Curcumin and its nano formulation inhibit proliferation and FGF21 expression in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent malignancy worldwide. Curcumin is a well-known phytochemical with proven anticancer properties. However, it has poor bioavailability and is unstable. Therefore, the purpose of this study was to develop curcumin nanoparticles and explore the antitumour effects of curcumin and nano-curcumin in ESCC. Nano-curcumin was successfully prepared by the thin-film hydration method. The results of MTT assay, colony formation assay, and apoptosis assays demonstrated that both curcumin and nano-curcumin inhibited the proliferation of ESCC cells. Curcumin and nano-curcumin could regulate the expression of BAX, BCL2, and caspase-3 in ESCC cells. We found that curcumin and nano-curcumin could also induce reactive oxygen species production and decrease the mitochondrial membrane potential. The sequencing results indicated that curcumin and nano-curcumin inhibited ESCC proliferation through calcium signalling pathways in KYSE450 cells. Furthermore, curcumin and nano-curcumin increased calcium levels. RT-qPCR and Western blot data also demonstrated that both curcumin and nano-curcumin promote endoplasmic reticulum (ER) stress in ESCC cells. By establishing a xenograft tumour model of ESCC, curcumin and nano-curcumin inhibited tumour proliferation and induced apoptosis and ER stress, indicating that curcumin and nano-curcumin exerted antitumour effects in vivo. Therefore, our findings provide a potential lead compound for treating ESCC.