5721

PSME2

proteasome (prosome, macropain) activator subunit 2 (PA28 beta);PSME2;proteasome (prosome, macropain) activator subunit 2 (PA28 beta)

11S regulator complex beta subunit|11S regulator complex subunit beta|MCP activator, 31-kD subunit|REG-beta|activator of multicatalytic protease subunit 2|cell migration-inducing protein 22|proteasome activator 28 subunit beta|proteasome activator 28-beta

14q11.2

protein-coding

PA28beta is a subunit of proteasome activator PA28. Previous study suggests that PA28beta is involved in the invasiveness and metastasis of gastric adenocarcinoma (GA), however, the mechanism is not fully understood. In the present study, we showed that invasive abilities of gastric cancer cells were enhanced when PA28beta being down-regulated, and were inhibited when PA28beta being overexpressed. To explore the possible mechanism of PA28beta associated elevated invasiveness, the protein profiles of PA28beta knock down and parental negative control gastric cancer cells were compared using proteomics approach. The results revealed that there were 43 proteins were differentially expressed, among them, chloride intracellular channel 1 (CLIC1) was significantly up-regulated and selected for further functional study. Down-regulation of CLIC1 by RNA interference was able to markedly inhibit cell invasion of PA28beta knock down gastric carcinoma cells. In addition, an inverse correlation between PA28beta and CLIC1 expressions was also verified in GA tissue samples, suggesting that knockdown of PA28beta could enhance tumor invasion and metastasis, at least in part, through up-regulation of CLIC1. Our results provide novel insight into the mechanisms of PA28beta related invasiveness and metastasis of GA, and suggest new alternative approaches for GA treatment.