Lycopene and β-carotene may act as potent anti-proliferative agents in ESCC cells. - GreenMedInfo Summary

The molecular mechanisms underlying the chemopreventive effects of carotenoids in different types of cancer are receiving increasing attention. In the present study, the role of peroxisome proliferator-activated receptorγ (PPARγ) in the effect of lycopene and β-carotene on the viability of EC109 human esophageal squamous carcinoma cells was investigated. The viability of EC109 cells was evaluated using MTT assays. The effects of lycopene and β-carotene on the expression of PPARγ, p21, cyclin D1 and cyclooxygenase-2 (COX-2) were analyzed by western blotting. Lycopene andβ-carotene (5-40 µM) dose- and time-dependently reduced the viability of the EC109 cells. GW9662, an irreversible PPARγ antagonist, partly attenuated the decrease in EC109 cell viability induced by these carotenoids. Lycopene and β-carotene treatments upregulated the expression of PPARγ and p21, and downregulated the expression of cyclin D1 and COX-2. These modulatory effects of the carotenoid treatments were suppressed by GW9662, suggesting that the inhibition of EC109 cell viability by lycopene andβ-carotene involves PPARγ signaling pathways and the modulation of p21, cyclin D1 and COX-2 expression.