Galectin-9 Expression is Correlated to Cervical Squamous Cell Carcinoma Progression and Overall Survival

PURPOSE: To determine whether galectin-9 gene (LGALS9) expression is correlated with cervical cancer progression, clinicopathological characteristics, and overall survival. To determine the biological processes and the abundance of tumour infiltrating immune cells related to the expression of LGALS9. PATIENTS AND METHODS: The study was conducted in two phases: 1) The expression level of LGALS9 was determined using the data of 193 squamous cell carcinoma (SCC) samples from The Cancer Genome Atlas (TCGA) database. Biological processes and tumour infiltrating cells associated to LGALS9 expression were evaluated using gene set enrichment analysis (GSEA) and tumour immune estimation resource (TIMER). 2) Independently, galectin-9 was identified in 40 SCC samples by immunohistochemistry and optical density quantified using ImagePro(®) software. RESULTS: The LGALS9 gene showed increased expression in cervical cancer samples. A higher expression level in SCC was related to better overall survival and to early clinical stages. GSEA showed that tumours with higher expression of LGALS9 were enriched in immune pathways such as interferon_alpha_response, and complement, the analysis of TIMER database showed a positive correlation between the expression level of LGALS9 and the abundance of tumour infiltrating immune cells. In addition, higher expression of galectin-9 was found in biopsies of SCC patients at early clinical stages, showing a trend of better survival. CONCLUSION: Higher expression levels of LGALS9 and galectin-9 in SCC were related to early clinical stages and better prognosis. GSEA and TIMER analysis suggested that galectin-9 could play an antitumor role in cervical SCC.