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In JoVE (1)
Other Publications (65)
- Cell Cycle (Georgetown, Tex.)
- Acta Oncologica (Stockholm, Sweden)
- The Laryngoscope
- The Journal of Biological Chemistry
- The Journal of Biological Chemistry
- The Laryngoscope
- Lancet
- Genetics
- Methods in Molecular Biology (Clifton, N.J.)
- Journal of Neurobiology
- Molecular Biology of the Cell
- Journal of Cellular Biochemistry
- Journal of Neurobiology
- Protein Science : a Publication of the Protein Society
- Journal of Cellular Biochemistry
- Chromosoma
- Journal of Cell Science
- Genesis (New York, N.Y. : 2000)
- Development (Cambridge, England)
- Ugeskrift for Laeger
- Biochimica Et Biophysica Acta
- Acta Oncologica (Stockholm, Sweden)
- Genetics
- Journal of Cell Science
- Chromosome Research : an International Journal on the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology
- Meat Science
- Genetica
- The Breast Journal
- Genetics
- Acta Oncologica (Stockholm, Sweden)
- Ugeskrift for Laeger
- Journal of Cell Science
- Breast (Edinburgh, Scotland)
- Genetics
- International Review of Cytology
- Head & Neck
- Lung Cancer (Amsterdam, Netherlands)
- Development (Cambridge, England)
- Breast Cancer Research and Treatment
- Acta Oncologica (Stockholm, Sweden)
- Development (Cambridge, England)
- The Journal of Biological Chemistry
- Methods (San Diego, Calif.)
- The Journal of Cell Biology
- Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology
- Developmental Biology
- Fly
- Developmental Dynamics : an Official Publication of the American Association of Anatomists
- Scandinavian Journal of Urology and Nephrology
- Acta Oncologica (Stockholm, Sweden)
- Integrative Psychological & Behavioral Science
- Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology
- PloS One
- Genetics
- Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology
- Chromosome Research : an International Journal on the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology
- Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology
- Genetics
- Ugeskrift for Laeger
- Oral Oncology
- Acta Oncologica (Stockholm, Sweden)
- Ugeskrift for Laeger
- Chromosoma
- Journal of Cell Science
- Oral Oncology
Articles by Jorgen Johansen in JoVE
Preparation of Drosophila Polytene Chromosome Squashes for Antibody Labeling
Weili Cai, Ye Jin, Jack Girton, Jorgen Johansen, Kristen M. Johansen
Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University
This video protocol illustrates the squash technique used in the Johansen laboratory to prepare Drosophila polytene chromosomes for antibody labeling.
Other articles by Jorgen Johansen on PubMed
Recent Glimpses of the Elusive Spindle Matrix
Cell Cycle (Georgetown, Tex.). Sep-Oct, 2002 | Pubmed ID: 12461290
A stationary spindle matrix has been proposed on theoretical grounds to help mediate force production at the mitotic spindle. Direct molecular evidence for the existence of such a matrix has the potential to profoundly influence our view of the molecular mechanisms leading to chromosome segregation during mitosis. Three recent papers suggest that the spindle matrix may be more than a theoretical idea.
Cosmetic Outcome and Breast Morbidity in Breast-conserving Treatment--results from the Danish DBCG-82TM National Randomized Trial in Breast Cancer
Acta Oncologica (Stockholm, Sweden). 2002 | Pubmed ID: 12234030
A total of 266 recurrence-free breast cancer patients from the randomized DBCG-82TM breast conservation trial were called in for a follow-up investigation to study the impact of surgical and radiation treatment factors on the cosmetic and functional outcome after breast conservation. The patients were interviewed and examined after a median follow-up time of 6.6 years, and 194 of them (73%) regarded the cosmetic result as excellent or good. Morbidity assessments showed that breast fibrosis, skin telangiectasia, and breast retraction were significantly associated with a less satisfactory cosmetic result. On univariate analysis, it was found that treatment with a direct anterior electron field produced more morbidity and inferior cosmetic outcomes compared with tangential photon treatment, while increasing breast size was associated with increased breast retraction and breast fibrosis. Treatment characteristics that emerged as independent prognostic factors of a poor cosmetic outcome on multivariate analysis were the use of a direct anterior electron field (OR = 2.15, CI 1.25-3.70) and adjuvant systemic therapy (OR = 2.13, 1.22-3.71). A significant but relatively low level of concordance was found between the patients' and the clinician's evaluations of cosmetic results but self-assessments of breast morbidity and psychological distress were significantly related to the observed treatment-induced side effects after breast-conserving treatment, indicating that subjective perceptions and observations as reported by the patients are relevant for the identification of treatment factors that impact on normal tissue reactions.
Implication of 18F-fluoro-2-deoxy-D-glucose Positron Emission Tomography on Management of Carcinoma of Unknown Primary in the Head and Neck: a Danish Cohort Study
The Laryngoscope. Nov, 2002 | Pubmed ID: 12439171
To demonstrate the efficacy of whole-body 18F-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) in the detection of a carcinoma of unknown primary after conventional diagnostic workup in patients with a metastatic neck lesion and to demonstrate how the treatment policy of wide-field irradiation can be safely modified in relation to the findings from PET scanning.
Proteolytic Cleavage of the Ectodomain of the L1 CAM Family Member Tractin
The Journal of Biological Chemistry. Feb, 2003 | Pubmed ID: 12446717
Tractin is a member of the L1 family of cell adhesion molecules in leech. Immunoblot analysis suggests that Tractin is constitutively cleaved in vivo at a proteolytic site with the sequence RKRRSR. This sequence conforms to the consensus sequence for cleavage by members of the furin family of convertases, and this proteolytic site is shared by a majority of other L1 family members. We provide evidence with furin-specific inhibitor experiments, by site-specific mutagenesis of Tractin constructs expressed in S2 cells, as well as by Tractin expression in furin-deficient LoVo cells that a furin convertase is the likely protease mediating this processing. Cross-immunoprecipitations with Tractin domain-specific antibodies suggest that the resulting NH(2)- and COOH-terminal cleavage fragments interact with each other and that this interaction provides a means for the NH(2)-terminal fragment to be tethered to the membrane. Furthermore, in S2 cell aggregation assays we show that the NH(2)-terminal fragment is necessary for homophilic adhesion and that cells expressing only the transmembrane COOH-terminal fragment are non-adhesive. However, tethering of exogeneously provided Tractin NH(2)-terminal fragment to S2 cells expressing only the COOH-terminal fragment can functionally restore the adhesive properties of Tractin.
A Developmentally Regulated Splice Variant from the Complex Lola Locus Encoding Multiple Different Zinc Finger Domain Proteins Interacts with the Chromosomal Kinase JIL-1
The Journal of Biological Chemistry. Mar, 2003 | Pubmed ID: 12538650
Using a yeast two-hybrid screen we have identified a novel isoform of the lola locus, Lola zf5, that interacts with the chromosomal kinase JIL-1. We characterized the lola locus and provide evidence that it is a complex locus from which at least 17 different splice variants are likely to be generated. Fifteen of these each have a different zinc finger domain, whereas two are without. This potential for expression of multiple gene products suggests that they serve diverse functional roles in different developmental contexts. By Northern and Western blot analyses we demonstrate that the expression of Lola zf5 is developmentally regulated and that it is restricted to early embryogenesis. Immunocytochemical labeling with a Lola zf5-specific antibody of Drosophila embryos indicates that Lola zf5 is localized to nuclei. Furthermore, by creating double-mutant flies we show that a reduction of Lola protein levels resulting from mutations in the lola locus acts as a dominant modifier of a hypomorphic JIL-1 allele leading to an increase in embryonic viability. Thus, genetic interaction assays provide direct evidence that gene products from the lola locus function within the same pathway as the chromosomal kinase JIL-1.
Parotid Carcinoma: Impact of Clinical Factors on Prognosis in a Histologically Revised Series
The Laryngoscope. Aug, 2003 | Pubmed ID: 12897568
To analyze clinical data and possible prognostic factors of patients with primary carcinoma of the parotid gland.
Five Compared with Six Fractions Per Week of Conventional Radiotherapy of Squamous-cell Carcinoma of Head and Neck: DAHANCA 6 and 7 Randomised Controlled Trial
Lancet. Sep, 2003 | Pubmed ID: 14511925
Although head and neck cancer can be cured by radiotherapy, the optimum treatment time for locoregional control is unclear. We aimed to find out whether shortening of treatment time by use of six instead of five radiotherapy fractions per week improves the tumour response in squamous-cell carcinoma.
Genetic and Phenotypic Analysis of Alleles of the Drosophila Chromosomal JIL-1 Kinase Reveals a Functional Requirement at Multiple Developmental Stages
Genetics. Nov, 2003 | Pubmed ID: 14668387
In this study we provide a cytological and genetic characterization of the JIL-1 locus in Drosophila. JIL-1 is an essential chromosomal tandem kinase and in JIL-1 null animals chromatin structure is severely perturbed. Using a range of JIL-1 hypomorphic mutations, we show that they form an allelic series. JIL-1 has a strong maternal effect and JIL-1 activity is required at all stages of development, including embryonic, larval, and pupal stages. Furthermore, we identified a new allele of JIL-1, JIL-1(h9), that encodes a truncated protein missing COOH-terminal sequences. Remarkably, the truncated JIL-1 protein can partially restore viability without rescuing the defects in polytene chromosome organization. This suggests that sequences within this region of JIL-1 play an important role in establishing and/or maintaining normal chromatin structure. By analyzing the effects of JIL-1 mutations we provide evidence that JIL-1 function is necessary for the normal progression of several developmental processes at different developmental stages such as oogenesis and segment specification. We propose that JIL-1 may exert such effects by a general regulation of chromatin structure affecting gene expression.
Studying Nuclear Organization in Embryos Using Antibody Tools
Methods in Molecular Biology (Clifton, N.J.). 2004 | Pubmed ID: 14707349
Leech Filamin and Tractin: Markers for Muscle Development and Nerve Formation
Journal of Neurobiology. Sep, 2004 | Pubmed ID: 15281074
The Lan3-14 and Laz10-1 monoclonal antibodies recognize a 400 kDa antigen that is specifically expressed by all muscle cells in leech. We show that the antigen recognized by both antibodies is a member of the filamin family of actin binding proteins. Leech filamin has two calponin homology domains and 35 filamin/ABP-repeat domains. In addition, we used the Laz10-1 antibody to characterize the development of the segmentally iterated dorsoventral flattener muscles. We demonstrate that the dorsoventral flattener muscle develops as three discrete bundles of myofibers and that CNS axons pioneering the DP nerve extend only along the middle bundle. Interestingly, the middle dorsoventral muscle anlage is associated with only non-neuronal expression of the L1-family cell adhesion molecule Tractin. This expression is transient and occurs at the precise developmental stages when DP nerve formation takes place. Based on these findings we propose that the middle dorsoventral muscle anlagen provides a substrate for early axonal outgrowth and nerve formation and that this function may be associated with differential expression of distinct cell adhesion molecules.
Megator, an Essential Coiled-coil Protein That Localizes to the Putative Spindle Matrix During Mitosis in Drosophila
Molecular Biology of the Cell. Nov, 2004 | Pubmed ID: 15356261
We have used immunocytochemistry and cross-immunoprecipitation analysis to demonstrate that Megator (Bx34 antigen), a Tpr ortholog in Drosophila with an extended coiled-coil domain, colocalizes with the putative spindle matrix proteins Skeletor and Chromator during mitosis. Analysis of P-element mutations in the Megator locus showed that Megator is an essential protein. During interphase Megator is localized to the nuclear rim and occupies the intranuclear space surrounding the chromosomes. However, during mitosis Megator reorganizes and aligns together with Skeletor and Chromator into a fusiform spindle structure. The Megator metaphase spindle persists in the absence of microtubule spindles, strongly implying that the existence of the Megator-defined spindle does not require polymerized microtubules. Deletion construct analysis in S2 cells indicates that the COOH-terminal part of Megator without the coiled-coil region was sufficient for both nuclear as well as spindle localization. In contrast, the NH2-terminal coiled-coil region remains in the cytoplasm; however, we show that it is capable of assembling into spherical structures. On the basis of these findings we propose that the COOH-terminal domain of Megator functions as a targeting and localization domain, whereas the NH2-terminal domain is responsible for forming polymers that may serve as a structural basis for the putative spindle matrix complex.
Chromator, a Novel and Essential Chromodomain Protein Interacts Directly with the Putative Spindle Matrix Protein Skeletor
Journal of Cellular Biochemistry. Nov, 2004 | Pubmed ID: 15389869
We have used a yeast two-hybrid interaction assay to identify Chromator, a novel chromodomain containing protein that interacts directly with the putative spindle matrix protein Skeletor. Immunocytochemistry demonstrated that Chromator and Skeletor show extensive co-localization throughout the cell cycle. During interphase Chromator is localized on chromosomes to interband chromatin regions in a pattern that overlaps that of Skeletor. However, during mitosis both Chromator and Skeletor detach from the chromosomes and align together in a spindle-like structure. Deletion construct analysis in S2 cells showed that the COOH-terminal half of Chromator without the chromodomain was sufficient for both nuclear as well as spindle localization. Analysis of P-element mutations in the Chromator locus shows that Chromator is an essential protein. Furthermore, RNAi depletion of Chromator in S2 cells leads to abnormal microtubule spindle morphology and to chromosome segregation defects. These findings suggest that Chromator is a nuclear protein that plays a role in proper spindle dynamics during mitosis.
D-Hillarin, a Novel W180-domain Protein, Affects Cytokinesis Through Interaction with the Septin Family Member Pnut
Journal of Neurobiology. Aug, 2005 | Pubmed ID: 15818553
By database searches of the Drosophila genome project we have identified D-hil as the fly member of a novel family of W180-domain containing proteins. Immunocytochemistry demonstrated that D-hil is localized to the neuropil of the embryonic CNS, to the cellular cortex of dividing neuroblasts from larval brains, and that it is up-regulated in the cleavage furrow of S2 cells. We show that D-hil distribution overlaps extensively with that of the septin family member Pnut. Cross-immunoprecipitation experiments further indicated that the two proteins may be members of the same protein complex. Analysis of a severe hypomorphic P-element mutation in the D-hil locus suggested that D-hil is a nonessential protein. However, by creating double mutant flies we show that the D-hil locus acts as a modulator of Pnut function by increasing the level of polyploidy of neuroblasts in Pnut(KG00478)/Pnut(KG00478) larval brains. Based on these results we propose that D-hil may function as a regulator of septin function during cytokinesis in the developing nervous system.
Solution Structure and Backbone Dynamics of Calsensin, an Invertebrate Neuronal Calcium-binding Protein
Protein Science : a Publication of the Protein Society. Jul, 2005 | Pubmed ID: 15937283
Calsensin is an EF-hand calcium-binding protein expressed by a subset of peripheral sensory neurons that fasciculate into a single tract in the leech central nervous system. Calsensin is a 9-kD protein with two EF-hand calcium-binding motifs. Using multidimensional NMR spectroscopy we have determined the solution structure and backbone dynamics of calcium-bound Calsensin. Calsensin consists of four helices forming a unicornate-type four-helix bundle. The residues in the third helix undergo slow conformational exchange indicating that the motion of this helix is associated with calciumbinding. The backbone dynamics of the protein as measured by (15)N relaxation rates and heteronuclear NOEs correlate well with the three-dimensional structure. Furthermore, comparison of the structure of Calsensin with other members of the EF-hand calcium-binding protein family provides insight into plausible mechanisms of calcium and target protein binding.
EAST Interacts with Megator and Localizes to the Putative Spindle Matrix During Mitosis in Drosophila
Journal of Cellular Biochemistry. Aug, 2005 | Pubmed ID: 15962301
We have used immunocytochemistry to demonstrate that the EAST protein in Drosophila, which forms an expandable nuclear endoskeleton at interphase, redistributes during mitosis to colocalize with the spindle matrix proteins, Megator and Skeletor. EAST and Megator also colocalize to the intranuclear space surrounding the chromosomes at interphase. EAST is a novel protein that does not have any previously characterized motifs or functional domains. However, we show by immunoprecipitation experiments that EAST is likely to molecularly interact with Megator which has a large NH2-terminal coiled-coil domain with the capacity for self assembly. On the basis of these findings, we propose that Megator and EAST interact to form a nuclear endoskeleton and as well are important components of the putative spindle matrix complex during mitosis.
The JIL-1 Kinase Regulates the Structure of Drosophila Polytene Chromosomes
Chromosoma. Aug, 2005 | Pubmed ID: 15986206
The JIL-1 kinase localizes to interband regions of Drosophila polytene chromosomes and phosphorylates histone H3 Ser10. Analysis of JIL-1 hypomorphic alleles demonstrated that reduced levels of JIL-1 protein lead to global changes in polytene chromatin structure. Here we have performed a detailed ultrastructural and cytological analysis of the defects in JIL-1 mutant chromosomes. We show that all autosomes and the female X chromosome are similarly affected, whereas the defects in the male X chromosome are qualitatively different. In polytene autosomes, loss of JIL-1 leads to misalignment of interband chromatin fibrils and to increased ectopic contacts between nonhomologous regions. Furthermore, there is an abnormal coiling of the chromosomes with an intermixing of euchromatic regions and the compacted chromatin characteristic of banded regions. In contrast, coiling of the male X polytene chromosome was not observed. Instead, the shortening of the male X chromosome appeared to be caused by increased dispersal of the chromatin into a diffuse network without any discernable banded regions. To account for the observed phenotypes we propose a model in which JIL-1 functions to establish or maintain the parallel alignment of interband chromosome fibrils as well as to repress the formation of contacts and intermingling of nonhomologous chromatid regions.
The JIL-1 Kinase Interacts with Lamin Dm0 and Regulates Nuclear Lamina Morphology of Drosophila Nurse Cells
Journal of Cell Science. Nov, 2005 | Pubmed ID: 16254246
We have used a yeast two-hybrid screen to identify lamin Dm0 as an interaction partner for the nuclear JIL-1 kinase. This molecular interaction was confirmed by GST-fusion protein pull-down assays and by co-immunoprecipitation experiments. Using deletion construct analysis we show that a predicted globular domain of the basic region of the COOH-terminal domain of JIL-1 was sufficient for mediating the molecular interactions with lamin Dm0. A reciprocal analysis with truncated lamin Dm0 constructs showed that the interaction with JIL-1 required sequences in the tail domain of lamin Dm0 that include the Ig-like fold. Further support for a molecular interaction between JIL-1 and lamin Dm0 in vivo was provided by genetic interaction assays. We show that nuclear positioning and lamina morphology were abnormal in JIL-1 mutant egg chambers. The most common phenotypes observed were abnormal nurse cell nuclear lamina protrusions through the ring canals near the oocyte, as well as dispersed and mislocalized lamin throughout the egg chamber. These phenotypes were completely rescued by a full-length JIL-1 transgenic construct. Thus, our results suggest that the JIL-1 kinase is required to maintain nuclear morphology and integrity of nurse cells during oogenesis and that this function may be linked to molecular interactions with lamin Dm0.
JIL-1 Kinase, a Member of the Male-specific Lethal (MSL) Complex, is Necessary for Proper Dosage Compensation of Eye Pigmentation in Drosophila
Genesis (New York, N.Y. : 2000). Dec, 2005 | Pubmed ID: 16307450
The upregulation of the JIL-1 kinase on the male X chromosome and its association with the male-specific lethal (MSL) complex suggest that JIL-1 may play a role in regulating dosage compensation. To directly test this hypothesis we measured eye pigment levels of mutants in the X-linked white gene in an allelic series of JIL-1 hypomorphic mutants. We show that dosage compensation of w(a) alleles that normally do exhibit dosage compensation was severely impaired in the JIL-1 mutant backgrounds. As a control we also examined a hypomorphic white allele w(e) that fails to dosage compensate in males due to a pogo element insertion. In this case the relative pigment level measured in males as compared to females remained approximately the same even in the most severe JIL-1 hypomorphic background. These results indicate that proper dosage compensation of eye pigment levels in males controlled by X-linked white alleles requires normal JIL-1 function.
The JIL-1 Histone H3S10 Kinase Regulates Dimethyl H3K9 Modifications and Heterochromatic Spreading in Drosophila
Development (Cambridge, England). Jan, 2006 | Pubmed ID: 16339185
In this study, we show that a reduction in the levels of the JIL-1 histone H3S10 kinase results in the spreading of the major heterochromatin markers dimethyl H3K9 and HP1 to ectopic locations on the chromosome arms, with the most pronounced increase on the X chromosomes. Genetic interaction assays demonstrated that JIL-1 functions in vivo in a pathway that includes Su(var)3-9, which is a major catalyst for dimethylation of the histone H3K9 residue, HP1 recruitment, and the formation of silenced heterochromatin. We further provide evidence that JIL-1 activity and localization are not affected by the absence of Su(var)3-9 activity, suggesting that JIL-1 is upstream of Su(var)3-9 in the pathway. Based on these findings, we propose a model where JIL-1 kinase activity functions to maintain euchromatic regions by antagonizing Su(var)3-9-mediated heterochromatization.
Mapping the Ca2+ -dependent Binding of an Invertebrate Homolog of Protein Phosphatase 4 Regulatory Subunit 2 to the Small EF-hand Protein, Calsensin
Biochimica Et Biophysica Acta. Mar, 2006 | Pubmed ID: 16600403
The EF-hand family of calcium-binding proteins regulates cellular signal transduction events via calcium-dependent interactions with target proteins. Here, we show that the COOH-terminal tail of the leech homolog of protein phosphatase 4 regulatory subunit 2 (PP4-R2) interacts with the small neuronal EF-hand calcium-binding protein, Calsensin, in a calcium-dependent manner. Using two-dimensional NMR spectroscopy and chemical shift perturbations we have identified and mapped the residues of Calsensin that form a binding surface for PP4-R2. We show that the binding groove is formed primarily of discontinuous hydrophobic residues located in helix 1, the hinge region, and helix 4 of the unicornate-type four helix structure of Calsensin. The findings suggest the possibility that calcium-dependent modulation of phosphatase complexes through interactions with small calcium-binding proteins may be a general mechanism for regulation of signal transduction pathways.
The Danish National Guidelines for Treatment of Oral Squamous Cell Carcinoma
Acta Oncologica (Stockholm, Sweden). 2006 | Pubmed ID: 16644572
The treatment strategy for oral squamous cell carcinoma in Denmark has traditionally varied between the different head and neck oncology centres. A study group within the Danish Society for Head and Neck Oncology (DSHHO) was formed with the aim of optimising and standardising the treatment strategy. The approach was to use single modality treatment for stage I, stage II and some stage III and combined modality treatment for stage III and IV. Surgery was the preferred treatment when it was considered possible to perform a radical excision of the tumour and possible lymph node metastases with acceptable aesthetic and functional outcome. The implementation of a recognised national guideline facilitates prospective studies on a large well-characterised cohort. This increases the possibility of obtaining valid data on parameters such as morbidity, loco-regional control and survival. In addition the establishment of a reference program facilitates national monitoring of the treatment using defined indicators and standards.
Loss-of-function Alleles of the JIL-1 Kinase Are Strong Suppressors of Position Effect Variegation of the Wm4 Allele in Drosophila
Genetics. Aug, 2006 | Pubmed ID: 16702418
In this article we show that hypomorphic loss-of-function alleles of the JIL-1 histone H3S10 kinase are strong suppressors of position effect variegation (PEV) of the wm4 allele and that lack of JIL-1 activity can counteract the effect of the dominant enhancer Evar2-1 on PEV.
The Chromodomain Protein, Chromator, Interacts with JIL-1 Kinase and Regulates the Structure of Drosophila Polytene Chromosomes
Journal of Cell Science. Jun, 2006 | Pubmed ID: 16723739
In this study we have generated two new hypomorphic Chro alleles and analyzed the consequences of reduced Chromator protein function on polytene chromosome structure. We show that in Chro(71)/Chro(612) mutants the polytene chromosome arms were coiled and compacted with a disruption and misalignment of band and interband regions and with numerous ectopic contacts connecting non-homologous regions. Furthermore, we demonstrate that Chromator co-localizes with the JIL-1 kinase at polytene interband regions and that the two proteins interact within the same protein complex. That both proteins are necessary and may function together is supported by the finding that a concomitant reduction in JIL-1 and Chromator function synergistically reduces viability during development. Overlay assays and deletion construct analysis suggested that the interaction between JIL-1 and Chromator is direct and that it is mediated by sequences in the C-terminal domain of Chromator and by the acidic region within the C-terminal domain of JIL-1. Taken together these findings indicate that Chromator and JIL-1 interact in an interband-specific complex that functions to establish or maintain polytene chromosome structure in Drosophila.
Regulation of Chromatin Structure by Histone H3S10 Phosphorylation
Chromosome Research : an International Journal on the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology. 2006 | Pubmed ID: 16821135
The epigenetic phospho-serine 10 modification of histone H3 has been a puzzle due to its association with two apparently opposed chromatin states. It is found at elevated levels on the highly condensed, transcriptionally inactive mitotic chromosomes yet is also correlated with the more extended chromatin configuration of active genes, euchromatic interband regions, and activated heat shock puffs of Drosophila polytene chromosomes. In addition, phosphorylation of histone H3S10 is up-regulated on the hypertranscribed male X chromosome. Here we review the cellular effects of histone H3S10 phosphorylation and discuss a model for its involvement in regulating chromatin organization and heterochromatization that would be applicable to both interphase and mitotic chromosomes.
Validation of the EUROP System for Lamb Classification in Norway; Repeatability and Accuracy of Visual Assessment and Prediction of Lamb Carcass Composition
Meat Science. Nov, 2006 | Pubmed ID: 22063054
The EUROP classification system is based on visual assessment of carcass conformation and fatness. The first objective was to test the EUROP classification repeatability and accuracy of the national senior assessors of the system in Norway. The second objective was to test the accuracy of the trained and certified abattoir EUROP classifiers in Norway relative to EU Commission's supervising assessors. The third and final objective was to test the accuracy of the EUROP classification system, as assessed by the National senior assessors, for prediction of lean meat, fat and bone percentage and lean meat in relation to bone ratio. The results showed that the repeatability and accuracy of the national senior assessors was good, achieving high correlations both for conformation and fatness. For the abattoir assessors, there were some systematic differences compared to EU Commission's assessors, but these differences were within limits accepted by EU Commission. The relationship between abattoir and national senior assessors was good, with only small systematic differences. This may suggest that there also is a systematic difference between the national senior assessors of the system and EU Commission's assessors. The EUROP system predicted lean meat percentage poorly (R(2)=0.407), with a prediction error for 3.027% lean. For fat and bone percentage, the results showed a fairly good prediction of fat percentage, but poorer for bone percentage, R(2)=0.796 and R(2)=0.450, respectively. The prediction error for fat and bone percentage was 2.300% and 2.125%, respectively. Lean: bone ratio was predicted poorly (R(2)=0.212), with a prediction error of 0.363 lean: bone ratio.
The Lamin Dm0 Allele Ari3 Acts As an Enhancer of Position Effect Variegation of the Wm4 Allele in Drosophila
Genetica. Mar, 2007 | Pubmed ID: 16897461
The association of lamin and lamin binding proteins with peripheral heterochromatin suggests the possibility that lamins may influence gene expression by participating in the epigenetic regulation of chromatin stucture. To test this hypothesis we have examined the effect of a recently generated partial loss-of-function lamin Dm0 allele Ari3 on PEV of the wm4 allele in the Drosophila eye. The Lam ( Ari3 ) allele is characterized by a truncation of the COOH-terminal domain and lacks the CaaX box that localizes lamin to the inner nuclear membrane. We show that the Lam ( Ari3 ) allele strongly increased silencing of wm4 expression, thus acting as an enhancer of PEV. These results indicate that lamins may be involved in regulating gene silencing and heterochromatic spreading at the wm4 locus and provide evidence that lamins may contribute to the regulation of higher-order chromatin organization.
Factors Determining Esthetic Outcome After Breast Cancer Conservative Treatment
The Breast Journal. Mar-Apr, 2007 | Pubmed ID: 17319854
The aim of this study was to evaluate the factors that determine esthetic outcome after breast cancer conservative treatment, based on a consensual classification obtained with an international consensus panel. Photographs were taken from 120 women submitted to conservative unilateral breast cancer surgery (with or without axillary surgery) and radiotherapy. The images were sent to a panel of observers from 13 different countries and consensus on the classification of esthetic result (recorded as excellent, good, fair or poor) was obtained in 113 cases by means of a Delphi method. For each patient, data were collected retrospectively regarding patient characteristics, tumor, and treatment factors. Univariate and multivariate analysis were used to evaluate the correlation between these factors and overall cosmetic results. On univariate analysis, younger and thinner patients as well as patients with lower body mass index (BMI) and premenopausal status obtained better cosmetic results. In the group of tumor- and treatment-related factors, larger removed specimens, clearly visible scars, the use of chemotherapy and longer follow-up period were associated with less satisfactory results. On multivariate analysis, only BMI and scar visibility maintained a significant association with cosmesis. BMI and scar visibility are the only factors significantly associated with cosmetic results of breast cancer conservative treatment, as evaluated by an international consensus panel.
Loss-of-function Alleles of the JIL-1 Histone H3S10 Kinase Enhance Position-effect Variegation at Pericentric Sites in Drosophila Heterochromatin
Genetics. Jun, 2007 | Pubmed ID: 17435241
In this study we show that loss-of-function alleles of the JIL-1 histone H3S10 kinase act as enhancers of position-effect variegation at pericentric sites whereas the gain-of-function JIL-1(Su(var)3-1[3]) allele acts as a suppressor strongly supporting a functional role for JIL-1 in maintaining euchromatic chromatin and counteracting heterochromatic spreading and gene silencing.
Effect of Adjuvant Systemic Treatment on Cosmetic Outcome and Late Normal-tissue Reactions After Breast Conservation
Acta Oncologica (Stockholm, Sweden). 2007 | Pubmed ID: 17497320
To investigate whether adjuvant treatment with CMF or tamoxifen predisposes to an unfavorable cosmetic outcome or increased breast morbidity after radiotherapy in breast conservation. Data from 266 patients who entered a randomized breast conservation trial (DBCG-82TM protocol) was analyzed. The patients were treated with lumpectomy and axillary dissection followed by external beam radiotherapy to the residual breast. High-risk patients (n = 94), as well as 31 low-risk patients, received additional radiation to the regional lymph nodes. Adjuvant systemic treatment was given to all high-risk patients: premenopausal patients (n = 67) received eight cycles of CMF intravenously (600/40/600 mg per m2) every fourth week; postmenopausal patients (n = 27) received 30 mg of tamoxifen daily for one year. Clinical assessments included cosmetic outcome, breast fibrosis, skin telangiectasia, and dyspigmentation which were scored on a 4-point categorical scale after median 6.6 years. The observations were analyzed in multivariate logistic regression analysis which included potential risk factors on outcome related to systemic treatment, surgery, radiation technique, tumor, and patient characteristics. In premenopausal patients, systemic treatment with CMF independently predicted a fair/poor cosmetic outcome, RR = 2.2 (95% CI 1.2-4.2), as well as increased skin telangiectasia, RR = 3.3 (1.4-8.2). There was no impact of tamoxifen treatment on cosmetic outcome in postmenopausal patients (p = 0.32). However, univariate analysis showed that tamoxifen was significantly associated with breast fibrosis (p < 0.004), as was radiation to the regional lymph nodes (p < 0.0001). A strong interaction between axillary irradiation and tamoxifen treatment occurred since 26 of 27 high-risk postmenopausal patients had received both tamoxifen and axillary irradiation. In multivariate regression analysis, axillary irradiation independently predicted moderate/severe breast fibrosis with a relative risk of 5.0 (2.0-12.5) and 9.6 (3.3-27.7) in premenopausal and postmenopausal patients, respectively. To circumvent the strong interaction between tamoxifen treatment and axillary irradiation, a subsequent analysis omitting axillary treatment from the multivariate regression showed a significant effect of both tamoxifen and CMF on the occurrence of breast fibrosis with relative risks of 5.3 (CI 1.8-15.8) and 4.4 (1.8-10.3), respectively. Adjuvant systemic treatment with CMF given sequentially to radiotherapy independently predicted an adverse cosmetic outcome as well as increased skin telangiectasia after breast conserving treatment. Due to a strong interaction between tamoxifen administration and radiation to the regional lymph nodes, the effect of tamoxifen on the development of fibrosis could not be fully discerned in this study. Axillary irradiation increased the incidence of moderate to severe breast fibrosis in both premenopausal and postmenopausal patients.
[Radical Prostatectomies for Localized Prostate Cancer Performed in Center Satellite Collaboration--is It Possible?]
Ugeskrift for Laeger. May, 2007 | Pubmed ID: 17553372
In an effort to comply with the increasing demand for surgery for localized prostate cancer a center satellite collaboration was established between a university department and two local urological departments. The purpose of the present study was to evaluate open radical prostatectomies performed by this collaboration.
Titin in Insect Spermatocyte Spindle Fibers Associates with Microtubules, Actin, Myosin and the Matrix Proteins Skeletor, Megator and Chromator
Journal of Cell Science. Jul, 2007 | Pubmed ID: 17591688
Titin, the giant elastic protein found in muscles, is present in spindles of crane-fly and locust spermatocytes as determined by immunofluorescence staining using three antibodies, each raised against a different, spatially separated fragment of Drosophila titin (D-titin). All three antibodies stained the Z-lines and other regions in insect myofibrils. In western blots of insect muscle extract the antibodies reacted with high molecular mass proteins, ranging between rat nebulin (600-900 kDa) and rat titin (3000-4000 kDa). Mass spectrometry of the high molecular mass band from the Coomassie-Blue-stained gel of insect muscle proteins indicates that the protein the antibodies bind to is titin. The pattern of staining in insect spermatocytes was slightly different in the two species, but in general all three anti-D-titin antibodies stained the same components: the chromosomes, prophase and telophase nuclear membranes, the spindle in general, along kinetochore and non-kinetochore microtubules, along apparent connections between partner half-bivalents during anaphase, and various cytoplasmic components, including the contractile ring. That the same cellular components are stained in close proximity by the three different antibodies, each against a different region of D-titin, is strong evidence that the three antibodies identify a titin-like protein in insect spindles, which we identified by mass spectrometry analysis as being titin. The spindle matrix proteins skeletor, megator and chromator are present in many of the same structures, in positions very close to (or the same as) D-titin. Myosin and actin also are present in spindles in close proximity to D-titin. The varying spatial arrangements of these proteins during the course of division suggest that they interact to form a spindle matrix with elastic properties provided by a titin-like protein.
Turning Subjective into Objective: the BCCT.core Software for Evaluation of Cosmetic Results in Breast Cancer Conservative Treatment
Breast (Edinburgh, Scotland). Oct, 2007 | Pubmed ID: 17606373
Twelve expert observers from nine different countries convened in a workshop to evaluate the validity of the Breast Cancer Conservative Treatment. Cosmetic results (BCCT.core) software, an objective method for the aesthetic evaluation of breast cancer conservative treatment. Experts were initially asked to subjectively classify the aesthetic results of 30 photographed cases submitted to breast cancer conservative treatment according to the four-point Harris scale. It was pre-established that if at least two-thirds [Cardoso MJ, Cardoso J, Santos AC, Barros H, Oliveira MC. Interobserver agreement and consensus over the esthetic evaluation of conservative treatment for breast cancer. Breast 2005] of participants provided the same classification this would be considered a consensual evaluation for that case. For cases where such agreement was not reached, consensus was obtained using a nominal group technique. Experts then individually performed objective evaluation of the same set of photographs using the BCCT.core software. This provides an automatic rating of aesthetic results, once scale and reference points in the photograph have been chosen. Agreement between observers, between each observer and the consensus, for computer evaluation obtained by the different participants and between software and consensus was calculated using multiple kappa (k) and weighted kappa (wk) statistics. In the subjective assessment, first-round consensus was achieved in 17 (57%) cases. Overall interobserver agreement was fair to moderate (k=0.40, wk=0.57). In the objective assessment there was a higher level of concordance between participants (k=0.86, wk=0.90). Agreement between software and consensus classification was fair (k=0.34, wk=0.53), but was higher in the 17 cases that reached first-round consensus (k=0.60, wk=0.73). Merging the two middle classes of the Harris scale, to form a three-point scale, led to an improvement of all non-weighted measures of agreement. These results show that the BCCT.core software provides consistent evaluation of cosmesis. It has the potential to become a gold standard method for assessment of breast cosmesis in clinical trials, as it can be used simultaneously by a panel of observers from different parts of the world to provide more reliable assessments than has been possible previously.
Reduced Levels of Su(var)3-9 but Not Su(var)2-5 (HP1) Counteract the Effects on Chromatin Structure and Viability in Loss-of-function Mutants of the JIL-1 Histone H3S10 Kinase
Genetics. Sep, 2007 | Pubmed ID: 17660558
It has recently been demonstrated that activity of the essential JIL-1 histone H3S10 kinase is a major regulator of chromatin structure and that it functions to maintain euchromatic domains while counteracting heterochromatization and gene silencing. In the absence of JIL-1 kinase activity, the major heterochromatin markers histone H3K9me2 and HP1 spread in tandem to ectopic locations on the chromosome arms. In this study, we show that the lethality as well as some of the chromosome morphology defects associated with the null JIL-1 phenotype to a large degree can be rescued by reducing the dose of the Su(var)3-9 gene. This effect was observed with three different alleles of Su(var)3-9, strongly suggesting it is specific to Su(var)3-9 and not to second site modifiers. This is in contrast to similar experiments performed with alleles of the Su(var)2-5 gene that codes for HP1 in Drosophila where no genetic interactions were detectable between JIL-1 and Su(var)2-5. Taken together, these findings indicate that while Su(var)3-9 histone methyltransferase activity is a major factor in the lethality and chromatin structure perturbations associated with loss of the JIL-1 histone H3S10 kinase, these effects are likely to be uncoupled from HP1.
Cell and Molecular Biology of the Spindle Matrix
International Review of Cytology. 2007 | Pubmed ID: 17725967
The concept of a spindle matrix has long been proposed to account for incompletely understood features of microtubule spindle dynamics and force production during mitosis. In its simplest formulation, the spindle matrix is hypothesized to provide a stationary or elastic molecular matrix that can provide a substrate for motor molecules to interact with during microtubule sliding and which can stabilize the spindle during force production. Although this is an attractive concept with the potential to greatly simplify current models of microtubule spindle behavior, definitive evidence for the molecular nature of a spindle matrix or for its direct role in microtubule spindle function has been lagging. However, as reviewed here multiple studies spanning the evolutionary spectrum from lower eukaryotes to vertebrates have provided new and intriguing evidence that a spindle matrix may be a general feature of mitosis.
Prospective Study of 18FDG-PET in the Detection and Management of Patients with Lymph Node Metastases to the Neck from an Unknown Primary Tumor. Results from the DAHANCA-13 Study
Head & Neck. Apr, 2008 | Pubmed ID: 18023031
The benefit of a complementary fluorodeoxyglucose-positron emission tomography (FDG-PET) scan to standard workup for carcinoma of unknown primary (CUP) and metastatic neck lesions was prospectively studied.
Topotecan and Cisplatin in Combination with Concurrent Twice-daily Chemoradiation in Limited Disease Small Cell Lung Cancer-a Danish Oncological Lung Cancer Group (DOLG) Phase II Trial
Lung Cancer (Amsterdam, Netherlands). May, 2008 | Pubmed ID: 18036701
The longest survival time reported in randomised trials of limited disease (LD) SCLC has been achieved with early twice-daily concurrent chemoradiation. Topotecan is active in recurrent SCLC and in extensive disease as first line treatment.
Ectopic Histone H3S10 Phosphorylation Causes Chromatin Structure Remodeling in Drosophila
Development (Cambridge, England). Feb, 2008 | Pubmed ID: 18199578
Histones are subject to numerous post-translational modifications that correlate with the state of higher-order chromatin structure and gene expression. However, it is not clear whether changes in these epigenetic marks are causative regulatory factors in chromatin structure changes or whether they play a mainly reinforcing or maintenance role. In Drosophila phosphorylation of histone H3S10 in euchromatic chromatin regions by the JIL-1 tandem kinase has been implicated in counteracting heterochromatization and gene silencing. Here we show, using a LacI-tethering system, that JIL-1 mediated ectopic histone H3S10 phosphorylation is sufficient to induce a change in higher-order chromatin structure from a condensed heterochromatin-like state to a more open euchromatic state. This effect was absent when a ;kinase dead' LacI-JIL-1 construct without histone H3S10 phosphorylation activity was expressed. Instead, the 'kinase dead' construct had a dominant-negative effect, leading to a disruption of chromatin structure that was associated with a global repression of histone H3S10 phosphorylation levels. These findings provide direct evidence that the epigenetic histone tail modification of H3S10 phosphorylation at interphase can function as a causative regulator of higher-order chromatin structure in Drosophila in vivo.
Is Face-only Photographic View Enough for the Aesthetic Evaluation of Breast Cancer Conservative Treatment?
Breast Cancer Research and Treatment. Dec, 2008 | Pubmed ID: 18204895
The breast cancer conservative treatment. cosmetic results (BCCT.core) is a new software tool created for the automatic and objective evaluation of the aesthetic result of BCCT. It makes use of a face-only photographic view of each patient and might thus have been considered insufficient for an accurate evaluation, as others have used multiple views of each patient. The purpose of this work is to compare the performance of the BCCT.core (using face-only views) with a subjective expert analysis using both the face-only and four-view assessment. Photographs in four-views of 150 patients, were evaluated by a panel of experts and a consensus classification was obtained. The agreement between the consensus and the BCCT.core (face-only view) was calculated using the kappa (k) and weighted kappa (wk) statistics. Face-only views, of the same 150 patients, were subsequently sorted out in a different order and sent for individual evaluation by three specialists from the previous panel of experts. The individual agreement between the face-only view and the four-view evaluation by each of the three experts and the consensus was calculated using the same methods. Obtained results were compared to the BCCT.core performance. The software obtained a moderate agreement with the consensus (k = 0.57; wk = 0.68). The highest value of agreement, from the three experts, between the four-view evaluation and the consensus was identical to the software agreement (k = 0.55; wk = 0.67). In the face-only view experiment, the highest value of agreement between the experts and the consensus was only fair (k = 0.37; wk = 0.54). Performance of the software was thus considered equal to that obtained by experts using a four-view evaluation.
Set-up Errors in Patients Undergoing Image Guided Radiation Treatment. Relationship to Body Mass Index and Weight Loss
Acta Oncologica (Stockholm, Sweden). 2008 | Pubmed ID: 18663647
The purpose of this study was to quantify the set-up errors of patient positioning during IGRT and to correlate set-up errors to patient-specific factors such as weight, height, BMI, and weight loss.
RNA Polymerase II-mediated Transcription at Active Loci Does Not Require Histone H3S10 Phosphorylation in Drosophila
Development (Cambridge, England). Sep, 2008 | Pubmed ID: 18667461
JIL-1 is the major kinase controlling the phosphorylation state of histone H3S10 at interphase in Drosophila. In this study, we used three different commercially available histone H3S10 phosphorylation antibodies, as well as an acid-free polytene chromosome squash protocol that preserves the antigenicity of the histone H3S10 phospho-epitope, to examine the role of histone H3S10 phosphorylation in transcription under both heat shock and non-heat shock conditions. We show that there is no redistribution or upregulation of JIL-1 or histone H3S10 phosphorylation at transcriptionally active puffs in such polytene squash preparations after heat shock treatment. Furthermore, we provide evidence that heat shock-induced puffs in JIL-1 null mutant backgrounds are strongly labeled by antibody to the elongating form of RNA polymerase II (Pol IIoser2), indicating that Pol IIoser2 is actively involved in heat shock-induced transcription in the absence of histone H3S10 phosphorylation. This is supported by the finding that there is no change in the levels of Pol IIoser2 in JIL-1 null mutant backgrounds compared with wild type. mRNA from the six genes that encode the major heat shock protein in Drosophila, Hsp70, is transcribed at robust levels in JIL-1 null mutants, as directly demonstrated by qRT-PCR. Taken together, these data are inconsistent with the model that Pol II-dependent transcription at active loci requires JIL-1-mediated histone H3S10 phosphorylation, and instead support a model in which transcriptional defects in the absence of histone H3S10 phosphorylation are a result of structural alterations of chromatin.
The COOH-terminal Domain of the JIL-1 Histone H3S10 Kinase Interacts with Histone H3 and is Required for Correct Targeting to Chromatin
The Journal of Biological Chemistry. Nov, 2008 | Pubmed ID: 18819909
The JIL-1 histone H3S10 kinase in Drosophila localizes specifically to euchromatic interband regions of polytene chromosomes and is enriched 2-fold on the male X chromosome. JIL-1 can be divided into four main domains including an NH(2)-terminal domain, two separate kinase domains, and a COOH-terminal domain. Our results demonstrate that the COOH-terminal domain of JIL-1 is necessary and sufficient for correct chromosome targeting to autosomes but that both COOH- and NH(2)-terminal sequences are necessary for enrichment on the male X chromosome. We furthermore show that a small 53-amino acid region within the COOH-terminal domain can interact with the tail region of histone H3, suggesting that this interaction is necessary for the correct chromatin targeting of the JIL-1 kinase. Interestingly, our data indicate that the COOH-terminal domain alone is sufficient to rescue JIL-1 null mutant polytene chromosome defects including those of the male X chromosome. Nonetheless, we also found that a truncated JIL-1 protein which was without the COOH-terminal domain but retained histone H3S10 kinase activity was able to rescue autosome as well as partially rescue male X polytene chromosome morphology. Taken together these findings indicate that JIL-1 may participate in regulating chromatin structure by multiple and partially redundant mechanisms.
Polytene Chromosome Squash Methods for Studying Transcription and Epigenetic Chromatin Modification in Drosophila Using Antibodies
Methods (San Diego, Calif.). Aug, 2009 | Pubmed ID: 19272452
The giant polytene chromosomes from Drosophila third instar larval salivary glands provide an important model system for studying the architectural changes in chromatin morphology associated with the process of transcription initiation and elongation. Especially, analysis of the heat shock response has proved useful in correlating chromatin structure remodeling with transcriptional activity. An important tool for such studies is the labeling of polytene chromosome squash preparations with antibodies to the enzymes, transcription factors, or histone modifications of interest. However, in any immunohistochemical experiment there will be advantages and disadvantages to different methods of fixation and sample preparation, the relative merits of which must be balanced. Here we provide detailed protocols for polytene chromosome squash preparation and discuss their relative pros and cons in terms of suitability for reliable antibody labeling and preservation of high resolution chromatin structure.
Spatiotemporal Control of Mitosis by the Conserved Spindle Matrix Protein Megator
The Journal of Cell Biology. Mar, 2009 | Pubmed ID: 19273613
A putative spindle matrix has been hypothesized to mediate chromosome motion, but its existence and functionality remain controversial. In this report, we show that Megator (Mtor), the Drosophila melanogaster counterpart of the human nuclear pore complex protein translocated promoter region (Tpr), and the spindle assembly checkpoint (SAC) protein Mad2 form a conserved complex that localizes to a nuclear derived spindle matrix in living cells. Fluorescence recovery after photobleaching experiments supports that Mtor is retained around spindle microtubules, where it shows distinct dynamic properties. Mtor/Tpr promotes the recruitment of Mad2 and Mps1 but not Mad1 to unattached kinetochores (KTs), mediating normal mitotic duration and SAC response. At anaphase, Mtor plays a role in spindle elongation, thereby affecting normal chromosome movement. We propose that Mtor/Tpr functions as a spatial regulator of the SAC, which ensures the efficient recruitment of Mad2 to unattached KTs at the onset of mitosis and proper spindle maturation, whereas enrichment of Mad2 in a spindle matrix helps confine the action of a diffusible "wait anaphase" signal to the vicinity of the spindle.
Long-term Results of Concurrent Radiotherapy and UFT in Patients with Locally Advanced Pancreatic Cancer
Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology. Aug, 2009 | Pubmed ID: 19435643
Definition and treatment options for locally advanced non-resectable pancreatic cancer (LAPC) vary. Treatment options range from palliative chemotherapy to chemoradiotherapy (CRT). Several studies have shown that a number of patients become resectable after complementary treatment prior to surgery.
Chromator is Required for Proper Microtubule Spindle Formation and Mitosis in Drosophila
Developmental Biology. Oct, 2009 | Pubmed ID: 19632217
The chromodomain protein, Chromator, has been shown to have multiple functions that include regulation of chromatin structure as well as coordination of muscle remodeling during metamorphosis depending on the developmental context. In this study we show that mitotic neuroblasts from brain squash preparations from larvae heteroallelic for the two Chromator loss-of-function alleles Chro(71) and Chro(612) have severe microtubule spindle and chromosome segregation defects that were associated with a reduction in brain size. The microtubule spindles formed were incomplete, unfocused, and/or without clear spindle poles and at anaphase chromosomes were lagging and scattered. Time-lapse analysis of mitosis in S2 cells depleted of Chromator by RNAi treatment suggested that the lagging and scattered chromosome phenotypes were caused by incomplete alignment of chromosomes at the metaphase plate, possibly due to a defective spindle-assembly checkpoint, as well as of frayed and unstable microtubule spindles during anaphase. Expression of full-length Chromator transgenes under endogenous promoter control restored both microtubule spindle morphology as well as brain size strongly indicating that the observed mutant defects were directly attributable to lack of Chromator function.
The Spindle Matrix Through the Cell Cycle in Drosophila
Fly. Jul-Sep, 2009 | Pubmed ID: 19690461
A spindle matrix has long been proposed to provide structural support for counterbalancing force production and a substrate for essential mitotic factors. For years the molecular identity of such a structure remained elusive. Recently a complex of nuclear proteins that reorganize into a spindle-like structure during prophase through metaphase that shows characteristics of a spindle matrix has been identified in Drosophila. We review how these results support the concept of a spindle matrix and discuss its possible function(s) during mitosis. Importantly, these molecules also appear to play critical roles during interphase in nuclear organization and function. Given that during cell division the entire nucleus undergoes a dynamic and tightly orchestrated reorganization, the reorganization of spindle matrix components during mitosis may comprise one phase of a continuum of "nuclear architectural remodeling events" that can be considered to extend throughout the entire cell cycle, even in the absence of a defined nucleus.
Asator, a Tau-tubulin Kinase Homolog in Drosophila Localizes to the Mitotic Spindle
Developmental Dynamics : an Official Publication of the American Association of Anatomists. Dec, 2009 | Pubmed ID: 19890914
We have used a yeast two-hybrid interaction assay to identify Asator, a tau-tubulin kinase homolog in Drosophila that interacts directly with the spindle matrix protein Megator. Using immunocytochemical labeling by an Asator-specific mAb as well as by transgenic expression of a GFP-labeled Asator construct, we show that Asator is localized to the cytoplasm during interphase but redistributes to the spindle region during mitosis. Determination of transcript levels using qRT-PCR suggested that Asator is expressed throughout development but at relatively low levels. By P-element excision, we generated a null or strong hypomorphic Asator(exc) allele that resulted in complete adult lethality when homozygous, indicating that Asator is an essential gene. That the observed lethality was caused by impaired Asator function was further supported by the partial restoration of viability by transgenic expression of Asator-GFP in the Asator(exc) homozygous mutant background. The finding that Asator localizes to the spindle region during mitosis and directly can interact with Megator suggests that its kinase activity may be involved in regulating microtubule dynamics and microtubule spindle function.
Laparoscopic Pelvic Lymph-node Dissection in Prostate Cancer Before External Beam Radiotherapy: Risk Factors of Nodal Involvement and Relapse Following Intended Curative Treatment
Scandinavian Journal of Urology and Nephrology. 2009 | Pubmed ID: 18752151
To report experience with laparoscopic pelvic lymph-node dissection (LPLND) in patients with prostate cancer before radiotherapy. Selection of risk factors for nodal involvement (N1) and recurrence following radiotherapy was made.
Carcinoma of the Nasal Cavity and Paranasal Sinuses in Denmark 1995-2004
Acta Oncologica (Stockholm, Sweden). Apr, 2010 | Pubmed ID: 20001493
To evaluate the treatment outcome for sino-nasal carcinomas in Denmark from 1995-2004 and compare the results to the previous Danish survey covering 1982-1991.
Feelings in Literature
Integrative Psychological & Behavioral Science. Sep, 2010 | Pubmed ID: 20162383
In this article it is argued that feelings are all important to the function of literature. In contradiction to music that is concerned with the inwardness of humankind, literature has, because of language, the capacity to create fictional worlds that in many respects are similar to and related to the life world within which we live. One of the most important reasons for our emotional engagement in literature is our empathy with others and our constant imagining and hypothesizing on possible developments in our interactions with them. Hence, we understand and engage ourselves in fictional worlds. It is further claimed and exemplified, how poetic texts are very good at rhetorically engage and manipulate our feelings. Finally, with reference to the important work of Ellen Dissanayake, it is pointed out that the first kind of communication in which we engage, that between mother and infant, is a kind of speech that positively engages the infant in a dialogue with the mother by means of poetic devices.
Single Arc Volumetric Modulated Arc Therapy of Head and Neck Cancer
Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology. May, 2010 | Pubmed ID: 20188427
The quality of Volumetric Modulated Arc Therapy (VMAT) plans is highly dependent on the performance of the optimization algorithm used. Recently new algorithms have become available which are capable of generating VMAT plans for Elekta accelerators. The VMAT algorithm in Pinnacle is named SmartArc and its capability to generate treatment plans for head and neck cancer was tested.
Phosphorylation of SU(VAR)3-9 by the Chromosomal Kinase JIL-1
PloS One. 2010 | Pubmed ID: 20386606
The histone methyltransferase SU(VAR)3-9 plays an important role in the formation of heterochromatin within the eukaryotic nucleus. Several studies have shown that the formation of condensed chromatin is highly regulated during development, suggesting that SU(VAR)3-9's activity is regulated as well. However, no mechanism by which this may be achieved has been reported so far. As we and others had shown previously that the N-terminus of SU(VAR)3-9 plays an important role for its activity, we purified interaction partners from Drosophila embryo nuclear extract using as bait a GST fusion protein containing the SU(VAR)3-9 N-terminus. Among several other proteins known to bind Su(VAR)3-9 we isolated the chromosomal kinase JIL-1 as a strong interactor. We show that SU(VAR)3-9 is a substrate for JIL-1 in vitro as well as in vivo and map the site of phosphorylation. These findings may provide a molecular explanation for the observed genetic interaction between SU(VAR)3-9 and JIL-1.
JIL-1 and Su(var)3-7 Interact Genetically and Counteract Each Other's Effect on Position-effect Variegation in Drosophila
Genetics. Aug, 2010 | Pubmed ID: 20457875
The essential JIL-1 histone H3S10 kinase is a key regulator of chromatin structure that functions to maintain euchromatic domains while counteracting heterochromatization and gene silencing. In the absence of the JIL-1 kinase, two of the major heterochromatin markers H3K9me2 and HP1a spread in tandem to ectopic locations on the chromosome arms. Here we address the role of the third major heterochromatin component, the zinc-finger protein Su(var)3-7. We show that the lethality but not the chromosome morphology defects associated with the null JIL-1 phenotype to a large degree can be rescued by reducing the dose of the Su(var)3-7 gene and that Su(var)3-7 and JIL-1 loss-of-function mutations have an antagonistic and counterbalancing effect on position-effect variegation (PEV). Furthermore, we show that in the absence of JIL-1 kinase activity, Su(var)3-7 gets redistributed and upregulated on the chromosome arms. Reducing the dose of the Su(var)3-7 gene dramatically decreases this redistribution; however, the spreading of H3K9me2 to the chromosome arms was unaffected, strongly indicating that ectopic Su(var)3-9 activity is not a direct cause of lethality. These observations suggest a model where Su(var)3-7 functions as an effector downstream of Su(var)3-9 and H3K9 dimethylation in heterochromatic spreading and gene silencing that is normally counteracted by JIL-1 kinase activity.
The Importance of Haemoglobin Level and Effect of Transfusion in HNSCC Patients Treated with Radiotherapy--results from the Randomized DAHANCA 5 Study
Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology. Jan, 2011 | Pubmed ID: 20970213
Patients with head and neck squamous cell carcinoma (HNSCC) and a low level of haemoglobin (Hb) often have a poor response to radiation which may be related to hypoxia induced radioresistance. The aim of the study was to evaluate the prognostic significance of low Hb level and its modification by transfusion in HNSCC patients treated with radiotherapy. The study was performed as a subrandomization in the DAHANCA 5 trial.
Do Nuclear Envelope and Intranuclear Proteins Reorganize During Mitosis to Form an Elastic, Hydrogel-like Spindle Matrix?
Chromosome Research : an International Journal on the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology. Apr, 2011 | Pubmed ID: 21274615
The idea of a spindle matrix has long been proposed in order to account for poorly understood features of mitosis. However, its molecular nature and structural composition have remained elusive. Here, we propose that the spindle matrix may be constituted by mainly nuclear-derived proteins that reorganize during the cell cycle to form an elastic gel-like matrix. We discuss this hypothesis in the context of recent observations from phylogenetically diverse organisms that nuclear envelope and intranuclear proteins form a highly dynamic and malleable structure that contributes to mitotic spindle function. We suggest that the viscoelastic properties of such a matrix may constrain spindle length while at the same time facilitating microtubule growth and dynamics as well as chromosome movement. A corollary to this hypothesis is that a key determinant of spindle size may be the amount of nuclear proteins available to form the spindle matrix. Such a matrix could also serve as a spatial regulator of spindle assembly checkpoint proteins during open and semi-open mitosis.
The Influence of HPV-associated P16-expression on Accelerated Fractionated Radiotherapy in Head and Neck Cancer: Evaluation of the Randomised DAHANCA 6&7 Trial
Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology. Jul, 2011 | Pubmed ID: 21429609
Tumour HPV-positivity is a favourable prognostic factor in the radiotherapy of HNSCC, but the optimal radiotherapy regimen for HPV-positive HNSCC is not yet defined. Reducing overall treatment time is known to improve outcome in the radiotherapy of HNSCC as was also demonstrated in the randomised DAHANCA 6&7 trial. We aimed to assess the influence of tumour HPV-status, expressed by p16, on the response to accelerated fractionated radiotherapy in HNSCC through evaluation of the DAHANCA 6&7 trial.
A Balance Between Euchromatic (JIL-1) and Heterochromatic [SU(var)2-5 and SU(var)3-9] Factors Regulates Position-effect Variegation in Drosophila
Genetics. Jul, 2011 | Pubmed ID: 21515582
In this study, we show that the haplo-enhancer effect of JIL-1 has the ability to counterbalance the haplo-suppressor effect of both Su(var)3-9 and Su(var)2-5 on position-effect variegation, providing evidence that a finely tuned balance between the levels of JIL-1 and the major heterochromatin components contributes to the regulation of gene expression.
Salivary Gland Carcinoma in Denmark 1990-2005: a National Study of Incidence, Site and Histology. Results of the Danish Head and Neck Cancer Group (DAHANCA)
Oral Oncology. Jul, 2011 | Pubmed ID: 21612974
To describe the incidence, site and histology (WHO 2005) of salivary gland carcinomas in Denmark. Nine hundred and eighty-three patients diagnosed from 1990 to 2005 were identified from three nation-wide registries. The associated clinical data were retrospectively retrieved from patient medical records. Histological revision was performed in 886 cases (90%). Based on histological revision, 31 patients (3%) were excluded from the study leaving 952 for epidemiological analysis. The mean crude incidence in Denmark was 1.1/100,000/year. The male vs. female ratio was 0.97 and the median age was 62 years. The parotid gland was the most common site (52.5%) followed by the minor salivary glands of the oral cavity (26.3%). The most frequent histological subtypes were adenoid cystic carcinoma (25.2%), mucoepidermoid carcinoma (16.9%), adenocarcinoma NOS (12.2%) and acinic cell carcinoma (10.2%). The revision process changed the histological diagnosis in 121 out of 886 cases (14%). The incidence of salivary gland carcinoma in Denmark is higher than previously reported. More than half of salivary gland carcinomas are located in the parotid gland with adenoid cystic carcinoma being the most frequent subtype. Histological classification of salivary gland carcinomas is difficult and evaluation by dedicated pathology specialists might be essential for optimal diagnosis and treatment.
Does Transfusion Improve the Outcome for HNSCC Patients Treated with Radiotherapy? - Results from the Randomized DAHANCA 5 and 7 Trials
Acta Oncologica (Stockholm, Sweden). Oct, 2011 | Pubmed ID: 21790306
Patients with head and neck squamous cell carcinoma (HNSCC) and a low level of hemoglobin often have a poor response to radiation that may be related to hypoxia-induced radioresistance. We have previously published the importance of hemoglobin level and the effect of transfusion by the results from the randomized DAHANCA 5 trial, including 414 patients in the analysis. Aim of the current analysis was to gain additional power by adding patients from the continued subrandomization in the DAHANCA 7 trial, now including a total of almost 1200 patients.
The Chromodomain-containing NH(2)-terminus of Chromator Interacts with Histone H1 and is Required for Correct Targeting to Chromatin
Chromosoma. Dec, 2011 | Pubmed ID: 22203189
The chromodomain protein, Chromator, can be divided into two main domains, a NH(2)-terminal domain (NTD) containing the chromodomain (ChD) and a COOH-terminal domain (CTD) containing a nuclear localization signal. During interphase Chromator is localized to chromosomes; however, during cell division Chromator redistributes to form a macro molecular spindle matrix complex together with other nuclear proteins that contribute to microtubule spindle dynamics and proper chromosome segregation during mitosis. It has previously been demonstrated that the CTD is sufficient for targeting Chromator to the spindle matrix. In this study, we show that the NTD domain of Chromator is required for proper localization to chromatin during interphase and that chromosome morphology defects observed in Chromator hypomorphic mutant backgrounds can be largely rescued by expression of this domain. Furthermore, we show that the ChD domain can interact with histone H1 and that this interaction is necessary for correct chromatin targeting. Nonetheless, that localization to chromatin still occurs in the absence of the ChD indicates that Chromator possesses a second mechanism for chromatin association and we provide evidence that this association is mediated by other sequences residing in the NTD. Taken together these findings suggest that Chromator's chromatin functions are largely governed by the NH(2)-terminal domain whereas functions related to mitosis are mediated mainly by COOH-terminal sequences.
The Epigenetic H3S10 Phosphorylation Mark is Required for Counteracting Heterochromatic Spreading and Gene Silencing in Drosophila Melanogaster
Journal of Cell Science. Dec, 2011 | Pubmed ID: 22247192
The JIL-1 kinase localizes specifically to euchromatin interband regions of polytene chromosomes and is the kinase responsible for histone H3S10 phosphorylation at interphase. Genetic interaction assays with strong JIL-1 hypomorphic loss-of-function alleles have demonstrated that the JIL-1 protein can counterbalance the effect of the major heterochromatin components on position-effect variegation (PEV) and gene silencing. However, it is unclear whether this was a causative effect of the epigenetic H3S10 phosphorylation mark, or whether the effect of the JIL-1 protein on PEV was in fact caused by other functions or structural features of the protein. By transgenically expressing various truncated versions of JIL-1, with or without kinase activity, and assessing their effect on PEV and heterochromatic spreading, we show that the gross perturbation of polytene chromosome morphology observed in JIL-1 null mutants is unrelated to gene silencing in PEV and is likely to occur as a result of faulty polytene chromosome alignment and/or organization, separate from epigenetic regulation of chromatin structure. Furthermore, the findings provide evidence that the epigenetic H3S10 phosphorylation mark itself is necessary for preventing the observed heterochromatic spreading independently of any structural contributions from the JIL-1 protein.
Salivary Gland Carcinoma in Denmark 1990-2005: Outcome and Prognostic Factors Results of the Danish Head and Neck Cancer Group (DAHANCA)
Oral Oncology. Feb, 2012 | Pubmed ID: 21968090
To describe outcome and prognostic factors in a national Danish series of patients treated for salivary gland carcinoma. From three Danish nation-wide registries and supplementary patient records, 871 patients diagnosed with primary major or minor salivary gland carcinoma in the period from 1990 to 2005 were identified. A total of 796 (91%) histological specimens were revised according to the WHO 2005 classification. The median follow-up time was 78months. Three hundred and thirty-four patients (38%) experienced recurrence. Crude survival, disease-specific survival and recurrence-free survival after 5 and 10years were 66%, 76%, 64% and 51%, 69%, 58%, respectively. In multivariate analysis age, latency, stage, microscopic margins, vascular invasion and histological grade were all independent prognostic factors with regards to crude and disease-specific survival. Stage, microscopic margins, vascular invasion and histological grade were independent prognostic factors for recurrence-free survival. Age over 61years, latency under 8months, stage 3+4 disease, involved or close microscopic margins, vascular invasion and high histological grade are all independent prognostic factors with a negative impact on survival in salivary gland carcinoma patients. This knowledge can be helpful in guiding clinicians in daily work and choice of treatment across the large variety of salivary gland carcinoma subtypes.
