Overexpression of as a prognostic marker in hepatocellular carcinoma: A TCGA data-based analysis.

Transcription elongation factor 1 () is a nuclear protein consisted of multiple protein structural domains that plays an important role in regulating the transcription, extension, and splicing regulation of RNA polymerase II. However, the prognostic and immunological role of 1 in human cancer remains unknown. In this study, we analyzed the expression of gene in hepatocellular carcinoma (HCC) patients, its clinical significance, and its possible prognostic value by bioinformatics. RNA sequencing data and clinicopathological characteristics of patients with HCC were collected from TCGA and CCLE databases. The Wilcoxon rank-sum test was used to analyze the expression of in HCC tissues and normal tissues. The protein levels of between normal and liver cancer tissues were analyzed by the Human Protein Atlas Database (HPA) (www.proteinatlas.org). Validation was performed using the Gene Expression Omnibus (GEO) dataset of 167 samples. The expression of in HCC cells were verified by qRT-PCR, and CCK-8, scratch assay and Transwell assay were performed to detect cell proliferation, migration and invasion ability. According to the median value of expression, patients were divided into high and low subgroups. Logistic regression, GSEA enrichment, TME, and single-sample set gene enrichment analysis (ssGSEA) were performed to explore the effects of on liver cancer biological function and immune infiltrates. co-expression networks were studied through the CCLE database and the LinkedOmics database to analyze genes that interact with . The expression levels of in HCC patient tissues were significantly higher than in normal tissues. Survival analysis showed that high levels of expression were significantly associated with low survival rates in HCC patients. Multifactorial analysis showed that high expression was an independent risk factor affecting tumor prognosis. This result was also verified in the GEO database. Cellular experiments demonstrated that cell proliferation, migration and invasion were inhibited after silencing of gene expression. Co-expression analysis revealed that and expression were positively correlated with . GSEA showed that in samples with high expression, relevant signaling pathways associated with cell cycle, apoptosis, pathways in cancer and enriched in known tumors included Wnt signaling pathway, Vegf signaling pathway, Notch signaling pathway, MAPK signaling pathway and MTOR pathways. The expression of was positively correlated with tumor immune infiltrating cells (T helper two cells, T helper cells). gene is highly expressed in hepatocellular carcinoma tissues, which is associated with the poor prognosis of liver cancer, and may be one of the markers for the diagnosis and screening of liver cancer and the prediction of prognosis effect. At the same time, may also become a new target for tumor immunotherapy.