MEOX2 serves as a novel biomarker associated with macrophage infiltration in oesophageal squamous cell carcinoma and other digestive system carcinomas.

Background: Oesophageal squamous cell carcinoma (ESCC) is a malignant tumour of the digestive system that is associated with high morbidity and mortality rates worldwide. With the increased use of immunotherapy in cancer treatment, there is an urgent need to elucidate the immune-related mechanisms in ESCC and other digestive system carcinomas.

Methods: In our study, single-sample gene set enrichment analysis (ssGSEA) was first performed to analyse the expression profile downloaded from the NCBI Gene Expression Omnibus (GEO) database. Then, a series of bioinformatic analyses, including the Mann-Whitney test, weighted gene co-expression network analysis (WGCNA), functional enrichment analysis and differentially expressed genes (DEGs) analysis, we identified target immunocytes and related genes. Finally, we validated the results with the TIMER database.

Results: Our analyses showed that the numbers of infiltrating macrophages were obviously higher in advanced stages in ESCC compared with other types of immunocytes. MEOX2 was identified as a biomarker correlated with macrophage infiltration in ESCC and other types of digestive system carcinomas. And MEOX2 expression was strongly associated with the mRNA expression of colony-stimulating factor 1 (CSF-1) and CSF-1 receptor (CSF-1R) in these kinds of carcinomas.

Conclusion: We speculated that MEOX2 could facilitate macrophage infiltration CSF-1/CSF-1R signalling in ESCC and other kinds of digestive system carcinomas, and MEOX2 might serve as a novel target in prospective tumour immunotherapies.