[Effect of disulfiram on epithelial-mesenchymal transformation of oral squamous cell carcinoma cells].

PURPOSE To investigate the effect of disulfiram on epithelial-mesenchymal transformation(EMT) in oral squamous cell carcinoma(OSCC) cells based on Smad4 mutation. METHODS The cancer tissues and adjacent normal tissues of 46 patients with OSCC who underwent tumor resection in the Affiliated Stomatological Hospital of Anhui Medical University from June 2017 to June 2018 were included in the study. Immunohistochemical staining was used to observe the expression of Smad4 in tissues, Western blot was used to determine the expression of Smad4 in tumor cells. The effects of disulfiram on TGF-β1-induced cell EMT migration, invasion, morphology and expression of p38, JNK and ERK were analyzed. SPSS 20.0 software package was used to analyze the data. RESULTS The positive expression rate of Smad4 in cancer tissues was significantly lower than that in adjacent normal tissues (P 0.05). The survival rate of human tongue cancer SCC-25 and CAL-27 cells was significantly lower than that of the control group at disulfiram concentrations ≥30 μmol/L(P<0.05). After treatment with TGF-β1, the morphology of SCC-25 and CAL-27 cells changed from epithelial to mesenchymal. E-cadherin expression was significantly reduced, Vimentin and Snail expression were significantly increased, and migration and invasion were enhanced (P<0.05). After disulfiram + TGF-β1 treatment, as the concentration of disulfiram increased, the morphological changes of SCC-25 and CAL-27 cells gradually decreased, the expression of E-cadherin protein gradually increased, the expression of Vimentin and Snail protein gradually decreased, and migration ability gradually weakened (P<0.05). After 5 minutes of TGF-β1 stimulation, p-ERK levels in SCC-25 and CAL-27 cells gradually increased, reached a maximum at 15 minutes, and then gradually decreased (P<0.05). After 20 μmol/L disulfiram + TGF-β1 treatment, p-ERK levels in SCC-25 and CAL-27 cells gradually decreased with the increase of the treatment time(P<0.05). CONCLUSIONS Disulfiram can inhibit EMT of Smad4 mutant and Smad4 non-mutated OSCC cells by blocking ERK phosphorylation in the MAPK signaling pathway.