Long noncoding RNA LSINCT5 is upregulated and promotes the progression of esophageal squamous cell carcinoma

Long stress-induced noncoding transcripts 5 (LSINCT5) has been reported to be upregulated in several human cancers and related to poor prognosis. However, its involvement in esophageal squamous cell carcinoma (ESCC) remains largely unknown. We aim to evaluate the expression and putative role of LSINCT5 on the progression of ESCC.

LSINCT5 expression was first examined in the ESCC cell lines using RT-qPCR, and the next-generation RNA-Seq technology was employed to analyze and functionally annotate the differential gene expression before and after LSINCT5 knockdown in ESCC was made. Based on the functional annotation results, the effects of LSINCT5 knockdown on cell growth, migration, invasion, and epithelial-to-mesenchymal transition (EMT) were assessed in the ESCC cell lines. Finally, the expression and clinicopathological significance of LSINCT5 in ESCC and corresponding nontumor tissues were further explored using RT-qPCR.

The RT-qPCR results showed that LSINCT5 expression was significantly upregulated in the ESCC cell lines. The differential gene expression analysis by next-generation RNA-Seq showed that 138 genes were up-regulated, and 227 genes were downregulated after LSINCT5 was knocked down in the ECA 109 cells. In addition, the functional annotation revealed that the differentially expressed genes were mainly functionally involved in tight junctions, ECM-receptor interactions, and MAPK signaling pathway. Further in vitro studies indicated that the knockdown of LSINCT5 significantly suppressed proliferation, migration, invasion, and EMT in ESCC cells. Finally, a comparative study of paired ESCC and corresponding nontumor tissues showed that LSINCT5 was upregulated in the ESCC tissues, and the increased LSINCT5 expression was related to late clinical stages, large tumor sizes, and lymph node metastasis.

The results indicate that LSINCT5 is upregulated in ESCC and may act as an oncogene promoting the progression of ESCC.