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Objective: To investigate the effect of siRNA silencing BAZ1A on radiosensitization of human lung adenocarcinoma A549 cells. Methods :A549 cells were randomly divided into transfection reagent control (Ctrl) group, negative control siRNA (siNC) group, and siBAZ1A group. The expression of BAZ1A protein was evaluated by Western blot. The clone formation assay was applied to investigate the survival fraction (SF) of the A549 cells treated with different radiation doses (0, 2, 4, 6, 8, and 10Gy), and one-hit multi-target model was applied to analyze the radiation dose survival curve. MTS assay, scratch assay, and flow cytometry were utilized to determine the relative survival, cell migration abilities, and apoptosis, respectively. Results: The expression level of BAZ1A protein in A549 cells was inhibited by BAZ1A-siRNA transfection. X-ray radiation inhibited the colony formation capacity of A549 cells, and the SF of siBAZ1A group was lower than that of the other two groups with radiation (P<0.05). Compared with those of Ctrl group, the sensitization enhancement ratio (SER) of siNC and siBAZ1A groups was 1.06 and 2.24. Moreover, with the transfection of BAZ1A-siRNA, the relative survival rate and cell migration ability were decreased after X-ray radiation. Besides, the apoptosis rate was higher in siBAZ1A group (P<0.05). Conclusion: Silencing the expression of BAZ1A by siRNA can efficiently improve the sensitization of radiotherapy for A549 cells.
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Objective To investigate the influence of down-regulation NEK-2 level on the radiosensitivity of A549 cells.Methods NEK-2 siRNA was transfected to A549 cells with liposome and NEK-2 expression level was inspected by Western blot.The radiosensitivity was detected by clone formation experiment.Cell cycle and cell apoptosis were analyzed by flow cytometry.Immunofluorescence experiment was used to detect the DNA double strand break and repair.Results NEK-2 siRNA successfully suppressed NEK-2 expression in A549 cells and resuced the cell proliferation ability after irradiation compared to the blank control group and the negative control group.It can improve the radiosensitivity of A549 cells (The radiosensitivity of A549 cells enhanced significantly.).The D0 values declined form 1.80 Gy to 1.40 Gy,and the sensitizing enhancement ratio was 1.32.After irradiation,compared to negative control group,the apoptosis rate was significantly improved (7.85％ to 17.17％),cells in G2/M phase were obviously increased (9.23％ to 30.16％),the DNA double strand break rate was increased (100％ to 165％) and the DNA damage repair rate was reduced (100％ to 48％) in NEK-2 siRNA group.The comparisons among the groups wer statistically significant (P＜0.05).Conclusions NEK-2 siRNA reduced the proliferation and increased the radiosensitivity of A549 cell line,probably by affecting the cell cycle,promoting cell apoptosis and suppressing DNA damage repair.
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@#With the development of nanomaterials and nanotechnology, nanomedicine possesses the vast application prospects in the field of cancer therapy. Although the proportion of radiotherapy in cancer comprehensive therapy is rising, the radiotherapy resistance of cancer cells and the side effects of radiotherapy are the existing problems. Compared with the traditional radiotherapy sensitization, it will present a higher treatment efficiency and lower toxicity to introduce nanomaterials and nanotechnology to cancer radiotherapy. This review elaborates the research of nanomaterials and nanotechnology on cancer radiotherapy sensitization.
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The triple negative breast cancer is one of importance in clinical subtypes of breast cancer, which is easy to recur and metastasis, and its prognosis is very poor.Radiotherapy, as an effective method for breast cancer,can reduce the risk of local recurrence.This article elaborates its characteristics,the progress of ra-diotherapy in the breast conserving surgery and modified radical mastectomy in triple negative breast cancer,when is the appropriate time for radiotherapy and radiotherapy sensitization,and hope that it will be helpful to the treat-ments.
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Objective To investigate the effects of radiotherapy combined with resveratrol( Res)on proliferation, invasion and apoptosis of hepatoma cell line Bel-7404. Methods Bel-7404 cell line was treated with Res(25 μmol·L-1 ) combined with radiotherapy,then divided into four groups( group 1:the control;group 2:radiation at dose of 2 Gy;group 3:radiation at dose of 4 Gy;group 4:radiation at dose of 6 Gy). Cell proliferation and invasion were detected by MTT assay. Cell apoptosis were observed by fluorescence microscopy. Expressions of MMP-2 and VEGF proteins were determined by Western blotting. Results Compared with the control group,cell proliferation and invasion were significantly inhibited,while cell apoptosis was increased in all radiation groups(P〈0. 05). Conclusion The sensitivity of hepatoma Bel-7404 cells to radiation can be enhanced by resveratrol. Radiation therapy combined with resveratrol can inhibit proliferation and invasion of hepatoma cells and increase the cell apoptosis,which may be related with the down-regulation of MMP-2 and VEGF proteins.