FKBP4 correlates with CD8⁺ T cells and lymphatic metastases in oral squamous cell carcinoma

Objectives: To identify the engagement of CD8(+) T cells in the lymph node metastasis (LNM) of oral squamous cell carcinoma (OSCC) and significant CD8(+) T cell-related genes regulating the LNM. Subjects and methods: Tumor samples of primary OSCC patients were obtained (n = 71). CD8 expression in LNM- and LNM+ tumors were identified using tissue microarray (TMA)-based immunohistochemistry (IHC) and compared using the Mann-Whitney U test. The LNM status, as well as the metagene expression of CD8(+) T cells of OSCC patients, were obtained from The Cancer Genome Atlas (TCGA) database. Metagenes related to LNM were screened using logistic regression analyses and further identified using TMA-based IHC. Results: CD8 was significantly positively associated with LNM (p < 0.05). Furthermore, tumors with higher expression of FKBP4 had significantly higher LNM rate (HR: 1.63; 95% CI: 1.08 - 2.53; p < 0.05), which was also proven using TMA-based IHC analysis. Conclusion: CD8(+) T cells might engage in the lymphatic metastases of OSCC. Among CD8(+) T cell-related genes, FKBP4 could be a promising biomarker to predict the risk of LNM of OSCC.