Synergistic anticancer effect of combined crocetin and cisplatin on KYSE-150 cells via p53/p21 pathway

BACKGROUND: More than 400,000 patients die from esophageal cancer annually. Considerable efforts have been made to develop new and effective treatments, one of which is directed toward herbal medication. Crocetin is a natural carotenoid dicarboxylic acid isolated from the Chinese herb saffron. We recently reported on the anticancer effects of saffron. This study aimed to determine whether crocetin combined cisplatin has synergistic effect in KYSE-150 cells and explore the underlying mechanism. METHODS: KYSE-150 cells were treated with crocetin and/or cisplatin. The effects on cell viability, cell apoptosis, mitochondrial membrane potential (MMP), as well as the expression levels of PI3K/AKT, MAPKs, p53/p21, and apoptosis-related protein were evaluated. MTT assay, Annexin V-FITC/PI staining, Rh123 staining, and Western blot analysis were used. RESULTS: The cell proliferation significantly decreased and cell apoptosis was induced with combined crocetin and cisplatin, compared with either crocetin only or cisplatin only. The outcome suggested that crocetin combined cisplatin has synergistic effects on inhibition of cell proliferation and pro-apoptotic effect of cisplatin on KYSE-150 cells. Disruption of MMP, upregulation of cleaved caspase-3 expression, and downregulation of Bcl-2 occurred in the group treated with combined treatment. No significant differences in p-PI3K, p-AKT, and MAPKs activity were indicated between combined treatment group and the individual treatment group. However, the expression levels of p53 and p21 were markedly higher in the combined treatment group than in the individual treatment group. The wild-type p53 inhibitor, PFT-α suppressed the overexpression of p53/p21 and the synergistic effect induced by the combination of crocetin and cisplatin. CONCLUSIONS: We concluded that crocetin combined with cisplatin exerts a synergistic anticancer effect by up-regulating the p53/p21 pathway.