Hypoxia-Induced LXRα Contributes to the Migration and Invasion of Gastric Cancer Cells.

Gastric cancer is characterized by the presence of high invasion ability, hypoxia and chemoresistance. Previous studies reported that liver X receptor α (LXRα) was involved in epithelial-mesenchymal transition (EMT) of gastric cancer cells. However, hypoxia-mediated EMT and the role of LXRα in gastric cancer remained elusive. In this study, we demonstrated that LXRa mRNA and protein levels were up-regulated by hypoxia treatment and LXRα played an important role in HIF-1 dimer induced-EMT. The putative HIF-1α binding site was identified in the LXRa promoter. Expression of LXRα and HIF-1α was significantly up-regulated in gastric cancer tissues compared to that in normal tissues. More importantly, we noticed that the expression of LXRα and HIF-1α was significantly correlated. Taken together, these data suggested that LXRα is regulated by the activity and accumulation of HIF-1α and contributes to EMT of gastric cancer cells. This suggests that targeting LXRα might be a potential approach for improving survival of gastric cancer patients.