Undifferentiated large cell lung carcinoma (LCLC) accounts for 2.9–9% of total lung cancers. Recently, RNA-seq based studies have revealed major genomic aberrations in LCLC. In this study, researchers from the Indian Institute of Technology aim to identify long non-coding RNAs (LncRNAs) expression pattern specific to LCLC. The RNA-seq profile of LCLC and other non-small cell lung carcinoma (NSCLC) was downloaded from Gene Expression Omnibus (GEO) and analyzed. Using 10 LCLC samples, the researchers found that 18% of all the annotated LncRNAs are expressed in LCLC samples. Among 1794 expressed LncRNAs, 11 were overexpressed and 14 were downregulated in LCLC compared to normal samples. Based on receiver operating characteristic (ROC) analysis, they showed that the top five differentially expressed LncRNAs were able to differentiate between LCLC and normal samples with high sensitivity and specificity. Guilt by association analysis using genes correlating with differentially expressed LncRNAs identified several cancer-associated pathways, suggesting the role of these deregulated LncRNA in LCLC biology. The researchers also identified the LncRNA differentially expressed in LCLC compared to lung squamous carcinoma (LUSC) and Lung-adenocarcinoma (LUAD). They found that LCLC sample showed more deregulated LncRNA in LUSC than LUAD. Interestingly, LCLC had more downregulated LncRNA compared to LUAD and LUSC. Our study provides novel insight into LncRNA deregulation in LCLC. This study also finds tools to diagnose LCLC and differentiate LCLC with other Non-Small Cell Lung Cancer.
(A) Venn diagram presenting total number of annotated LncRNA and expressed RNA. Big circle represents total number of LncRNA annotated and smaller circle represents the expressed LncRNA in LCLC. (B) Bar diagram showing number of intergenic and antisense LncRNA in expressed LncRNAs. (C) A volcano plot to show the significantly differentially expressed LncRNA in LCLC. Black dots show overexpressed genes and blue dots show underexpressed LncRNAs. (D) Heat map repressing the expression pattern of significantly differently regulated gene in LCLC. Color bar indicates the expression level with black high expression and Blue low expression. (E) Bar diagram to show the number of Antisense (AS) and Long intergenic differential expressed in LCLC.