Abstract:Objective To study the radiosensitizing effect of gemcitabine on human tongue squamous cell carcinoma Tca8113 cells and its related mechanisms. Methods After 24 hours-treatment of human tongue squamous cell carcinoma Tca8113 cells with different concentrations of gemcitabine, cell viability and the concentration of subsequent experiments was determined. Tca8113 cells were treated with radiotherapy alone or combined with gemcitabine. MTT assay was used to determine cell viability. Plate colony formation assay was used to study cell colonies. Flow cytometry was used to verify the sensitivity of Tca8113 cells to radiation, and Western blotting was used to detect Bcl-2, Bax, Cleaved Caspase-3, Cleaved Caspase-9 protein expression. Results The cell viability of different concentrations of gemcitabine was analyzed by variance, and the difference was statistically significant (P < 0.05). Compared with the blank control group, the cell viability of the 0.01, 0.02, 0.03, 0.1, and 1 μmol/L gemcitabine concentrations were lower, and the difference was statistically significant (P < 0.05). When the irradiation dose was 4Gy, the cell survival rate of gemcitabine combined with radiotherapy group was lower than that of radiotherapy alone (P < 0.05). Cloning formation experiment showed the colony formation ability of gemcitabine combined with radiotherapy group was the weakest (P < 0.05); flow cytometry further confirmed that the apoptotic rate was higher in gemcitabine combined with radiotherapy group than that in radiotherapy alone group (P < 0.05); The apoptosis of Tca8113 cells in gemcitabine combined with radiotherapy group was higher than that in other groups, and the expression levels of Bax, Cleaved Caspase-3 and Cleaved Caspase-9 in gemcitabine combined with radiotherapy group were higher than those in other groups (P < 0.05), while Bcl-2 protein was opposite. (P < 0.05). Conclusions Gemcitabine has a proliferation-inhibiting effect on tongue squamous cell carcinoma Tca8113 cells, and combined radiotherapy can effectively improve radiosensitivity, and both may have synergistic anti-tumor effects.