P53-induced gene 11 (PIG11) involved in arsenic trioxide-induced apoptosis in human gastric cancer MGC-803 cells.

Arsenic trioxide (As2O3) has been used as an effective chemotherapy agent for some human cancer, such as acute promyelocytic leukemia. We have demonstrated that low level of As2O3 relatively selectively inhibited growth of the solid tumor MGC-803 cells by triggering apoptosis. In this study, we found PIG11, a p53-induced gene, was upregulated markedly by As2O3 using the technique of differential display reverse transcriptase PCR (DDRT-PCR). Addition of anti-PIG11 phosphorothioated oligonucleotide (5'-GGC CGC CAT CTT CTC CTC-3') before As2O3 treatment, abolished the transient increase in PIG11 gene expression. Furthermore, it significantly inhibited the As2O3-induced apoptosis of MGC-803 cells, but had no effect in addition of missense (5'-GAG GAG AAG ATG GCG GCC-3') phosphorothioated oligonucleotides. These results suggest that PIG11, as a downstream target of p53, is involved in apoptosis of MGC-803 cells.