Long noncoding RNA MEG3 plays a promoting role in the proliferation, invasion, and angiogenesis of lung adenocarcinoma cells through the AKT pathway. 
The role of long noncoding RNA maternally expressed gene 3 (MEG3) in lung adenocarcinoma has not been explored entirely.  In this study, it was demonstrated that the expression of MEG3 was enhanced in lung adenocarcinoma tissues from TCGA database and some specific cell lines, while the survival analysis showed that patients with higher MEG3 levels had lower survival probabilities, which suggested that MEG3 might serve as a lung adenocarcinoma promoter.  In addition, the results suggested that the overexpression of MEG3 could promote the proliferation and invasion of lung adenocarcinoma cells.  Furthermore, increased MEG3 expression could result in a notable increase in angiogenesis-related factors as well as in the capillary tube formation of endothelial cells, which indicates that the overexpression of MEG3 could promote the angiogenesis of lung adenocarcinoma.  From a mechanistic perspective, the results obtained revealed that the upregulation of MEG3 could stimulate the AKT signaling pathway and consequently lead to the biological behaviors mentioned above.  In summary, all the results obtained from this study indicated that MEG3 plays a promoting role in the tumorigenesis and angiogenesis of lung adenocarcinoma, which deserves special attention when considered as a potential therapeutic target for lung adenocarcinoma.