MiR-1587 Regulates DNA Damage Repair and the Radiosensitivity of CRC Cells via Targeting LIG4.
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ABSTRACT:
SUBMITTER: Liu R
PROVIDER: S-EPMC7315685 | biostudies-literature | 2020 Apr-Jun
REPOSITORIES: biostudies-literature
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Project description:Recent reports have made important revelations, uncovering direct regulation of DNA damage response (DDR)-associated proteins and chromatin ubiquitination (Ubn) by macroautophagy/autophagy. Here, we report a previously unexplored connection between autophagy and DDR, via a deubiquitnase (DUB), USP14. Loss of autophagy in prostate cancer cells led to unrepaired DNA double-strand breaks (DSBs) as indicated by persistent ionizing radiation (IR)-induced foci (IRIF) formation for ?H2AFX, and decreased protein levels and IRIF formation for RNF168, an E3-ubiquitin ligase essential for chromatin Ubn and recruitment of critical DDR effector proteins in response to DSBs, including TP53BP1. Consistently, RNF168-associated Ubn signaling and TP53BP1 IRIF formation were reduced in autophagy-deficient cells. An activity assay identified several DUBs, including USP14, which showed higher activity in autophagy-deficient cells. Importantly, inhibiting USP14 could overcome DDR defects in autophagy-deficient cells. USP14 IRIF formation and protein stability were increased in autophagy-deficient cells. Co-immunoprecipitation and colocalization of USP14 with MAP1LC3B and the UBA-domain of SQSTM1 identified USP14 as a substrate of autophagy and SQSTM1. Additionally, USP14 directly interacted with RNF168, which depended on the MIU1 domain of RNF168. These findings identify USP14 as a novel substrate of autophagy and regulation of RNF168-dependent Ubn and TP53BP1 recruitment by USP14 as a critical link between DDR and autophagy. Given the role of Ubn signaling in non-homologous end joining (NHEJ), the major pathway for repair of IR-induced DNA damage, these findings provide unique insights into the link between autophagy, DDR-associated Ubn signaling and NHEJ DNA repair.AbbreviationsATG7: autophagy related 7; CQ: chloroquine; DDR: DNA damage response; DUB: deubiquitinase; HR: homologous recombination; IR: ionizing radiation; IRIF: ionizing radiation-induced foci; LAMP2: lysosomal associated membrane protein 2; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MIU1: motif interacting with ubiquitin; NHEJ: non homologous end-joining; PCa: prostate cancer; TP53BP1/53BP1: tumor protein p53 binding protein 1; RNF168: ring finger protein 168; SQSTM1/p62 sequestosome 1; ?H2AFX/?H2AX: H2A histone family member X: phosphorylated, UBA: ubiquitin-associated; Ub: ubiquitin; Ubn: ubiquitination; USP14: ubiquitin specific peptidase 14.
| S-EPMC6152509 | biostudies-literature
Project description:Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world and is associated with high mortality. Ionizing radiation (IR)-based therapy causes DNA damage, exerting a curative effect; however, DNA damage repair signaling pathways lead to HCC resistance to IR-based therapy. RAD21 is a component of the cohesion complex, crucial for chromosome segregation and DNA damage repair, while it is still unclear whether RAD21 is implicated in DNA damage and influences IR sensitivity in HCC. The current research explores the effect and upstream regulatory mechanism of RAD21 on IR sensitivity in HCC. In the present study, RAD21 mRNA and protein expression were increased within HCC tissue samples, particularly within IR-insensitive HCC tissues. The overexpression of RAD21 partially attenuated the roles of IR in HCC by promoting the viability and suppressing the apoptosis of HCC cells. RAD21 overexpression reduced the culture medium 8-hydroxy-2-deoxyguanosine concentration and decreased the protein levels of γH2AX and ATM, suggesting that RAD21 overexpression attenuated IR treatment-induced DNA damage to HCC cells. miR-320b targeted RAD21 3'-UTR to inhibit RAD21 expression. In HCC tissues, particularly in IR-insensitive HCC tissues, miR-320b expression was significantly downregulated. miR-320b inhibition also attenuated IR treatment-induced DNA damage to HCC cells; more importantly, RAD21 silencing significantly attenuated the effects of miR-320b inhibition on IR treatment-induced DNA damage, suggesting that miR-320b plays a role through targeting RAD21. In conclusion, an miR-320b/RAD21 axis modulating HCC sensitivity to IR treatment through acting on IR-induced DNA damage was demonstrated. The miR-320b/RAD21 axis could be a novel therapeutic target for further study of HCC sensitivity to IR treatment.
| S-EPMC7894001 | biostudies-literature
Project description:BackgroundGlioblastoma multiforme (GBM) is one of the most deadly and recalcitrant illnesses of the neurocentral nervous system in humans. MicroRNAs (miRNAs) are a class of noncoding RNAs that play important roles in the regulation of gene expression and biological processes, including radiosensitivity. In this study, we demonstrated the relationship between miR-3059-3p and radiation in GBM.Materials and methodsRadioresistant (RR) cells were obtained by exposing GBM8401 cells to 80 Gy radiation in 20 weekly 4 Gy fractions. miR-3059-3p mRNA and DNA replication helicase/nuclease 2 (DNA2) protein expressions were detected using real-time polymerase chain reaction and immunoblotting. Using flow cytometry, colony formation and apoptosis were identified using miR-3059-3p mimic, miR-3059-3p inhibitor, DNA2 siRNA, and DNA2 plasmid. Immunoblotting was used to detect DNA repair proteins.ResultsLow levels of miR-3059-3p and high levels of DNA2 were observed in RR cells. Colony formation and apoptosis assays revealed that miR-3059-3p targeted DNA2 to regulate radioresistance. Immunoblotting revealed that miR-3059-3p regulated the homologous recombination (HR) pathway (Rad51 and Rad52) but not the nonhomologous end joining pathway (ku70 and ku80).ConclusionDownregulation of DNA2 via miR-3059-3p enhanced the radiosensitivity of GBM cells through the inhibition of the HR pathway.
| S-EPMC9519319 | biostudies-literature
Project description:Embryonic stem cells (ESCs) enable rapid proliferation that also causes DNA damage. To maintain genomic stabilization during rapid proliferation, ESCs must have an efficient system to repress genotoxic stress. Here, we show that withdrawal of leukemia inhibitory factor (LIF), which maintains the self-renewal capability of mouse ESCs (mESCs), significantly inhibits the cell proliferation and DNA damage of mESCs and upregulates the expression of miR-590. miR-590 promotes single-strand break (SSB) and double-strand break (DSB) damage repair, thus slowing proliferation of mESCs without influencing stemness. miR-590 directly targets Activin receptor type 2a (Acvr2a) to mediate Activin signaling. We identified the homologous recombination-mediated repair (HRR) gene, Rad51b, as a downstream molecule of the miR-590/Acvr2a pathway regulating the SSB and DSB damage repair and cell cycle. Our study shows that a miR-590/Acvr2a/Rad51b signaling axis ensures the stabilization of mESCs by balancing DNA damage repair and rapid proliferation during self-renewal.
| S-EPMC4264031 | biostudies-literature
Project description:The dependency of prostate cancer (PCa) growth on androgen receptor (AR) signaling has been harnessed to develop first-line therapies for high-risk localized and metastatic PCa treatment. However, the occurrence of aberrant expression, mutated or splice variants of AR confers resistance to androgen ablation therapy (ADT), radiotherapy or chemotherapy in AR-positive PCa. Therapeutic strategies that effectively inhibit the expression and/or transcriptional activity of full-length AR, mutated AR and AR splice variants have remained elusive. In this study, we report that mithramycin (MTM), an antineoplastic antibiotic, suppresses cell proliferation and exhibits dual inhibitory effects on expression and transcriptional activity of AR and AR splice variants. MTM blocks AR recruitment to its genomic targets by occupying AR enhancers and causes downregulation of AR target genes, which includes key DNA repair factors in DNA damage repair (DDR). We show that MTM significantly impairs DDR and enhances the effectiveness of ionizing radiation or the radiomimetic agent Bleomycin in PCa. Thus, the combination of MTM treatment with RT or radiomimetic agents, such as bleomycin, may present a novel effective therapeutic strategy for patients with high-risk, clinically localized PCa.
| S-EPMC7370677 | biostudies-literature
Project description:Although the p53 tumor suppressor is relatively well characterized, much less is known about the functions of other members of the p53 family, p73 and p63. Here, we present evidence that in specific pathological conditions caused by exposure of normal cells to bile acids in acidic conditions, p73 protein plays the predominant role in the DNA damage response. These pathological conditions frequently occur during gastric reflux in the human esophagus and are associated with progression to esophageal adenocarcinoma. We found that despite strong DNA damage induced by bile acid exposure, only p73 (but not p53 and p63) is selectively activated in a c-Abl kinase-dependent manner. The activated p73 protein induces DNA damage repair. Using a human DNA repair PCR array, we identified multiple DNA repair genes affected by p73. Two glycosylases involved in base excision repair, SMUG1 and MUTYH, were characterized and found to be transcriptionally regulated by p73 in DNA damage conditions. Using a surgical procedure in mice, which recapitulates bile acid exposure, we found that p73 deficiency is associated with increased DNA damage. These findings were further investigated with organotypic and traditional cell cultures. Collectively our studies demonstrate that p73 plays an important role in the regulation of DNA damage repair.
| S-EPMC3236618 | biostudies-literature
Project description:ObjectiveTo determine the function of miR-125a-5p in laryngeal squamous cell carcinoma (LSCC), its correlation with radiation sensitivity, and the underlying regulatory mechanism.Materials and methodsWe conducted the analysis on the correlation between miR-125a-5p and head and neck squamous cell carcinoma (HNSCC) using data obtained from The Cancer Genome Atlas (TCGA). The putative gene targeted by miR-125a-5p has been identified as HK2, while the expression levels of miR-125a-5p and HK2 were measured in laryngeal cancer tissues and cells using RT-PCR. MiR-125a-5p and HK2 were introduced into the lentiviral vector and the vector was used to transfect AMC-HN-8 cells. The roles of miR-125a-5p and HK2 in LSCC and on radiosensitivity were determined by evaluating cell growth, examining colony formation, analyzing flow cytometry, and utilizing the single hit multi-target model. Western blotting was used to measure H2AX and rH2AX levels in the DNA damage response (DDR) pathway. The validation of the interaction between miR-125a-5p and HK2 was conducted through the dual-luciferase assay. To further confirm the association between miR-125a-5p and HK2, as well as its influence on radiosensitivity, rescue experiments were performed.ResultsThe expression of miR-125a-5p is downregulated in LSCC, while upregulating its expression could suppress cell growth, induce apoptosis, and enhance radiosensitivity. Additionally, HK2 exhibited high expression in LSCC and the biological function was opposite to miR-125a-5p. Western blotting analysis revealed that miR-125a-5p increased rH2AX levels and decreased H2AX levels, conversely, HK2 had the opposite effect on miR-125a-5p. These findings suggested that HK2 may serve as the target gene of miR-125a-5p. The double luciferase assay confirmed the binding of HK2 to miR-125a-5p, and rescue trials confirmed the role of miR-125a-5p in regulating the effects and radiation sensitivity of LSCC by targeting HK2 via the DDR pathway.ConclusionBy targeting HK2 and impacting the DDR pathway, miR-125a-5p has been found to inhibit cellular proliferation, enhance apoptosis, and heighten radiosensitivity in LSCC.
| S-EPMC11366599 | biostudies-literature
Project description:Opinion statementMetastatic (and locally advanced) pancreatic adenocarcinoma (mPDA) represents a major challenge for the oncology community given the rising mortality burden from the disease and the preponderance of patients diagnosed with unresectable disease. Although systemic therapies have become more potent with the development of fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX) and gemcitabine plus nab-paclitaxel as first-line treatments, the median overall survival for patients treated with either of these regimens remains just above 1 year. A significant need exists to build upon the effectiveness of first-line regimens, incorporate tolerable maintenance treatments, and add effective later-line options for patients with this disease. We believe every newly diagnosed mPDA patient should undergo next-generation sequencing (NGS) testing, preferably from tumor tissue, to assess for the presence of DNA damage repair (DDR) defects, microsatellite instability, and other possible actionable molecular alterations (such as neurotrophic tropomysin receptor kinase (NTRK) fusions, anaplastic lymphoma kinase (ALK) rearrangements, or human epidermal growth factor receptor 2 (HER2) amplification). Existing clinical data suggests that patients, whose tumors harbor DDR defects, benefit from treatment with platinum-based chemotherapy and poly (ADP-ribose) polymerase (PARP) inhibitors. Preclinically, inhibitors of other critical players in DDR such as ataxia-telangiectasia and Rad3 related (ATR), ataxia-telangiectasia mutated (ATM), DNA-dependent protein kinase (DNA-PK), and WEE1 have demonstrated promising anti-tumor activity in PDA cell lines and xenografts. How to move forward the preclinical promise of these newer DDR-targeting therapies into rational clinical trial combinations and sequence PARP inhibitors in relation to platinum chemotherapy remain areas of tremendous clinical research interest. We believe clinical trials should be considered early for mPDA patients, in all treatment lines, so that novel therapies may be added to the treatment armamentarium for patients with this disease. Beyond NGS testing from tumor tissue, we believe it is important to consider germline genetic testing for all patients diagnosed with PDA given recent data suggesting a much stronger hereditary component of the disease than previously understood, and the potential screening implications for family members.
| S-EPMC8130833 | biostudies-literature
Project description:Pancreas ductal adenocarcinoma (PDAC) is the third most common cause of cancer death in the USA. While other cancers with historically poor prognoses have benefited from new immunotherapies and targeted agents, the 5-year survival rate for PDAC patients has remained static. The accessibility to genomic testing has improved in recent years, and it is now clear that PDAC is a heterogenous disease, with a subset of patients harboring actionable mutations. There are several targeted therapies approved by the Food and Drug administration (FDA) in PDAC: EGFR inhibitor erlotinib (combined with gemcitabine) in unselected patients, TRK inhibitors larotrectinib and entrectinib for patients with NTRK fusion mutation, the PD-1 inhibitor pembrolizumab for mismatch repair-deficient patients, and the poly-ADP-ribose polymerase (PARP) inhibitor olaparib in patients with germline BRCA mutation as a maintenance therapy. DNA damage repair (DDR) is paramount to genomic integrity and cell survival. The defective repair of DNA damage is one of the hallmarks of cancer, and abnormalities in DDR pathways are closely linked with the development of malignancies and upregulation of these pathways linked with resistance to treatment. The prevalence of somatic and germline mutations in DDR pathways in metastatic PDAC is reported to be approximately 15-25%. Patients with DDR gene alterations benefit from a personalized approach to treatment. Recently, the POLO trial demonstrated a progression-free survival (PFS) benefit in metastatic PDAC patients with a germline BRCA1/2 mutation treated with maintenance olaparib following platinum-based induction chemotherapy. This was the first phase 3 randomized trial to establish a biomarker-driven approach in the treatment of PDAC and establishes a precedent for maintenance therapy in PDAC. The review herein aims to outline the current treatment landscape for PDAC patients with DDR gene-mutated tumors, highlight novel therapeutic approaches focused on surmounting tumor resistance, and explore new strategies which may lead to an expansion in the number of patients who benefit from these targeted treatments.
| S-EPMC9391023 | biostudies-literature
Project description:Impaired DNA damage repair (DDR) is increasingly recognised as a hallmark in pancreatic ductal adenocarcinoma (PDAC). It is estimated that around 14% of human PDACs harbour mutations in genes involved in DDR, including, amongst others, BRCA1/2, PALB2, ATM, MSH2, MSH6 and MLH1. Recently, DDR intervention by PARP inhibitor therapy has demonstrated effectiveness in germline BRCA1/2-mutated PDAC. Extending this outcome to the significant proportion of human PDACs with somatic or germline mutations in DDR genes beyond BRCA1/2 might be beneficial, but there is a lack of data, and consequently, no clear recommendations are provided in the field. Therefore, an expert panel was invited by the European Society of Digestive Oncology (ESDO) to assess the current knowledge and significance of DDR as a target in PDAC treatment. The aim of this virtual, international expert meeting was to elaborate a set of consensus recommendations on testing, diagnosis and treatment of PDAC patients with alterations in DDR pathways. Ahead of the meeting, experts completed a 27-question survey evaluating the key issues. The final recommendations herein should aid in facilitating clinical practice decisions on the management of DDR-deficient PDAC.
| S-EPMC8428219 | biostudies-literature