Repression of CRNDE enhances the anti‐tumour activity of CD8 + T cells against oral squamous cell carcinoma through regulating miR‐545‐5p and TIM‐3

Immunotherapy has been identified a promising treatment of cancers, including Oral squamous cell carcinoma (OSCC). CRNDE is highly overexpressed in various cancers. Many lncRNAs have been reported in CD8 T lymphocytes. Little is investigated about their effects in the functions of CD8 + T cells in OSCC. Currently, the influence of lncRNA CRNDE on the function of CD8 + T cells in OSCC progression was investigated. Here, CRNDE was obviously elevated and negatively correlated with IFN‐γ production in tumour‐infiltrating CD8 + T cells isolated from OSCC patients. CRNDE can exhibit a crucial role in activating CD8 + T‐cell exhaustion. Mechanistically, CRNDE specifically sponged miR‐545‐5p to induce T‐cell immunoglobulin and mucin domain‐3 (TIM‐3), thus contributing to CD8 + T‐cell exhaustion. The function of miR‐545‐5p on T‐cell function remains poorly known. TIM‐3 is a significant immune checkpoint, and it inhibits cancer immunity. TIM‐3 can demonstrate an important role in CD8 + T‐cell exhaustion. In summary, loss of CRNDE could induce miR‐545‐5p and inhibit TIM3 expression, thus significantly activated the anti‐tumour effect of CD8 + T cells.