Inhibitory Effect of Selenium on Esophagus Cancer Cells and the Related Mechanism

Selenium has been associated with many malignant tumors including esophagus cancer (EC). In current study, we examined the effects of three types of selenium, sodium selenite (SSE), methylseleninic acid (MSA) and methylselenocysteine (MSC) on EC cell line Eca109. Here, selenium attenuated cell viability and increased cell apoptosis, especially in MSC, when compared with control group (p<0.05). Meanwhile, MSC and MSA, but no SSE, arrested cell cycle in G0/G1 phase (p<0.05). Mechanistically, FAL1 and PTEN were found to participate in regulating cell cycle and cell apoptosis process by decreasing cyclinD1, CDK2, and promoting caspase-3, caspase-8. In addition, we found that cyclinD1, CDK2 were significantly downregulated by MSA and MSC, while caspase-3, caspase-8 were dramatically upregulated by SSE (p<0.05). Based on these results, we concluded that MSC and MSA inhibit the viability of Eca109 mainly through reducing cell proliferation, while SSE by promoting apoptosis.