GRAIL inhibits the growth, migration and invasion of lung adenocarcinoma cells by modulating STAT3/C-MYC signaling pathways

Purpose: To explore the role and possible regulatory mechanisms of GRAIL in lung adenocarcinoma cells. Methods: Online databases were used to analyze the expression and prognosis of GRAIL in patients with lung adenocarcinoma. Lung adenocarcinoma cells (A549 and H1299) were transfected with small interfering RNA or infected with lentivirus. The constructed cell models were validated by real-time fluorescence quantitative PCR. Cell proliferation ability was detected by CCK8 assay, cell migration and invasion ability were detected by scratch assay and Transwell assay. Suppressed hallmark gene sets of GRAIL in lung adenocarcinoma was performed by GeneSet Enrichment Analysis. The mRNA and protein level of C-MYC were detected by real-time fluorescence quantitative PCR and western blot. The protein level of STAT3 and phosphorylated STAT3 were detected by western blot. Results: GRAIL is poorly expressed in lung adenocarcinoma tissue. Down-regulation of GRAIL is associated with poor prognosis of lung adenocarcinoma patients. GRAIL expression is negatively correlated with the proliferation, migration, and invasion of lung adenocarcinoma cells. GRAIL inhibits activation of STAT3 and transcription of C-MYC. Conclusions: GRAIL inhibits the growth, migration and invasion of lung adenocarcinoma cells. GRAIL might play an anti-cancer role through regulating STAT3/C-MYC signaling pathways.