DHX9 inhibits epithelial-mesenchymal transition in human lung adenocarcinoma cells by regulating STAT3.

DHX9 has numerous functions regulating transcription, translation, RNA processing and transport, and DNA replication and maintenance of genomic stability. It is involved in human cancers as either an oncogene or tumor suppressor. However, its role in the progression of lung cancer and underlying mechanisms remains unclear. In this study, we demonstrated that DHX9 is overexpressed in human lung cancer tissues and serum. Also, a favorable prognosis of lung adenocarcinoma is predicted when DHX9 is at a high level. DHX9 knockdown promoted cell proliferation, migration, and invasion and inhibited apoptosis progression in A549 cells. Moreover, DHX9 knockdown led to a significant decrease of E-cadherin expression, an increase of vimentin and snail, and a significant increase in the phosphorylation of STAT3 in A549 cells. In summary, our studies identified a novel role of DHX9 in driving tumor growth and epithelial-mesenchymal transition progress of A549 cells. We propose that the STAT3 pathway may be implicated in the DHX9-related epithelial-mesenchymal transition of lung adenocarcinoma. Therefore, DHX9 may be a prognostic marker or potential therapeutic target for lung adenocarcinoma.