HA-ADT suppresses esophageal squamous cell carcinoma progression via apoptosis promotion and autophagy inhibition

Esophageal squamous cell carcinoma (ESCC) is a major cause of cancer-related deaths. We have previously connected a non-sulfated glycosaminoglycan, hyaluronic acid (HA), with a common hydrogen sulfide (H2S) donor, 5-(4-hydroxyphenyl)-3H-1,2-dithiol-3-thione (ADT-OH), to reconstruct a novel conjugate, HA-ADT. In this study, we determined the effect of HA-ADT on the growth of ESCC. Our data suggested that HA-ADT exerted more potent effects than sodium hydrosulfide (NaHS, a fast H2S-releasing donor) and morpholin-4-ium (4-methoxyphenyl)-morpholin-4-ylsulfanylidenesulfido-λ5-phosphane (GYY4137, a slow H2S-releasing donor) on inhibiting the viability, proliferation, migration, and invasion of human ESCC cells. HA-ADT increased apoptosis by suppressing the protein expressions of phospho (p)-Ser473-protein kinase B (PKB/AKT), p-Tyr199/Tyr458-phosphatidylinositol 3-kinase (PI3K), and p-Ser2448-mammalian target of rapamycin (mTOR), but suppressed autophagy through the inhibition of the protein levels of p-Ser552-β‐catenin, p‐Ser9-glycogen synthase kinase‐3β (GSK-3β), and Wnt3a in human ESCC cells. In addition, HA-ADT was more effective in terms of the growth inhibition of human ESCC xenograft tumor than NaHS and GYY4137. In conclusion, HA-ADT can suppress ESCC progression via apoptosis promotion and autophagy inhibition. HA-ADT might be efficacious for the treatment of cancer.