Nitric oxide synthase 1 inhibits the progression of esophageal cancer through interacting with nitric oxide synthase 1 adaptor protein.

BACKGROUND: Esophageal cancer (ESCA) is among the most prevalent and lethal tumors globally. While nitric oxide synthase 1 (NOS1) is recognized for its important involvement in various cancers, its specific function in ESCA remains unclear. AIM: To explore the potential role and underlying mechanisms of NOS1 in ESCA. METHODS: Survival rates were analyzed using GeneCards and Gene Expression Profiling Interactive Analysis. The effects and mechanisms of NOS1 on ESCA cells were evaluated via the Cell Counting Kit-8 assay, scratch assay, Transwell assay, flow cytometry, quantitative polymerase chain reaction, western blotting, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining. The protein interaction network was used to screen the interacting proteins of NOS1 and validate these interactions through co-immunoprecipitation and dual luciferase assays. Additionally, a nude mouse xenograft model was established to evaluate the effect of NOS1 in vivo. RESULTS: The survival rate of patients with ESCA with high NOS1 expression was higher than that of patients with low NOS1 expression. NOS1 expression in ESCA cell lines was lower than that in normal esophageal epithelial cells. Overexpression of NOS1 (oe-NOS1) inhibited proliferation, invasion, and migration abilities in ESCA cell lines, resulting in decreased autophagy levels and increased apoptosis, pyroptosis, and ferroptosis. Protein interaction studies confirmed the interaction between NOS1 and NOS1 adaptor protein (NOS1AP). Following oe-NOS1 and the silencing of NOS1AP, levels of P62 and microtubule-associated protein 1 light chain 3 beta increased both in vitro and in vivo. Furthermore, the expression levels of E-cadherin, along with the activation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT), were inhibited in ESCA cell lines. CONCLUSION: NOS1 and NOS1 proteins interact to suppress autophagy, activate the PI3K/AKT pathway, and exert anti-cancer effects in ESCA.