Purpose: Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed digestive cancers and the fourth leading cause of death worldwide. Long noncoding RNAs (lncRNAs) with key roles in HCC development and progression have emerged and are used in the diagnosis and prognostic prediction of HCC. The lncRNA gradually increased during hepatocarcinogenesis (GIHCG ) is a novel lncRNA with aberrant expression in many tumors, but its prognostic value and biological role in HCC have not been fully studied. Thus, the aim of this study was to explore the expression pattern and potential biological role of GIHCG  in HCC.
Patients and Methods: The expression pattern of GIHCG  in HCC was analyzed in our HCC cohort and validated in The Cancer Genome Atlas (TCGA) database. To assess the prognostic value of GIHCG , survival analyses and Cox regression analyses were carried out in two HCC cohorts. Functional enrichment analysis was used to predict the gene sets and pathways related to aberrant GIHCG  expression. Furthermore, the relationship between GIHCG  expression and immune infiltration in HCC was analyzed.
Results: GIHCG  was highly expressed in HCC tissues compared with normal liver tissues. In addition, high GIHCG  expression was significantly correlated with inferior clinicopathological characteristics and shorter survival times. High GIHCG  expression was an independent prognostic factor for overall survival and disease-free survival in the HCC cohort in our center and in the TCGA-LIHC cohort. Hallmark terms such as “G2M checkpoint”, “MYC  targets” and “DNA repair” were enriched in the GIHCG  high-expression groups. High GIHCG  expression negatively correlated with the infiltration of memory CD4+ and CD8+ T cells, natural killer cells, macrophages, dendritic cells, neutrophils and monocytes.
Conclusion: The findings of our study indicate that GIHCG  is a biomarker that can be used to predict the prognosis of HCC patients and is correlated with immune cell infiltration in HCC.
Keywords: GIHCG , prognosis, immune cell infiltration