Opposite Biological Effects of Arsenic Trioxide and Arsacetin Involve a Different Regulation of Signaling in Human Gastric Cancer MGC-803 Cells

Abstract

Opposite biological effects of arsenic trioxide (As(2)O(3)) and arsacetin on the growth of human gastric cancer MGC-803 cells have been observed. Results show that As(2)O(3) inhibited the growth of MGC-803 cells by triggering apoptosis, whereas arsacetin promoted the cell proliferation and seemed to stimulate the secretion of some growth factors at the same micromolar concentrations. Further studies showed that As(2)O(3) could regulate protein tyrosine kinase activity, protein tyrosine phosphorylation, and Bcl-2 protein and upregulate p53 protein. The ability of arsacetin to promote cell proliferation is linked with causing the opposite effects on these factors. These results indicate that the opposite biological effects of As(2)O(3) and arsacetin involve different regulations of molecular mechanisms in MGC-803 cells and that arsacetin may be a potential tumor promoter.