scholarly journals Recruitment of DNA repair synthesis machinery to sites of DNA damage/repair in living human cells

2007 ◽  
Vol 35 (9) ◽  
pp. 2913-2923 ◽  
Author(s):  
Kazunari Hashiguchi ◽  
Yoshihiro Matsumoto ◽  
Akira Yasui
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Repair ◽  
Human Cells ◽  
Repair Synthesis ◽  
Damage Repair ◽  
Dna Repair Synthesis

scholarly journals The Tardigrade Damage Suppressor Protein Promotes Transcription Factor Activation and Expression of DNA Repair Genes in Human Cells in Response to Hydroxyl Radicals and UV-C Exposure

2021 ◽  
Author(s):  
Claudia Ricci ◽  
Giulia Riolo ◽  
Carlotta Marzocchi ◽  
Jlenia Brunetti ◽  
Alessandro Pini ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Expression Patterns ◽  
Dna Damage Repair ◽  
Human Cells ◽  
H2o2 Treatment ◽  
Damage Repair ◽  
Transcription Factor Activation ◽  
Uv C ◽  
Repair Genes

The Ramazzottius varieornatus tardigrade is an extremotolerant terrestrial invertebrate belonging to the phylum of Tardigrada. At a length of 0.1-1.0 mm, tardigrades are small animals with an exceptional tolerance to extreme conditions such as high pressure, chemicals and irradia-tion. These properties have been attributed to the recently-discovered Dsup protein. Dsup is a nucleosome-binding protein that prevents DNA damage against X-ray and oxidative stress without impairing cell life, also in Dsup-transfected animal and plant cells. However, the precise “protective” role of this protein is still under study. We performed experiments on human cells and shows that, as compared to control cells, Dsup+ cells are more resistant to UV-C exposure and H2O2. Real-time PCR identified different expression patterns of endogenous genes involved in apoptosis, cell survival and DNA damage repair in Dsup+ cells in response to H2O2 and UV-C. While H2O2 treatment in Dsup+ cells only marginally involved the activation of pathways responsible for DNA repair reinforcing the idea of a direct protective effect of the protein on DNA, in UV-C exposed cells, Dsup efficiently upregulates DNA damage repair genes. In conclusion, our data may help to delineate the different mechanisms by which the Dsup protein operates in response to different insults.

scholarly journals MicroRNA-146a-5p enhances radiosensitivity in hepatocellular carcinoma through replication protein A3-induced activation of the DNA repair pathway

2019 ◽  
Vol 316 (3) ◽  
pp. C299-C311 ◽  
Author(s):  
Jing Luo ◽  
Zhong-Zhou Si ◽  
Ting Li ◽  
Jie-Qun Li ◽  
Zhong-Qiang Zhang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Repair ◽  
Replication Protein ◽  
Repair Pathway ◽  
Related Factors ◽  
Damage Repair ◽  
Hcc Cells

Hepatocellular carcinoma (HCC) is known for its high mortality rate worldwide. Based on intensive studies, microRNA (miRNA) expression functions in tumor suppression. Therefore, we aimed to evaluate the contribution of miR-146a-5p to radiosensitivity in HCC through the activation of the DNA damage repair pathway by binding to replication protein A3 (RPA3). First, the limma package of R was performed to differentially analyze HCC expression chip, and regulative miRNA of RPA3 was predicted. Expression of miR-146a-5p, RPA3, and DNA damage repair pathway-related factors in tissues and cells was determined. The effects of radiotherapy on the expression of miR-146a-5p and RPA3 as well as on cell radiosensitivity, proliferation, cell cycle, and apoptosis were also assessed. The results showed that there exists a close correlation between miR-146a and the radiotherapy effect on HCC progression through regulation of RPA3 and the DNA repair pathway. The positive rate of ATM, pCHK2, and Rad51 in HCC tissues was higher when compared with that of the paracancerous tissues. SMMC-7721 and HepG2 cell proliferation were significantly inhibited following 8 Gy 6Mv dose. MiR-146a-5p restrained the expression of RPA3 and promoted the expression of relative genes associated with the DNA repair pathway. In addition, miR-146a-5p overexpression suppresses cell proliferation and enhances radiosensitivity and cell apoptosis in HCC cells. In conclusion, the present study revealed that miR-146a-5p could lead to the restriction of proliferation and the promotion of radiosensitivity and apoptosis in HCC cells through activation of DNA repair pathway and inhibition of RPA3.

In situ enzymology of DNA replication and ultraviolet-induced DNA repair synthesis in permeable human cells

Biochemistry ◽  
1988 ◽  
Vol 27 (19) ◽  
pp. 7247-7254 ◽  
Author(s):  
Steven L. Dresler ◽  
Mark G. Frattini ◽  
Rona M. Robinson-Hill
Keyword(s):  
Dna Repair ◽  
Dna Replication ◽  
Human Cells ◽  
Repair Synthesis ◽  
Dna Repair Synthesis

Bortezomib Enhances Melphalan Response by Altering Fanconi Anemia (FA)/BRCA Pathway Expression and Function.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 840-840 ◽  
Author(s):  
Danielle N. Yarde ◽  
Lori A. Hazlehurst ◽  
Vasco A. Oliveira ◽  
Qing Chen ◽  
William S. Dalton
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Dna Repair ◽  
Low Dose ◽  
Dna Damage Repair ◽  
Myeloma Cell ◽  
Myeloma Cells ◽  
Multiple Myeloma Cell ◽  
Damage Repair ◽  
Pre Treatment

Abstract The FA/BRCA pathway is involved in DNA damage repair and its importance in oncogenesis has only recently been implicated. Briefly, 8 FA/BRCA pathway family members facilitate the monoubiquitination of FANCD2. Upon monoubiquitination, FANCD2 translocates to the DNA repair foci where it interacts with other proteins to initiate DNA repair. Previously, we reported that the FA/BRCA pathway is upregulated in multiple myeloma cell lines selected for resistance to melphalan (Chen, et al, Blood 2005). Further, reducing FANCF in the melphalan resistant 8226/LR5 myeloma cell line partially reversed resistance, whereas overexpressing FANCF in the drug sensitive 8226/S myeloma line conferred resistance to melphalan. Others have reported, and we have also verified, that bortezomib enhances melphalan response in myeloma cells; however, the mechanism of enhanced melphalan activity in combination with bortezomib has not been reported. Based on our observation that the FA/BRCA pathway confers melphalan resistance, we hypothesized that bortezomib enhances melphalan response by targeting FA/BRCA DNA damage repair pathway genes. To investigate this hypothesis, we first analyzed FA/BRCA gene expression in 8226/S and 8226/LR5 cells treated with bortezomib, using a customized microfluidic card (to detect BRCA1, BRCA2, FANCA, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCL, RAD51 and RAD51C) and q-PCR. Interestingly, we found that low dose (5nM) bortezomib decreased many FA/BRCA pathway genes as early as 2 hours, with maximal decreases seen at 24 hours. Specifically, 1.5- to 2.5-fold decreases in FANCA, FANCC, FANCD2, FANCE and RAD51C were seen 24 hours post bortezomib exposure. Moreover, pre-treatment of myeloma cells with low dose bortezomib followed by melphalan treatment revealed a greater than 2-fold reduction in FANCD2 gene expression levels. We also found that melphalan treatment alone enhanced FANCD2 protein expression and activation (monoubiquitination), whereas the combination treatment of bortezomib followed by melphalan decreased activation and overall expression of FANCD2 protein. Taken together, these results suggest that bortezomib enhances melphalan response in myeloma by targeting the FA/BRCA pathway. Further understanding of the role of the FA/BRCA pathway in determining melphalan response may allow for more customized and effective treatment of myeloma.

ATM as a biomarker for DNA damage repair deficiency in pancreatic ductal adenocarcinoma.

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 308-308
Author(s):  
Talia Golan ◽  
Sharon Halparin ◽  
Chani Stossel ◽  
Maria Raitses-Gurevich ◽  
Dikla Atias ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Protein Expression ◽  
Dna Damage Repair ◽  
Personal History ◽  
Nuclear Staining ◽  
Repair Pathway ◽  
Damage Repair ◽  
History Of ◽  
Atm Protein

308 Background: Approximately 15% of PDAC tumors display DNA damage repair (DDR) deficiency. Germline BRCA (gBRCA) mutation serves as a robust biomarker for the DDR deficiency. A subset of patients displays a similar clinical phenotype but lack the gBRCA mutation. Identification of these BRCA-like subset of patients remains a challenge and an alternative approach may include DDR functional assays. Here we suggest loss of the ATM protein as one of the biomarkers for the identification of the DDR deficiency signature in PDAC. Methods: Patients were identified from the Sheba pancreatic cancer database based on strong family/personal history of BRCA- associated cancers or a durable response to platinum containing regimens ( ≥ 6 month) or harboring germline/somatic mutations in the DNA repair pathway (excluding gBRCA mutation). Archival FFPE blocks of primary tumors/metastatic lesions were used to explore ATM protein expression by IHC. Nuclear staining was regarded as positive. Tumor infiltrating lymphocytes served as an internal positive control. ATM loss was defined as less than10% neoplastic nuclear staining at any intensity in the presence of positive lymphocytes staining. Results: We identified 53 patients with DDR deficiency phenotype between 2014-2016 from the Sheba PDAC database (n = 250). Median age at diagnosis was 65 years (46-81) and the majority were female (62%). 47% were diagnosed at stage I/II and 53% stage IV. In the subgroup of patients with DDR deficiency phenotype, 55% displayed a family history of BRCA-associated cancers, 19% had a personal history of malignancy and23% had known mutation in DNA repair pathway. 23/53 identified subjects have been analyzed to date. We identified 52% loss of ATM in the analyzed group (n = 23). Conclusions: Loss of ATM in an unselected PDAC population is 12% (H. Kim et al, 2014). Our data demonstrate that 52% of the highly selected subgroup of PDAC patients (DDR deficiency phenotype) was found to have loss of ATM protein expression, suggesting it to be one of the biomarker for DDR signature. Identification of these patients, based on ATM protein expression profile may lead to personalized treatment options.

Retrospective analysis of patients using olaparib (O) in pancreatic cancer (PC).

2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 389-389
Author(s):  
Erkut Hasan Borazanci ◽  
Carol Guarnieri ◽  
Susan Haag ◽  
Ronald Lee Korn ◽  
Courtney Edwards Snyder ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Dna Damage ◽  
Dna Repair ◽  
Retrospective Analysis ◽  
Pearson Correlation ◽  
Brca2 Mutation ◽  
Dna Damage Repair ◽  
Parp Inhibitors ◽  
Damage Repair ◽  
Repair Deficiency

389 Background: Molecular analysis has revealed four subtypes of PC giving clinicians further insight into treating this deadly disease. One subtype that was elucidated termed “unstable” is significant for the presence of DNA damage repair deficiency and can be targeted therapeutically. One such therapy, O, from the drug class poly ADP ribose polymerase (PARP) inhibitors, has already been FDA approved for individuals with BRCA mutated ovarian cancers. We performed a retrospective analysis on patients with PC treated at a single institution who have DNA damage repair deficiency mutations and have been treated with O. Methods: A chart review identified pancreatic cancer patients with DNA repair pathway mutations who were treated with O. The primary objective examined ORR in patients with PC with DNA repair mutations receiving O. Secondary objectives included tolerability, overall survival (OS), CA 19-9 change, and changes in quantitative textural analysis (QTA) on CT. Results: 11 individuals were identified, 5 carriers of a pathogenic germline (g) BRCA2 mutation, 1 carrier of a pathogenic g ATM mutation, 1 carrier of a pathogenic g BRCA1 mutation. Variants of uncertain significance (VUS) included 1 g ATM mutation, 1 g PALB2 mutation, 1 somatic (s) C11orf30 mutation, and 1 s BRCA2 mutation. Median age at diagnosis was 59, with 4 M and 7 F. No patients met criteria for familial PC and 7 had a family history consistent for breast and ovarian cancer syndrome. All individuals had metastatic PC and had progressed on at least 1 line of systemic therapy. ORR was 18%. Median time of therapy on O was 5 months (mo) (Range 1.4 to 29.567 mo) with 5 of the individuals still undergoing treatment at the time of analysis. Mean OS was 12.35 mo, 9 of the 11 individuals still alive. QTA of baseline CTs from subjects with liver (8/11) and pancreatic tumors (7/11) revealed a strong association between lesion texture and OS (Pearson correlation coefficient (PCC): hepatic mets = 0.952, p = 0.0003) and time on O (PCC: panc lesions = 0.889, p = 0.006). Conclusions: In individuals with metastatic PC with mutations involved in DNA repair, O may provide clinical benefit. QTA of individual tumors may allow for additional information that predicts outcomes to PARP inhibitors in this population.

Integrative analyses of signaling and DNA damage repair pathways in patient-derived xenograft (PDX) models from NCI’s patient-derived models repository (PDMR).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 3111-3111
Author(s):  
Biswajit Das ◽  
Yvonne A. Evrard ◽  
Li Chen ◽  
Rajesh Patidar ◽  
Tomas Vilimas ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Large Fraction ◽  
Dna Damage Repair ◽  
Damage Repair ◽  
Pathway Activation ◽  
Integrative Analyses ◽  
Multiple Data Sets ◽  
Repair Pathways ◽  
Pdx Models

3111 Background: Patient-derived xenografts (PDXs) are increasingly being used in translational cancer research for preclinical drug efficacy studies. The National Cancer Institute (NCI) has developed a Patient-Derived Models Repository (NCI PDMR; pdmr.cancer.gov ) of PDXs with clinical annotation, proteomics, and comprehensive genomic datasets to facilitate these studies. Here, we present an integrative genomic, transcriptomic, and proteomic analysis of critical signaling and DNA damage repair pathways in these PDX models, which represent 9 common and multiple rare tumor histologies. Methods: 304 PDX models from 294 patients were established from various solid tumor histologies from patients with primary or metastatic cancer. Whole Exome Sequencing, RNA-Seq and Reverse Phase Protein Array (RPPA) were performed on 2-9 PDXs per model across multiple passages. An integrative workflow was applied on multiple data sets to detect pathway activation. Results: We profiled 10 signaling and 5 DNA repair pathways in the PDMR dataset. We observed that: (i) a large fraction (40%) of PDX models have at least 1 targetable mutation in the RTK/RAS and/or PIK3CA pathways; (ii) 131 models (45%) have putative driver and oncogenic mutations and copy number variants (CNVs) in the WNT, TGFRb , NRF2 and NOTCH pathways. In addition, 17% of PDX models have targetable mutations in DNA damage repair pathways and 20 PDMR models have a DNA mismatch repair defect (MSI-H). We confirmed activation of the signaling pathways in a subset of PDX models by pathway enrichment analysis on gene expression data from RNASeq and phosphoprotein-specific antibody binding data from RPPA. Activation of DNA repair processes was confirmed by enrichment of relevant mutational signatures and loss of heterozygosity in these PDX models. Conclusions: Genomic analysis of NCI PDMR models revealed that a large fraction have clinically relevant somatic alterations in key signaling and DNA damage repair pathways. Further integrative analyses with matched transcriptomic and proteomic profiles confirmed pathway activation in a subset of these models, which may prioritize them for preclinical drug studies.

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