Objective To investigate the role and mechanism of the small-molecule inhibitor CIL56 in the death of esophageal squamous cell carcinoma cells.

Methods SRB method and plate-cloning method were used to detect the effect of CIL56 on the proliferation of esophageal squamous cell carcinoma. The effect of CIL56 on the migration of esophageal squamous cell carcinoma cells was investigated by scratch-healing test. The effect of CIL56 on the concentration of iron ions in esophageal squamous cell carcinoma was detected with an iron-detection kit. A total glutathione test kit was used to examine the effect of CIL56 on glutathione concentration in esophageal squamous cell carcinoma. Western blot was used to investigate the effect of CIL56 on the expression of xCT and GPX4 proteins related to iron death, as well as YAP1 protein, in esophageal squamous cell carcinoma.

Results CIL56 could significantly inhibit the proliferation (P < 0.05) and migration (P < 0.001) of esophageal squamous cell carcinoma. With the increased CIL56 concentration, the iron concentration in esophageal squamous cell carcinoma increased (P < 0.05). CIL56 could reduce the glutathione content in esophageal squamous cell carcinoma (P < 0.01). CIL56 could reduce the expression of xCT and GPX4 proteins related to iron death and decrease the level of YAP1 protein in esophageal squamous cell carcinoma (both P < 0.001).

Conclusion The small-molecule inhibitor CIL56 can significantly inhibit the proliferation and migration of esophageal squamous cell carcinoma cells and reduce the expression of the iron-death-related proteins xCT and GPX4, as well as YAP1 protein.