mTORC1 and -2 Coordinate Transcriptional and Translational Reprogramming in Resistance to DNA Damage and Replicative Stress in Breast Cancer Cells

ABSTRACT mTOR coordinates growth signals with metabolic pathways and protein synthesis and is hyperactivated in many human cancers. mTOR exists in two complexes: mTORC1, which stimulates protein, lipid, and ribosome biosynthesis, and mTORC2, which regulates cytoskeleton functions. While mTOR is known to be involved in the DNA damage response, little is actually known regarding the functions of mTORC1 compared to mTORC2 in this regard or the respective impacts on transcriptional versus translational regulation. We show that mTORC1 and mTORC2 are both required to enact DNA damage repair and cell survival, resulting in increased cancer cell survival during DNA damage. Together mTORC1 and -2 enact coordinated transcription and translation of protective cell cycle and DNA replication, recombination, and repair genes. This coordinated transcriptional-translational response to DNA damage was not impaired by rapalog inhibition of mTORC1 or independent inhibition of mTORC1 or mTORC2 but was blocked by inhibition of mTORC1/2. Only mTORC1/2 inhibition reversed cancer cell resistance to DNA damage and replicative stress and increased tumor cell killing and tumor control by DNA damage therapies in animal models. When combined with DNA damage, inhibition of mTORC1/2 blocked transcriptional induction more strongly than translation of DNA replication, survival, and DNA damage response mRNAs.

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STING Promotes Breast Cancer Cell Survival by an Inflammatory-Independent Nuclear Pathway Enhancing the DNA Damage Response

10.1101/2020.07.11.196790 ◽

2020 ◽

Author(s):

Laura Cheradame ◽

Ida Chiara Guerrera ◽

Julie Gaston ◽

Alain Schmitt ◽

Vincent Jung ◽

...

Keyword(s):

Breast Cancer ◽

Dna Damage ◽

Cell Survival ◽

Cancer Cell ◽

Breast Cancer Cell ◽

Dna Damage Response ◽

Breast Cancer Cell Lines ◽

Inflammatory Pathway ◽

Damage Response ◽

Cancer Cell Survival

AbstractSTING (Stimulator of Interferon Genes) is a well-known endoplasmic reticulum-anchored adaptor of the innate immunity that triggers the expression of inflammatory cytokines in response to pathogen infection. In cancer cells, this pro-inflammatory pathway can be activated by genomic DNA damage potentiating antitumor immune responses. Here we report that STING promotes cancer cell survival and resistance to genotoxic treatment in a cell-autonomous manner. Mechanistically, we show that STING partly localizes at the inner nuclear membrane in various breast cancer cell lines and clinical tumor samples, and interacts with several proteins of the DNA damage response (DDR). STING overexpression enhances the amount of chromatin-bound DNA-dependent Protein Kinase (DNA-PK) complex, while STING silencing impairs DDR foci formation and DNA repair efficacy. Importantly, this function of STING is independent of its canonical pro-inflammatory pathway. This study highlights a previously unappreciated cell-autonomous tumor-promoting mechanism of STING that opposes its well-documented role in tumor immunosurveillance.Graphical abstract

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Gene co-expression analysis applied to RNASEH2A reveals functional networks associated with DNA replication, DNA damage response, as well as cell cycle regulation

10.26226/morressier.5ebd45acffea6f735881b15e ◽

2020 ◽

Author(s):

Stefania Marsili

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Dna Replication ◽

Dna Damage Response ◽

Expression Analysis ◽

Cell Cycle Regulation ◽

Functional Networks ◽

Damage Response ◽

Cycle Regulation

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NKX3.1 contributes to S phase entry and regulates DNA damage response (DDR) in prostate cancer cell lines

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2011.09.035 ◽

2011 ◽

Vol 414 (1) ◽

pp. 123-128 ◽

Cited By ~ 8

Author(s):

Burcu Erbaykent-Tepedelen ◽

Besra Özmen ◽

Lokman Varisli ◽

Ceren Gonen-Korkmaz ◽

Bilge Debelec-Butuner ◽

...

Keyword(s):

Prostate Cancer ◽

Dna Damage ◽

Cell Lines ◽

Cancer Cell ◽

Dna Damage Response ◽

Prostate Cancer Cell ◽

S Phase ◽

Prostate Cancer Cell Lines ◽

Damage Response ◽

Phase Entry

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Dysregulation of hsa-miR-34a and hsa-miR-449a leads to overexpression of PACS-1 and loss of DNA damage response (DDR) in cervical cancer

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.014048 ◽

2020 ◽

Vol 295 (50) ◽

pp. 17169-17186

Author(s):

Mysore S. Veena ◽

Santanu Raychaudhuri ◽

Saroj K. Basak ◽

Natarajan Venkatesan ◽

Parameet Kumar ◽

...

Keyword(s):

Cell Cycle ◽

Cervical Cancer ◽

Dna Damage ◽

Cell Growth ◽

Cell Lines ◽

Cancer Cell ◽

Dna Damage Response ◽

S Phase ◽

Cervical Cancer Cell ◽

Damage Response

We have observed overexpression of PACS-1, a cytosolic sorting protein in primary cervical tumors. Absence of exonic mutations and overexpression at the RNA level suggested a transcriptional and/or posttranscriptional regulation. University of California Santa Cruz genome browser analysis of PACS-1 micro RNAs (miR), revealed two 8-base target sequences at the 3′ terminus for hsa-miR-34a and hsa-miR-449a. Quantitative RT-PCR and Northern blotting studies showed reduced or loss of expression of the two microRNAs in cervical cancer cell lines and primary tumors, indicating dysregulation of these two microRNAs in cervical cancer. Loss of PACS-1 with siRNA or exogenous expression of hsa-miR-34a or hsa-miR-449a in HeLa and SiHa cervical cancer cell lines resulted in DNA damage response, S-phase cell cycle arrest, and reduction in cell growth. Furthermore, the siRNA studies showed that loss of PACS-1 expression was accompanied by increased nuclear γH2AX expression, Lys382-p53 acetylation, and genomic instability. PACS-1 re-expression through LNA-hsa-anti-miR-34a or -449a or through PACS-1 cDNA transfection led to the reversal of DNA damage response and restoration of cell growth. Release of cells post 24-h serum starvation showed PACS-1 nuclear localization at G1-S phase of the cell cycle. Our results therefore indicate that the loss of hsa-miR-34a and hsa-miR-449a expression in cervical cancer leads to overexpression of PACS-1 and suppression of DNA damage response, resulting in the development of chemo-resistant tumors.

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Werner Helicase Control of Human Papillomavirus 16 E1-E2 DNA Replication Is Regulated by SIRT1 Deacetylation

mBio ◽

10.1128/mbio.00263-19 ◽

2019 ◽

Vol 10 (2) ◽

Cited By ~ 7

Author(s):

Dipon Das ◽

Molly L. Bristol ◽

Nathan W. Smith ◽

Claire D. James ◽

Xu Wang ◽

...

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Life Cycle ◽

Dna Replication ◽

Homologous Recombination ◽

Dna Damage Response ◽

Human Papillomaviruses ◽

Repair Protein ◽

Damage Response ◽

Dna Repair Protein

ABSTRACTHuman papillomaviruses (HPV) are double-stranded DNA viruses causative in a host of human diseases, including several cancers. Following infection, two viral proteins, E1 and E2, activate viral replication in association with cellular factors and stimulate the DNA damage response (DDR) during the replication process. E1-E2 uses homologous recombination (HR) to facilitate DNA replication, but an understanding of host factors involved in this process remains incomplete. Previously, we demonstrated that the class III deacetylase SIRT1, which can regulate HR, is recruited to E1-E2-replicating DNA and regulates the level of replication. Here, we demonstrate that SIRT1 promotes the fidelity of E1-E2 replication and that the absence of SIRT1 results in reduced recruitment of the DNA repair protein Werner helicase (WRN) to E1-E2-replicating DNA. CRISPR/Cas9 editing demonstrates that WRN, like SIRT1, regulates the quantity and fidelity of E1-E2 replication. This is the first report of WRN regulation of E1-E2 DNA replication, or a role for WRN in the HPV life cycle. In the absence of SIRT1 there is an increased acetylation and stability of WRN, but a reduced ability to interact with E1-E2-replicating DNA. We present a model in which E1-E2 replication turns on the DDR, stimulating SIRT1 deacetylation of WRN. This deacetylation promotes WRN interaction with E1-E2-replicating DNA to control the quantity and fidelity of replication. As well as offering a crucial insight into HPV replication control, this system offers a unique model for investigating the link between SIRT1 and WRN in controlling replication in mammalian cells.IMPORTANCEHPV16 is the major viral human carcinogen responsible for between 3 and 4% of all cancers worldwide. Following infection, this virus activates the DNA damage response (DDR) to promote its life cycle and recruits DDR proteins to its replicating DNA in order to facilitate homologous recombination during replication. This promotes the production of viable viral progeny. Our understanding of how HPV16 replication interacts with the DDR remains incomplete. Here, we demonstrate that the cellular deacetylase SIRT1, which is a part of the E1-E2 replication complex, regulates recruitment of the DNA repair protein WRN to the replicating DNA. We demonstrate that WRN regulates the level and fidelity of E1-E2 replication. Overall, the results suggest a mechanism by which SIRT1 deacetylation of WRN promotes its interaction with E1-E2-replicating DNA to control the levels and fidelity of that replication.

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Replication-Dependent DNA Damage Response Triggered by Roscovitine Induces an Uncoupling of DNA Replication Proteins

Cell Cycle ◽

10.4161/cc.5.18.3235 ◽

2006 ◽

Vol 5 (18) ◽

pp. 2153-2159 ◽

Cited By ~ 9

Author(s):

Monica Savio ◽

Michaela Cerri ◽

Ornella Cazzalini ◽

Paola Perucca ◽

Lucia A. Stivala ◽

...

Keyword(s):

Dna Damage ◽

Dna Replication ◽

Dna Damage Response ◽

Replication Proteins ◽

Damage Response

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Bocavirus Infection Induces a DNA Damage Response That Facilitates Viral DNA Replication and Mediates Cell Death

Journal of Virology ◽

10.1128/jvi.01534-10 ◽

2010 ◽

Vol 85 (1) ◽

pp. 133-145 ◽

Cited By ~ 36

Author(s):

Y. Luo ◽

A. Y. Chen ◽

J. Qiu

Keyword(s):

Dna Damage ◽

Cell Death ◽

Dna Replication ◽

Dna Damage Response ◽

Viral Dna ◽

Viral Dna Replication ◽

Damage Response

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Coordinated Chromatin-Association of Fanconi Anemia Network Proteins Requires Replication-Coupled DNA Damage Recognition.

Blood ◽

10.1182/blood.v104.11.723.723 ◽

2004 ◽

Vol 104 (11) ◽

pp. 723-723

Author(s):

Alexandra Sobeck ◽

Stacie Stone ◽

Bendert deGraaf ◽

Vincenzo Costanzo ◽

Johan deWinter ◽

...

Keyword(s):

Dna Damage ◽

Dna Replication ◽

Dna Damage Response ◽

Fanconi Anemia ◽

Bone Marrow Failure ◽

S Phase ◽

Dependent Manner ◽

Core Complex ◽

Damage Response ◽

Crosslinking Agents

Abstract Fanconi anemia (FA) is a genetic disorder characterized by hypersensitivity to DNA crosslinking agents and diverse clinical symptoms, including developmental anomalies, progressive bone marrow failure, and predisposition to leukemias and other cancers. FA is genetically heterogeneous, resulting from mutations in any of at least eleven different genes. The FA proteins function together in a pathway composed of a mulitprotein core complex that is required to trigger the DNA-damage dependent activation of the downstream FA protein, FANCD2. This activation is thought to be the key step in a DNA damage response that functionally links FA proteins to major breast cancer susceptibility proteins BRCA1 and BRCA2 (BRCA2 is FA gene FANCD1). The essential function of the FA proteins is unknown, but current models suggest that FA proteins function at the interface between cell cycle checkpoints, DNA repair and DNA replication, and are likely to play roles in the DNA damage response during S phase. To provide a platform for dissecting the key functional events during S-phase, we developed cell-free assays for FA proteins based on replicating extracts from Xenopus eggs. We identified the Xenopus homologs of human FANCD2 (xFANCD2) and several of the FA core complex proteins (xCCPs), and biochemically characterized these proteins in replicating cell-free extracts. We found that xCCPs and a modified isoform of xFANCD2 become associated with chromatin during normal and disrupted DNA replication. Blocking initiation of replication with geminin demonstrated that association of xCCPs and xFANCD2 with chromatin occurs in a strictly replication-dependent manner that is enhanced following DNA damage by crosslinking agents or by addition of aphidicolin, an inhibitor of replicative DNA polymerases. In addition, chromatin binding of xFANCD2, but not xBRCA2, is abrogated when xFANCA is quantitatively depleted from replicating extracts suggesting that xFANCA promotes the loading of xFANCD2 on chromatin. The chromatin-association of xFANCD2 and xCCPs is diminished in the presence of caffeine, an inhibitor of checkpoint kinases. Taken together, our data suggest a model in which the ordered loading of FA proteins on chromatin is required for processing a subset of DNA replication-blocking lesions that are resolved during late stages of replication.

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