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.

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.

scholarly journals NUSAP1 Enhances Drug Resistance By Binding to RAD51 through DNA Damage Repair Pathway in Chronic Lymphocytic Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 13-14
Author(s):  
Yang Han ◽  
Ya Zhang ◽  
Xinting Hu ◽  
Xiang Sun ◽  
Xin Wang
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Damage ◽  
Drug Resistance ◽  
Dna Damage Repair ◽  
Repair Process ◽  
Lymphocytic Leukemia ◽  
Repair Pathway ◽  
Damage Repair

Introduction: Enhanced DNA damage repair effect is an important mechanism for drug-resistance in chronic lymphocytic leukemia (CLL). Moreover, the ability of cancer cells to repair under radiation or chemotherapy drug induced DNA damage also serves as one of the mechanisms for therapy resistance. It is reported that nucleolar and spindle associated protein 1 (NUSAP1), a microtubule binding protein, has been involved in DNA damage repair process and plays important roles in the development, progression, and metastasis in several types of cancer. However, its role and mechanism in the development of CLL are still unclear. Methods: Expression levels of NUSAP1 mRNA and protein in CLL cell lines and patient specimens were detected by qRT-PCR and Western blot, and Kaplan-Meier survival curve and overall survival were analyzed by log-rank test. Peripheral blood samples from de novo CLL patients and healthy volunteers were collected with informed consents at the Department of Hematology in Shandong Provincial Hospital Affiliated to Shandong University (SPHASU). Microarray datasets GSE22762 were obtained from Gene Expression Omnibus. With altering NUSAP1 expression by lentivirus-transfected cells in vitro, the effects of NUSAP1 on cell proliferation, apoptosis and cycle were detected by CCK8, Annexin V-PE /7AAD staining and PI/RNase staining respectively. Bioinformatics analysis, luciferase reporter analysis, immunoprecipitation and were applied to discern and examine the relationship between NUSAP1 and its potential targets. Results: According to clinical specimens and bioinformatics analysis, the expression level of NUSAP1 gene in samples of CLL patients was significantly increased than that of healthy donors (P<0.05) (Figure A). Besides, the results indicated that the OS of patients with highly expressed NUSAP1 was significantly worse than in patients with low expression with the statistical analysis database GSE22762. mRNA and protein expression levels of NUSAP1 were significantly higher in CLL cell lines than in PBMCs from healthy donors (Figure C). Our findings indicated that NUSAP1 knockdown notably inhibited cell proliferation when compared with the Scramble group (Figure D). Moreover, the amounts of DNA fragmentation of the apoptotic cells were remarkably increased by NUSAP1 shRNA in MEC-1 and EHEB cells when compared with the Scramble group (Figure E). In addition, after knocking down NUSAP1, MEC-1 and EHEB cells were blocked in G0/G1 phase (Figure F). Moreover, addition to fludarabine or ibrutinib with shNUSAP1 group showed enhanced cytotoxicity in CLL cells (Figure G). The differential genes were analyzed via RNA-seq between Scramble and ShNUSAP1 group. Intriguingly, annotations of gene ontology (GO) analysis indicated that NUSAP1 was closely related to biological processes including cell cycle and response to drug. Kyoto encyclopedia of genes and genomes (KEGG) analysis showed that NUSAP1 were enriched in pathways in cancer, DNA replication and cell cycle. Gene set enrichment analysis (GSEA) implicated that NUSAP1 was functionally enriched in DNA replication, cell cycle and proteasome (Figure H). Immunofluorescence showed that NUSAP1 was mainly distributed in the cell nucleus, and the expression level of RAD51 was positively correlated with the change of NUSAP1 expression (Figure I). Surppression of NUSAP1 inhibited the action of proteins in DNA damage repair pathway (Figure J). Through COIP, NUSAP1 was identified to bind with RAD51 and play an important role in DNA damage repair pathway (Figure K). Hence, NUSAP1 participates in the DNA damage repair process and enhances the drug resistance in CLL. Conclusions: This study first demonstrated that the high expression of NUSAP1 in CLL patients is associated with poor prognosis through database analysis and experiments in vitro. Interference of NUSAP1 expression led to a slower CLL cell proliferation and a higher apoptosis rate, meanwhile induced the G1 phase arrest. Collectively, our findings demonstrated that NUSAP1 contributes to DNA damage repairing by binding to RAD51 and enhances drug resistance in CLL. Therefore, NUSAP1 is expected to be a potential target for the treatment of CLL with drug-resistance. Figure 1 Disclosures No relevant conflicts of interest to declare.

Co-targeting WIP1 and PARP induces synthetic lethality in hepatocellular carcinoma

2021 ◽  
Author(s):  
Miaoqin Chen ◽  
Weikai Wang ◽  
Shiman Hu ◽  
Yifan Tong ◽  
Yiling Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Dna Damage ◽  
Poor Prognosis ◽  
Synthetic Lethality ◽  
Dna Damage Repair ◽  
Gene Set Enrichment Analysis ◽  
Parp Inhibition ◽  
Damage Repair ◽  
Hcc Cells

Abstract BackgroundHepatocellular carcinoma (HCC) is one of the most fatal cancers. Due to limited strategies for effective treatments, patients with advanced HCC have a very poor prognosis. This study aims to identify novel druggable candidate genes for patients with HCC.MethodsThe role of WIP1 (wild type p53 induced protein phosphatase1) in HCC was analyzed in HCC cells, nude mice assay, WIP1 knockout mice, and TCGA database. DNA damage was evaluated by Gene Set Enrichment Analysis, Western blotting, comet assay, and Immunofluorescence.ResultsHigh expression of WIP1 is associated with poor prognosis of patients with HCC. Genetically and chemically suppression of WIP1 drastically reduced HCC cell proliferation in vitro and in vivo via inducing DNA damage. WIP1 knockout retarded DEN (Diethylnitrosamine) induced mice hepato-carcinogenesis. In addition, suppression of WIP1 together with PARP inhibition induced synthetic lethality in HCC cells by disrupting DNA damage repair.ConclusionWIP1 plays an oncogenic effect in HCC development, and targeting WIP1-dependent DNA damage repair might be a novel strategy for HCC management.

scholarly journals The Fanconi anemia DNA damage repair pathway in the spotlight for germline predisposition to colorectal cancer

2016 ◽  
Vol 24 (10) ◽  
pp. 1501-1505 ◽  
Author(s):  
Clara Esteban-Jurado ◽  
◽  
Sebastià Franch-Expósito ◽  
Jenifer Muñoz ◽  
Teresa Ocaña ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Dna Damage ◽  
Fanconi Anemia ◽  
Dna Damage Repair ◽  
Repair Pathway ◽  
Damage Repair

scholarly journals MTA1 promotes cell proliferation via DNA damage repair in epithelial ovarian cancer

2014 ◽  
Vol 13 (4) ◽  
pp. 10269-10278 ◽  
Author(s):  
Q.Y. Yang ◽  
J.H. Li ◽  
Q.Y. Wang ◽  
Y. Wu ◽  
J.L. Qin ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cell Proliferation ◽  
Dna Damage ◽  
Epithelial Ovarian Cancer ◽  
Dna Damage Repair ◽  
Damage Repair

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.

Sign in / Sign up

Export Citation Format

Share Document