Beclin-1 expression serves as an important biomarker for carcinogenesis and evolution in lung adenocarcinoma presenting as ground glass opacity

Background: The prognostic impact of Beclin-1 and relationship between Beclin-1 expression and carcinogenesis of lung adenocarcinoma has not been clarified. Methods: The data of 10 patients with atypical adenomatoid hyperplasia (AAH), 20 patients with adenocarcinoma in situ (AIS), 28 patients with minimally invasive adenocarcinoma (MIA), and 50 patients with invasive adenocarcinoma (IA) who underwent surgical resection, were retrospectively reviewed. Normal lung tissues (NTs) were also collected for comparison. The expression levels of Beclin-1 mRNA and protein were detected by RT-PCR and western blotting, respectively. Immunohistochemistry was also performed. Results: The transcriptional expression of Beclin-1 in lung adenocarcinoma presenting as GGO was significantly lower than that in NTs (P<0.05), and patients with MIA and IA showed a lower expression of Beclin-1 than that in patients with AAH and AIS (P<0.01). Lung adenocarcinomas with low expression of Beclin-1 were in more advanced stage (stage 0-I vs. stageII_III: 0.24 +/- 0.11 vs. 0.17 +/- 0.03, P<0.01), had more lymph node metastasis (P<0.01), and were of more invasive pathological subtype (P<0.01) than lung adenocarcinomas with high expression of Beclin-1. Low expression of Beclin-1 predicted worse survival in patients with IA (P<0.05). Conclusions: Beclin-1 expression was related with the evolution of lung adenocarcinoma. Beclin-1 may be an important marker for predicting the prognosis of patients with lung adenocarcinoma manifested as GGO.