Objective
ghrelin is a protein that regulate appetite and energy balance in the human body, which is encoded by the ghrelin prepropeptide gene (GHRL). GHRL is linked with carcinogenesis and immune regulation. However, the correlation of GHRL to prognosis and tumor-infiltrating lymphocytes in gastric cancer remains unclear.
Materials and methods
In this study, we assessed the transcriptional expression, protein expression, prognosis, different clinicopathological features and co-expressed genes about GHRL, the correlation between GHRL and tumor infiltration immune cells in GC patients based on the data published in the following databases: TIMER, GEPIA, GEO, UALCAN, TISIDB, Kaplan–Meier Plotter and HPA databases.
Results
We found that GHRL expression in GC samples was lower than in normal samples. However, sample type, cancer stage, and worse survival were correlated to high GHRL expression. We also found that the expression of GHRL in dysplasia was significantly lower than that in CNAG and in GC. A total of 10 hub genes were identified from the co-expressed genes, including GHRH, GHSR, CCK, GPR39, MBOAT4, UCN, LEP, INS, GH1 and IGF1. High GHRL expression was connected with immunomodulators, chemokines, and infiltrating levels of B cells, CD8 + T cells, CD4 + T cells, macrophages, neutrophils, and dendritic cells in GC.
Conclusions
GHRL is a prognostic biomarker for GC patients, and it is correlated with progression of precancerous lesions in GC. It might lead to poor prognosis by regulating tumor immune microenvironment. Studies are important to explore therapeutic targeting GHRL in the future.