The lncRNA CCAT2 induces chromosomal instability through the BOP1 – Aurora Kinase B axis in cancers
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ABSTRACT:
ORGANISM(S): Mus musculus Homo sapiens
PROVIDER: GSE133590 | GEO | 2020/06/01
REPOSITORIES: GEO
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Project description:The lncRNA CCAT2 induces chromosomal instability through the BOP1 – Aurora Kinase B axis in cancers
| PRJNA551976 | ENA
Project description:Heterochromatin Protein 1 α (HP1α) associates with members of the chromosome passenger complex (CPC) during mitosis, at centromeres where it is required for full Aurora Kinase B (AURKB) activity. Conversely, recent reports have identified AURKB as the major kinase responsible for phosphorylation of HP1α at Serine 92 (S92) during mitosis. Thus, the current study was designed to better understand the functional role of this posttranslationally modified form of HP1α. We find that S92-phosphorylated HP1α is generated in cells at early prophase, localizes to centromeres, and associates with regulators of chromosome stability, such as Inner Centromere Protein, INCENP. In mouse embryonic fibroblasts, HP1α knockout alone or reconstituted with a non-phosphorylatable (S92A) HP1α mutant results in mitotic chromosomal instability characterized by the formation of anaphase/telophase chromatin bridges and micronuclei. These effects are rescued by exogenous expression of wild type HP1α or a phosphomimetic (S92D) variant. Thus, the results from the current study extend our knowledge of the role of HP1α in chromosomal stability during mitosis.
| S-EPMC6592258 | biostudies-literature
Project description:Doublecortin-like kinase 1 (DCLK1) is a serine/threonine-kinase with two doublecortin (DCX) domains. DCLK1 is associated with microtubules via DCX domains and regulates microtubule polymerization. DCLK1 is known to be expressed in cancer stem cells and provides cancer cells with tumor-initiating capacity. Accumulating clinical evidence supports that DCLK1 is associated with tumor aggressiveness and is an important prognostic marker in various human cancers. However, the mechanism, by which DCLK1 causes oncogenesis, is not yet elucidated. In this study, we showed that DCLK1 empowers human mammary epithelial MCF10A cells to form spheres under floating condition in serum-free medium, which are reminiscent of mammospheres formed by mammary epithelial stem cells. We demonstrated that DCLK1 causes chromatin instability in MCF10A cells. DCLK1 impairs DNA repairs in human colon cancer HCT116 and lung cancer H1299 cells. The kinase-negative DCLK1 mutant and the mutant that is not associated with microtubules compromise DNA repair. In conclusion, DCLK1 interferes with DNA repair and induces tumorigenesis through genomic instability and this function is independent of the kinase activity and the regulation of microtubules.
| S-EPMC6216093 | biostudies-literature
Project description:PurposeHuman papillomavirus (HPV) causes >5% of cancers, but no therapies uniquely target HPV-driven cancers.Experimental designWe tested the cytotoxic effect of 864 drugs in 16 HPV-positive and 17 HPV-negative human squamous cancer cell lines. We confirmed apoptosis in vitro and in vivo using patient-derived xenografts. Mitotic pathway components were manipulated with drugs, knockdown, and overexpression.ResultsAurora kinase inhibitors were more effective in vitro and in vivo in HPV-positive than in HPV-negative models. We hypothesized that the mechanism of sensitivity involves retinoblastoma (Rb) expression because the viral oncoprotein E7 leads to Rb protein degradation, and basal Rb protein expression correlates with Aurora inhibition-induced apoptosis. Manipulating Rb directly, or by inducing E7 expression, altered cells' sensitivity to Aurora kinase inhibitors. Rb affects expression of the mitotic checkpoint genes MAD2L1 and BUB1B, which we found to be highly expressed in HPV-positive patient tumors. Knockdown of MAD2L1 or BUB1B reduced Aurora kinase inhibition-induced apoptosis, whereas depletion of the MAD2L1 regulator TRIP13 enhanced it. TRIP13 is a potentially druggable AAA-ATPase. Combining Aurora kinase inhibition with TRIP13 depletion led to extensive apoptosis in HPV-positive cancer cells but not in HPV-negative cancer cells.ConclusionsOur data support a model in which HPV-positive cancer cells maintain a balance of MAD2L1 and TRIP13 to allow mitotic exit and survival in the absence of Rb. Because it does not affect cells with intact Rb function, this novel combination may have a wide therapeutic window, enabling the effective treatment of Rb-deficient cancers.
| S-EPMC9588713 | biostudies-literature
Project description:Background and Aims: Telomere dysfunction can increase tumor initiation by induction of chromosomal instability, but initiated tumor cells need to reactivate telomerase for genome stabilization and tumor progression. However, this concept has not been proven in vivo since appropriate mouse models were lacking. Here, we analyzed hepatocarcinogenesis (i) in a novel mouse model of inducible telomere dysfunction on a telomerase-proficient background, (ii) in telomerase knockout mice with chronic telomere dysfunction (G3 mTerc-/-), and (iii) in wild-type mice with functional telomeres and telomerase. Transient or chronic telomere dysfunction enhanced the rates of chromosomal aberrations during hepatocarcinogenesis, but only telomerase-proficient mice exhibited significantly increased rates of macroscopic tumor formation and cancer cell proliferation in response to telomere dysfunction. In contrast, telomere dysfunction resulted in pronounced accumulation of DNA damage, cell cycle arrest and apoptosis in telomerase-deficient liver tumors. Together, these data provide the first in vivo evidence that transient telomere dysfunction during early and late stages of tumorigenesis can promote chromosomal instability and carcinogenesis in telomerase-proficient mice in the absence of additional genetic checkpoint defects at germline level. RNA from liver tumors derived from from DEN treated TTD+ mice TTD- mice and RNA from normal liver 48h-72h after doxycycline induced transient telomere dysfunction in TTD+ and TTD- liver were isolated and RNA was extracted. Agilent Mouse 4x44K v2 arrays were used. DNA from liver tumors and corrresponding kidney as control derived from from DEN treated TTD+ mice, TTD- mice and mTERC-/- G3 mice was isolated and extracted using Phenol/Chloroform. Agilent Mouse 4x44K and Mouse 1x244K arrays were used.
2012-03-30 | E-GEOD-36813 | biostudies-arrayexpress
Project description:Background and Aims: Telomere dysfunction can increase tumor initiation by induction of chromosomal instability, but initiated tumor cells need to reactivate telomerase for genome stabilization and tumor progression. However, this concept has not been proven in vivo since appropriate mouse models were lacking. Here, we analyzed hepatocarcinogenesis (i) in a novel mouse model of inducible telomere dysfunction on a telomerase-proficient background, (ii) in telomerase knockout mice with chronic telomere dysfunction (G3 mTerc-/-), and (iii) in wild-type mice with functional telomeres and telomerase. Transient or chronic telomere dysfunction enhanced the rates of chromosomal aberrations during hepatocarcinogenesis, but only telomerase-proficient mice exhibited significantly increased rates of macroscopic tumor formation and cancer cell proliferation in response to telomere dysfunction. In contrast, telomere dysfunction resulted in pronounced accumulation of DNA damage, cell cycle arrest and apoptosis in telomerase-deficient liver tumors. Together, these data provide the first in vivo evidence that transient telomere dysfunction during early and late stages of tumorigenesis can promote chromosomal instability and carcinogenesis in telomerase-proficient mice in the absence of additional genetic checkpoint defects at germline level.
2012-03-31 | GSE36813 | GEO
Project description:The BRAF oncogene is mutated in 15% of sporadic colorectal cancers. Approximately half of these BRAF mutant cancers demonstrate frequent frameshift mutations termed microsatellite instability (MSI), but are diploid and chromosomally stable. BRAF wild type cancers are typically microsatellite stable (MSS) and instead acquire chromosomal instability (CIN). In these cancers, CIN is associated with a poor outcome. BRAF mutant cancers that are MSS, typically present at an advanced stage and have a particularly poor prognosis. We have previously demonstrated clinical and molecular similarities between MSS cancers with or without a BRAF mutation, and therefore hypothesised that CIN may also be frequent in BRAF mutant/MSS cancers. BRAF mutant/MSS (n?=?60), and BRAF wild type/MSS CRCs (n?=?90) were investigated for CIN using loss of heterozygosity analysis over twelve loci encompassing chromosomal regions 5q, 8p, 17p and 18q. CIN was frequent in BRAF mutant/MSS cancers (41/57, 72%), which was comparable to the rate found in BRAF wild type/MSS cancers (74/90, 82%). The greatest loss in BRAF mutant/MSS cancers occurred at 8p (26/44, 59%), and the least at 5q (19/49, 39%). CIN in BRAF mutant/MSS cancers correlated with advanced stage (AJCC III/IV: 15/17, 88%; p?=?0.02); showed high rates of co-occurrence with the CpG Island Methylator Phenotype (17/23, 74%); and CIN at 18q and 8p associated with worse survival (p?=?0.02, p<0.05). This study demonstrates that CIN commonly occurs in advanced BRAF mutant/MSS colorectal cancers where it may contribute to poorer survival, and further highlights molecular similarities occurring between these and BRAF wild type cancers.
| S-EPMC3478278 | biostudies-literature
Project description:Loss of CBX2 induces genome instability and senescence-associated chromosomal rearrangements
| PRJNA657852 | ENA
Project description:We used genome-wide microarray comparative genomic hybridization to investigate the response of control HT1080 cells and HT1080 cells infected with a lentivirus expressing eGFP, GLI2-eGFP or CCND1-RFP to challenge with methotrexate to address the question if GLI2 overexpression induces genomic instability. Keywords: aCGH Array CGH experiments of cell line genomic DNA as test samples and normal human genomic DNA as reference sample.
2009-01-05 | E-GEOD-10132 | biostudies-arrayexpress
Project description:Gastrointestinal (GI) cancers are a major cause of cancer-related deaths. During the last two decades, several studies have shown amplification and overexpression of Aurora kinase A (AURKA) in several GI malignancies. These studies demonstrated that AURKA not only plays a role in regulating cell cycle and mitosis, but also regulates a number of key oncogenic signaling pathways. Although AURKA inhibitors have moved to phase III clinical trials in lymphomas, there has been slower progress in GI cancers and solid tumors. Ongoing clinical trials testing AURKA inhibitors as a single agent or in combination with conventional chemotherapies are expected to provide important clinical information for targeting AURKA in GI cancers. It is, therefore, imperative to consider investigations of molecular determinants of response and resistance to this class of inhibitors. This will improve evaluation of the efficacy of these drugs and establish biomarker based strategies for enrollment into clinical trials, which hold the future direction for personalized cancer therapy. In this review, we will discuss the available data on AURKA in GI cancers. We will also summarize the major AURKA inhibitors that have been developed and tested in pre-clinical and clinical settings.
| S-EPMC4436812 | biostudies-literature