Prognostic value of long non-coding RNA in hepatocellular carcinoma: A study based on multi-omics analysis and RT-PCR validation.

This study aimed to explore the relationship between and the prognosis of patients with hepatocellular carcinoma (HCC). We constructed a protein-protein interaction network using the STRING database and a network of competing endogenous RNAs (ceRNAs) using the StarBase database. Using data from the GEPIA2 database, we studied the association between genes in these networks and survival of patients with HCC. The potential mechanisms underlying the relationship between and HCC prognosis were studied using combined data from RNA sequencing, DNA methylation, and somatic mutation data from The Cancer Genome Atlas (TCGA) liver cancer cohort. Tumor tissues and 19 paired adjacent non-tumor tissues (PANTs) from HCC patients who underwent radical resection were analyzed for mRNA levels using real-time PCR, and associations of expression with clinicopathological features or prognosis of patients were analyzed using log-rank test and Gehan-Breslow-Wilcoxon test. Five interacting proteins and five target genes of in the ceRNA network significantly correlated with poor survival of patients with HCC ( < 0.05). High expression was associated with mutations in two genes leading to poor prognosis and may upregulate some prognostic risk genes through methylation. was significantly co-expressed with various signatures of genes involved in HCC progression, including the cell cycle, DNA damage repair, mismatch repair, homologous recombination, molecular cancer m6A, exosome, ferroptosis, infiltration of lymphocyte ( < 0.05). The expression of was markedly upregulated in HCC tissues compared with PANTs. In Kaplan-Meier analysis, patients with high expression had significantly shorter progression-free survival (PFS) ( = 0.033) and overall survival (OS) ( = 0.023) than those with low expression. Median PFS was 19.2 months for patients with high expression and 52.8 months for patients with low expression, while the corresponding median OS was 40.5 and 78.3 months. In subgroup analysis of patients with vascular invasion, cirrhosis, and HBsAg positive or AFP positive, MALAT1 overexpression was significantly associated with shorter PFS and OS. Models for predicting PFS and OS constructed based on expression and clinicopathological features had moderate predictive power, with areas under the receiver operating characteristic curves of 0.661-0.731. Additionally, expression level was significantly associated with liver cirrhosis, vascular invasion, and tumor capsular infiltration ( < 0.05 for all). is overexpressed in HCC, and higher expression is associated with worse prognosis. mRNA level may serve as a prognostic marker for patients with HCC after hepatectomy.