PIG3 suppresses gastric cancer proliferation by regulating p53- mediated apoptosis.

Gastric cancer (GC), the third leading cause of cancer mortality and the fifth most common cancer in the world, still is an important health problem worldwide. P53-inducible gene 3 (PIG3) was initially isolated in an investigation to identify the genes that were induced by p53 in human colorectal cancer cells. PIG3 can also regulate the stability of p53 through suppressing the process of the MDM2-mediated ubiquitination of p53. The aim of this study is to explore the expression level of PIG3 in human GC and further investigate the function and mechanism of PIG3 in human GC. Five cell lines and 30 matched GC tissue samples and adjacent tissue samples were used for this study, and MTT assay, colony formation assay, flow cytometry analysis and Western blot were carried out. Expression of PIG3 was found to be frequently reduced in GC. Restoration of the expression of PIG3 inhibited cell proliferation, induced cell apoptosis and further activated P53 signaling in BGC823 cells. In conclusion, we demonstrated that expression of PIG3 is frequently reduced in GC tissue, and PIG3 suppressed human GC growth through p53- mediated apoptosis. PIG3 may act as a potential diagnostic marker and a potential therapeutic target of GC.