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1.
Biol Psychiatry ; 94(4): 341-351, 2023 08 15.
Article in English | MEDLINE | ID: mdl-36958377

ABSTRACT

BACKGROUND: Schizophrenia (SCZ) is caused by an interplay of polygenic risk and environmental factors, which may alter regulators of gene expression leading to pathogenic misexpression of SCZ risk genes. The CPEB family of RNA-binding proteins (CPEB1-4) regulates translation of target RNAs (approximately 40% of overall genes). We previously identified CPEB4 as a key dysregulated translational regulator in autism spectrum disorder (ASD) because its neuronal-specific microexon (exon 4) is mis-spliced in ASD brains, causing underexpression of numerous ASD risk genes. The genetic factors and pathogenic mechanisms shared between SCZ and ASD led us to hypothesize CPEB4 mis-splicing in SCZ leading to underexpression of multiple SCZ-related genes. METHODS: We performed MAGMA-enrichment analysis on Psychiatric Genomics Consortium genome-wide association study data and analyzed RNA sequencing data from the PsychENCODE Consortium. Reverse transcriptase polymerase chain reaction and Western blot were performed on postmortem brain tissue, and the presence/absence of antipsychotics was assessed through toxicological analysis. Finally, mice with mild overexpression of exon 4-lacking CPEB4 (CPEB4Δ4) were generated and analyzed biochemically and behaviorally. RESULTS: First, we found enrichment of SCZ-associated genes for CPEB4-binder transcripts. We also found decreased usage of CPEB4 microexon in SCZ probands, which was correlated with decreased protein levels of CPEB4-target SCZ-associated genes only in antipsychotic-free individuals. Interestingly, differentially expressed genes fit those reported for SCZ, specifically in the SCZ probands with decreased CPEB4-microexon inclusion. Finally, we demonstrated that mice with mild overexpression of CPEB4Δ4 showed decreased protein levels of CPEB4-target SCZ genes and SCZ-linked behaviors. CONCLUSIONS: We identified aberrant CPEB4 splicing and downstream misexpression of SCZ risk genes as a novel etiological mechanism in SCZ.


Subject(s)
Antipsychotic Agents , Autism Spectrum Disorder , Schizophrenia , Animals , Mice , Antipsychotic Agents/therapeutic use , Autism Spectrum Disorder/genetics , Brain/metabolism , Genetic Predisposition to Disease , Genome-Wide Association Study , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Schizophrenia/genetics , Schizophrenia/drug therapy
2.
iScience ; 25(2): 103790, 2022 Feb 18.
Article in English | MEDLINE | ID: mdl-35243213

ABSTRACT

Upon tissue injury, cytokine expression reprogramming transiently remodels the inflammatory immune microenvironment to activate repair processes and subsequently return to homeostasis. However, chronic inflammation induces permanent changes in cytokine production which exacerbate tissue damage and may even favor tumor development. Here, we address the contribution of post-transcriptional regulation, by the RNA-binding protein CPEB4, to intestinal immune homeostasis and its role in inflammatory bowel diseases (IBD) and colorectal cancer (CRC) development. We found that intestinal damage induces CPEB4 expression in adaptive and innate immune cells, which is required for the translation of cytokine mRNA(s) such as the one encoding interleukin-22. Accordingly, CPEB4 is required for the development of gut-associated lymphoid tissues and to maintain intestinal immune homeostasis, mediating repair and remodeling after acute inflammatory tissue damage and promoting the resolution of intestinal inflammation. CPEB4 is chronically overexpressed in inflammatory cells in patients with IBD and in CRC, favoring tumor development.

3.
J Voice ; 35(5): 807.e1-807.e23, 2021 Sep.
Article in English | MEDLINE | ID: mdl-32305174

ABSTRACT

Twang-like vocal qualities have been related to a megaphone-like shape of the vocal tract (epilaryngeal tube and pharyngeal narrowing, and a wider mouth opening), low-frequency spectral changes, and tighter and/or increased vocal fold adduction. Previous studies have focused mainly on loud and high-pitched singing, comfortable low-pitched spoken vowels, or are based on modeling and simulation. There is no data available related to twang-like voices in loud, low-pitched singing. PURPOSE: This study investigates the possible contribution of the lower and upper vocal tract configurations during loud twang-like singing on high and low pitches in a real subject. METHODS: One male contemporary commercial music singer produced a sustained vowel [a:] in his habitual speaking pitch (B2) and loudness. The same vowel was also produced in a loud twang-like singing voice on high (G4) and low pitches (B2). Computerized tomography, acoustic analysis, inverse filtering, and audio-perceptual assessments were performed. RESULTS: Both loud twang-like voices showed a megaphone-like shape of the vocal tract, being more notable on the low pitch. Also, low-frequency spectral changes, a peak of sound energy around 3 kHz and increased vocal fold adduction were found. Results agreed with audio-perceptual evaluation. CONCLUSIONS: Loud twang-like phonation seems to be mainly related to low-frequency spectral changes (under 2 kHz) and a more compact formant structure. Twang-like qualities seem to require different degrees of twang-related vocal tract adjustments while phonating in different pitches. A wider mouth opening, pharyngeal constriction, and epilaryngeal tube narrowing may be helpful strategies for maximum power transfer and improved vocal economy in loud contemporary commercial music singing and potentially in loud speech. Further studies should focus on vocal efficiency and vocal economy measurements using modeling and simulation, based on real-singers' data.


Subject(s)
Singing , Voice , Acoustics , Humans , Male , Phonation , Voice Quality
4.
Sci Adv ; 6(20): eaax3868, 2020 05.
Article in English | MEDLINE | ID: mdl-32440535

ABSTRACT

Organogenesis is directed by coordinated cell proliferation and differentiation programs. The hierarchical networks of transcription factors driving mammary gland development and function have been widely studied. However, the contribution of posttranscriptional gene expression reprogramming remains largely unexplored. The 3' untranslated regions of messenger RNAs (mRNAs) contain combinatorial ensembles of cis-regulatory elements that define transcript-specific regulation of protein synthesis through their cognate RNA binding proteins. We analyze the contribution of the RNA binding cytoplasmic polyadenylation element-binding (CPEB) protein family, which collectively regulate mRNA translation for about 30% of the genome. We find that CPEB2 is required for the integration of hormonal signaling by controlling the protein expression from a subset of ER/PR- regulated transcripts. Furthermore, CPEB2 is critical for the development of ER-positive breast tumors. This work uncovers a previously unknown gene expression regulation level in breast morphogenesis and tumorigenesis, coordinating sequential transcriptional and posttranscriptional layers of gene expression regulation.


Subject(s)
Breast Neoplasms , Mammary Glands, Human , 3' Untranslated Regions , Breast Neoplasms/genetics , Female , Hormones , Humans , Mammary Glands, Human/metabolism , Organogenesis , RNA, Messenger/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism
5.
Sci Rep ; 9(1): 14065, 2019 10 01.
Article in English | MEDLINE | ID: mdl-31575908

ABSTRACT

CD98 heavy chain (CD98hc) forms heteromeric amino acid (AA) transporters by interacting with different light chains. Cancer cells overexpress CD98hc-transporters in order to meet their increased nutritional and antioxidant demands, since they provide branched-chain AA (BCAA) and aromatic AA (AAA) availability while protecting cells from oxidative stress. Here we show that BCAA and AAA shortage phenocopies the inhibition of mTORC1 signalling, protein synthesis and cell proliferation caused by CD98hc ablation. Furthermore, our data indicate that CD98hc sustains glucose uptake and glycolysis, and, as a consequence, the pentose phosphate pathway (PPP). Thus, loss of CD98hc triggers a dramatic reduction in the nucleotide pool, which leads to replicative stress in these cells, as evidenced by the enhanced DNA Damage Response (DDR), S-phase delay and diminished rate of mitosis, all recovered by nucleoside supplementation. In addition, proper BCAA and AAA availability sustains the expression of the enzyme ribonucleotide reductase. In this regard, BCAA and AAA shortage results in decreased content of deoxynucleotides that triggers replicative stress, also recovered by nucleoside supplementation. On the basis of our findings, we conclude that CD98hc plays a central role in AA and glucose cellular nutrition, redox homeostasis and nucleotide availability, all key for cell proliferation.


Subject(s)
Amino Acids/metabolism , Cell Cycle , Fusion Regulatory Protein 1, Heavy Chain/metabolism , Nucleotides/metabolism , Amino Acids, Aromatic/metabolism , Amino Acids, Branched-Chain/metabolism , Cell Division , DNA Damage , DNA Repair , Fusion Regulatory Protein 1, Heavy Chain/physiology , Gene Expression Profiling , Gene Knockout Techniques , Humans , Mechanistic Target of Rapamycin Complex 1/metabolism , Oxidative Stress
6.
Foods ; 8(2)2019 Feb 04.
Article in English | MEDLINE | ID: mdl-30720722

ABSTRACT

The quality of packaged dried foods depends on storage conditions and is determined largely by the initial gas composition inside and the transference through the container. The aim of this work was to analyze the O2 and CO2 concentrations within the internal atmosphere of the packaging. In this study, dried apricots and raisins were packaged in glass jars and polypropylene trays thermosealed with different polymers, and stored at 5, 15, 25, and 35 °C. Some trays were flushed with nitrogen just before sealing. In addition, the work relates to other previous papers to investigate the effect of these gases and packages on the stored products, and compares the influence of permeable and impermeable containers on food quality parameters. When packages were flushed with nitrogen before sealing, the O2 level in the headspace increased until the outside O2 concentration was reached. The CO2 concentration increased over time, regardless of the initial atmosphere. Nitrogen had a great influence on the concentration of O2, but not on that of CO2. Finally, this paper shows that the films and initial gas used in this study had no significant effect on the quality of the stored dried fruit.

7.
J Voice ; 33(4): 412-419, 2019 Jul.
Article in English | MEDLINE | ID: mdl-29625720

ABSTRACT

BACKGROUND: Vocal tract setting in hyperfunctional patients is characterized by a high larynx and narrowing of the epilaryngeal and pharyngeal region. Similar observations have been made for various singing styles, eg, belting. The voice quality in belting has been described to be loud, speech like, and high pitched. It is also often described as sounding "pressed" or "tense". The above mentioned has led to the hypothesis that belting may be strenuous to the vocal folds. However, singers and teachers of belting do not regard belting as particularly strenuous. PURPOSE: This study investigates possible similarities and differences between hyperfunctional voice production and belting. This study concerns vocal tract setting. METHODS: Four male patients with hyperfunctional dysphonia and one male contemporary commercial music singer were registered with computerized tomography while phonating on [a:] in their habitual speaking pitch. Additionally, the singer used the pitch G4 in belting. The scannings were studied in sagittal and transversal dimensions by measuring lengths, widths, and areas. RESULTS: Various similarities were found between belting and hyperfunction: high vertical larynx position, small hypopharyngeal width, and epilaryngeal outlet. On the other hand, belting differed from dysphonia (in addition to higher pitch) by a wider lip and jaw opening, and larger volumes of the oral cavity. CONCLUSIONS: Belting takes advantage of "megaphone shape" of the vocal tract. Future studies should focus on modeling and simulation to address sound energy transfer. Also, they should consider aerodynamic variables and vocal fold vibration to evaluate the "price of decibels" in these phonation types.


Subject(s)
Dysphonia/diagnostic imaging , Phonation , Singing , Tomography, X-Ray Computed , Vocal Cords/diagnostic imaging , Voice Quality , Adult , Dysphonia/physiopathology , Humans , Male , Predictive Value of Tests , Vocal Cords/physiopathology
8.
J Voice ; 31(1): 124.e1-124.e10, 2017 Jan.
Article in English | MEDLINE | ID: mdl-26852823

ABSTRACT

PURPOSE: The present study aimed to observe the effect of two types of tubes on vocal tract bidimensional and tridimensional images. METHODS: Ten participants with hyperfunctional dysphonia were included. Computerized tomography was performed during production of sustained [a:], followed by sustained phonation into a drinking straw, and then repetition of sustained [a:]. A similar procedure was performed with a stirring straw after 15 minutes of vocal rest. Anatomic distances and area measures were obtained from computerized tomography midsagittal and transversal images. Vocal tract total volume was also calculated. RESULTS: During tube phonation, increases were measured in the vertical length of the vocal tract, oropharyngeal area, hypopharyngeal area, outlet of the epilaryngeal tube, and inlet to the lower pharynx. Also, the larynx was lower, and more closure was noted between the velum and the nasal passage. CONCLUSION: Tube phonation causes an increased total vocal tract volume, mostly because of the increased cross-sectional areas in the pharyngeal region. This change is more prominent when the tube offers more airflow resistance (stirring straw) compared with less airflow resistance (drinking straw). Based on our data and previous studies, it seems that vocal tract changes are not dependent on the voice condition (vocally trained, untrained, or disordered voices), but on the exercise itself and the type of instructions given to subjects. Tube phonation is a good option to reach therapeutic goals (eg, wide pharynx and low larynx) without giving biomechanical instructions, but only asking patients to feel easy voice and vibratory sensations.


Subject(s)
Dysphonia/diagnostic imaging , Dysphonia/therapy , Larynx/diagnostic imaging , Pharynx/diagnostic imaging , Phonation , Tomography, X-Ray Computed , Voice Training , Voice , Adult , Biomechanical Phenomena , Dysphonia/physiopathology , Equipment Design , Female , Humans , Laryngoscopy , Larynx/physiopathology , Male , Pharynx/physiopathology , Predictive Value of Tests , Vibration , Young Adult
9.
Gut ; 66(7): 1306-1320, 2017 07.
Article in English | MEDLINE | ID: mdl-26984852

ABSTRACT

OBJECTIVE: Pathological neovascularisation is intimately involved in portal hypertension (PH). Here, we determined the contribution of vascular stem/progenitor cells (VSPCs) to neovessel growth in PH and whether the RNA-binding protein cytoplasmic polyadenylation element binding protein-4 (CPEB4) was behind the mechanism controlling VSPC function. DESIGN: To identify and monitor VSPCs in PH rats (portal vein-ligated), we used a combinatorial approach, including sphere-forming assay, assessment of self-renewal, 5-bromo-2'-desoxyuridine label retention technique, in vitro and in vivo stem/progenitor cell (SPC) differentiation and vasculogenic capability, cell sorting, as well as immunohistochemistry, immunofluorescence and confocal microscopy expression analysis. We also determined the role of CPEB4 on VSPC proliferation using genetically engineered mouse models. RESULTS: We demonstrated the existence in the mesenteric vascular bed of VSPCs displaying capability to form cellular spheres in suspension culture, self-renewal ability, expression of molecules commonly found in SPCs, slow-cycling features, in addition to other cardinal properties exhibited by SPCs, like capacity to differentiate into endothelial cells and pericytes with remarkable vasculogenic activity. Such VSPCs showed, after PH induction, an early switch in proliferation, and differentiated in vivo into endothelial cells and pericytes, contributing, structurally and functionally, to abnormal neovessel formation. Quantification of VSPC-dependent neovessel formation in PH further illustrated the key role played by VSPCs. We also demonstrated that CPEB4 regulates the proliferation of the activated VSPC progeny upon PH induction. CONCLUSIONS: These findings demonstrate that VSPC-derived neovessel growth (ie, vasculogenesis) and angiogenesis cooperatively stimulate mesenteric neovascularisation in PH and identify VSPC and CPEB4 as potential therapeutic targets.


Subject(s)
Hypertension, Portal/pathology , Neovascularization, Pathologic , RNA-Binding Proteins/metabolism , Stem Cells/cytology , Animals , Cell Differentiation , Cell Proliferation , Mice , Rats
10.
Bioessays ; 38 Suppl 1: S96-S106, 2016 07.
Article in English | MEDLINE | ID: mdl-27417127

ABSTRACT

Polo-like kinase 1 (PLK1) is a serine/threonine kinase that plays multiple and essential roles during the cell division cycle. Its inhibition in cultured cells leads to severe mitotic aberrancies and cell death. Whereas previous reports suggested that Plk1 depletion in mice leads to a non-mitotic arrest in early embryos, we show here that the bi-allelic Plk1 depletion in mice certainly results in embryonic lethality due to extensive mitotic aberrations at the morula stage, including multi- and mono-polar spindles, impaired chromosome segregation and cytokinesis failure. In addition, the conditional depletion of Plk1 during mid-gestation leads also to severe mitotic aberrancies. Our data also confirms that Plk1 is completely dispensable for mitotic entry in vivo. On the other hand, Plk1 haploinsufficient mice are viable, and Plk1-heterozygous fibroblasts do not harbor any cell cycle alterations. Plk1 is overexpressed in many human tumors, suggesting a therapeutic benefit of inhibiting Plk1, and specific small-molecule inhibitors for this kinase are now being evaluated in clinical trials. Therefore, the different Plk1 mouse models here presented are a valuable tool to reexamine the relevance of the mitotic kinase Plk1 during mammalian development and animal physiology.


Subject(s)
Cell Cycle Proteins/physiology , Chromosome Segregation , Cytokinesis , Mitosis , Protein Serine-Threonine Kinases/physiology , Proto-Oncogene Proteins/physiology , Spindle Apparatus/metabolism , Animals , Female , Male , Mice , Spindle Apparatus/physiology , Polo-Like Kinase 1
11.
Gastroenterology ; 150(4): 982-97.e30, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26627607

ABSTRACT

BACKGROUND & AIMS: Vascular endothelial growth factor (VEGF) regulates angiogenesis, yet therapeutic strategies to disrupt VEGF signaling can interfere with physiologic angiogenesis. In a search for ways to inhibit pathologic production or activities of VEGF without affecting its normal production or functions, we investigated the post-transcriptional regulation of VEGF by the cytoplasmic polyadenylation element-binding proteins CPEB1 and CPEB4 during development of portal hypertension and liver disease. METHODS: We obtained transjugular liver biopsies from patients with hepatitis C virus-associated cirrhosis or liver tissues removed during transplantation; healthy human liver tissue was obtained from a commercial source (control). We also performed experiments with male Sprague-Dawley rats and CPEB-deficient mice (C57BL6 or mixed C57BL6/129 background) and their wild-type littermates. Secondary biliary cirrhosis was induced in rats by bile duct ligation, and portal hypertension was induced by partial portal vein ligation. Liver and mesenteric tissues were collected and analyzed in angiogenesis, reverse transcription polymerase chain reaction, polyA tail, 3' rapid amplification of complementary DNA ends, Southern blot, immunoblot, histologic, immunohistochemical, immunofluorescence, and confocal microscopy assays. CPEB was knocked down with small interfering RNAs in H5V endothelial cells, and translation of luciferase reporters constructs was assessed. RESULTS: Activation of CPEB1 promoted alternative nuclear processing within noncoding 3'-untranslated regions of VEGF and CPEB4 messenger RNAs in H5V cells, resulting in deletion of translation repressor elements. The subsequent overexpression of CPEB4 promoted cytoplasmic polyadenylation of VEGF messenger RNA, increasing its translation; the high levels of VEGF produced by these cells led to their formation of tubular structures in Matrigel assays. We observed increased levels of CPEB1 and CPEB4 in cirrhotic liver tissues from patients, compared with control tissue, as well as in livers and mesenteries of rats and mice with cirrhosis or/and portal hypertension. Mice with knockdown of CPEB1 or CPEB4 did not overexpress VEGF or have signs of mesenteric neovascularization, and developed less-severe forms of portal hypertension after portal vein ligation. CONCLUSIONS: We identified a mechanism of VEGF overexpression in liver and mesentery that promotes pathologic, but not physiologic, angiogenesis, via sequential and nonredundant functions of CPEB1 and CPEB4. Regulation of CPEB4 by CPEB1 and the CPEB4 autoamplification loop induces pathologic angiogenesis. Strategies to block the activities of CPEBs might be developed to treat chronic liver and other angiogenesis-dependent diseases.


Subject(s)
Hypertension, Portal/metabolism , Liver Cirrhosis, Biliary/metabolism , Liver Cirrhosis/metabolism , Neovascularization, Pathologic , RNA-Binding Proteins/metabolism , Transcription Factors/metabolism , Vascular Endothelial Growth Factor A/metabolism , mRNA Cleavage and Polyadenylation Factors/metabolism , 3' Untranslated Regions , Adult , Animals , Case-Control Studies , Cell Line , Chronic Disease , Disease Models, Animal , Female , Gene Expression Regulation , Humans , Hypertension, Portal/genetics , Hypertension, Portal/pathology , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Liver Cirrhosis, Biliary/genetics , Liver Cirrhosis, Biliary/pathology , Male , Mice, 129 Strain , Mice, Inbred C57BL , Middle Aged , Polyadenylation , RNA Interference , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Proteins/genetics , Rats, Sprague-Dawley , Signal Transduction , Time Factors , Transcription Factors/deficiency , Transcription Factors/genetics , Transfection , mRNA Cleavage and Polyadenylation Factors/deficiency , mRNA Cleavage and Polyadenylation Factors/genetics
12.
Rev. gastroenterol. Perú ; 35(4): 355-357, oct.-dic.2015. ilus, tab
Article in Spanish | LILACS, LIPECS | ID: lil-790116

ABSTRACT

La diarrea crónica secretora es una entidad frecuente. Las causas son múltiples, por lo que llegar al diagnóstico definitivo puede resultar demorado con las complicaciones que esto ocasiona en el estado general del paciente. Se presenta el caso de un adulto mayor que cursa con diarrea crónica asociada a hipokalemia leve y acidosis metabolica hiperclorémica secundaria a un VIPoma a nivel de retroperitoneo, la cual es una localización inusual de este tipo de tumores, que en este caso fue diagnosticado mediante una biopsia guiada por tomografía...


Chronic secretory diarrhea is a frequent entity. Causes are multiple, that is why reaching final diagnosis can result in delay with complications that this causes in the general condition of the patient. We present the case of one older adult with chronic diarrhea, mild hypokalemia and metabolic hyperchloremic acidosis secondary to a VIPoma in retroperitoneum which is an unusual location of this type of tumor that was diagnosed by biopsy guided by tomography...


Subject(s)
Humans , Male , Aged , Retroperitoneal Neoplasms , Vipoma
13.
Nat Cell Biol ; 17(10): 1304-16, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26322680

ABSTRACT

Blocking mitotic progression has been proposed as an attractive therapeutic strategy to impair proliferation of tumour cells. However, how cells survive during prolonged mitotic arrest is not well understood. We show here that survival during mitotic arrest is affected by the special energetic requirements of mitotic cells. Prolonged mitotic arrest results in mitophagy-dependent loss of mitochondria, accompanied by reduced ATP levels and the activation of AMPK. Oxidative respiration is replaced by glycolysis owing to AMPK-dependent phosphorylation of PFKFB3 and increased production of this protein as a consequence of mitotic-specific translational activation of its mRNA. Induction of autophagy or inhibition of AMPK or PFKFB3 results in enhanced cell death in mitosis and improves the anti-tumoral efficiency of microtubule poisons in breast cancer cells. Thus, survival of mitotic-arrested cells is limited by their metabolic requirements, a feature with potential implications in cancer therapies aimed to impair mitosis or metabolism in tumour cells.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Autophagy/physiology , Fibroblasts/metabolism , Glycolysis , M Phase Cell Cycle Checkpoints/physiology , Phosphofructokinase-2/metabolism , AMP-Activated Protein Kinases/genetics , Animals , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Apoptosis/genetics , Apoptosis/physiology , Autophagy/genetics , Blotting, Western , Cdc20 Proteins/genetics , Cdc20 Proteins/metabolism , Cell Line, Tumor , Cell Survival/drug effects , Cell Survival/genetics , Cell Survival/physiology , Cells, Cultured , Embryo, Mammalian/cytology , Embryo, Mammalian/metabolism , Female , Fibroblasts/ultrastructure , Humans , M Phase Cell Cycle Checkpoints/genetics , MCF-7 Cells , Mice, Knockout , Mice, Nude , Microscopy, Confocal , Paclitaxel/pharmacology , Phosphofructokinase-2/genetics , RNA Interference , Xenograft Model Antitumor Assays
14.
Mol Cell Biol ; 35(20): 3566-78, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26240282

ABSTRACT

Aurora kinase B, one of the three members of the mammalian Aurora kinase family, is the catalytic component of the chromosomal passenger complex, an essential regulator of chromosome segregation in mitosis. Aurora B is overexpressed in human tumors although whether this kinase may function as an oncogene in vivo is not established. Here, we report a new mouse model in which expression of the endogenous Aurkb locus can be induced in vitro and in vivo. Overexpression of Aurora B in cultured cells induces defective chromosome segregation and aneuploidy. Long-term overexpression of Aurora B in vivo results in aneuploidy and the development of multiple spontaneous tumors in adult mice, including a high incidence of lymphomas. Overexpression of Aurora B also results in a reduced DNA damage response and decreased levels of the p53 target p21(Cip1) in vitro and in vivo, in line with an inverse correlation between Aurora B and p21(Cip1) expression in human leukemias. Thus, overexpression of Aurora B may contribute to tumor formation not only by inducing chromosomal instability but also by suppressing the function of the cell cycle inhibitor p21(Cip1).


Subject(s)
Aneuploidy , Aurora Kinase B/physiology , Cyclin-Dependent Kinase Inhibitor p21/genetics , Animals , Carcinogenesis/genetics , Carcinogenesis/metabolism , Cells, Cultured , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Fibroblasts/metabolism , Gene Expression , Gene Silencing , Mice, Inbred C57BL , Precursor Cell Lymphoblastic Leukemia-Lymphoma/enzymology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
15.
An. Fac. Med. (Perú) ; 76(2): 193-197, abr.-jun. 2015. ilus, tab
Article in Spanish | LILACS, LIPECS | ID: lil-780463

ABSTRACT

Los tumores neuroendocrinos (TNE) presentan dificultad en el diagnóstico por sus síntomas inespecíficos y el manejo es un reto. Se presenta el caso de un varón de 78 años de edad, con dolor crónico en hemiabdomen superior. Ingresó a emergencia con obstrucción intestinal y síntomas de síndrome carcinoide (SC). En cirugía se resecó tumor ileal con resultado anatomopatológico de tumor neuroendocrino, cromogranina positivo, índice proliferativo ki 67 de 2 a 3 por ciento. El paciente continuó con síntomas de SC, altos niveles de 5-HIA, metástasis hepáticas en RMN. Se inició octreotide con adecuada respuesta clínica. La experiencia con el presente caso indica estar alerta con los síntomas de TNE funcionantes, debido al aumento en su incidencia. Es de utilidad solicitar marcadores inmunohistoquimicos. La identificación de un TNE con índice de mitosis y proliferación bajo indica buen pronóstico...


The neuroendocrine tumor (NET) is of difficult diagnosis due to nonspecific symptoms; management is also a challenge. We present the case of a 78 year-old male who suffered of chronic upper abdominal pain and was admitted to emergency with intestinal obstruction and symptoms of carcinoid syndrome (CS). At surgery an ileal tumor was resected with pathology report of NET positive for chromogranin A and ki 67 proliferative index of 2-3 per cent. The patient continued with CS symptoms and presented high levels of 5-HIAA and liver metastases by MRI. Octreotide was started with good outcome. Experience with this case indicates to be alert at symptoms of functioning NET, due to an increase in its incidence. It is useful to request immunohistochemical markers. Identification of NET with low grade mitosis and proliferation signal good prognosis...


Subject(s)
Humans , Aged , Prognosis , Malignant Carcinoid Syndrome/diagnosis , Neuroendocrine Tumors/diagnosis , Neuroendocrine Tumors/therapy , Case Reports
17.
Rev Gastroenterol Peru ; 35(4): 355-7, 2015.
Article in Spanish | MEDLINE | ID: mdl-26802890

ABSTRACT

Chronic secretory diarrhea is a frequent entity. Causes are multiple, that is why reaching final diagnosis can result in delay with complications that this causes in the general condition of the patient. We present the case of one older adult with chronic diarrhea, mild hypokalemia and metabolic hyperchloremic acidosis secondary to a VIPoma in retroperitoneum which is an unusual location of this type of tumor that was diagnosed by biopsy guided by tomography.


Subject(s)
Diarrhea/etiology , Retroperitoneal Neoplasms/diagnosis , Vipoma/diagnosis , Aged , Biopsy , Chronic Disease , Humans , Male , Radiography, Interventional , Retroperitoneal Neoplasms/complications , Retroperitoneal Neoplasms/pathology , Tomography, X-Ray Computed , Vipoma/complications , Vipoma/pathology
19.
Cancer Res ; 73(22): 6804-15, 2013 Nov 15.
Article in English | MEDLINE | ID: mdl-24242071

ABSTRACT

Aurora-A is a kinase involved in the formation and maturation of the mitotic spindle and chromosome segregation. This kinase is frequently overexpressed in human cancer, and its activity may confer resistance to antitumoral drugs such as Taxol. Inhibition of Aurora-A results in mitotic defects, and this kinase is considered as an attractive therapeutic target for cancer. Nevertheless, the specific requirements for this kinase in adult mammalian tissues remain unclear. Conditional genetic ablation of Aurora-A in adult tissues results in polyploid cells that display a DNA-damage-like response characterized by the upregulation of p53 and the cell-cycle inhibitor p21(Cip1). This is accompanied by apoptotic, differentiation, or senescence markers in a tissue-specific manner. Therapeutic elimination of Aurora-A prevents the progression of skin and mammary gland tumors. However, this is not due to significant levels of apoptosis or senescence, but because Aurora-A-deficient tumors accumulate polyploid cells with limited proliferative potential. Thus, Aurora-A is required for tumor formation in vivo, and the differential response observed in various tissues might have relevant implications in current therapeutic strategies aimed at inhibiting this kinase in the treatment of human cancer.


Subject(s)
Aurora Kinase A/physiology , Cell Transformation, Neoplastic/genetics , Neoplasms/genetics , Regeneration/genetics , Animals , Aurora Kinase A/genetics , Cells, Cultured , Embryo, Mammalian , Female , Humans , Mice , Mice, Inbred C57BL , Mice, Transgenic
20.
Cell Cycle ; 12(7): 1030-41, 2013 Apr 01.
Article in English | MEDLINE | ID: mdl-23428904

ABSTRACT

Aurora kinase B is a critical component of the chromosomal passenger complex, which is involved in the regulation of microtubule-kinetochore attachments and cytokinesis. By using conditional knockout cells and chemical inhibition, we show here that inactivation of Aurora B results in delayed G(1)/S transition and premature mitotic exit. Aurora B deficiency results in delayed DNA replication in cultured fibroblasts as well as liver cells after hepatectomy. This is accompanied by increased transcription of the cell cycle inhibitor p21 (Cip1). Lack of Aurora B does not prevent mitotic entry but results in a premature exit from prometaphase in the presence of increased p21(Cip1)-Cdk1 inactive complexes. Aurora B-null cells display reduced degradation of cyclin B1, suggesting the presence of phenomenon known as adaptation to the mitotic checkpoint, previously described in yeast. Elimination of p21(Cip1) rescues Cdk1 activity and prevents premature mitotic exit in Aurora B-deficient cells. These results suggest that Aurora B represses p21(Cip1), preventing delayed DNA replication, Cdk inhibition and premature mitotic exit. The upregulation of p21(Cip1) observed after inhibition of Aurora B may have important implications in cell cycle progression, tetraploidy, senescence or cancer therapy.


Subject(s)
Cyclin-Dependent Kinase Inhibitor p21/metabolism , Mitosis , Protein Serine-Threonine Kinases/metabolism , Animals , Aurora Kinase B , Aurora Kinases , CDC2 Protein Kinase/metabolism , Cell Line , Cyclin B1/metabolism , Cyclin-Dependent Kinase Inhibitor p21/antagonists & inhibitors , Cyclin-Dependent Kinase Inhibitor p21/genetics , DNA Replication , G1 Phase Cell Cycle Checkpoints , Interphase , Liver/metabolism , Mice , Mice, Inbred C57BL , Protein Serine-Threonine Kinases/deficiency , Protein Serine-Threonine Kinases/genetics , RNA Interference , RNA, Small Interfering/metabolism
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