Co-expression and transcriptional regulation network analysis of PD-L1 in lung squamous cell carcinoma / 解放军医学杂志

ABSTRACT

Objective To construct a programmed cell death ligand 1(PD-L1) co-expression network in lung squamous cell carcinoma,screen potential PD-L1 co-expression biomarkers,and try to find the genes and pathways participating in PD-L1-regulated tumor immune response.Methods The lung squamous cell carcinoma dataset extracted from TCGA was used to screen the co-expression genes of PD-L 1 at the whole-genome transcriptional level by Venny analysis,and the target genes were screened by multiple types of cluster and molecular network analysis to construct a PD-L1 co-expression network.Results A total of 126 genes moderately co-expressed with PD-L1 were retrieved,most of them are plasma membrane targeting genes participating in immune response.Three transcription factors (IRF2/NFKB1/IRF1) were involved in more than 30％ the regulation of the PD-L1 genes transcription.By screening the core molecules of co-expression of PD-L1 gene set and analyzing the connectivity of network node,6 network nodes genes with the highest connectivity were retrieved as followsIFNG,JAK2,STAT1,CTLA4,CD80 and CCR5.Analysis of the relations of the different expression levels of these genes to the survival situation of patients with lung cancer revealed that CCR5 was a significant prognostic marker.Analysis of the PD-L1 expression and CCR5 gene spectrum data showed the Pearson correlation coefficient is 0.47(P＜0.05);GO-BP cluster analysis showed that the function of CCR5 mainly focused on immune regulation,T cell regulation and signal transduction,in accordance with the PD-L1 function of network regulation.Conclusions The main nodes of PD-L1 co-expressing gene set are immune-related molecules,among which IFNG/CCR5/NFKB1 play the most significant regulatory effects in the gene network.This finding lays a foundation for the research and immunotherapy for lung squamous cell carcinoma.