Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo. | Du et al. Radiation Oncology 2010 5 70 http content 5 1 70 RADIATION ONCOLOGY RESEARCH Open Access Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo Li Du Li-Jun Zhou Xiu-Jie Pan Yu-Xiao Wang2 Qin-Zhi Xu Zhi-Hua Yang Yu Wang Xiao-Dan Liu Mao-Xiang Zhu1 Ping-Kun Zhou1 Abstract Background Overexpression of DNA-dependent protein kinase catalytic subunit DNA-PKcs is commonly occurred in cancers and causes radioresistance and poor prognosis. In present study the single-chain variable antibody fragments scFv targeting DNA-PKcs was developed for the application of radiosensitization in vitro and in vivo. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. Methods DNA-PKcs epitopes were predicted and cloned. A humanized semisynthetic scFv library and the phagedisplay antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA damage repair was analyzed by comet assay and immunofluorescence detection of gH2AX foci. The radiosensitization in vivo was determined on Balb c athymic mice transplanted tumours of HeLa cells. Results Four epitopes of DNA-PKcs have been predicted and expressed as the antigens and a specific human anti-DNA-PKcs scFv antibody gene anti-DPK3-scFv was obtained by screening the phage antibody library using the DNA-PKcs peptide DPK3. The specificity of anti-DPK3-scFv was verified in vitro. Transfection of HeLa cells with the anti-DPK3-scFv gene resulted in an increased sensitivity to IR decreased repair capability of DNA double-strand breaks DSB detected by comet assay and immunofluorescence detection of gH2AX foci. Moreover the kinase activity of DNA-PKcs was inhibited by anti-DPK3-scFv which was displayed by the decreased phosphorylation levels of its target Akt S473 and the autophosphorylation of DNA-PKcs on S2056 induced by radiation. Measurement of the growth and
