title: Bidirectional function of shenghe powder on repair of radiation-induced DNA damage in glioma and astrocyte.
abstract: The study assessed the effect of Chinese herbs of Shenghe Powder (SHP) on the repair capacity of gamma-radiation-induced DNA damage in rat glioma cells (C6) compared with normal human astrocytes (NHA). C6 and NHA Cells treated with SHP and irradiated with 2Gy of gamma radiation. Cells growth inhibition were analysed by MTT assay, DNA damage and repair were evaluated using phosphorylated histone H2AX (γH2AX) at the appointed time. Apoptosis was observed by flow cytometry, and the expression of DNA-dependent protein kinase (DNA-PK) and surviving proteins were assessed by Western blot analysis. SHP depressed the radiation-induced DNA double-strand break and enhanced the DNA repair capacity in NHA, which correlated with promotion of DNA-PK phosphorylation. In contrast, SHP enhanced radiosensitivity of C6 cells, the pre-treatment with SHP resulted in reduced numbers of γH2AX foci in irradiated C6 cells, and decreased the expression of DNA-PK and survivn(P<0.005). It significant effect on inhibition of C6 cell proliferation and induced C6 cells apoptosis in a time-depdendent manner than radiation alone (P<0.001). SHP showed a novel bidirectional function to improve the radioresistance of NHA and enhanced radiosensitivity of C6 cells. This implies that SHP can protect the NHA from radiant damage and enhanced the sensitivity of C6 cells to radiation, which could be attributed to the alteration of survivin DNA-PK in DNA repair processes.
authors.affiliation: Xijing Hospital, Fourth Ministry Medical University, Xi'an City, Shaanxi Province, China. hsiayuer@hotmail.com
authors.forename: Yuesheng
authors.initials: Y
authors.lastname: Xia
authors.forename: Yongqi
authors.initials: Y
authors.lastname: Li
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Kang
authors.forename: Baoying
authors.initials: B
authors.lastname: Wang
authors.forename: Zengxia
authors.initials: Z
authors.lastname: Hou
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D001253:Astrocytes / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D004260:DNA Repair / Q000187:drug effects*; D051747:DNA-Activated Protein Kinase / Q000187:drug effects / Q000528:radiation effects; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005720:Gamma Rays; D005910:Glioma / Q000378:metabolism / Q000532:radiotherapy*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000187:drug effects / Q000528:radiation effects; D008517:Phytotherapy; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D051381:Rats
chemical_list: D004365:Drugs, Chinese Herbal; D051034:Inhibitor of Apoptosis Proteins; D011838:Radiation-Sensitizing Agents; C527025:shenghe; D051747:DNA-Activated Protein Kinase