Phosphorylation and chromatin tethering prevent cGAS activation during mitosis

The cyclic GMP-AMP synthase (cGAS) detects microbial and self-DNA in the cytosol to activate immune and inflammatory programs. cGAS also associates with chromatin especially after nuclear envelope breakdown when cells enter mitosis. How cGAS is regulated during cell cycle transition is not clear. Here we found direct biochemical evidence that cGAS activity was selectively suppressed during mitosis, and uncovered two parallel mechanisms underlying this suppression. First, cGAS was hyperphosphorylated at the N terminus by mitotic kinases, including Aurora kinase B. The N terminus of cGAS was critical for sensing nuclear chromatin, but not mitochondrial DNA. Chromatin sensing was blocked by hyperphosphorylation. Secondly, oligomerization of chromatin-bound cGAS, which is required for its activation,was prevented. Together, these mechanisms ensure that cGAS is inactive when associated with chromatin during mitosis, which may help to prevent autoimmune reaction.

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Inhibition of Aurora Kinase B activity disrupts development and differentiation of salivary glands

Cell Death Discovery ◽

10.1038/s41420-020-00393-w ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Abeer K. Shaalan ◽

Tathyane H. N. Teshima ◽

Abigail S. Tucker ◽

Gordon B. Proctor

Keyword(s):

Cell Cycle ◽

Embryonic Development ◽

Salivary Glands ◽

Aurora Kinase ◽

Serine Threonine Kinase ◽

Aurora Kinase B ◽

Development And Differentiation ◽

Differentiation Marker ◽

Key Events

AbstractLittle is known about the key molecules that regulate cell division during organogenesis. Here we determine the role of the cell cycle promoter aurora kinase B (AURKB) during development, using embryonic salivary glands (E-SGs) as a model. AURKB is a serine/threonine kinase that regulates key events in mitosis, which makes it an attractive target for tailored anticancer therapy. Many reports have elaborated on the role of AURKB in neoplasia and cancer; however, no previous study has shown its role during organ development. Our previous experiments have highlighted the essential requirement for AURKB during adult exocrine regeneration. To investigate if AURKB is similarly required for progression during embryonic development, we pharmacologically inhibited AURKB in developing submandibular glands (SMGs) at embryonic day (E)13.5 and E16.5, using the highly potent and selective drug Barasertib. Inhibition of AURKB interfered with the expansion of the embryonic buds. Interestingly, this effect on SMG development was also seen when the mature explants (E16.5) were incubated for 24 h with another cell cycle inhibitor Aphidicolin. Barasertib prompted apoptosis, DNA damage and senescence, the markers of which (cleaved caspase 3, γH2AX, SA-βgal and p21, respectively), were predominantly seen in the developing buds. In addition to a reduction in cell cycling and proliferation of the epithelial cells in response to AURKB inhibition, Barasertib treatment led to an excessive generation of reactive oxygen species (ROS) that resulted in downregulation of the acinar differentiation marker Mist1. Importantly, inhibition of ROS was able to rescue this loss of identity, with Mist1 expression maintained despite loss of AURKB. Together, these data identify AURKB as a key molecule in supporting embryonic development and differentiation, while inhibiting senescence-inducing signals during organogenesis.

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Elevated FoxM1 Expression Promotes Cell Cycle Progression by Induction of KIS Expression and Contributes to the Development of Leukemia Cells.

Blood ◽

10.1182/blood.v110.11.888.888 ◽

2007 ◽

Vol 110 (11) ◽

pp. 888-888 ◽

Cited By ~ 1

Author(s):

Okinaka Keiji ◽

Satoki Nakamura ◽

Isao Hirano ◽

Takaaki Ono ◽

Shinya Fujisawa ◽

...

Keyword(s):

Cell Cycle ◽

Cell Lines ◽

Leukemia Cell ◽

Aurora Kinase ◽

Leukemia Cells ◽

Clinical Samples ◽

Acute Leukemias ◽

Aurora Kinase B ◽

Leukemia Cell Lines ◽

Foxm1 Expression

Abstract [Background] FoxM1, a member of the Fox transcription factor family, plays an important cell cycle regulator of both the transition from G1 to S phase and progression to mitosis. FoxM1 expression was also found to be up-regulated in some solid tumors (basal cell carcinomas, hepatocellular carcinoma, and primary breast cancer). These results suggested that FoxM1 plays a role in the oncogenesis of malignancies. However, it is unknown whether FoxM1 expression contributes to the development or progression of leukemia cells. Therefore, we investigated how FoxM1 regulated the cell cycle of leukemia cells and the expression analysis of the FoxM1 gene in patients with acute leukemias. [Methods] The cells used in this study were human acute leukemia cell lines, U937 and YRK2 cells. Primary acute myeloblastic (25 AML (4 M1, 11 M2, 6 M4, 4 M5)) cells were obtained from the peripheral blood. Human normal mononuclear cells (MNCs) were isolated from peripheral blood (PB) of healthy volunteers after obtaining informed consents. For analysis of proliferation and mitotic regulatory proteins (p27, p21, Skp2, Cdc25B, Cyclin D1, Survivin, Aurora kinase B, and KIS) in leukemia cells, MTT assays and western blot were performed in all cell lines, which untransfected or transfected with siRNA FoxM1, respectively. For cell cycle analysis, flow cytometory analysis was performed in leukemia cells untransfected or transfected with siRNAFoxM1 by PI staining. For analysis of FoxM1 mRNA, quantitative RT-PCR was performed in all cell lines and clinical samples. [Results] In all leukemia cell lines, the expression of FoxM1B mRNA were significantly higher than normal MNCs. When transfected with the siRNA FoxM1 in leukemia cells, suppression of FoxM1 caused a mean 71% (range 62 to 80%) reduction in S phase cells and a mean 4.4-fold (range 3.2 to 5.6-fold) increase in G2/M phase cells compared to controls. MTT assay demonstrated that the proliferation of the siRNA FoxM1 transfected cells was inhibited compared to the untransfected cells. Moreover, FoxM1 knockdown by siRNA in leukemia cells reduced protein and mRNA expression of Aurora kinase B, Survivin, Cyclin D1, Skp2 and Cdc25B, while increased protein expression of p21and p27. In the clinical samples obtained from patients with acute leukemias, the FoxM1B gene was overexpressed in 22/25 (88%). The relative folds of FoxM1B gene expression were for AML: 2.83 compared to normal MNCs. [Conclusions] In this study, we report in the first time that FoxM1 is overexpressed in myeloid leukemia cells. These results demonstrated that expression of FoxM1 is an essential transcription factor for growth of leukemia cells, and regulate expression of the mitotic regulators. Moreover, we showed that FoxM1 induced the expression of KIS protein. Therefore, FoxM1 might be one of moleculer targets of therapy for acute leukemias.

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Analysis of FoxM1 Expression and Regulation of Cell Cycle, and Anti-Leukemic Effectss by FoxM1 Knockdown on Leukemia Cells Transfected with siRNA FoxM1.

Blood ◽

10.1182/blood.v108.11.4320.4320 ◽

2006 ◽

Vol 108 (11) ◽

pp. 4320-4320

Author(s):

Satoki Nakamura ◽

Takaaki Ono ◽

Yuya Sugimoto ◽

Miki Kobayashi ◽

Naohi Sahara ◽

...

Keyword(s):

Cell Cycle ◽

Cyclin D1 ◽

Cell Lines ◽

Leukemia Cell ◽

Aurora Kinase ◽

Leukemia Cells ◽

Rt Pcr ◽

Aurora Kinase B ◽

Leukemia Cell Lines ◽

Foxm1 Expression

Abstract [Background] FoxM1, a member of the Fox transcription factor family, plays an important cell cycle regulator of both the transition from G1 to S phase and progression to mitosis. FoxM1 expression was also found to be up-regulated in some solid tumors (basal cell carcinomas, hepatocellular carcinoma, and primary breast cancer). These results suggested that FoxM1 plays a role in the oncogenesis of malignancies. However, it is unknown whether FoxM1 expression contributes to the development or progression of leukemia cells. Therefore, we investigated whether and how FoxM1 regulated the cell cycle of leukemia cells. [Methods] The cells used in this study were human leukemia cell lines, K562, HL60, U937 cells. For analysis of FoxM1 mRNA, RT-PCR was performed in all cell lines. For analysis of proliferation and mitotic regulatory proteins (p27, p21, Skp2, Cdc25B, Cyclin D1, Survivin, and Aurora kinase B) in leukemia cells, MTT assays and western blot were performed in all cell lines untransfected or transfected with siRNA FoxM1, respectively. For cell cycle analysis, flow cytometory analysis was performed in leukemia cells untransfected or transfected with siRNAFoxM1 by PI staining. [Results] In all leukemia cell lines, the expression of FoxM1B mRNA were significantly higher than normal MNCs. In K562, HL60, and U937 cells transfected with the siRNA FoxM1, suppression of FoxM1 caused a mean 71% (range 62 to 80%) reduction in S phase cells and a mean 4.4-fold (range 3.2 to 5.6-fold) increase in G2/M phase cells compared to untransfected cells. MTT assay demonstrated that the proliferation of the siRNA FoxM1 transfected cells was inhibited compared to the untransfected cells at 2, 3, 4, or 5 days after siRNA FoxM1 transfection. FoxM1 has been reported to regulate transcription of essential mitotic regulatory genes. We showed that FoxM1 knockdown by siRNA in leukemia cells reduced protein and mRNA expression of Aurora kinase B, Survivin, Cyclin D1, Skp2 and Cdc25B, while increased protein expression of p21and p27 in RT-PCR and western blot analysis. [Conclusions] In this study, we report in the first time that FoxM1 is overexpressed in myeloid leukemia cells. These results demonstrated that expression of FoxM1 is an essential transcription factor for growth of leukemia cells, and regulate expression of the mitotic regulators, Cdc25B, Cyclin D1, Survivin, Aurora kinase B, and p21. Moreover, we showed that FoxM1 regulated the expression of Skp2 protein, which is known to promote degradation of the cell cycle regulator p27. Our study found that inhibition of FoxM1 expression in leukemia cells suppressed their growth in vitro. Therefore, FoxM1 might be a new potential target of therapy for leukemias. We will have further study whether the level of FoxM1 expression in leukemia cells is correlated with patient survival or sensitivity for chemotherapy.

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DIPG-79. H3K27M INDUCES EPIGENETIC AND ONCOGENIC CHANGES THAT ARE PARTIALLY REVERSED BY SMALL MOLECULE AURORA KINASE B/C INHIBITION

Neuro-Oncology ◽

10.1093/neuonc/noaa222.121 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii302-iii303

Author(s):

Hannah Chatwin ◽

Rakeb Lemma ◽

John DeSisto ◽

Aaron Knox ◽

Shelby Mestnik ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Regulation ◽

Synthetic Lethality ◽

Aurora Kinase ◽

Therapeutic Modality ◽

Rna Seq ◽

Mesenchymal Transition ◽

Aurora Kinase B ◽

Cycle Regulation ◽

H3k27m Mutation

Abstract Diffuse intrinsic pontine glioma (DIPG) is a fatal pediatric brain tumor with no curative treatments. Approximately 80% of DIPGs contain an H3K27M mutation. The implications of the mutation and how they may be targeted are not fully understood. We established an H3K27M effect-isolating model by transducing H3K27-wildtype lines (HSJD-GBM-001, normal human astrocytes) with lentiviral-packaged H3K27M. We characterized H3K27M-related changes through western blot, phenotypic assays, and RNA-seq. Drug screening of H3K27-wildtype and matched H3K27M-transduced lines was used to identify targets more effective with H3K27M present. Patient-derived pediatric glioblastoma and DIPG lines (BT-245, SU-DIPG-IV, HSJD-DIPG-007, SU-DIPG-XIII*, SF7761) were used for validation. We observed increased H3K27ac and decreased H3K27me3, as well as increased proliferative and migratory abilities, with the addition of H3K27M to H3K27-wildtype lines. RNA-seq showed downregulation of cell cycle regulation and upregulation of epithelial-mesenchymal transition. GSK1070916, an Aurora kinase B/C inhibitor, was isolated from a synthetic lethality screen with H3K27M. GSK1070916 showed strong efficacy in native H3K27M lines (IC50s=60nM-1250nM), superior to the Aurora kinase A inhibitor alisertib, to which all cell lines showed substantial resistance. Combination of both drugs was not synergistic. GSK1070916 treatment caused increased H3K27me3 and decreased H3S10ph and H3S28ph. GSK1070916 induced apoptosis and S-phase stall. The H3K27M mutation induces epigenetic, phenotypic, and cell cycle regulation changes resulting in relaxation of transcriptional controls and more aggressive growth. Aurora kinase B/C inhibition is a novel therapeutic modality for DIPG that appears capable of reversing some H3K27M-related epigenetic changes, inducing apoptosis, and repressing uncontrolled cellular division.

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Abstract 2358: Impact of MDM2 inhibition on cell cycle regulation through Aurora Kinase B - CDK1 axis in prostate cancer cells

10.1158/1538-7445.am2017-2358 ◽

2017 ◽

Author(s):

Thanigaivelan Kanagasabai ◽

Khalid Alhazzani ◽

Thiagarajan Venkatesan ◽

Sivanesan Dhandayuthapani ◽

Ali Alaseem ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Cycle ◽

Cancer Cells ◽

Cell Cycle Regulation ◽

Aurora Kinase ◽

Prostate Cancer Cells ◽

Aurora Kinase B ◽

Cycle Regulation

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Aurkb/PP1-mediated resetting of Oct4 during the cell cycle determines the identity of embryonic stem cells

eLife ◽

10.7554/elife.10877 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 24

Author(s):

Jihoon Shin ◽

Tae Wan Kim ◽

Hyunsoo Kim ◽

Hye Ji Kim ◽

Min Young Suh ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Embryonic Stem Cells ◽

Cell Cycle Progression ◽

Embryonic Stem ◽

Aurora Kinase ◽

Cycle Progression ◽

Aurora Kinase B ◽

Somatic Cell Reprogramming ◽

M Phase

Pluripotency transcription programs by core transcription factors (CTFs) might be reset during M/G1 transition to maintain the pluripotency of embryonic stem cells (ESCs). However, little is known about how CTFs are governed during cell cycle progression. Here, we demonstrate that the regulation of Oct4 by Aurora kinase b (Aurkb)/protein phosphatase 1 (PP1) during the cell cycle is important for resetting Oct4 to pluripotency and cell cycle genes in determining the identity of ESCs. Aurkb phosphorylates Oct4(S229) during G2/M phase, leading to the dissociation of Oct4 from chromatin, whereas PP1 binds Oct4 and dephosphorylates Oct4(S229) during M/G1 transition, which resets Oct4-driven transcription for pluripotency and the cell cycle. Aurkb phosphor-mimetic and PP1 binding-deficient mutations in Oct4 alter the cell cycle, effect the loss of pluripotency in ESCs, and decrease the efficiency of somatic cell reprogramming. Our findings provide evidence that the cell cycle is linked directly to pluripotency programs in ESCs.

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14-3-3 protein Bmh1 triggers short-range compaction of mitotic chromosomes by recruiting sirtuin deacetylase Hst2

10.1101/2020.06.09.142752 ◽

2020 ◽

Author(s):

Neha Jain ◽

Petra Janning ◽

Heinz Neumann

Keyword(s):

Cell Cycle ◽

Short Range ◽

Aurora Kinase ◽

List Type ◽

Mitotic Chromosomes ◽

Aurora Kinase B ◽

C Terminus ◽

Lysine Deacetylase ◽

M Phase ◽

Cycle Dependent

AbstractMitotic chromosome compaction is licensed by kinetochores in yeast. Recruitment of Aurora kinase B elicits a cascade of events starting with phosphorylation of H3 S10, which signals the recruitment of lysine deacetylase Hst2 and the removal of H4 K16ac. The unmasked H4 tails interact with the acidic patch of neighbouring nucleosomes to drive short-range compaction of chromatin. Here, we demonstrate that the interaction of Hst2 with H3 S10ph is mediated by 14-3-3 protein Bmh1. As a homodimer, Bmh1 binds simultaneously to H3 S10ph and the phosphorylated C-terminus of Hst2. The Hst2-Bmh1 interaction is cell cycle dependent, reaching its maximum in M phase. Furthermore, we show that phosphorylation of C-terminal residues of Hst2 stimulates its deacetylase activity. Hence, the data presented here identify Bmh1 as a key player in the mechanism of licensing of chromosome compaction in mitosis.Key Points14-3-3 protein Bmh1 bridges the interaction of Hst2 with phosphorylated H3 tailsHst2 is multiply phosphorylated on its unstructured C-terminal tailThe interaction of Bmh1 with Hst2 is cell cycle dependentHst2 phosphorylation enhances its enzymatic activity

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Regulation of cell cycle by MDM2 in prostate cancer cells through Aurora Kinase-B and p21WAF1/CIP1 mediated pathways

Cellular Signalling ◽

10.1016/j.cellsig.2019.109435 ◽

2020 ◽

Vol 66 ◽

pp. 109435

Author(s):

Thanigaivelan Kanagasabai ◽

Thiagarajan Venkatesan ◽

Umamaheswari Natarajan ◽

Saad Alobid ◽

Khalid Alhazzani ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Cycle ◽

Cancer Cells ◽

Aurora Kinase ◽

Prostate Cancer Cells ◽

Aurora Kinase B ◽

Regulation Of Cell Cycle

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Development and Characterization of Phospha Sugar Derivatives, DMPP and TMPP, with Anti-Leukemic Effects

Blood ◽

10.1182/blood.v112.11.5057.5057 ◽

2008 ◽

Vol 112 (11) ◽

pp. 5057-5057

Author(s):

Satoki Nakamura ◽

Mitsuji Yamashita ◽

Daisuke Yokota ◽

Isao Hirano ◽

Takaaki Ono ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Leukemia Cell ◽

Aurora Kinase ◽

Leukemia Cells ◽

Aurora Kinase B ◽

Leukemia Cell Lines ◽

Foxm1 Expression ◽

Induced Apoptosis ◽

Sugar Derivatives

Abstract [Background] Sugar derivatives, whose oxygen atom in the hemiacetal ring is replaced by a carbon, nitrogen, sulfur atom, and etc., are celled as pseudo sugars. The synthesis and bioassay of these pseudo sugars are well investigated and are known as potential bioactive materials. Phospha sugar, which is one of pseudo sugars, having a phosphorus atom instead of the oxygen atom in the hemiacetal ring, is little known. The synthesis and bioassay of phospha sugars are not well studied in detail. We synthesized the 2,3,4-tribromo-3-methyl-1-phenyl phospholane 1-oxide (TMPP) and 2,3-dibromo-3-methyl-1-phenyl phospholane 1-oxide (DMPP) by the nucleophilic substitution reactions, and found their anti-leukemic activities. [Purpose] The aims of the present study were to evaluate the inhibition of proliferation and induction of apoptosis in leukemia cell treated with TMPP or DMPP, and defines the target molecules for TMPP in leukemia cells. [Methods] The cells used in this study were human leukemia cell lines, K562, U937, and YRK2 cells. For proliferation analysis, MTT assays were performed in leukemia cells treated with TMPP. For cell cycle analysis, flow cytometory analysis was performed in leukemia cells treated with TMPP or DMPP by PI staining. For analysis of mitotic regulatory proteins (p27, p21, Skp2, Cdc25B, Cyclin D1, Survivin, and Aurora kinase B), Western blotting was performed in leukemia cells treated with TMPP. For colony analysis, the colonies of CFU-GEMM, CFU-GM, and BFU-E were counted in AML stem/progenitor cells treated with TMPP. [Results] In leukemia cell lines, DMPP and TMPP significantly inhibited the cell proliferation, and TMPP more strongly inhibited the cell proliferation than DMPP. 10 μM TMPP significantly induced G2/M phase arrest, and 25 μM TMPP induced apoptosis in leukemia cells. In leukemia cells, 10μM TMPP reduced protein of Aurora kinase B, Survivin, Cyclin D1, Skp2 KIS, and FoxM1, while increased protein expression of p21and p27 by western blot analysis. Moreover, 25μM TMPP activated caspase-3 and caspase-9, cleaved PARP, and reduced Bcl-2. Moreover, the treatment with TMPP decreased the counts of CFU-GEMM, CFU-GM and BFU-E by depletion of FoxM1 expression. [Conclusions] In this study, we report in the first time the possibility of phospha sugar derivatives as anti-leukemic agents in therapy for leukemias, and analysis of their characterizations. DMPP and TMPP significantly inhibited the proliferation, and induced apoptosis of leukemia cells. DMPP and TMPP induced cell cycle arrest by suppression of FoxM1 expression and apoptosis by Bcl-2 down-regulation in leukemia cells. Moreover, TMPP inhibited colony formation of leukemia progenitors. Therefore, TMPP has new agents with anti-leukemic effects by regulation of cell cycle and apoptosis in leukemia therapy.

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Activity of Serono-AS703569, a Dual Inhibitor of Bcr-Abl and Aurora Kinases in Bcr-Abl Transformed Cells, Is Dependent On Aurora B Inhibition, and Is Not Affected by the Presence of the Highly Imatinib Resistant Bcr-Abl Mutation T315I.

Blood ◽

10.1182/blood.v114.22.3247.3247 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3247-3247 ◽

Cited By ~ 1

Author(s):

Anna Katharina Seitz ◽

Nikolas von Bubnoff ◽

Samantha M. Sarno ◽

Christian Peschel ◽

Justus Duyster

Keyword(s):

Cell Cycle ◽

Kinase Inhibitor ◽

Conflicts Of Interest ◽

Point Mutations ◽

Aurora Kinase ◽

Aurora B ◽

Dual Inhibitor ◽

Aurora Kinases ◽

Aurora Kinase B

Abstract Abstract 3247 Poster Board III-1 The tyrosine kinase inhibitor Imatinib is the gold standard in conventional treatment of CML. However, the emergence of resistance to IM remains a major problem. Alternative therapeutic strategies of IM-resistant BCR-ABL positive leukemias are urgently needed. One promising target for anticancer therapeutics is represented by the Aurora kinase family. These serine/threonine kinases are involved in regulating multiple steps of mitosis, including formation of bipolar spindle, chromosome alignment, spindle checkpoint function and cytokinesis. We report on studies accomplished with a small molecule inhibitor AS703569 (Merck Serono), which targets Bcr-Abl and Aurora kinases A-C. We could show that AS703569 exhibited strong anti-proliferative and pro-apoptotic activity against murine BaF3- cells ectopically expressing wild type (wt) or IM-resistant BCR-ABL mutants, including those harbouring the strongly resistant T315I mutation. This effect was observed already at rather low-AS703569 concentrations, at which Aurora- but not the Bcr-Abl kinase was inhibited. Furthermore, in cell cycle analysis we observed cells with a large 4N peak and DNA content more than 4N, indicating extensive polyploidisation, a consequence of continued cell cycle progression in the absence of cell division. Recent studies have revealed that this phenotype is based on suppression of Aurora B kinase activity, indicating that Aurora B inhibition is the major effect of AS703569 in Bcr-Abl positive cells. To confirm this assumption we designed MSCV based retroviruses encoding different point mutations in the Aurora B ATP binding site, which should lead to resistance against AS703569. By this strategy we were able to identify an AS703569 resistant mutant (Aurora B G216V). This mutant shows significant resistance in vitro and is able to augment the antiproliferative capacity of AS703569 in Bcr-Abl positive cells. Taken together, our data demonstrate that anti-proliferative effects of AS703569 in Bcr-Abl positive cells are primarily mediated by functional inhibition of Aurora kinases, especially of Aurora kinase B. Since Aurora kinases are clearly implicated in tumorgenesis, they will become a high potential therapeutic target for anticancer therapy. Disclosures: No relevant conflicts of interest to declare.

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