scholarly journals The Nexus of Endocrine Signaling and Cancer: How Steroid Hormones Influence Genomic Stability

Endocrinology ◽  
2020 ◽  
Vol 162 (1) ◽  
Author(s):  
Shinjini Ganguly ◽  
Divya Naik ◽  
Andrew Muskara ◽  
Omar Y Mian

Abstract Endocrine-driven malignancies, including breast and prostate cancer, are among the most common human cancers. The relationship between sex steroid hormones (eg, androgen, estrogen, and progesterone), their cognate receptors, and genomic stability lie at the center of endocrine-driven cancer development, progression, and therapeutic resistance. A variety of direct and indirect mechanisms have been described that link steroid hormone signaling to the loss of genomic integrity that drives early carcinogenesis. These effects are often enriched within endocrine receptor cistromes, accounting for the high proportion of mutations and rearrangements in the region of hormone response elements. In other cases, the effects are generalized and rely on a complex array of genetic, epigenetic, and metabolic interactions. Both androgen and estrogen receptors directly modulate the DNA damage response by trans-activating DNA damage response genes and redirecting the cellular repair machinery in the wake of genotoxic stress. Here we review the key mechanistic underpinnings of the relationship between sex steroid hormone receptors and genomic stability. In addition, we summarize emerging research in this area and discuss important implications for cancer prevention and treatment.

2020 ◽  
Vol 21 (21) ◽  
pp. 8273
Author(s):  
Antje M. Wengner ◽  
Arne Scholz ◽  
Bernard Haendler

Steroid hormone signaling induces vast gene expression programs which necessitate the local formation of transcription factories at regulatory regions and large-scale alterations of the genome architecture to allow communication among distantly related cis-acting regions. This involves major stress at the genomic DNA level. Transcriptionally active regions are generally instable and prone to breakage due to the torsional stress and local depletion of nucleosomes that make DNA more accessible to damaging agents. A dedicated DNA damage response (DDR) is therefore essential to maintain genome integrity at these exposed regions. The DDR is a complex network involving DNA damage sensor proteins, such as the poly(ADP-ribose) polymerase 1 (PARP-1), the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), the ataxia–telangiectasia-mutated (ATM) kinase and the ATM and Rad3-related (ATR) kinase, as central regulators. The tight interplay between the DDR and steroid hormone receptors has been unraveled recently. Several DNA repair factors interact with the androgen and estrogen receptors and support their transcriptional functions. Conversely, both receptors directly control the expression of agents involved in the DDR. Impaired DDR is also exploited by tumors to acquire advantageous mutations. Cancer cells often harbor germline or somatic alterations in DDR genes, and their association with disease outcome and treatment response led to intensive efforts towards identifying selective inhibitors targeting the major players in this process. The PARP-1 inhibitors are now approved for ovarian, breast, and prostate cancer with specific genomic alterations. Additional DDR-targeting agents are being evaluated in clinical studies either as single agents or in combination with treatments eliciting DNA damage (e.g., radiation therapy, including targeted radiotherapy, and chemotherapy) or addressing targets involved in maintenance of genome integrity. Recent preclinical and clinical findings made in addressing DNA repair dysfunction in hormone-dependent and -independent prostate and breast tumors are presented. Importantly, the combination of anti-hormonal therapy with DDR inhibition or with radiation has the potential to enhance efficacy but still needs further investigation.


2019 ◽  
Vol 47 (16) ◽  
pp. 8502-8520 ◽  
Author(s):  
Lin Zhang ◽  
Da-Qiang Li

Abstract Microrchidia family CW-type zinc finger 2 (MORC2) is a newly identified chromatin remodeling enzyme with an emerging role in DNA damage response (DDR), but the underlying mechanism remains largely unknown. Here, we show that poly(ADP-ribose) polymerase 1 (PARP1), a key chromatin-associated enzyme responsible for the synthesis of poly(ADP-ribose) (PAR) polymers in mammalian cells, interacts with and PARylates MORC2 at two residues within its conserved CW-type zinc finger domain. Following DNA damage, PARP1 recruits MORC2 to DNA damage sites and catalyzes MORC2 PARylation, which stimulates its ATPase and chromatin remodeling activities. Mutation of PARylation residues in MORC2 results in reduced cell survival after DNA damage. MORC2, in turn, stabilizes PARP1 through enhancing acetyltransferase NAT10-mediated acetylation of PARP1 at lysine 949, which blocks its ubiquitination at the same residue and subsequent degradation by E3 ubiquitin ligase CHFR. Consequently, depletion of MORC2 or expression of an acetylation-defective PARP1 mutant impairs DNA damage-induced PAR production and PAR-dependent recruitment of DNA repair proteins to DNA lesions, leading to enhanced sensitivity to genotoxic stress. Collectively, these findings uncover a previously unrecognized mechanistic link between MORC2 and PARP1 in the regulation of cellular response to DNA damage.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 10509-10509
Author(s):  
R. D. Kennedy ◽  
P. Stuckert ◽  
E. Archila ◽  
M. De LaVega ◽  
C. Chen ◽  
...  

10509 Loss of the fanconi anemia (FA) pathway function has been described in a number of sporadic tumor types including breast, ovarian, pancreatic, head and neck and hematological malignancies. Functionally, the FA pathway responds to stalled DNA replication following DNA damage. Given the importance of the FA pathway in the response to DNA damage, we hypothesized that cells deficient in this pathway may become hyper-dependent on alternative DNA damage response pathways in order to respond to endogenous genotoxic stress such as occurs during metabolism. Therefore, targeting these alternative pathways could offer therapeutic strategies in FA pathway deficient tumors. To identify new therapeutic targets we treated FA pathway competent and deficient cells with a DNA damage response siRNA library, that individually knocked out 230 genes. We identified a number of gene targets that were specifically toxic to FA pathway deficient cells, amongst which was the DNA damage response kinase Ataxia Telangiectasia Mutated (ATM). To test the requirement for ATM in FA pathway deficient cells, we interbred Fancg ± Atm± mice. Consistent with the siRNA screen result, Fancg-/- Atm-/- mice were non viable and Fancg± Atm-/- and Fancg-/- Atm ± progeny were less frequent that would have been expected. Several human cell lines with FA gene mutations were observed to have constitutive activation of ATM which was markedly reduced on correction with the appropriate wild-type FA gene. Interestingly, FA pathway deficient cells, including the FANCC mutant and FANCG mutant pancreatic cancer cell lines, were selectively sensitive to monotherapy with the ATM inhibitor KU55933, as measured by dose inhibition and colony count assays. FA pathway deficient cells also demonstrated an increased level of chromosomal breakage, cell cycle arrest and apoptosis following KU55933 treatment when compared to FA pathway corrected cells. We conclude that FA pathway deficient cells have an increased requirement for ATM activation in order to respond to sporadic DNA damage. This offers the possibility that monotherapy with ATM inhibitors could be a therapeutic strategy for tumors that are deficient for the FA pathway. No significant financial relationships to disclose.


2009 ◽  
Vol 130 (9) ◽  
pp. 637-647 ◽  
Author(s):  
Kirk Simon ◽  
Anju Mukundan ◽  
Samantha Dewundara ◽  
Holly Van Remmen ◽  
Alan A. Dombkowski ◽  
...  

2012 ◽  
Vol 445 (3) ◽  
pp. 393-401 ◽  
Author(s):  
Georgina E. Drury ◽  
Adam A. Dowle ◽  
David A. Ashford ◽  
Wanda M. Waterworth ◽  
Jerry Thomas ◽  
...  

DNA damage detection and repair take place in the context of chromatin, and histone proteins play important roles in these events. Post-translational modifications of histone proteins are involved in repair and DNA damage signalling processes in response to genotoxic stresses. In particular, acetylation of histones H3 and H4 plays an important role in the mammalian and yeast DNA damage response and survival under genotoxic stress. However, the role of post-translational modifications to histones during the plant DNA damage response is currently poorly understood. Several different acetylated H3 and H4 N-terminal peptides following X-ray treatment were identified using MS analysis of purified histones, revealing previously unseen patterns of histone acetylation in Arabidopsis. Immunoblot analysis revealed an increase in the relative abundance of the H3 acetylated N-terminus, and a global decrease in hyperacetylation of H4 in response to DNA damage induced by X-rays. Conversely, mutants in the key DNA damage signalling factor ATM (ATAXIA TELANGIECTASIA MUTATED) display increased histone acetylation upon irradiation, linking the DNA damage response with dynamic changes in histone modification in plants.


Author(s):  
Andrew M. Cobb ◽  
Syabira Yusoff ◽  
Robert Hayward ◽  
Sadia Ahmad ◽  
Mengxi Sun ◽  
...  

Objective: The development of ectopic vascular calcification is strongly linked with organismal aging, which is primarily caused by the accumulation of DNA damage over time. As Runx2 (Runt-related transcription factor 2) has been identified as a regulator of vascular smooth muscle cell osteogenic transition, a key component of vascular calcification, we examined the relationship between DNA damage and Runx2 activation. Approach and Results: We found genotoxic stress-stimulated Runx2 accumulation and transactivation of its osteogenic target genes, leading to enhanced calcification. Inhibition of DNA damage signaling attenuated this response. Runx2 localized to sites of DNA damage and participated in DNA repair by regulating phosphorylation events on histone H2AX, with exogenous expression of Runx2 resulting in unrepaired DNA damage and increased apoptosis. Mechanistically, Runx2 was PARylated in response to genotoxic stress, and inhibition of this modification disrupted its localization at DNA lesions and reduced its binding to osteogenic gene promoters. Conclusions: These data identify Runx2 as a novel component of the DNA damage response, coupling DNA damage signaling to both osteogenic gene transcription and apoptosis and providing a mechanism for accelerated mineralization in aging and chronic disease.


2020 ◽  
Vol 31 (5) ◽  
pp. 348-359 ◽  
Author(s):  
Jinrong Feng ◽  
Amjad Islam ◽  
Bjorn Bean ◽  
Jia Feng ◽  
Samantha Sparapani ◽  
...  

Fifty-six strains from the GRACE collection were found to be sensitive to MMS upon repression. Deletion of the HOF1 gene renders sensitivity to genotoxic stress. Hof1 is genetically linked to the Rad53 pathway and is down-regulated in a Rad53-dependent manner. The importance of Hof1 in MMS response is reduced in a Rad23 or Rad4 mutant strain.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1265-1265
Author(s):  
Christine von Klitzing ◽  
Florian Bassermann ◽  
Stephan W. Morris ◽  
Christian Peschel ◽  
Justus Duyster

Abstract The nuclear interaction partner of ALK (NIPA) is a nuclear protein identified by our group in a screen for NPM-ALK interaction partners. We recently reported that NIPA is an F-box protein that assembles with SKP1, Cul1 and Roc1 to establish a novel SCF-type E3 ubiquitin ligase. The formation of the SCFNIPA complex is regulated by cell cycle-dependent phosphorylation of NIPA that restricts SCFNIPA assembly from G1- to late S-phase, thus allowing its substrates to be active from late S-phase throughout mitosis. Proteins involved in cell cycle regulation frequently play a role in DNA damage checkpoints. We therefore sought to determine whether NIPA has a function in the cellular response to genotoxic stress. For this reason we treated NIH/3T3 cells with various DNA-damaging agents. Surprisingly, we observed phosphorylation of NIPA in response to some of these agents, including UV radiation. This phosphorylation was cell cycle phase independent and thus independent of the physiological cell cycle dependent phosphorylation of NIPA. The relevant phosphorylation site is identical to the respective site in the course of cell cycle-dependent phosphorylation of NIPA. Thus, phosphorylation of NIPA upon genotoxic stress would inactivate the SCFNIPA complex in a cell cycle independent manner. Interestingly, this phosphorylation site lies within a consensus site of the Chk1/Chk2 checkpoint kinases. These kinases are central to DNA damage checkpoint signaling. Chk1 is activated by ATR in response to blocked replication forks as they occur after treatment with UV. We performed experiments using the ATM/ATR inhibitor caffeine and the Chk1 inhibitor SB218078 to investigate a potential role of Chk1 in NIPA phosphorylation. Indeed, we found both inhibitors to prevent UV-induced phosphorylation of NIPA. Current experiments applying Chk1 knock-out cells will unravel the role of Chk1 in NIPA phosphorylation. Additional experiments were performed to investigate a function for NIPA in DNA-damage induced apoptosis. In this regard, we observed overexpression of NIPA WT to induce apoptosis in response to UV, whereas no proapoptotic effect was seen with the phosphorylation deficient NIPA mutant. Therefore, the phosphorylated form of NIPA may be involved in apoptotic signaling pathways. In summary, we present data suggesting a cell cycle independent function for NIPA. This activity is involved in DNA damage response and may be involved in regulating apoptosis upon genotoxic stress.


2018 ◽  
Vol 10 ◽  
pp. 175883591878665 ◽  
Author(s):  
Anna Minchom ◽  
Caterina Aversa ◽  
Juanita Lopez

Maintenance of genomic stability is a critical determinant of cell survival and relies on the coordinated action of the DNA damage response (DDR), which orchestrates a network of cellular processes, including DNA replication, DNA repair and cell-cycle progression. In cancer, the critical balance between the loss of genomic stability in malignant cells and the DDR provides exciting therapeutic opportunities. Drugs targeting DDR pathways taking advantage of clinical synthetic lethality have already shown therapeutic benefit – for example, the PARP inhibitor olaparib has shown benefit in BRCA-mutant ovarian and breast cancer. Olaparib has also shown benefit in metastatic prostate cancer in DDR-defective patients, expanding the potential biomarker of response beyond BRCA. Other agents and combinations aiming to block the DDR while pushing damaged DNA through the cell cycle, including PARP, ATR, ATM, CHK and DNA-PK inhibitors, are in development. Emerging work is also uncovering how the DDR interacts intimately with the host immune response, including by activating the innate immune response, further suggesting that clinical applications together with immunotherapy may be beneficial. Here, we review recent considerations related to the DDR from a clinical standpoint, providing a framework to address future directions and clinical opportunities.


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