| Background and objective:Lymphoepithelial Carcinoma of the lung is a distinct subtype of non-small-cell lung carcinoma.This tumor has distinct pathologic features,accompanied by abundant lymphocyte infiltration,which was similar to undifferentiated nasopharyngeal carcinoma.However,the subtype and distribution of tumor-infiltrating lymphocytes(TIL)in the tumor microenvironment were unclear.Unlike other non-small cell lung cancer(NSCLC),Lymphoepithelial Carcinoma of the lung has a distinct genome profile.Moreover,the proportion of Programmed Cell Death Receptor-ligand 1(PD-L1)positivity is higher than that in lung adenocarcinoma.The relationship between PD-L1expression,lymphocyte infiltrating,clinicopathological features,and the clinical prognosis was still unclear.This study will explore the clinicopathological features,lymphocyte infiltration,and differential genomics of PD-L1 expression in Lymphoepithelial Carcinoma of the lung.Methods:(1)82 Lymphoepithelial Carcinoma of the lung patients who underwent surgical resection from Xiangya Hospital,the Second Xiangya Hospital,and the Third Xiangya Hospital of Central South University from 2014 to December 2021 were screened.The clinical and corresponding pathological data of Lymphoepithelial Carcinoma of the lung patients have been collected.T lymphocyte(CD3~+),CD4~+T lymphocyte(CD4~+),Cytotoxic T-lymphocyte(CTLs)(CD8~+),B lymphocytes(CD20~+),and Natural Killer Cells(CD56~+)were detected by immunohistochemical method from paraffin-embedded tissues of 38Lymphoepithelial Carcinoma of the lung patients,which were used to describe the cell density and distribution of tumor-infiltrating lymphocytes.The correlation between the subtype of TIL in Lymphoepithelial Carcinoma of the lung and clinicopathological features was analyzed.(2)The expression of PD-1 and PD-L1 protein in 38 Lymphoepithelial Carcinoma of the lung paraffin-embedded tissues was detected by immunohistochemistry,and the relationship between PD-1 and PD-L1expression and clinicopathological characteristics,and the correlation between PD-L1 expression and the cell counts of CD3~+T lymphocytes,CD4~+T lymphocytes,CD8~+T lymphocytes,and CD20~+B lymphocytes was analyzed by statistical methods.(3)According to the expression of PD-L1,All cases of Lymphoepithelial Carcinoma of the lung were divided into three groups,including the negative group,low expression group,and high expression group.To screen the differential gene mutation between the two groups,we selected three pairs of paraffin-embedded tissues from the negative and high expression groups for whole-exome sequencing(WES).Furthermore,this research performed Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment,and Protein-Protein Interaction(PPI)network analysis for the differential gene mutation to find key gene mutation.Result:(1)The densities of CD3~+T lymphocytes,CD4~+T lymphocytes,CD8~+T lymphocytes,CD20~+B lymphocytes,and CD56~+NK cells infiltrated in the tumor stroma were significantly higher than that in the tumor nest(P<0.05).The densities of T lymphocytes infiltrated in the tumor stroma and in the tumor nest were both significantly higher than the densities of B lymphocytes(P<0.05),and the density of CD4+T lymphocytes was significantly higher than CD8~+T lymphocytes(P<0.05).(2)The denser infiltration of CD8~+T lymphocytes in the tumor nest were significantly correlated with the pleural invasion(P<0.05).(3)The expressions of PD-1 and PD-L1 in Lymphoepithelial Carcinoma of the lung were not significantly correlated with tumor size,lymph node metastasis,pleural invasion,TNM stage,and Ki-67 in patients of Lymphoepithelial Carcinoma of the lung(P<0.05),PD-L1 expression was correlated with CD20~+B lymphocytes(P<0.05),and there was no significant correlation between PD-L1 expression and the the densities of different subtypes of T lymphocytes(P>0.05).(4)A total of 8213 SNVs and 1109 Indels were detected by Whole-exome sequencing of two groups with different PD-L1 expressions.We filtered all synonymous mutations of mutated genes,obtaining 94differentially mutated genes.(5)GO,KEGG,and PPI were performed on all differentially mutated genes.We further screened ten core genes,including PLEC,TTN,FLNA,TJP1,OBSCN,NEB,PXN,SYNE2,DYSF,and AHNAK.Conclusions:(1)Both the tumor stroma and the tumor nest were dominated by T lymphocyte infiltration,and the infiltration of CD4~+T lymphocytes was more obvious than CD8~+T cells in Lymphoepithelial Carcinoma of the lung.(2)The pathways involved in the differentially mutated genes based on PD-L1 expression were mainly related to the tight junctions and Rap1signaling pathway.11 figures,21 tables,71 references... |
PDF Full Text Request