Abstract: Objective: To explore the expression and clinical significance of DDIT4 gene in oral squamous cell carcinoma (OSCC). Methods: The OSCC cohort data from TCGA database and GSE42743 dataset from GEO database were downloaded. DDIT4 expression in OSCC group and normal control group were compared, and the association of DDIT4 with clinical data and prognosis were analyzed. Moreover, bioinformatics analysis was used to identify the potential biological functions associated with DDIT4. Results: The expression of DDIT4 was higher in OSCC than in control groups, with statistical significance between groups (P<0.001). In patients with OSCC, DDIT4 expression was positively correlated with tumor stage (P<0.001), and the survival rate of high DDIT4 group was significantly higher than that of low DDIT4 group (Log-rank P<0.01). Additional, Cox regression analysis indicated that high expression of DDIT4 was an independent predictor for poor prognosis of OSCC patients (P<0.05). Bioinformatics analysis showed that DDIT4 may be associated with hypoxia, glycolysis, mTORC1 signaling, TNF-α signaling via NF-κb, G₂M checkpoint, and p53 pathway. Conclusion: DDIT4 expression is increased in OSCC patients, which is associated with the tumor stage. OSCC patients with high DDIT4 have a poor prognosis. Therefore, DDIT4 is a potential biomarker for prognostic evaluation of GC.

Key words: oral squamous cell carcinoma, DNA damage inducible transcript 4, prognosis, biomarker