Excess ribonucleotide reductase R2 subunits coordinate the S phase checkpoint to facilitate DNA damage repair and recovery from replication stress

2007 ◽  
Vol 73 (6) ◽  
pp. 760-772 ◽  
Author(s):  
Z. Ping Lin ◽  
Michael F. Belcourt ◽  
Rocco Carbone ◽  
Jana S. Eaton ◽  
Philip G. Penketh ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ribonucleotide Reductase ◽  
Dna Damage Repair ◽  
Replication Stress ◽  
S Phase ◽  
Damage Repair ◽  
Ribonucleotide Reductase R2 ◽  
S Phase Checkpoint

scholarly journals Targeting DNA Replication Stress and DNA Double-Strand Break Repair for Optimizing SCLC Treatment

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1289 ◽  
Author(s):  
Xing Bian ◽  
Wenchu Lin
Keyword(s):  
Lung Cancer ◽  
Dna Damage ◽  
Dna Replication ◽  
Dna Damage Repair ◽  
Predictive Biomarkers ◽  
Replication Stress ◽  
Genotoxic Stress ◽  
Repair System ◽  
Damage Repair ◽  
Repair Pathways

Small cell lung cancer (SCLC), accounting for about 15% of all cases of lung cancer worldwide, is the most lethal form of lung cancer. Despite an initially high response rate of SCLC to standard treatment, almost all patients are invariably relapsed within one year. Effective therapeutic strategies are urgently needed to improve clinical outcomes. Replication stress is a hallmark of SCLC due to several intrinsic factors. As a consequence, constitutive activation of the replication stress response (RSR) pathway and DNA damage repair system is involved in counteracting this genotoxic stress. Therefore, therapeutic targeting of such RSR and DNA damage repair pathways will be likely to kill SCLC cells preferentially and may be exploited in improving chemotherapeutic efficiency through interfering with DNA replication to exert their functions. Here, we summarize potentially valuable targets involved in the RSR and DNA damage repair pathways, rationales for targeting them in SCLC treatment and ongoing clinical trials, as well as possible predictive biomarkers for patient selection in the management of SCLC.

scholarly journals Novel Insights into the Molecular Regulation of Ribonucleotide Reductase in Adrenocortical Carcinoma Treatment

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4200
Author(s):  
Christina Bothou ◽  
Ashish Sharma ◽  
Adrian Oo ◽  
Baek Kim ◽  
Pal Perge ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ribonucleotide Reductase ◽  
Ataxia Telangiectasia ◽  
Therapeutic Option ◽  
Treatment Options ◽  
Dna Damage Repair ◽  
Repair System ◽  
Clinical Patient ◽  
Damage Repair ◽  
Adrenocortical Carcinomas

Current systemic treatment options for patients with adrenocortical carcinomas (ACCs) are far from being satisfactory. DNA damage/repair mechanisms, which involve, e.g., ataxia-telangiectasia-mutated (ATM) and ataxia-telangiectasia/Rad3-related (ATR) protein signaling or ribonucleotide reductase subunits M1/M2 (RRM1/RRM2)-encoded ribonucleotide reductase (RNR) activation, commonly contribute to drug resistance. Moreover, the regulation of RRM2b, the p53-induced alternative to RRM2, is of unclear importance for ACC. Upon extensive drug screening, including a large panel of chemotherapies and molecular targeted inhibitors, we provide strong evidence for the anti-tumoral efficacy of combined gemcitabine (G) and cisplatin (C) treatment against the adrenocortical cell lines NCI-H295R and MUC-1. However, accompanying induction of RRM1, RRM2, and RRM2b expression also indicated developing G resistance, a frequent side effect in clinical patient care. Interestingly, this effect was partially reversed upon addition of C. We confirmed our findings for RRM2 protein, RNR-dependent dATP levels, and modulations of related ATM/ATR signaling. Finally, we screened for complementing inhibitors of the DNA damage/repair system targeting RNR, Wee1, CHK1/2, ATR, and ATM. Notably, the combination of G, C, and the dual RRM1/RRM2 inhibitor COH29 resulted in previously unreached total cell killing. In summary, we provide evidence that RNR-modulating therapies might represent a new therapeutic option for ACC.

scholarly journals Lamin A/C Depletion Enhances DNA Damage-Induced Stalled Replication Fork Arrest

2013 ◽  
Vol 33 (6) ◽  
pp. 1210-1222 ◽  
Author(s):  
Mayank Singh ◽  
Clayton R. Hunt ◽  
Raj K. Pandita ◽  
Rakesh Kumar ◽  
Chin-Rang Yang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Replication Fork ◽  
Dna Damage Repair ◽  
Genomic Stability ◽  
Replication Stress ◽  
Lamin A ◽  
Replicative Stress ◽  
Damage Repair ◽  
Repair Factor ◽  
Recombination Pathway

The humanLMNAgene encodes the essential nuclear envelope proteins lamin A and C (lamin A/C). Mutations inLMNAresult in altered nuclear morphology, but how this impacts the mechanisms that maintain genomic stability is unclear. Here, we report that lamin A/C-deficient cells have a normal response to ionizing radiation but are sensitive to agents that cause interstrand cross-links (ICLs) or replication stress. In response to treatment with ICL agents (cisplatin, camptothecin, and mitomycin), lamin A/C-deficient cells displayed normal γ-H2AX focus formation but a higher frequency of cells with delayed γ-H2AX removal, decreased recruitment of the FANCD2 repair factor, and a higher frequency of chromosome aberrations. Similarly, following hydroxyurea-induced replication stress, lamin A/C-deficient cells had an increased frequency of cells with delayed disappearance of γ-H2AX foci and defective repair factor recruitment (Mre11, CtIP, Rad51, RPA, and FANCD2). Replicative stress also resulted in a higher frequency of chromosomal aberrations as well as defective replication restart. Taken together, the data can be interpreted to suggest that lamin A/C has a role in the restart of stalled replication forks, a prerequisite for initiation of DNA damage repair by the homologous recombination pathway, which is intact in lamin A/C-deficient cells. We propose that lamin A/C is required for maintaining genomic stability following replication fork stalling, induced by either ICL damage or replicative stress, in order to facilitate fork regression prior to DNA damage repair.

scholarly journals CRM1 inhibitor anti-tumor activity is enhanced with salicylates by S-phase arrest and impaired DNA-damage repair

Blood ◽  
2020 ◽  
Author(s):  
Jithma Abeykoon ◽  
Xiaosheng Wu ◽  
Kevin Edward Nowakowski ◽  
Surendra Dasari ◽  
Jonas Paludo ◽  
...  
Keyword(s):  
Dna Damage ◽  
Nuclear Export ◽  
Dna Damage Repair ◽  
Cancer Therapeutics ◽  
B Cell Lymphoma ◽  
S Phase ◽  
Solid Organ ◽  
Malignant Cells ◽  
Damage Repair ◽  
Anti Tumor Activity

Chromosome region maintenance protein1 (CRM1) mediates protein export from the nucleus and is a new target for anti-cancer therapeutics. Broader application of KPT-330 (selinexor), a first in class CRM1 inhibitor recently approved for relapsed multiple myeloma and diffuse large B-cell lymphoma, have been limited by substantial toxicity. We discovered that salicylates markedly enhance the anti-tumor activity of CRM1 inhibitors by extending the mechanisms of action beyond CRM1 inhibition. Using salicylates in combination enables targeting of a range of blood cancers with a much lower dose of selinexor, thereby potentially mitigating prohibitive clinical adverse effects. Choline salicylate (CS) with low-dose KPT-330 (K+CS) had potent, broad activity across high-risk hematological malignancies and solid organ cancers ex vivo and in vivo. The K+CS combination was not toxic to non-malignant cells as compared to malignant cells and was safe without inducing toxicity to normal organs in mice. Mechanistically, compared to KPT-330 alone, K+CS suppresses the expression of CRM1, Rad51 and thymidylate synthase proteins, leading to more efficient inhibition of CRM1-mediated nuclear export, impairment of DNA-damage repair, reduced pyrimidine synthesis, cell cycle arrest in S-phase, and cell apoptosis. Moreover, the addition of PARP inhibitors further potentiates the K+CS anti-tumor effect. K+CS represents a new class of therapy for multiple types of blood cancers and will stimulate future investigations to exploit DNA-damage repair and nucleocytoplasmic transport for cancer therapy in general.

scholarly journals Abstract 3217: Newly identified role of tumor treating fields in DNA damage repair and replication stress pathways

2018 ◽  
Author(s):  
Narasimha Kumar Karanam ◽  
Lianghao Ding ◽  
Brock Sishc ◽  
Debabrata Saha ◽  
Michael D. Story
Keyword(s):  
Dna Damage ◽  
Dna Damage Repair ◽  
Replication Stress ◽  
Tumor Treating Fields ◽  
Damage Repair

scholarly journals Fanconi Anemia FANCM/FNCM-1 and FANCD2/FCD-2 are required for maintaining histone methylation levels and interact with the histone demethylase LSD1/SPR-5 in C. elegans

2018 ◽  
Author(s):  
Hyun-Min Kim ◽  
Sara E. Beese-Sims ◽  
Monica P. Colaiácovo
Keyword(s):  
Dna Damage ◽  
Fanconi Anemia ◽  
Histone Methylation ◽  
Dna Damage Repair ◽  
Replication Stress ◽  
Histone Demethylase ◽  
Histone Demethylases ◽  
Checkpoint Activation ◽  
C Elegans ◽  
Damage Repair

ABSTRACTThe histone demethylase LSD1 was originally discovered as removing methyl groups from di- and monomethylated histone H3 lysine 4 (H3K4me2/1), and several studies suggest it plays roles in meiosis as well as epigenetic sterility given that in its absence there is evidence of a progressive accumulation of H3K4me2 through generations. In addition to transgenerational sterility, growing evidence for the importance of histone methylation in the regulation of DNA damage repair has attracted more attention to the field in recent years. However, we are still far from understanding the mechanisms by which histone methylation is involved in DNA damage repair and only a few studies have been focused on the roles of histone demethylases in germline maintenance. Here, we show that the histone demethylase LSD1/CeSPR-5 is interacting with the Fanconi Anemia (FA) protein FANCM/CeFNCM-1 based on biochemical, cytological and genetic analyses. LSD1/CeSPR-5 is required for replication stress-induced S-phase checkpoint activation and its absence suppresses the embryonic lethality and larval arrest observed in fncm-1 mutants. FANCM/CeFNCM-1 re-localizes upon hydroxyurea exposure and co-localizes with FANCD2/CeFCD-2 and LSD1/CeSPR-5 suggesting coordination between this histone demethylase and FA components to resolve replication stress. Surprisingly, the FA pathway is required for H3K4me2 maintenance regardless of the presence of replication stress. Our study reveals a connection between Fanconi Anemia and epigenetic maintenance, therefore providing new mechanistic insight into the regulation of histone methylation in DNA repair.

366-OR: TCF19 Promotes Functional Beta-Cell Mass and Proliferative Capacity by Regulating DNA Damage Repair Pathways

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 366-OR
Author(s):  
GRACE H. YANG ◽  
JEE YOUNG HAN ◽  
SUKANYA LODH ◽  
JOSEPH T. BLUMER ◽  
DANIELLE FONTAINE ◽  
...  
Keyword(s):  
Dna Damage ◽  
Beta Cell ◽  
Dna Damage Repair ◽  
Cell Mass ◽  
Beta Cell Mass ◽  
Proliferative Capacity ◽  
Damage Repair ◽  
Repair Pathways
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