To investigate the levels of the Twist and Vimentin proteins in oral squamous cell carcinoma (OSCC) and analyze the clinical significance of Twist and Vimentin.

Eighty-five samples of OSCC and fifteen samples of normal oral mucosa were collected. Immunohistochemistry (SP method) was used to detect the expression of proteins, including Twist and vimentin. The relationship among these proteins and clinical pathological parameters was analyzed using SPSS statistical software.

In the normal group, 13.3% (2/15) of samples were positive for the Twist protein; this value was significantly lower than that in OSCC group (80.0%, 66/85) (χ²＝26.98, P < 0.001). The expression of Twist was associated with clinical stage (χ²＝5.40, P＝0.02) and lymph node metastasis (χ²＝8.35, P＝0.006), while no correlations were found between the expression of Twist and sex (χ²＝0.23, P＝0.63), age (χ²＝0.31, P＝0.58), location (χ²＝1.46, P＝0.235) or degree of differentiation (χ²＝1.52, P＝0.47). Additionally, 6.7% of samples (1/15) were positive for vimentin; this value was significantly lower than that in OSCC group (74.1%, 63/85) (χ²＝20.71, P < 0.001). The expression of vimentin was associated with clinical stage (χ²＝4.51, P＝0.034) and lymph node metastasis (χ²＝6.75, P＝0.009), while no correlations were found between the expression of vimentin and sex (χ²＝0.40, P＝0.53), age (χ²＝0.17, P＝0.68), location (χ²＝0.74， P＝0.39) or degree of differentiation (χ²＝4.58, P＝ 0.10). Spearman correlation analyses showed that Twist protein expression was positively correlated with vimentin (r＝ 0.578, P＜0.05).

Our data demonstrate that in OSCC, Twist and vimentin levels were upregulated, and Twist protein expression was positively correlated with vimentin, which indicates that both Twist and vimentin may be involved in the occurrence of OSCC.