Background: Non-small cell lung cancer (NSCLC) is a common clinical cancer with high mortality. The lectin galactoside-binding soluble 1 (LGALS1) is an RNA-binding protein (RBP) involved in NSCLC progression. Alternative splicing (AS) is a vital function of RBPs that contributes to tumor progression. It is unknown whether LGALS1 regulates NSCLC progression through AS events.
Objectives: To profile the transcriptomic landscape and LGALS1-regulated AS events in NSCLC.
Material and methods: The A549 cells either with silenced LGALS1 (siLGALS1 group) or without them (siCtrl group) were subjected to RNA sequencing; differentially expressed genes (DEGs) and AS events were discovered and then the AS ratio was validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR).
Results: High LGALS1 expression indicates poor overall survival (OS), first progression (FP) and post-progression survival (PPS). A total of 225 DEGs were identified, including 81 downregulated and 144 upregulated in the siLGALS1 group compared to the siCtrl group. Differentially expressed genes were mainly enriched in interaction-related Gene Ontology (GO) terms and involved in cGMP-protein kinase G (PKG) and calcium signaling pathways. The RT-qPCR validation showed that the expressions of ELMO1 and KCNJ2 were upregulated, while HSPA6 was downregulated after LGALS1 silencing. The expressions of KCNJ2 and ELMO1 were upregulated to a peak at 48 h after LGALS1 knockdown, while HSPA6 expression decreased, after which their expressions returned to baseline. The overexpression of LGALS1 rescued the elevation in KCNJ2 and ELMO1 expression, and decrease in HSPA6 expression induced by siLGALS1. A total of 69,385 LGALS1-related AS events were detected, which produced 433 upregulated and 481 downregulated AS events after LGALS1 silencing. The LGALS1-related AS genes were mainly enriched in the apoptosis and ErbB signaling pathways. The LGALS1 silencing led to a decrease in the AS ratio of BCAP29 and an increase in CSNKIE and MDFIC.
Conclusions: We characterized the transcriptomic landscape and profiled AS events in A549 cells following LGALS1 silencing. Our study provides abundant candidate markers and new insights into NSCLC.
Keywords: LGALS1 silencing; NSCLC; RNA binding proteins; alternative splicing; transcriptome landscape.