Abstract: Abstract：Objective To investigate the effect of dextran sulfate (DS) on the proliferation and apoptosis in human gastric cancer MGC-803 cells and its mechanisms. Methods Human gastric cancer MGC-803 cells were cultured and divided into control group (PBS group) and experimental group (DS group). The effect of DS on the proliferation of gastric cancer MGC-803 cells was detected by EdU cell proliferation assay. Plate colony formation assay was used to detect the effect of DS on colony forming ability of MGC-803 cells. Changes of the apoptosis were determined by AnnexinV-PI double staining. Western blot assay was also used to analyze the protein expression levels of EZH2, Cleaved-caspase3 at different time points (2 h, 8 h, 12 h and 24 h). Results EdU results showed that DS significantly inhibited the proliferation of gastric cancer MGC-803 cells compared with that of the control group (P＜0.01). The plate colony formation experiment showed that cell colony forming ability was significantly decreased in experimental group than that of the control group (P＜0.01). The result of AnnexinV-PI double staining showed that the apoptosis rate was significantly higher in the experimental group than that of the control group (P＜0.01). Western blot analysis showed that after DS intervention the protein expression of EZH2 was significantly decreased in MGC-803 cells compared with that of control (P＜0.05), and the protein expression level of Cleaved-caspase3 was significantly increased (P＜0.05). Conclusion DS can significantly inhibit the proliferation and induce apoptosis of human gastric cancer MGC-803 cells, which may be related to the inhibition of EZH2 expression.

Key words: stomach neoplasms, cell line, tumor, cell proliferation, apoptosis, enhancer of zeste homolog 2 protein, dextran sulfate