Inhibition Of EGFR Activation-mediated EMT And Stemness In Esophageal Cancer Cells And Radio Sensitization

Objective: The aim of this study was to investigate EGFRactivation-mediated EMT and stemness via inducing Twist-1and Bmi-1,and its effect on radiosensitivity of esophageal squamous cancer cellTE-1. Methods: Morphological features of TE-1cells were detected byreal-time microscopic observation after EGFR ligand and inhibitors. Thenwestern blot assay was conducted to detect the expression of Twist-1andBmi-1. Cloning assay was used to study the radiosensitivity of TE-1afterEGFR ligand and inhibitors, and the radiobiology parameters werecalculated from the curve fitted by linear-quadratic model [SF=e^(-αD-βD2)] and the single-hit multitarget model [SF=1-(-e-D/D0)N].SPSS19.0software was used for statistical analysis. Results:1. With thetreatment of different concentration of EGF on TE-1cells for24hours,cells got spindle change, the cell morphology got EMT, and theexpression of Twsit-1was obviously up-regulated（P〈0.01）, while theexpression of Bmi-1was siginificantly knocked down（P〈0.001）, Thevalues of D0, Dq, SF2, α/βand SER of TE-1cells were1.996Gy,1.249Gy,0.645,3.856and0.83respectively. And cloning assay analysis showed itcan make TE-1cells radioresistant.2. When combination with cetuximab,the cell morphology also got EMT, and the expression of Twsit-1wasknocked down along with the concentration of cetuximab, while theexpression of Bmi-1was siginificantly up-regulated（P<0.001）. The values of D0, Dq, SF2, α/βand SER of TE-1cells were1.973Gy,1.215Gy,0.614,3.881and0.871respectively. And cloning assay analysis showed itcan make TE-1cells radioresistant,. While when using cetuximab alone,the cell morphology had no change, the expression of Twsit-1wassiginificantly knocked down（P<0.05）, the expression of Bmi-1wassiginificantly up-regulated（P<0.001）. The values of D0, Dq, SF2, α/βandSER of TE-1cells were1.286Gy,0.396Gy,0.276,7.35and1.983respectively. And cloning assay analysis showed it can enhance theradiosensitivity of TE-1.3. When combination with gefitinib, the cellmorphology had not get EMT, and the expression of Twsit-1wasobviously knocked down（P<0.001）, while the expression of Bmi-1wassiginificantly up-regulated（P<0.001）. The values of D0, Dq, SF2, α/βandSER of TE-1cells were1.46Gy,0.599Gy,0.357,5.834and1.499respectively. And cloning assay analysis showed it can enhance theradiosensitivity of TE-1. When using gefitinib alone, the cell morphologyhad no change, the expression of Twsit-1was obviously knocked down（P<0.05）, while the expression of Bmi-1was siginificantlyup-regulated（P<0.01）. The values of D0, Dq, SF2, α/βand SER of TE-1cells were1.45Gy,0.598Gy,0.355,5.799and1.507respectively. Andcloning assay analysis showed it can enhance the radiosensitivity of TE-1.4. When combination with dihydroartemisinin, the cell morphology gotEMT, the expression of Twsit-1and Bmi-1were siginificantly knockeddown（P<0.001and P<0.01）. The values of D0, Dq, SF2, α/βand SER of TE-1cells were1.516Gy,0.766Gy,0.403,4.128and1.328respectively.And cloning assay analysis showed it can enhance the radiosensitivity ofTE-1. When using dihydroartemisinin alone, the cell morphology had nochange, the expression of Twsit-1also had no change（P>0.05）, theexpression of Bmi-1was knocked down（P<0.05）. The values of D0, Dq,SF2, α/βand SER of TE-1cells were1.5Gy,0.748Gy,0.396,4.236and1.351respectively. And cloning assay analysis showed it can enhance theradiosensitivity of TE-1. Conclusion:1. When EGFR binding with itsligand, TE-1cells get EMT change.2. It can make TE-1cellsradioresistant when cells get EMT change.3. It can enhance theradiosensitivity of esophageal cancer cells via inhibiting the EGFRmediated EMT.