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Bidirectional Function Of Shenghe Powder On Repair Of Radiationinduced Dna Damage In Glioma And Astrocyte
Yuesheng Xia; Yongqi Li; v; Huan Wang; Jing Kang; Baoying Wang & Zengxia Hou
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.
Keywords
DNA repair, radiation, glioma, astrocyte, Chinese herbs
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