title: [Effects and its mechanism of Nimotuzumab on radiosensitivity of esophageal carcinoma ECA-109 and TE-13 cell lines].
abstract: Objective:To investigate the effects of nimotuzumab on radiosensitivity of ECA-109 and TE-13 esophageal carcinoma cell lines and explore its possible mechanism.Methods:The ECA-109 and TE-13 cells were divided into control group, irradiation group, medicine group, and combined group (irradiation + medicine). In the combined group, ECA-109 and TE-13 cells were treated with nimotuzumab for 24 h before irradiation, and the cells were collected 2 h after irradiation. The radiosensitizing effects of nimotuzumab on ECA-109 and TE-13 cells were evaluated by clone formation assay. Cell apoptosis was detected by flow cytometry. Western blotting was used to evaluate the expression of EGFR, p-EGFR, DNA-PKcs, p-DNA-PKcs and γH2AX.Results:The values of Dq(quasithreshold dose), D0(mean lethal dose)and SF2(surviving fraction at 2 Gy) of ECA-109 and TE-13 cells in the combined group were significantly lower than those of the radiation group (for ECA-109 cells, 1.11 vs. 1.72, 1.40 vs. 2.14, 0.42 vs. 0.66, respectively; for TE-13 cells, 0.41 vs. 0.46, 0.43 vs. 0.65, 0.40 vs. 0.71, respectively (allP<0.05). The sensitivity enhancement ratio (SER) of ECA-109 and TE-13 cells were 1.35 and 1.43, respectively. Flow cytometry showed that the apoptosis rate of ECA-109 and TE-13 cells in the combined group were significantly higher than those of the radiation group [for ECA-109 cells, (41.31±1.52)% vs. (9.54±0.52)%; for TE-13 cells, (46.28±0.28)% vs. (11.32±0.31)%, bothP<0.01]. Western blotting showed that the expression levels of EGFR and DNA-PKcs were not significantly different in all groups (allP>0.05). Compared with those of the control group, p-EGFR and p-DNA-PKcs of the radiation group were significantly higher in both cell lines (P<0.05), and the γH2AX levels in the radiation group and medicine group were significantly higher than that of the control group (P<0.05). Compared with those of the radiation group and medicine group, p-EGFR and p-DNA-PKcs protein expression in the combined group were decreased significantly (P<0.05), while γH2AX protein expression was significantly increased (P<0.05).Conclusions:Nimotuzumab can enhance the radiosensitivity of esophageal cancer ECA-109 and TE-13 cells. The potential mechanism may be related to the inhibition of EGFR phosphorylation and down-regulation of DNA damage repair proteins. The radiosensitizing effect of nimotuzumab is greater on poorly differentiated esophageal cancer cells.
authors: Department of Radiation Oncology, Tianjin Medical University Cancer Institute & Hospital, Tianjin 300070, China (Present Unit: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China); Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: J
authors: J
authors: Wang
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: W
authors: W
authors: Wang
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: Y
authors: Y
authors: Guo
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: S W
authors: SW
authors: Jing
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: K
authors: K
authors: Shang
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: M C
authors: MC
authors: Miao
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: J
authors: J
authors: Wang
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: Y J
authors: YJ
authors: Wu
authors: Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.
authors: L N
authors: LN
authors: Liu
authors: Department of Radiation Oncology, Shandong Cancer Hospital, Jinan 250117, China.
authors: J M
authors: JM
authors: Yu
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology*; D017209:Apoptosis; D045744:Cell Line, Tumor; D059248:Chemoradiotherapy; D051747:DNA-Activated Protein Kinase / Q000378:metabolism; D015536:Down-Regulation; D066246:ErbB Receptors / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D006657:Histones / Q000378:metabolism; D006801:Humans; D007928:Lethal Dose 50; D009363:Neoplasm Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D011836:Radiation Tolerance / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
chemical_list: D061067:Antibodies, Monoclonal, Humanized; C468783:H2AX protein, human; D006657:Histones; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011838:Radiation-Sensitizing Agents; C501466:nimotuzumab; C512478:EGFR protein, human; D066246:ErbB Receptors; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human