Aurora Kinase C: Aurora kinase C is a chromosomal passenger protein that interacts with aurora kinase B in the regulation of MITOSIS. It is found primarily in GERM CELLS in the TESTIS, and may mediate CHROMOSOME SEGREGATION during SPERMATOGENESIS.Aurora Kinases: A family of highly conserved serine-threonine kinases that are involved in the regulation of MITOSIS. They are involved in many aspects of cell division, including centrosome duplication, SPINDLE APPARATUS formation, chromosome alignment, attachment to the spindle, checkpoint activation, and CYTOKINESIS.Aurora Kinase A: An aurora kinase that localizes to the CENTROSOME during MITOSIS and is involved in centrosome regulation and formation of the MITOTIC SPINDLE. Aurora A overexpression in many malignant tumor types suggests that it may be directly involved in NEOPLASTIC CELL TRANSFORMATION.Aurora Kinase B: An aurora kinase that is a component of the chromosomal passenger protein complex and is involved in the regulation of MITOSIS. It mediates proper CHROMOSOME SEGREGATION and contractile ring function during CYTOKINESIS.Protein Kinase C: An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.Protein-Serine-Threonine Kinases: A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.Centrosome: The cell center, consisting of a pair of CENTRIOLES surrounded by a cloud of amorphous material called the pericentriolar region. During interphase, the centrosome nucleates microtubule outgrowth. The centrosome duplicates and, during mitosis, separates to form the two poles of the mitotic spindle (MITOTIC SPINDLE APPARATUS).Spindle Apparatus: A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.Mitosis: A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.Aneugens: Agents which affect CELL DIVISION and the MITOTIC SPINDLE APPARATUS resulting in the loss or gain of whole CHROMOSOMES, thereby inducing an ANEUPLOIDY.Protein Kinase Inhibitors: Agents that inhibit PROTEIN KINASES.Period Circadian Proteins: Circadian rhythm signaling proteins that influence circadian clock by interacting with other circadian regulatory proteins and transporting them into the CELL NUCLEUS.Medical Oncology: A subspecialty of internal medicine concerned with the study of neoplasms.RNA Interference: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.Biotechnology: Body of knowledge related to the use of organisms, cells or cell-derived constituents for the purpose of developing products which are technically, scientifically and clinically useful. Alteration of biologic function at the molecular level (i.e., GENETIC ENGINEERING) is a central focus; laboratory methods used include TRANSFECTION and CLONING technologies, sequence and structure analysis algorithms, computer databases, and gene and protein structure function analysis and prediction.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Health Facility Merger: The combining of administrative and organizational resources of two or more health care facilities.Cystadenocarcinoma, Serous: A malignant cystic or semicystic neoplasm. It often occurs in the ovary and usually bilaterally. The external surface is usually covered with papillary excrescences. Microscopically, the papillary patterns are predominantly epithelial overgrowths with differentiated and undifferentiated papillary serous cystadenocarcinoma cells. Psammoma bodies may be present. The tumor generally adheres to surrounding structures and produces ascites. (From Hughes, Obstetric-Gynecologic Terminology, 1972, p185)Cystadenoma: A benign neoplasm derived from glandular epithelium, in which cystic accumulations of retained secretions are formed. In some instances, considerable portions of the neoplasm, or even the entire mass, may be cystic. (Stedman, 25th ed)Ovarian Neoplasms: Tumors or cancer of the OVARY. These neoplasms can be benign or malignant. They are classified according to the tissue of origin, such as the surface EPITHELIUM, the stromal endocrine cells, and the totipotent GERM CELLS.Simazine: A triazine herbicide.Ploidies: The degree of replication of the chromosome set in the karyotype.Genital Neoplasms, Female: Tumor or cancer of the female reproductive tract (GENITALIA, FEMALE).Aneuploidy: The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).Cyclooctanes: A group of compounds with an 8-carbon ring. They may be saturated or unsaturated.Tetrahydronaphthalenes: Partially saturated 1,2,3,4-tetrahydronaphthalene compounds.Polycyclic Compounds: Compounds consisting of two or more fused ring structures.

The zinc finger domain of Tzfp binds to the tbs motif located at the upstream flanking region of the Aie1 (aurora-C) kinase gene. (1/30)

Our previous studies showed that Aie1 (aurora-C), is a novel testis kinase belonging to the aurora kinase family (). In this report, we describe a testis zinc finger protein (Tzfp) that binds to the upstream flanking sequence of the Aie1 gene. The mouse Tzfp gene, mapped to chromosome 7 B2-B3, encodes a 465-amino acid transcription factor containing a conserved N-terminal BTB/POZ domain and three C-terminal PLZF-like C(2)H(2) zinc fingers. The zinc finger domain of Tzfp binds to the TGTACAGTGT motif (Tzfp binding site, termed tbs) located at the upstream flanking sequence of the Aie1 gene by gel mobility shift, DNase I footprinting, and competition analyses. When the C-terminal zinc fingers of Tzfp were fused to the transactivation domain of VP16, the chimera activated transcription of a reporter construct containing multiple copies of the tbs. In contrast, the same chimera did not activate the reporter gene when an essential nucleotide fifth C was mutated to A at the tbs. Furthermore, we showed that the N-terminal BTB/POZ domain of TZFP has a repressor activity. Taken together, our results indicate that Tzfp recognizes a sequence-specific motif (tbs) and may play a role in the regulation of the genes carrying the tbs.  (+info)

On the role of aurora-A in centrosome function. (2/30)

Mammalian aurora-A belongs to a multigenic family of mitotic serine/threonine kinases comprising two other members: aurora-B and aurora-C. In this review we will focus on aurora-A that starts to localize to centrosomes only in S phase as soon as centrioles have been duplicated, the protein is then degraded in early G1. Works in various organisms have revealed that the kinase is involved in centrosome separation, duplication and maturation as well as in bipolar spindle assembly and stability. Aurora kinases are found in all organisms in which their function has been conserved throughout evolution, namely the control of chromosome segregation. In human, aurora-A has focused a lot of attention, since its overexpression has been found to be correlated with the grade of various solid tumours. Ectopic kinase overexpression in any culture cell line leads to polyploidy and centrosome amplification. However, overexpression of aurora-A in particular cell lines such as NIH3T3 is sufficient to induce growth on soft agar. Those transformed cells form tumours when implanted in immunodeficient mice, indicating that the kinase is an oncogene.  (+info)

Direct association with inner centromere protein (INCENP) activates the novel chromosomal passenger protein, Aurora-C. (3/30)

A family of serine/threonine kinase Aurora constitutes a key regulator in the orchestration of mitotic events. The human Aurora paralogues Aurora-A, Aurora-B, and Aurora-C have a highly conserved catalytic domain. Extensive studies on the role of Aurora-A and Aurora-B have revealed distinct localizations and functions in regulating mitotic processes, whereas little is known about Aurora-C. The present study shows that human Aurora-C is a chromosomal passenger protein that forms complexes with Aurora-B and inner centromere protein (INCENP), which are known passenger proteins. We show that INCENP binds and activates Aurora-C in vivo and in vitro. Furthermore, Aurora-C co-expressed with INCENP elicits the phosphorylation of endogenous histone H3 in mammalian cells, even though this phosphorylation is not sufficient to establish chromosome condensation in interphase cells. We therefore suggest that Aurora-C is a novel chromosomal passenger protein that cooperates with Aurora-B to regulate mitotic chromosome dynamics in mammalian cells.  (+info)

Evolutionary relationships of Aurora kinases: implications for model organism studies and the development of anti-cancer drugs. (4/30)

BACKGROUND: As key regulators of mitotic chromosome segregation, the Aurora family of serine/threonine kinases play an important role in cell division. Abnormalities in Aurora kinases have been strongly linked with cancer, which has lead to the recent development of new classes of anti-cancer drugs that specifically target the ATP-binding domain of these kinases. From an evolutionary perspective, the species distribution of the Aurora kinase family is complex. Mammals uniquely have three Aurora kinases, Aurora-A, Aurora-B, and Aurora-C, while for other metazoans, including the frog, fruitfly and nematode, only Aurora-A and Aurora-B kinases are known. The fungi have a single Aurora-like homolog. Based on the tacit assumption of orthology to human counterparts, model organism studies have been central to the functional characterization of Aurora kinases. However, the ortholog and paralog relationships of these kinases across various species have not been rigorously examined. Here, we present comprehensive evolutionary analyses of the Aurora kinase family. RESULTS: Phylogenetic trees suggest that all three vertebrate Auroras evolved from a single urochordate ancestor. Specifically, Aurora-A is an orthologous lineage in cold-blooded vertebrates and mammals, while structurally similar Aurora-B and Aurora-C evolved more recently in mammals from a duplication of an ancestral Aurora-B/C gene found in cold-blooded vertebrates. All so-called Aurora-A and Aurora-B kinases of non-chordates are ancestral to the clade of chordate Auroras and, therefore, are not strictly orthologous to vertebrate counterparts. Comparisons of human Aurora-B and Aurora-C sequences to the resolved 3D structure of human Aurora-A lends further support to the evolutionary scenario that vertebrate Aurora-B and Aurora-C are closely related paralogs. Of the 26 residues lining the ATP-binding active site, only three were variant and all were specific to Aurora-A. CONCLUSIONS: In this study, we found that invertebrate Aurora-A and Aurora-B kinases are highly divergent protein families from their chordate counterparts. Furthermore, while the Aurora-A family is ubiquitous among all vertebrates, the Aurora-B and Aurora-C families in humans arose from a gene duplication event in mammals. These findings show the importance of understanding evolutionary relationships in the interpretation and transference of knowledge from studies of model organism systems to human cellular biology. In addition, given the important role of Aurora kinases in cancer, evolutionary analysis and comparisons of ATP-binding domains suggest a rationale for designing dual action anti-tumor drugs that inhibit both Aurora-B and Aurora-C kinases.  (+info)

Identification of V23RalA-Ser194 as a critical mediator for Aurora-A-induced cellular motility and transformation by small pool expression screening. (5/30)

Human Aurora kinases have three gene family members: Aurora-A, Aurora-B, and Aurora-C. It is not yet established what the specificity of these kinases are and what signals relayed by their reactions. Therefore, we employed small pool expression screening to search for downstream substrates of Aurora-A. Interestingly, all of the identified Aurora-A substrates were resistant to serve as substrates for Aurora-B or Aurora-C, suggesting that these Aurora family members may have distinct substrate specificity for propagation of diverse signaling pathways, even though they share a conserved catalytic kinase domain. Of the candidate substrates, Aurora-A could increase the functional activity of RalA. Mutational analysis revealed that RalA-Ser194 was the phosphorylation site for Aurora-A. Ectopic expression of V23RalA-WT could enhance collagen I-induced cell migration and anchorage-independent growth in Madin-Darby canine kidney (MDCK) Aurora-A stable cell lines. In contrast, overexpression of V23RalA-S194A in MDCK Aurora-A-stable cell lines abolished the intrinsic migration and transformation abilities of Aurora-A. To our knowledge, this is the first systematic search for the downstream substrates of Aurora-A kinase. Moreover, these results support the notion that Aurora-A may act in concert with V23RalA through protein phosphorylation on Ser194 to promote collagen I-induced cell motility and anchorage-independent growth in MDCK epithelial cells.  (+info)

The absence of p53 aggravates polyploidy and centrosome number abnormality induced by Aurora-C overexpression. (6/30)

Aurora-C is the third member of the aurora serine/threonine kinase family and was found only in mammals. Because Aurora-C is overexpressed in many different types of cancer cells we decided to analyze the consequences of Aurora-C overexpression in human cells. We first investigated the subcellular localization of overexpressed GFP-Aurora-C in mitosis and interphase in HeLa cells. As expected, during mitosis, we found that Aurora-C mimics Aurora-B. Surprisingly, in few interphase cells, we found that Aurora-C localized to the centrosome, like Aurora-A. We then examined the phenotype generated by Aurora-C overexpression. Basically it looked similar to the phenotypes observed after overexpression of the other Aurora kinases. We observed an augmentation of polyploid cells containing more than two centrosomes. More interestingly this phenotype was aggravated in the absence of a functional p53. Although the physiological function of Aurora-C in somatic cells remains to be clarified, our results, just like for the two other Aurora kinases, raised the question of a role of Aurora-C in the development and progression of cancer especially in the presence of mutated p53.  (+info)

Dynamic localization and functional implications of Aurora-C kinase during male mouse meiosis. (7/30)

Aurora-C was first identified during screening for kinases expressed in mouse sperm and eggs. Herein, we report for the first time the precise subcellular localization of endogenous Aurora-C during male meiotic division. The localization of Aurora-C was analyzed by immunofluorescence staining on chromosome spreads of mouse spermatocytes or in squashed seminiferous tubules. Aurora-C was first detected at clusters of chromocenters in diplotene spermatocytes and was concentrated at centromeres in metaphase I and II. Interestingly, Aurora-C was also found along the chromosome axes, including both the regions of centromeres and the chromosome arms in diakinesis. During the anaphase I/telophase I and anaphase II/telophase II transitions, Aurora-C was relocalized to the spindle midzone and midbody. A similar distribution pattern was also observed for Aurora-B during male meiotic divisions. Surprisingly, we detected no Aurora-C in mitotic spermatogonia. Furthermore, immunoprecipitation analyses revealed that INCENP associated with Aurora-C in the male testis. We propose that INCENP recruits Aurora-C (or some other factor(s) recruit INCENP and Aurora-C) to meiotic chromosomes, while Aurora-C may either work alone or cooperate with Aurora-B to regulate chromosome segregation during male meiosis.  (+info)

The human cumulus--oocyte complex gene-expression profile. (8/30)

BACKGROUND: The understanding of the mechanisms regulating human oocyte maturation is still rudimentary. We have identified transcripts differentially expressed between immature and mature oocytes and cumulus cells. METHODS: Using oligonucleotide microarrays, genome-wide gene expression was studied in pooled immature and mature oocytes or cumulus cells from patients who underwent IVF. RESULTS: In addition to known genes, such as DAZL, BMP15 or GDF9, oocytes up-regulated 1514 genes. We show that PTTG3 and AURKC are respectively the securin and the Aurora kinase preferentially expressed during oocyte meiosis. Strikingly, oocytes overexpressed previously unreported growth factors such as TNFSF13/APRIL, FGF9, FGF14 and IL4 and transcription factors including OTX2, SOX15 and SOX30. Conversely, cumulus cells, in addition to known genes such as LHCGR or BMPR2, overexpressed cell-to-cell signalling genes including TNFSF11/RANKL, numerous complement components, semaphorins (SEMA3A, SEMA6A and SEMA6D) and CD genes such as CD200. We also identified 52 genes progressively increasing during oocyte maturation, including CDC25A and SOCS7. CONCLUSION: The identification of genes that were up- and down-regulated during oocyte maturation greatly improves our understanding of oocyte biology and will provide new markers that signal viable and competent oocytes. Furthermore, genes found expressed in cumulus cells are potential markers of granulosa cell tumours.  (+info)

  • Collectively, our results are the first demonstration that the Decitabine price activity of mitotic kinases can influence cell fate decisions in mammalian preimplantation embryos and have important implications to Decitabine price assisted reproduction. (
  • Aurora kinase inhibitor ZM447439 induces apoptosis via mitochondrial pathways. (
  • The phylogenetic analysis of available Aurora sequences from different eukaryotic origins suggests that, although a plant Aurora gene has been duplicated early in the evolution of plants, the paralogs nevertheless maintained a role in cell cycle-related signal transduction pathways. (
  • The major signaling pathways activated by EGFR are the RAS-RAF-MAP kinase pathway, which is mainly involved in proliferation, and the PI3K-PTEN-AKT pathway, which is mainly involved in survival [ 16 ]. (
  • Recent findings on the interactions of Aurora kinases with tumor suppressor gene and oncogene-regulated networks as well as involvement in other nonmitotic processes such as ciliary disassembly affecting important signaling pathways and developmental disorders termed ciliopathies, have led to a greater recognition of the functional significance of these kinases in development and disease. (
  • Among the three members of the kinase family, Aurora- A, -B, and -C identified in humans, Aurora-A and -B have been reported to express at detectable levels in most proliferating somatic cells and characterized in detail for their involvement in cellular pathways relevant to cell proliferation and development of cancer-associated phenotypes. (
  • The transcripts and proteins of all three kinases are most abundant in tissues containing dividing cells. (
  • The interaction with certain proteins not only contributes to kinase activation but also governs the spatially and temporally distinct subcellular localization of the three family members. (
  • Though the first Aurora kinase inhibitor, alisertib, entered the clinic several years ago, success has been limited possibly because of inhibition of Aurora B and C as well as off-target effects on unrelated proteins. (
  • Purpose Review aberrations of insulin signaling to atypical proteins kinase C (aPKC) in muscles and liver that generate cardiovascular risk elements, including, weight problems, hypertriglyceridemia, hypercholesterolemia, insulin level of resistance and blood sugar intolerance in type 2 diabetes mellitus (T2DM), and obesity-associated metabolic symptoms (MetSyn). (
  • as well as the downstream molecule extracellular indication regulated proteins kinase (ERK) 1/2, which induced the upregulation of p53 and Bcl-2-linked X proteins, mediating the next mobile apoptosis and proliferation in IECs. (
  • Aurora B can regulate this process by acting on checkpoint proteins (Mps1, Mad, Bud). (
  • Millennium, a unit of Takeda Pharmaceutical Co. Ltd., may soon be able to add peripheral T-cell lymphoma (PTCL) to its list of cancers that can be treated with its investigational Aurora A kinase inhibitor, MLN8237 (alisertib). (
  • Besides being implicated as mitotic regulators, these three kinases have generated significant interest in the cancer research field due to their elevated expression profiles in many human cancers. (
  • In human tumor xenografts, MLN8054 induced mitotic accumulation and apoptosis, phenotypes consistent with inhibition of Aurora A. MLN8054 is a selective inhibitor of Aurora A kinase that robustly inhibits growth of human tumor xenografts and represents an attractive modality for therapeutic intervention of human cancers. (
  • The Aurora A gene is amplified and overexpressed in cancers originating from multiple tissue types ( 19 ). (
  • Here, weevaluated Aurora-A and Aurora-B mRNA expression and its prognostic relevance in a series of 87 papillary thyroid cancers (PTC), with a median follow-up of 63 months. (
  • However, differently from other human solid cancers, detection of Aurora-A or Aurora-B mRNAs is not a prognostic biomarker inPTC patients. (
  • Considering that Aurora kinase inhibitors are currently under clinical investigation in hematologic cancers, the identification of molecular events that limit the response to such agents is essential for enhancing clinical outcomes. (
  • The functional relevance of this newly discovered regulatory axis is found to be highly correlated with triple-negative breast cancer, suggesting that an inhibitor for Aurora A will be valuable in similar cancers. (
  • Additionally, Aurora A kinase plays an unexpected role in systematic tumor recurrences of glioblastoma, which opens new possibilities for selective inhibitors in treating one of the deadliest cancers. (
  • Over-expression of Aurora-A or -B protein can lead to aneuploid cells and is frequently observed in various human cancers such as prostate, breast, and esophageal cancers. (
  • Such compounds have utility in the treatment of proliferative diseases resulting from unregulated and/or disturbed kinase activity such as cancers, psoriasis, viral and bacterial infections, inflammatory and autoimmune diseases. (
  • In thyroid cancer tissues a deregulated expression of Aurora kinases has been also demonstrated, butno information regarding its possible prognostic role in differentiated thyroid cancer is available. (
  • The data reported here demonstrate that the expression of Aurora kinases is deregulated in the majority of PTC tissues, likely contributing to PTC progression. (
  • To elucidate the expression of Aurora kinases (AURK) and the anticancer effects of pan-aurora kinase inhibitor Danusertib in hepatocarcinogenesis model in C56Bl6 mice. (
  • Aurora-B is the catalytic component of the chromosomal passenger complex (CPC), which is composed of three additional non-catalytic subunits that direct its activity: survivin, inner centromere protein (INCENP) and borealin. (
  • These findings indicate that in addition to Aurora B regulating kinetochore- microtubule binding, the kinetochore also controls Aurora B recruitment to the inner centromere. (
  • Increased Aurora A expression may lead to increased kinase activity, which is thought to contribute to tumor initiation and progression ( 20 ). (
  • We therefore hypothesize that forced alterations in Aurora A expression may influence this process by acting, directly or indirectly, as an upstream regulator of BRCA1 expression, thereby preventing polyploidy and stabilizing the genome. (
  • This suspected oncogenic role of Aurora A, in addition to its essential role in mitotic progression, make it an attractive target for anticancer therapy. (