Identification of key immune cells infiltrated in lung adenocarcinoma microenvironment and their related long noncoding RNA

Highlights•Treg cell was screened as tumor-associated immune cell by machine learning•Multiple visualization toolkits interpret model prediction criteria•Treg cell-associated lncRNA was screened as PCBP1-AS1 by machine learning method•PCBP1-AS1 regulates the TGF-β pathway and response to immunotherapySummaryLncRNA associated with immune cell infiltration in tumor microenvironment (TME) may be a potential therapeutic target for lung adenocarcinoma. We established a machine learning (ML) model based on 3896 samples characterized by the degree of immune cell infiltration, and further screened the key lncRNA. In vitro experiments were applied to validate the prediction. Treg is the key immune cell in the TME of lung adenocarcinoma, and the degree of infiltration is negatively correlated with the prognosis. PCBP1-AS1 may affect the infiltration of Tregs by regulating the TGF-β pathway, which is a potential predictor of clinical response to immunotherapy. PCBP1-AS1 regulates cell proliferation, cell cycle, invasion, migration, and apoptosis in lung adenocarcinoma. The results of clinical sample staining and in vitro experiments showed that PCBP1-AS1 was negatively correlated with Treg infiltration and TGF-β expression. Tregs and related lncRNA PCBP1-AS1 can be used as targets for the diagnosis and treatment of lung adenocarcinoma.Graphical abstract