Published online Dec 28, 2019. doi: 10.3748/wjg.v25.i48.6902
Peer-review started: September 29, 2019
First decision: November 10, 2019
Revised: November 27, 2019
Accepted: December 13, 2019
Article in press: December 13, 2019
Published online: December 28, 2019
Liver cancer, the sixth most common cancer worldwide, is the second leading cause of cancer mortality. A lncRNA is a non-coding RNA with a length exceeding 200 nucleotides. Previous studies have found that lncRNAs are involved in the development and progression of hepatocellular carcinoma (HCC), but whether they can be used as potential diagnostic and prognostic indicators is unclear.
LncRNA is a newly discovered non-coding RNA. Some studies have revealed that lncRNAs are differentially expressed in HCC and are expected to be measures of potential outcome. In this study, we found that lncRNA CASC9 was highly expressed in HCC patients based on the Cancer Genome Atlas (TCGA) database analysis and patients with high expression of CASC9 had a poor prognosis, which indicated that lncRNA CASC9 may be a potential diagnostic and prognostic indicator of HCC.
This study aimed to identify the expression of lncRNA CASC9 in HCC, its diagnostic and prognostic value and to construct ceRNA network maps to further explore its underlying mechanism.
Data on the expression of lncRNA CASC9 in TCGA were extracted, clinical samples were collected to further determine the expression of lncRNA CASC9 in HCC, and the correlation between lncRNA CASC9 and pathological data and survival of HCC patients were analyzed. Potential microRNA and target genes of lncRNA CASC9 were analyzed using on-line prediction websites, and ceRNA maps were drawn. In addition, Kyoto Encyclopedia of Genes and Genomes and GO enrichment analysis were employed to analyze the potential mechanisms of lncRNA CASC9 in biological processes.
Analysis revealed that lncRNA CASC9 was highly expressed in the tissues and serum of HCC patients and high expression of CASC9 was related to tumor size, TNM staging, lymph node metastasis, differentiation, and AFP. Further analysis showed that lncRNA CASC9 could be used as a diagnostic indicator of the above indices. Prognostic analysis revealed that the survival rate of patients with high expression of lncRNA CASC9 decreased, and Cox regression analysis showed that lncRNA CASC9 could be used as an independent prognostic indicator in HCC patients. The bioinformatics analysis revealed that lncRNA CASC9 potentially targeted 17 miRs. A total of 89 mRNAs were found in mRNA prediction. GO enrichment and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that lncRNA CASC9 participated in 18 GO functions and 8 signal transduction pathways.
LncRNA CASC9 is highly expressed in HCC patients, and may be a potential diagnostic and prognostic indicator of HCC.
It is necessary to further explore the value of lncRNA CASC9 in HCC, and prospective experiments and multi-center clinical studies are required to obtain more robust conclusions. In addition, we hope to further verify the relevant mechanisms of lncRNA CASC9 in HCC by carrying out relevant basic experiments, in order to address the deficiencies in this study.