GTSE1 is possibly involved in the DNA damage repair and cisplatin resistance in osteosarcoma

Abstract Background G2 and S phase-expressed-1 (GTSE1) negatively regulates the tumor-suppressive protein p53 and is potentially correlated with chemoresistance of cancer cells. This study aims to explore the effect of GTSE1 on the DNA damage repair and cisplatin (CDDP) resistance in osteosarcoma (OS). Materials and methods Expression of GTSE1 in OS was predicted in bioinformatics system GEPIA and then validated in clinically obtained tissues and acquired cell lines using RT-qPCR, immunohistochemical staining, and western blot assays. Gain- and loss-of-function studies of GTSE1 were performed in MG-63 and 143B cells to examine its function in cell cycle progression, DNA replication, and CDDP resistance. Stably transfected MG-63 cells were administrated into mice, followed by CDDP treatment to detect the role of GTSE1 in CDDP resistance in vivo. Results GTSE1 was highly expressed in patients with OS and correlated with poor survival according to the bioinformatics predictions. Elevated GTSE1 expression was detected in OS tissues and cell lines. GTSE1 silencing reduced S/G2 transition and DNA replication, and it increased the CDDP sensitivity and decreased the expression of DNA repair-related biomarkers in MG-63 cells. GTSE1 overexpression in 143B cells led to inverse trends. In vivo, downregulation of GTSE1 strengthened the treating effect of CDDP and significantly repressed growth of xenograft tumors in nude mice. However, overexpression of GTSE1 blocked the anti-tumor effect of CDDP. Conclusion This study demonstrates that GTSE1 is possibly involved in the DNA damage repair and cisplatin resistance in OS.

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SIRT7-mediated ATM deacetylation is essential for its deactivation and DNA damage repair

Science Advances ◽

10.1126/sciadv.aav1118 ◽

2019 ◽

Vol 5 (3) ◽

pp. eaav1118 ◽

Cited By ~ 19

Author(s):

Ming Tang ◽

Zhiming Li ◽

Chaohua Zhang ◽

Xiaopeng Lu ◽

Bo Tu ◽

...

Keyword(s):

Dna Damage ◽

Dna Damage Repair ◽

Class Iii ◽

Ataxia Telangiectasia Mutated ◽

Damage Repair ◽

Damage Response ◽

Late Stages

The activation of ataxia-telangiectasia mutated (ATM) upon DNA damage involves a cascade of reactions, including acetylation by TIP60 and autophosphorylation. However, how ATM is progressively deactivated after completing DNA damage repair remains obscure. Here, we report that sirtuin 7 (SIRT7)–mediated deacetylation is essential for dephosphorylation and deactivation of ATM. We show that SIRT7, a class III histone deacetylase, interacts with and deacetylates ATM in vitro and in vivo. In response to DNA damage, SIRT7 is mobilized onto chromatin and deacetylates ATM during the late stages of DNA damage response, when ATM is being gradually deactivated. Deacetylation of ATM by SIRT7 is prerequisite for its dephosphorylation by its phosphatase WIP1. Consequently, depletion of SIRT7 or acetylation-mimic mutation of ATM induces persistent ATM phosphorylation and activation, thus leading to impaired DNA damage repair. Together, our findings reveal a previously unidentified role of SIRT7 in regulating ATM activity and DNA damage repair.

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Effect of inhibition of receptor tyrosine kinase AXL by a selective small molecular inhibitor R428 (BGB321) on DNA damage repair response in ovarian cancer cells.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.e15640 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. e15640-e15640

Author(s):

Ruby Yun-Ju Huang ◽

Xun Hui Yeo ◽

Wai Leong Tam

Keyword(s):

Dna Damage ◽

Tyrosine Kinase ◽

Cell Lines ◽

Dna Damage Response ◽

Receptor Tyrosine Kinase ◽

Dna Damage Repair ◽

Damage Repair ◽

Damage Response ◽

Dna Damage Responses

e15640 Background: AXL is a receptor tyrosine kinase that is often overexpressed in many cancers. It contributes to tumor progression, metastasis and drug resistance through activating downstream signaling cascades, making it an emerging therapeutic target. The first-in-class AXL inhibitor R428 (BGB321) was approved by the FDA for the treatment of relapsed or refractory acute myeloid leukemia. R428 (BGB321) was also reported to show selective sensitivity towards ovarian cancers (OC) with a Mesenchymal (Mes) molecular subtype. Recently, a novel role of AXL in the regulation of DNA damage responses has been described. In this study, we explored further the role of AXL in mediating DNA damage responses by using OC as a disease model. Methods: OC cell lines were treated with R428. Accumulation of γH2AX positive foci was assessed for DNA damage response. Western blotting for γH2AX, ATM and ATR levels were performed. Dose response curves of ATR inhibitors were generated by treating OC cells with the fixed dose of R428 (IC20 concentration of each cell line). Results: AXL inhibition by using R428 resulted in the increase of DNA damage foci in Mes OC cells SKOV3 and HeyA8. This occurred concurrently with the up-regulation of classic DNA damage response signaling molecules such as γH2AX, ATM and ATR. The IC50 of the ATR inhibitor significantly decreased for 2-3 folds in all OC cell lines tested. AXL inhibitor R428 sensitized both BRCA-mutated and non-BRCA-mutated OC cells to a potent and highly selective ATR inhibitor. Conclusions: Our results showed that AXL inhibition rendered cells more sensitive to the inhibition of ATR, a crucial mediator for replication stress, paving ways to the rationale for potential combinatory use of AXL and DNA damage repair inhibitors.

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Paradoxical Role of AT-rich Interactive Domain 1A in Restraining Pancreatic Carcinogenesis

Cancers ◽

10.3390/cancers12092695 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2695

Author(s):

Sammy Ferri-Borgogno ◽

Sugata Barui ◽

Amberly M. McGee ◽

Tamara Griffiths ◽

Pankaj K. Singh ◽

...

Keyword(s):

Dna Damage ◽

Cell Lines ◽

Cultured Cells ◽

Dna Damage Repair ◽

Genetically Engineered ◽

Cellular Growth ◽

Loss Of Function ◽

Pdac Cell ◽

Ki 67 ◽

Damage Repair

Background & Aims: ARID1A is postulated to be a tumor suppressor gene owing to loss-of-function mutations in human pancreatic ductal adenocarcinomas (PDAC). However, its role in pancreatic pathogenesis is not clear despite recent studies using genetically engineered mouse (GEM) models. We aimed at further understanding of its direct functional role in PDAC, using a combination of GEM model and PDAC cell lines. Methods: Pancreas-specific mutant Arid1a-driven GEM model (Ptf1a-Cre; KrasG12D; Arid1af/f or “KAC”) was generated by crossing Ptf1a-Cre; KrasG12D (“KC”) mice with Arid1af/f mice and characterized histologically with timed necropsies. Arid1a was also deleted using CRISPR-Cas9 system in established human and murine PDAC cell lines to study the immediate effects of Arid1a loss in isogenic models. Cell lines with or without Arid1a expression were developed from respective autochthonous PDAC GEM models, compared functionally using various culture assays, and subjected to RNA-sequencing for comparative gene expression analysis. DNA damage repair was analyzed in cultured cells using immunofluorescence and COMET assay. Results: Retention of Arid1a is critical for early progression of mutant Kras-driven pre-malignant lesions into PDAC, as evident by lower Ki-67 and higher apoptosis staining in “KAC” as compared to “KC” mice. Enforced deletion of Arid1a in established PDAC cell lines caused suppression of cellular growth and migration, accompanied by compromised DNA damage repair. Despite early development of relatively indolent cystic precursor lesions called intraductal papillary mucinous neoplasms (IPMNs), a subset of “KAC” mice developed aggressive PDAC in later ages. PDAC cells obtained from older autochthonous “KAC” mice revealed various compensatory (“escaper”) mechanisms to overcome the growth suppressive effects of Arid1a loss. Conclusions: Arid1a is an essential survival gene whose loss impairs cellular growth, and thus, its expression is critical during early stages of pancreatic tumorigenesis in mouse models. In tumors that arise in the setting of ARID1A loss, a multitude of “escaper” mechanisms drive progression.

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Mitotic Errors Promote Genomic Instability and Leukemia in a Novel Mouse Model of Fanconi Anemia

Frontiers in Oncology ◽

10.3389/fonc.2021.752933 ◽

2021 ◽

Vol 11 ◽

Author(s):

Donna M. Edwards ◽

Dana K. Mitchell ◽

Zahi Abdul-Sater ◽

Ka-Kui Chan ◽

Zejin Sun ◽

...

Keyword(s):

Dna Damage ◽

Genomic Instability ◽

Fanconi Anemia ◽

Spindle Assembly Checkpoint ◽

Dna Damage Repair ◽

Spindle Assembly ◽

Dependent Manner ◽

Damage Repair

Fanconi anemia (FA) is a disease of genomic instability and cancer. In addition to DNA damage repair, FA pathway proteins are now known to be critical for maintaining faithful chromosome segregation during mitosis. While impaired DNA damage repair has been studied extensively in FA-associated carcinogenesis in vivo, the oncogenic contribution of mitotic abnormalities secondary to FA pathway deficiency remains incompletely understood. To examine the role of mitotic dysregulation in FA pathway deficient malignancies, we genetically exacerbated the baseline mitotic defect in Fancc-/- mice by introducing heterozygosity of the key spindle assembly checkpoint regulator Mad2. Fancc-/-;Mad2+/- mice were viable, but died from acute myeloid leukemia (AML), thus recapitulating the high risk of myeloid malignancies in FA patients better than Fancc-/-mice. We utilized hematopoietic stem cell transplantation to propagate Fancc-/-; Mad2+/- AML in irradiated healthy mice to model FANCC-deficient AMLs arising in the non-FA population. Compared to cells from Fancc-/- mice, those from Fancc-/-;Mad2+/- mice demonstrated an increase in mitotic errors but equivalent DNA cross-linker hypersensitivity, indicating that the cancer phenotype of Fancc-/-;Mad2+/- mice results from error-prone cell division and not exacerbation of the DNA damage repair defect. We found that FANCC enhances targeting of endogenous MAD2 to prometaphase kinetochores, suggesting a mechanism for how FANCC-dependent regulation of the spindle assembly checkpoint prevents chromosome mis-segregation. Whole-exome sequencing revealed similarities between human FA-associated myelodysplastic syndrome (MDS)/AML and the AML that developed in Fancc-/-; Mad2+/- mice. Together, these data illuminate the role of mitotic dysregulation in FA-pathway deficient malignancies in vivo, show how FANCC adjusts the spindle assembly checkpoint rheostat by regulating MAD2 kinetochore targeting in cell cycle-dependent manner, and establish two new mouse models for preclinical studies of AML.

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A methylation-phosphorylation switch determines Plk1 kinase activity and function in DNA damage repair

Science Advances ◽

10.1126/sciadv.aau7566 ◽

2019 ◽

Vol 5 (3) ◽

pp. eaau7566 ◽

Cited By ~ 10

Author(s):

Weizhe Li ◽

Hong-Yan Wang ◽

Xiaolu Zhao ◽

Hongguo Duan ◽

Binghua Cheng ◽

...

Keyword(s):

Dna Damage ◽

Cell Cycle Progression ◽

Kinase Activity ◽

Critical Role ◽

Dna Damage Repair ◽

Cycle Progression ◽

Sister Chromatids ◽

Damage Repair ◽

And Function

Polo-like kinase 1 (Plk1) is a crucial regulator of cell cycle progression; but the mechanism of regulation of Plk1 activity is not well understood. We present evidence that Plk1 activity is controlled by a balanced methylation and phosphorylation switch. The methyltransferase G9a monomethylates Plk1 at Lys209, which antagonizes phosphorylation of T210 to inhibit Plk1 activity. We found that the methyl-deficient Plk1 mutant K209A affects DNA replication, whereas the methyl-mimetic Plk1 mutant K209M prolongs metaphase-to-anaphase duration through the inability of sister chromatids separation. We detected accumulation of Plk1 K209me1 when cells were challenged with DNA damage stresses. Ablation of K209me1 delays the timely removal of RPA2 and RAD51 from DNA damage sites, indicating the critical role of K209me1 in guiding the machinery of DNA damage repair. Thus, our study highlights the importance of a methylation-phosphorylation switch of Plk1 in determining its kinase activity and functioning in DNA damage repair.

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Nucleolar and spindle associated protein 1 enhances chemoresistance through DNA damage repair pathway in chronic lymphocytic leukemia by binding with RAD51

Cell Death and Disease ◽

10.1038/s41419-021-04368-2 ◽

2021 ◽

Vol 12 (11) ◽

Author(s):

Yang Han ◽

Xinting Hu ◽

Xiaoya Yun ◽

Jiarui Liu ◽

Juan Yang ◽

...

Keyword(s):

Dna Damage ◽

Chronic Lymphocytic Leukemia ◽

Dna Damage Repair ◽

Chemotherapy Resistance ◽

Lymphocytic Leukemia ◽

Damage Repair ◽

G1 Phase Arrest ◽

Chromosome Attachment

AbstractNucleolar and spindle-associated protein 1 (NUSAP1) is an essential regulator of mitotic progression, spindle assembly, and chromosome attachment. Although NUSAP1 acts as an oncogene involved in the progression of several cancers, the exact role of chronic lymphocytic leukemia (CLL) remains elusive. Herein, we first discovered obvious overexpression of NUSAP1 in CLL associated with poor prognosis. Next, the NUSAP1 level was modulated by transfecting CLL cells with lentivirus. Silencing NUSAP1 inhibited the cell proliferation, promoted cell apoptosis and G0/G1 phase arrest. Mechanistically, high expression of NUSAP1 strengthened DNA damage repairing with RAD51 engagement. Our results also indicated that NUSAP1 knockdown suppressed the growth CLL cells in vivo. We further confirmed that NUSAP1 reduction enhanced the sensitivity of CLL cells to fludarabine or ibrutinib. Overall, our research investigates the mechanism by which NUSAP1 enhances chemoresistance via DNA damage repair (DDR) signaling by stabilizing RAD51 in CLL cells. Hence, NUSAP1 may be expected to be a perspective target for the treatment of CLL with chemotherapy resistance.

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LINC-PINT impedes DNA repair and enhances radiotherapeutic response by targeting DNA-PKcs in nasopharyngeal cancer

Cell Death and Disease ◽

10.1038/s41419-021-03728-2 ◽

2021 ◽

Vol 12 (5) ◽

Author(s):

You-hong Wang ◽

Zhen Guo ◽

Liang An ◽

Yong Zhou ◽

Heng Xu ◽

...

Keyword(s):

Dna Damage ◽

Nasopharyngeal Cancer ◽

Noncoding Rnas ◽

Dependent Protein Kinase ◽

Damage Repair ◽

Dependent Protein ◽

Cancer Tissues

AbstractRadioresistance continues to be the leading cause of recurrence and metastasis in nasopharyngeal cancer. Long noncoding RNAs are emerging as regulators of DNA damage and radioresistance. LINC-PINT was originally identified as a tumor suppressor in various cancers. In this study, LINC-PINT was significantly downregulated in nasopharyngeal cancer tissues than in rhinitis tissues, and low LINC-PINT expressions showed poorer prognosis in patients who received radiotherapy. We further identified a functional role of LINC-PINT in inhibiting the malignant phenotypes and sensitizing cancer cells to irradiation in vitro and in vivo. Mechanistically, LINC-PINT was responsive to DNA damage, inhibiting DNA damage repair through ATM/ATR-Chk1/Chk2 signaling pathways. Moreover, LINC-PINT increased radiosensitivity by interacting with DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and negatively regulated the expression and recruitment of DNA-PKcs. Therefore, these findings collectively support the possibility that LINC-PINT serves as an attractive target to overcome radioresistance in NPC.

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

Cancers ◽

10.3390/cancers11091289 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1289 ◽

Cited By ~ 4

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.

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PAICS contributes to gastric carcinogenesis and participates in DNA damage response by interacting with histone deacetylase 1/2

Cell Death and Disease ◽

10.1038/s41419-020-2708-5 ◽

2020 ◽

Vol 11 (7) ◽

Author(s):

Nan Huang ◽

Chang Xu ◽

Liang Deng ◽

Xue Li ◽

Zhixuan Bian ◽

...

Keyword(s):

Dna Damage ◽

Histone Deacetylase ◽

Dna Damage Response ◽

De Novo ◽

Dna Damage Repair ◽

Histone Deacetylase 1 ◽

Damage Repair ◽

Damage Response

AbstractPhosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), an essential enzyme involved in de novo purine biosynthesis, is connected with formation of various tumors. However, the specific biological roles and related mechanisms of PAICS in gastric cancer (GC) remain unclear. In the present study, we identified for the first time that PAICS was significantly upregulated in GC and high expression of PAICS was correlated with poor prognosis of patients with GC. In addition, knockdown of PAICS significantly induced cell apoptosis, and inhibited GC cell growth both in vitro and in vivo. Mechanistic studies first found that PAICS was engaged in DNA damage response, and knockdown of PAICS in GC cell lines induced DNA damage and impaired DNA damage repair efficiency. Further explorations revealed that PAICS interacted with histone deacetylase HDAC1 and HDAC2, and PAICS deficiency decreased the expression of DAD51 and inhibited its recruitment to DNA damage sites by impairing HDAC1/2 deacetylase activity, eventually preventing DNA damage repair. Consistently, PAICS deficiency enhanced the sensitivity of GC cells to DNA damage agent, cisplatin (CDDP), both in vitro and in vivo. Altogether, our findings demonstrate that PAICS plays an oncogenic role in GC, which act as a novel diagnosis and prognostic biomarker for patients with GC.

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