Effect of the TGFβ induced lncRNA TBILA on non-small cell lung cancer progression by regulating HGAL and binding with S100A7.

Abstract

e24203 Background: Long non-coding RNAs (lncRNAs) play critical roles in multiple cellular processes of non-small cell lung cancer (NSCLC); however, their involvement in transforming growth factor-beta (TGFβ) signal pathway, the critical pathway of tumor cell epithelial-mesenchymal transition and metastasis, remains poorly understood. Methods: RNA-Seq was used to compare the global gene expression patterns of NSCLC cells treated with and without TGFβ1. Dual luciferase reporter assay and ChIP assay were performed to verify the regulation of TBILA by TGFβ. Rapid amplification of cDNA ends, northern blot, RNA Scope and nuclear/cytoplasm fractionation were performed to find out molecular characteristics and subcellular localization of TBILA. TBILA and HGAL expression levels in NSCLC tissues and adjacent tissues were detected by RT-qPCR. Loss and gain of function assay were used to explore the role of TBILA in NSCLC progression in vitro and in vivo. RNA immunoprecipitation and RNA pull down were used to explore TBILA binding proteins. Co-IP, GST pull down and western blot assays were performed to detect activation and alteration of downstream signaling pathways. Results: We observed 423 lncRNAs were upregulated, and 246 lncRNAs were downregulated in TGFβ1-treated cells compared with control cells. And one of the most prominent hits, named as TGFβ-induced lncRNA (TBILA), promoted NSCLC progression and was upregulated in tumor tissues (p < 0.001). Upregulated by TGFβ classical signaling pathway, TBILA promotes HGAL expression by binding with the Smad transcription factor complex, thereby enhancing RhoA activation. In addition, TBILA induces the S100A7-JAB1 pathway by binding with nuclear S100A7 and enhances pro-survival pathways in NSCLC. Moreover, TBILA expression level and invasiveness of NSCLC cells was upregulated by cancer associated fibroblasts culture supernatant. Conclusions: Our findings demonstrate that TBILA acts as key regulator of the TGFβ signaling pathway and revealed that TGFβ plays a role in regulating lncRNAs in NSCLC. TBILA has pleiotropic pro-survival and invasion-metastasis cascade-inducing effects; thus, TBILA may be an effective target in NSCLC treatment.