Research progress of SUMOylation modification in DNA double-strand break repair / 国际生物医学工程杂志

The small ubiquitin-like modified protein (SUMO) is a protein structurally similar to ubiquitin which is involved in post-translational modification of proteins. SUMOylation refers to the process that SUMO molecule covalently binding to the specific lysine site of target proteins through maturation, activation, binding and ligation by ubiquitin-like specific protease 1 (Ulp1), E1 activating enzyme, E2 binding enzyme, and E3 ligase. SUMOylation alters the activity of target proteins, which is involved in the regulation of various cellular functions such as transcriptional regulation, regulation of embryonic development, cellular stress, maintenance of chromatin structure and genomic stability. In recent years, it has been found that SUMOylation modification is also widely involved in DNA damage repair, especially DNA double-strand breaks (DSBs), which are the most serious types of DNA damage. SUMOylation is involved in almost all processes of DSBs repair, so its role in DNA damage repair has become a research hotspot. In this paper, the research progress of the regulation of SUMOylation in DSBs repair was reviewed.

Effect of Olaparib on proliferation activity and radiosensitization of human non-small cell lung cancer cells / 国际生物医学工程杂志

Objective To investigate the effects of Olaparib on cell proliferation and radiosensitization of human non-small cell lung cancer cells.Methods Non-small cell lung H460 and H1299 cell lines were cultured in vitro and the cells in logarithmic growth phase were selected for experiments.MTT and colony formation assays were used to determine cell proliferation and radiosensitization,respectively.Single cell gel electrophoresis assay (comet assay) was used to detect irradiation-induced DNA damage.Results The results of MTT assay showed that Olaparib inhibited the proliferation of H460 and H1299 cells in a dose-dependent pattern (all P＜0.05).H1299 cell line was more sensitive to Olaparib than H460 cells.The results of colony formation assay showed that Olaparib enhanced the radiosensitizition of H460 and H1299 cells (all P＜0.05).The results of comet assay showed that Olaparib increased γ ray-induced DNA damage.Conclusions Olapani can enhance the radiosensitization of human non-small cell lung cancer cells,and the radiosensitization effect of Olaparib may be associated with the inhibition of cell proliferation and induction of irradiation-induced DNA damage.

The dynamic changes of gene expressions in radiation-injured intestine based on RNA-sequence analysis / 中华放射医学与防护杂志

Objective To investigate the dynamic changes of gene expressions in mouse jejunum after lethal dose abdomen irradiation (ABI).Methods RNA was extracted from mouse jejunum at 0 and 6 h,3.5 and 5 d after 14 Gy 137Cs γ-ray ABI and then subjected to RNA-sequence analysis.Gene with expressions changed more than 2-fold of control were identified as differentially expressed ones.The selected genes were subsequently analyzed using IPA,Funrich,GO and KEGG software.Results Gene analysis of mouse jejunum samples showed that radiation activated p53 pathway at 6 h and 3.5 d after ABI.Interaction network analysis of genes suggested that Lck,Cdkl and Fyn,genes could play an important role in jejunum damage at 3.5 d after ABI.The gene expression profiles demonstrated that ABI up-regulated DNA damage repair pathways and down-regulated cell adhesion molecules,focal adhesion and IgA production pathways.Conclusions The p53 signaling pathway and some key genes such as Lck,Cdkl,and Fyn may contribute to the radiation-induced intestinal injury.