Several modes of eukaryotic of DNA double strand break repair (DSBR) depend on synapsis of complementary DNA. The Rad51 ATPase, the S. cerevisiae homolog of E. coli RecA, plays a key role in this process by catalyzing...Several modes of eukaryotic of DNA double strand break repair (DSBR) depend on synapsis of complementary DNA. The Rad51 ATPase, the S. cerevisiae homolog of E. coli RecA, plays a key role in this process by catalyzing homology searching and strand exchange between an invading DNA strand and a repair template (e.g. sister chromatid or homologous chromosome). Synthesis dependent strand annealing (SDSA), a mode of DSBR, requires Rad51. Another repair enzyme, the Rad1-Rad10 endonuclease, acts in the final stages of SDSA, hydrolyzing 3￠ overhanging single-stranded DNA. Here we show in vivo by fluo-rescence microscopy that the ATP binding function of yeast Rad51 is required to recruit Rad10 SDSA sites indicating that Rad51 pre-synaptic filament formation must occur prior to the recruitment of Rad1-Rad10. Our data also show that Rad51 ATPase activity, an important step in Rad51 filament disassembly, is not absolutely required in order to recruit Rad1- Rad10 to DSB sites.展开更多
The Rad1 gene is evolutionarily conserved from yeast to human.The fission yeast Schizosaccharomyces pombe Rad1 ortholog promotes cell survival against DNA damage and is required for G_(2)/M checkpoint activation.In th...The Rad1 gene is evolutionarily conserved from yeast to human.The fission yeast Schizosaccharomyces pombe Rad1 ortholog promotes cell survival against DNA damage and is required for G_(2)/M checkpoint activation.In this study,mouse embryonic stem(ES)cells with a targeted deletion of Mrad1,the mouse ortholog of this gene,were created to evaluate its function in mammalian cells.Mrad1^(−/−)ES cells were highly sensitive to ultraviolet-light(UV light),hydroxyurea(HU)and gamma rays,and were defective in G_(2)/M as well as S/M checkpoints.These data indicate that Mrad1 is required for repairing DNA lesions induced by UV-light,HU and gamma rays,and for mediating G_(2)/M and S/M checkpoint controls.We further demonstrated that Mrad1 plays an important role in homologous recombination repair(HRR)in ES cells,but a minor HRR role in differentiated mouse cells.展开更多
Objective:Epidermal growth factor receptor variant III(EGFRvIII)is a constitutively-activated mutation of EGFR that contributes to the malignant progression of glioblastoma multiforme(GBM).Temozolomide(TMZ)is a standa...Objective:Epidermal growth factor receptor variant III(EGFRvIII)is a constitutively-activated mutation of EGFR that contributes to the malignant progression of glioblastoma multiforme(GBM).Temozolomide(TMZ)is a standard chemotherapeutic for GBM,but TMZ treatment benefits are compromised by chemoresistance.This study aimed to elucidate the crucial mechanisms leading to EGFRvIII and TMZ resistance.Methods:CRISPR-Cas13a single-cell RNA-seq was performed to thoroughly mine EGFRvIII function in GBM.Western blot,realtime PCR,flow cytometry,and immunofluorescence were used to determine the chemoresistance role of E2F1 and RAD51-associated protein 1(RAD51AP1).Results:Bioinformatic analysis identified E2F1 as the key transcription factor in EGFRvIII-positive living cells.Bulk RNA-seq analysis revealed that E2F1 is a crucial transcription factor under TMZ treatment.Western blot suggested enhanced expression of E2F1 in EGFRvIII-positive and TMZ-treated glioma cells.Knockdown of E2F1 increased sensitivity to TMZ.Venn diagram profiling showed that RAD51AP1 is positively correlated with E2F1,mediates TMZ resistance,and has a potential E2F1 binding site on the promoter.Knockdown of RAD51AP1 enhanced the sensitivity of TMZ;however,overexpression of RAD51AP1 was not sufficient to cause chemotherapy resistance in glioma cells.Furthermore,RAD51AP1 did not impact TMZ sensitivity in GBM cells with high O6-methylguanine-DNA methyltransferase(MGMT)expression.The level of RAD51AP1 expression correlated with the survival rate in MGMT-methylated,but not MGMT-unmethylated TMZ-treated GBM patients.Conclusions:Our results suggest that E2F1 is a key transcription factor in EGFRvIII-positive glioma cells and quickly responds to TMZ treatment.RAD51AP1 was shown to be upregulated by E2F1 for DNA double strand break repair.Targeting RAD51AP1 could facilitate achieving an ideal therapeutic effect in MGMT-methylated GBM cells.展开更多
Background:The DNA damage repair mechanism plays a crucial role in the occurrence and development of hepatocellular carcinoma(HCC),and RAD51-associated protein 1(RAD51AP1)has received increasing attention as an import...Background:The DNA damage repair mechanism plays a crucial role in the occurrence and development of hepatocellular carcinoma(HCC),and RAD51-associated protein 1(RAD51AP1)has received increasing attention as an important protein in the homologous recombination repair pathway.However,the role of RAD51AP1 and its molecular regulatory mechanism in HCC still need further investigation.Methods:We first analysed RAD51AP1 expression,functional enrichment and prognostic value in HCC.Then,the miRWalk,miRDB,and Encyclopedia of RNA Interactomes databases were used to predict the corresponding microRNAs and long noncoding RNAs of RAD51AP1,and their expression levels and prognostic value were analysed.Results:RAD51AP1 was upregulated in the majority of cancers include HCC.The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that RAD51AP1 was mainly involved in pathways related to the cell cycle and repair in HCC.Moreover,the expression level of RAD51AP1 was significantly correlated with T stage,pathologic stage,histologic grade and the level of alpha-fetoprotein.In addition,RAD51AP1 was an independent risk factor significantly and had a high predictive value in HCC.Based on ceRNA network,RAD51AP1 may be regulated by upstream MSC-AS1 and hsa-miR-23c to affect the HCC occurrence and development.Conclusions:High expression of RAD51AP1 plays an important biological role in the cell cycle and repair pathways,and has important diagnostic and prognostic value in HCC.Based on the regulatory mechanism of ceRNA network,we speculate that lncRNA MSC-AS1 acts on hsa-miR-23c and regulates DNA damage repair of HCC through RAD51AP1.It provides a new perspective for further study of DNA damage repair mechanism and potential related treatment of HCC.展开更多
目的通过研究DLG5(discs large homolog5)在肾透明细胞癌(ccRCC)临床组织中的表达,阐明其对ccRCC诊断与预后的作用。方法结合癌症基因组图谱(TCGA)数据库与基因表达综合(GEO)数据库、免疫组织化学法分析DLG5在ccRCC组织与正常肾组织中...目的通过研究DLG5(discs large homolog5)在肾透明细胞癌(ccRCC)临床组织中的表达,阐明其对ccRCC诊断与预后的作用。方法结合癌症基因组图谱(TCGA)数据库与基因表达综合(GEO)数据库、免疫组织化学法分析DLG5在ccRCC组织与正常肾组织中的表达差异,运用LinkedOmics、GEPIA、String-DB等分析DLG5表达与ccRCC临床病理指标、预后的关系及与其可能发生相互作用的蛋白网络。结果ccRCC中DLG5mRNA表达高于正常组织,LinkedOmics网站分析发现,其高表达患者总生存率低于低表达者(P=2.997×10-5);DLG5表达随TNM分期等级升高而增加;DLG5与增殖细胞核抗原(PCNA)表达的相关系数R=0.19(P=1.1×10-6),与RAD1表达的相关系数R=0.18(P=5.7×10-6),均呈正相关。结论DLG5高表达是ccRCC不良预后的指标,有望作为预测患者转移、复发、预后等的分子靶标。展开更多
基金supported by grants from The National Natural Science Foundation of China(Y4JM061001,Y5JY011001,81072093)The Natural Science Foundation of Hebei Province(C2012401039)~~
文摘Several modes of eukaryotic of DNA double strand break repair (DSBR) depend on synapsis of complementary DNA. The Rad51 ATPase, the S. cerevisiae homolog of E. coli RecA, plays a key role in this process by catalyzing homology searching and strand exchange between an invading DNA strand and a repair template (e.g. sister chromatid or homologous chromosome). Synthesis dependent strand annealing (SDSA), a mode of DSBR, requires Rad51. Another repair enzyme, the Rad1-Rad10 endonuclease, acts in the final stages of SDSA, hydrolyzing 3￠ overhanging single-stranded DNA. Here we show in vivo by fluo-rescence microscopy that the ATP binding function of yeast Rad51 is required to recruit Rad10 SDSA sites indicating that Rad51 pre-synaptic filament formation must occur prior to the recruitment of Rad1-Rad10. Our data also show that Rad51 ATPase activity, an important step in Rad51 filament disassembly, is not absolutely required in order to recruit Rad1- Rad10 to DSB sites.
基金supported by the National Natural Science Foundation of China(Grant No.30900813 to ZSH)the Knowledge Innovation Program of Chinese Academy of Sciences to HH(Grant No.KSCX2-YW-R63).
文摘The Rad1 gene is evolutionarily conserved from yeast to human.The fission yeast Schizosaccharomyces pombe Rad1 ortholog promotes cell survival against DNA damage and is required for G_(2)/M checkpoint activation.In this study,mouse embryonic stem(ES)cells with a targeted deletion of Mrad1,the mouse ortholog of this gene,were created to evaluate its function in mammalian cells.Mrad1^(−/−)ES cells were highly sensitive to ultraviolet-light(UV light),hydroxyurea(HU)and gamma rays,and were defective in G_(2)/M as well as S/M checkpoints.These data indicate that Mrad1 is required for repairing DNA lesions induced by UV-light,HU and gamma rays,and for mediating G_(2)/M and S/M checkpoint controls.We further demonstrated that Mrad1 plays an important role in homologous recombination repair(HRR)in ES cells,but a minor HRR role in differentiated mouse cells.
基金supported by the Science and Technology Project of Tianjin Municipal Health Commission(Grant Nos.TJWJ2022MS003 and TJWJ2021ZD008)the Tianjin Science and Technology Plan Project(Grant Nos.21JCYBJC01520 and 20JCYBJC01070)。
文摘Objective:Epidermal growth factor receptor variant III(EGFRvIII)is a constitutively-activated mutation of EGFR that contributes to the malignant progression of glioblastoma multiforme(GBM).Temozolomide(TMZ)is a standard chemotherapeutic for GBM,but TMZ treatment benefits are compromised by chemoresistance.This study aimed to elucidate the crucial mechanisms leading to EGFRvIII and TMZ resistance.Methods:CRISPR-Cas13a single-cell RNA-seq was performed to thoroughly mine EGFRvIII function in GBM.Western blot,realtime PCR,flow cytometry,and immunofluorescence were used to determine the chemoresistance role of E2F1 and RAD51-associated protein 1(RAD51AP1).Results:Bioinformatic analysis identified E2F1 as the key transcription factor in EGFRvIII-positive living cells.Bulk RNA-seq analysis revealed that E2F1 is a crucial transcription factor under TMZ treatment.Western blot suggested enhanced expression of E2F1 in EGFRvIII-positive and TMZ-treated glioma cells.Knockdown of E2F1 increased sensitivity to TMZ.Venn diagram profiling showed that RAD51AP1 is positively correlated with E2F1,mediates TMZ resistance,and has a potential E2F1 binding site on the promoter.Knockdown of RAD51AP1 enhanced the sensitivity of TMZ;however,overexpression of RAD51AP1 was not sufficient to cause chemotherapy resistance in glioma cells.Furthermore,RAD51AP1 did not impact TMZ sensitivity in GBM cells with high O6-methylguanine-DNA methyltransferase(MGMT)expression.The level of RAD51AP1 expression correlated with the survival rate in MGMT-methylated,but not MGMT-unmethylated TMZ-treated GBM patients.Conclusions:Our results suggest that E2F1 is a key transcription factor in EGFRvIII-positive glioma cells and quickly responds to TMZ treatment.RAD51AP1 was shown to be upregulated by E2F1 for DNA double strand break repair.Targeting RAD51AP1 could facilitate achieving an ideal therapeutic effect in MGMT-methylated GBM cells.
基金the financial support from Shandong Traditional Chinese Medicine Science and Technology Project(No.2020M139)the Scientific Research Project of Shandong College of Traditional Chinese Medicine(No.2021FY02)the Development Plan of Laizhou Science and Technology Project(No.2022L01).
文摘Background:The DNA damage repair mechanism plays a crucial role in the occurrence and development of hepatocellular carcinoma(HCC),and RAD51-associated protein 1(RAD51AP1)has received increasing attention as an important protein in the homologous recombination repair pathway.However,the role of RAD51AP1 and its molecular regulatory mechanism in HCC still need further investigation.Methods:We first analysed RAD51AP1 expression,functional enrichment and prognostic value in HCC.Then,the miRWalk,miRDB,and Encyclopedia of RNA Interactomes databases were used to predict the corresponding microRNAs and long noncoding RNAs of RAD51AP1,and their expression levels and prognostic value were analysed.Results:RAD51AP1 was upregulated in the majority of cancers include HCC.The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that RAD51AP1 was mainly involved in pathways related to the cell cycle and repair in HCC.Moreover,the expression level of RAD51AP1 was significantly correlated with T stage,pathologic stage,histologic grade and the level of alpha-fetoprotein.In addition,RAD51AP1 was an independent risk factor significantly and had a high predictive value in HCC.Based on ceRNA network,RAD51AP1 may be regulated by upstream MSC-AS1 and hsa-miR-23c to affect the HCC occurrence and development.Conclusions:High expression of RAD51AP1 plays an important biological role in the cell cycle and repair pathways,and has important diagnostic and prognostic value in HCC.Based on the regulatory mechanism of ceRNA network,we speculate that lncRNA MSC-AS1 acts on hsa-miR-23c and regulates DNA damage repair of HCC through RAD51AP1.It provides a new perspective for further study of DNA damage repair mechanism and potential related treatment of HCC.
文摘目的通过研究DLG5(discs large homolog5)在肾透明细胞癌(ccRCC)临床组织中的表达,阐明其对ccRCC诊断与预后的作用。方法结合癌症基因组图谱(TCGA)数据库与基因表达综合(GEO)数据库、免疫组织化学法分析DLG5在ccRCC组织与正常肾组织中的表达差异,运用LinkedOmics、GEPIA、String-DB等分析DLG5表达与ccRCC临床病理指标、预后的关系及与其可能发生相互作用的蛋白网络。结果ccRCC中DLG5mRNA表达高于正常组织,LinkedOmics网站分析发现,其高表达患者总生存率低于低表达者(P=2.997×10-5);DLG5表达随TNM分期等级升高而增加;DLG5与增殖细胞核抗原(PCNA)表达的相关系数R=0.19(P=1.1×10-6),与RAD1表达的相关系数R=0.18(P=5.7×10-6),均呈正相关。结论DLG5高表达是ccRCC不良预后的指标,有望作为预测患者转移、复发、预后等的分子靶标。
基金This work was supported by grants from the National Basic Research Program of China （2015CB910600）, the National Natural Science Foundation of China （31700688）, the National Key Research and Development Program of China （2017YFA0503900）, and the Natural Science Foundation of Zhejiang Province （LY16C050003） to Y.I.H. and H.X. A part of the work presented in the current article was supported by the National Institutes of Health grants ROICA073764 to B.H.S and R50CA211397 to L.Z.
