle arrest and apoptosis. Moreover, RNA-seq, KEGG and GSEA confirmed that the PI3K/mTOR signalling pathway is the primary target of Omipalisib in OSCC cells. Omipalisib treatment suppressed the PI3K/mTOR signalling pathway. Furthermore, Omipalisib exerted a significant antineoplastic effect on OSCC tumour xenografts in BALB/c nude mice without obvious side effects. The present study supports the rationale for using Omipalisib as a therapeutic approach for OSCC cases and suggests the potential clinical evaluation of this strategy. In this study, we investigated the therapeutic effects and underlying mechanisms of Omipalisib in OSCC cells based on a screen of compound library.